2020 - Paradise Pond Sediment Redistribution Project Report.pdf
Facilities Management
Northampton, Massachusetts 01063
August 12, 2022
Department of Environmental Protection
Water Quality Certification Program
One Winter Street, 5th Floor, Boston, MA 02108
Attn: Stephanie Moura, Director, Division of Wetlands and Waterways
Photo of Paradise Pond sediment redistribution project site during dozer work ‐ Thursday, Nov. 18, 2020. (view to Northeast)
Mill River channel on left flowing away from camera.
Re: Paradise Pond Sediment Redistribution Project – 2020 Report
Pertaining to: Combined Permit – Chapter 91 Permit and 401 Water Quality Certification
At: Smith College
Paradise Pond Sediment Management Project
Northampton, MA 01063
Referencing: 401 WQC Transmittal No. X281564, Wetlands File No. 246‐0725, Chapter 91 Permit No. 15001
EOEEA Certificate No. 15282, ACoE Application No. NAE‐2012‐02550
Dear Ms. Moura,
The attached reports describe in detail the work of the Paradise Pond Sediment Redistribution Project and the potential
impacts of that work to the Mill River downstream of Paradise Pond in Northampton Massachusetts. This is the 6th report
submitted to State regulators as required by the permits referenced above. The 2020 Report contains 3 reports, from 3 authors.
“Paradise Pond Sediment Management Report 2020”, Robert M. Newton, Geoscience Solutions LLC – pdf page
“Freshwater Mussel Monitoring in the Mill River”, Ethan Nadeau, Biodrawversity – pdf page
“Impact of Sediment Redistribution on Macroinvertebrates in the Mill River”, Marney Pratt, Smith Bioscience – pdf page
The 2020 sediment redistribution activity was started on Nov. 13, 2020 (partial drawdown) and completed on January 29, 2021.
I have included a brief summary of the work, in a timeline format with accompanying photographs.
Sediment Redistribution work & sluice gate operations summary: I was the sole sluice gate operator for the project. My
drawdown log is attached at the end of this report. The excavation contractor, Hatfield Construction, reported to me.
1. Drawdown commenced at 6:52 am, Friday, 11/13/2020. Gate opened to 50%.
2. Pre‐project Pond bottom survey with drone flights conducted on Tuesday, 11/17/2020.
3. Dozer entered Pond mid‐morning same day and started sediment redistribution.
4. Finished dozer work Tuesday morning 11/24/2020. Dozer left site, same day.
5. Pond remained partially drawn down while waiting for post dredge survey with drone flights.
6. River flow exceeded sluice gate capacity on 11/26/2020 (3/4” rain) and Pond filled.
7. Was unable to complete post dredge survey prior to next rain event on 11/30. Flow peaked ~ midnight at 2,200 cfs.
8. Partial drawdown resumed on 12/2/2020. Storm flow brought in significant quantities of sediment.
9. Dozer came back on 12/15/2020 and completed a 2nd sediment redistribution on 12/17.
10. Received 15” of snow on 12/16 & 12/17. Pond slowly filling on 12/17/2020. Dozer off site.
11. Pond spilling at 1:17 PM on 12/18/2020. Closed gate to 16%. Would not go below 16%.
12. Met Rob Kibler from Rodney Hunt (sluice gate manufacturer) on 12/22/2020. Closed gate to 6.7%
13. High temps (60F) & 1.5” rain raised flow to *3,240 cfs at 10:15 am on 12/25/2020 (upstream USGS gauge station)
14. Storm brought high sediment loads back into sediment redistribution area, damaged flashboards and large debris dam
formed against Lamont Bridge downstream.
15. Pond remained slightly below normal pool (damaged flashboards) until partial drawdown on 1/14/2021. Sluice gate
closed to 36% after attempts to clear debris jamb at sluice.
16. Pond stage rose during precip on 1/15 into 1/16 (gate position at 36% open).
17. Partial drawdown on 1/21/2021. Pond bottom survey with drone flight 1/22/2021.
18. Dozer returned 1/25/2021. Ice caused loss of USGS upstream reporting.
19. Dozer completed a 3rd sediment redistribution 1/29/2021.
20. Opened gate to 100% after ¾” rain fall on 2/16 hoping to clear gate debris jamb. Upstream station reporting “ice”.
21. Downstream station stopped reporting due to “ice” on 2/2/2021.
22. Gate remained at 100% open from 2/16 through 3/29 as attempts were made to clear gate debris jamb w/ grapple.
23. Upstream station started reporting again on 3/24/2021. Downstream station reporting on 3/26/2021.
24. Closed gate to 33.7% on 3/29/2021. Woody debris prevented gate from fully closing.
25. Opened gate to 100% on 4/28 for partial drawdown needed to install new fall protection anchors on upstream face of
spillway. Smith operations group removed all remaining flash boards & pipe same day.
26. 5/12/2021 – Flashboard repair complete.
27. 5/13/2021 – Started refilling pond at 7:05 am. Pond spilling at 4:00 pm. Gate closed to 29%. (woody debris)
28. 10/13/2021 – Commercial diver tied cables to logs jammed in gate. Operated gate with facilities operations group
using power winch cable and tractor. (no drawdown) Jamb clear early afternoon. Gate closed fully by 1:30 pm.
Observations:
o The dozer was very efficient at redistributing the course sediments nearest the river entry point. As the work moved
further downstream into softer/finer sediments, redistribution of sediment using a dozer was difficult.
o High precipitation events & the frequency of precipitation made sediment redistribution difficult. New sediment
replaced redistributed sediment twice. The slice gate clogged with woody debris preventing full closure of gate.
o It was easy to control sediment release during low river flow. Much more difficult with variable and high river flow.
o Duration of partial drawdown, and at times full drawdown, contributed to sluice gate jamb & sediment release.
o Sluiced sediment falls out quickly under low flow conditions, collecting in the plunge pool and further downstream.
o High flow events remove accumulated downstream sediment consistently and quickly. New sediment collects in the
Pond with equal speed and reliability. Several high flow events demonstrated how much sediment can be moved.
Conclusions:
A dozer is the most appropriate piece of equipment to redistribute course sediment within the Pond. Less so with
finer/ softer organic sediment.
Sediment released through the sluice gate fell out and accumulated in the plunge pool, and in the river beyond
Lamont Bridge.
The sediment remained in place until higher flows mobilized it and transported it further downstream.
Respectfully submitted,
Gary Hartwell, Project Manager
Smith College, Facilities Management
126 West St., Northampton, MA 01063
Ecc: David Wong and Susan You, MassDEP Div. Wetlands & Waterways, Boston; David Cameron and Mark Stinson,
MassDEP WERO; Paul Sneeringer and Barbara Newman, USACoE; Misty‐Anne Marold, and Thomas W. French, NHESP,
Mass. Div. F&W; Sarah LaValley and Kevin Lake, Northampton Conservation Commission; David Veleta, PE, and
Kristine Baker, PE, Northampton DPW; Robert M. Newton, Smith College Geosciences; Marney Pratt, Smith College
Biological Sciences; Ethan Nadeau, Biodrawversity; Peter Gagnon, Scott Richards, Smith College Facilities Management
Sarah Pierce, PARE Corp
2020 – Paradise Pond Sediment Redistribution Project Photos
11/24/2020 – Finished Sediment Redistribution 1 12/3/2020 – New sediment post 12/1/2020 storm (12” x 12” sq.)
12/16/2020 – Pond bottom post Sed Red 2 Paradise Pond Spillway & Plunge pool (Lamont Bridge
downstream) about 3 hours after peak flow on
12/25/2020.
1/22/2021 – New sediment post 12/25/2020 storm 1/30/2021 – Pond bottom post Sed Red 3
Paradise Pond Sediment Management
Report
2020
Robert M Newton
Geoscience Solutions LLC
June 16, 2022
Figure 1. Sediment redistribution operations on December 16, 2020.
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INTRODUCTION
Operations during the 2020 sediment redistribution were complicated by two large storm events
that transported large volumes of sediment into the pond. As a result, 3 separate redistribution
operations were required to maintain functional water depth, but there was still a net increase of
about 1,070m3 of sediment added to the pond during this period. In addition, a considerable
amount of bedload sediment was released downstream, in part because the sluice gate remained
partially open until October of 2021 due to logs jammed in the gate.
Initial sediment redistribution operations were begun on November 13 with the lowering of pond
level to approximately 6ft below the dam spillway. A drone flight was completed on November
16 to collect vertical air photos that were used to create a Digital Elevation Model (DEM) of the
pond bottom prior to sediment redistribution. Operations ended on November 18 but the post
operations drone flight was delayed until December 4 due to the Thanksgiving break and weather
issues. A 2.17in rain event on November 30 caused significant sediment transport into the pond
associated with this greater than 2000cfs discharge event. A second sediment redistribution was
done during the period December 15 – 18 to deal with the additional sediment from the
November 30th storm but a 12in snowstorm on December 17 complicated the effort. No drone
flights were done due to the heavy snow cover. A second major flow event occurred on
December 25 as a result of a rain on snow event. Flow in the Mill River exceeded 4000cfs
during this event and much sediment was deposited in the pond. A third sediment redistribution
was conducted between January 21 and January 30, 2021. A drone mission on January 22
documented the pre-redistribution conditions and one on the 30th allowed for the comparison
needed to quantify the amount of sediment redistributed. Table 1 summarizes the timing of
sediment redistribution operations.
TABLE 1. Summary of Redistribution Operations
Sediment
Redistribution
1
2
3
Operation Date Date Date
Pond Drawdown 11/13/20 11/13/20* 1/20/21
Drone Mission 11/17/20 12/4/20* 1/22/21
Bulldozing 11/17 – 11/24/20 12/15 – 12/18/20 1/25 – 1/30/21
Drone Mission 12/4/20 1/22/21* 1/30/21
Pond Fill 12/18/20 12/18/20* 3/28/21
*indicates operations associated with other sediment distributions
Although these 3 sediment redistributions failed to remove all the sediment added during these
two storms, the average water depth in the central part of the pond was kept deep enough to
maintain its recreational functionality.
HYDROLOGY
2020 was a fairly dry year. A total of about 36in of rain was measured at the Dam Monitoring
Station. (NOTE: Measurements are from an unheated tipping bucket rain gauge that
underestimates snowfall.). There was a total of 6 days during the year when daily rainfall
exceeded 1in with one of those days receiving more than 2in of rain in a 24-hour period. There
were only 4 high streamflow events when discharge exceeded 1000cfs (Figure 2). Minimum
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discharge measured at the USGS Clements Street Bridge station (#01171500) was 6cfs on
August 26, while the maximum flow was approximately 4,200cfs on December 25.
There was a drought from early May to late June.
The high flow events on February 27 (1,100cfs) and May 1 (1,250cfs) did not appear to transport
much sediment into the pond, while the events on November 30 (2,400cfs) and December 25
(4,500cfs) added considerable amounts of sediment to the pond. From this we might expect that
bedload sediment is mainly added to the pond when flows exceed 2,000cfs.
Figure 2. USGS Mill River Clement St Bridge station 2020 hydrograph showing 4 events with discharge exceeding
1000cfs. Also note drought period from May 7 to June 27 marked by baseflow recession.
REDISTRIBUTION OPERATIONS
This year there were 3 periods during which a bulldozer was used to redistribute sediment on the
pond bottom in the upstream area of the pond. During each redistribution, the water level was
first lowered by approximately 6ft and the pond bottom was allowed to dry before the bulldozer
was used to move the sediment. A drone was used to collect vertical air photos for
photogrammetric analysis both before and after redistribution. The resulting DEMs were
analyzed using Geographic Information System (GIS) software to quantitatively determine
where sediment was moved during the redistribution. Comparison of DEMs from year to year
allows us to estimate how much new sediment is added each year and sometimes storms during
the redistribution project, like this year, allow us to estimate how much sediment accumulates
from a single storm.
DEM Creation and Analysis
Drone missions photograph an area of approximately 13.5 acres upstream of the Smith College
Conference Center (figure 2). These missions typically collect about 350 overlapping
photographs of the mission area. Control points (8-12) are set out prior to the mission and their
location is precisely determined using an EOS Arrow Gold RTK GNSS receiver paired with the
HAMP CORS station located on the roof of Sabin Reed. This receiver provides an accuracy of
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8mm horizontal and 2cm vertical. During photogrammetric analysis of the photos using Pix4D
software, at least 4 of these points are designated as Ground Control Points while the rest are
used as Check Points. Pix4D creates both an orthophoto and a Digital Scene Model (DSM)
(Figure 3). The DSM differs from a DEM in that, elevations of trees and vegetation as well as
buildings are included in the model. A DEM only includes elevations of the bare earth. The
Pix4D DSM error is generally less than 3cm and has a cell size of approximately 1cm2.
Figure 2. Orthophoto created from drone imagery collected on December 4, 2020. Although this photo was taken
after the first sediment redistribution, a major storm on November 30 added significant amounts of
sediment to the pond. Some of this is clearly visible near the inlet to the pond (lower left).
The process of converting the DSM to a DEM is done using ArcMap GIS software. The
conversion from a DSM to a DEM requires removal of all the pixels with vegetation. This is
accomplished by first clipping the DSM to the area of the pond. Unfortunately, there are still
trees and other vegetation that overhang the pond. These are identified by finding all the pixels
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that have elevations above the mean water elevation of 41.5m. These pixels are then nulled to
create a DEM that only includes unvegetated pond bottom elevations. This DEM is the basis for
the quantitative analysis of the effectiveness of the sediment redistribution. Topographic profiles
can be directly constructed from the DEM using ArcMap’s 3D Analyst extension. Before
Figure 3. Digital Scene Model from drone data collected on December 4, 2020. Colors are keyed to elevations and
red dots represent control points.
and after DEMs can be subtracted using the raster calculator and the results integrated to
determine volume changes (figure 4). For example, to determine the total volume of sediment
accumulated between November 17 and December 4, it is first necessary to subtract each raster
cell in the December 4 DEM from the same cells in the November 17 DEM. Since both DEMs
are constructed using the same coordinate system, and both have the same cell size, this analysis
can be easily accomplished by simple raster subtraction.
!Difference!,#)=!Nov17DEM!,#)−!Dec4DEM!,#) (Equation 1)
Where:
i,j = easting and northing in Massachusetts State Plane Coordinates.
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The DEM includes water filled areas of the river channel that can’t be accurately measured using
drone-based photogrammetry and these areas need to be excluded from the analysis. This is best
done by constructing a screening polygon and limiting calculations to that area (figure 4).
Figure 4. The result of the subtraction of the November 17 DEM from the December 4 DEM. The value of each
cell in the raster is the change in pond bottom elevation. Positive values indicate removal of sediment
while negative values represent deposition. The black line filled polygon indicates the analysis area.
The difference raster can be integrated to determine the net change in the area of interest. Since
the cell size is known, the sum of the differences times the raster pixel area will result in the total
change in volume (m3).
Volume =:raster!,#× w × h
$
%
(Equation 2)
Where:
n = number of raster cells in the area of interest.
𝑟𝑎𝑠𝑡𝑒𝑟&,’= individual cell within the area of interest.
𝑤= width of the raster cell (0.0114m)
ℎ= height of the raster cell (0.0114m)
7
It is also possible to quantify the total amount of sediment that was removed from or added to the
area of interest, independent of the net total. It is first necessary to identify the cells that have
undergone the change of interest (gain or loss). This is done by querying the difference raster
using the raster calculator (difference > 0 = loss; difference < 0 = gain). However, because the
newly exposed pond bottom undergoes subsidence due to drying the difference criteria is set to
±0.05 rather than 0. The resulting raster of 0’s and 1’s can be used to identify the zones of
interest. Then simply apply equation 3 to determine the total volume of sediment gain or loss.
𝑉𝑜𝑙𝑢𝑚𝑒=:|𝐺𝑎𝑖𝑛&,’× w × ℎ
$
%
(Equation 3)
Where:
𝑛 = number of raster cells in the gain area.
𝐺𝑎𝑖𝑛&,’= individual cell within the gain raster.
𝑤= width of the raster cell (0.0114m)
ℎ= height of the raster cell (0.0114m)
Using these methods, it is possible to quantify the amount of sediment that was just moved from
one place to another verses that which was carried downstream. This year was unusual in that
there was more sediment present after two of the three sediment distributions than was there at
the start. This was entirely due to the two large storms that occurred during the project.
Sediment Redistribution 1 and 2
Pond level was lowered on November 13 and the initial drone mission was flown on November
17. Bulldozer operations ran from November 17 to November 24 and sediment was moved from
the central part of the pond to the active channel of the Mill River running along the north and
east edges of the pond (figure 5).
Figure 5. View downstream (NE) showing tracks from sediment redistribution operations on November 24.
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There were a number of rain events during the drawdown period that caused significant
variations in pond level (figure 6). On two occasions, the increased inflow to the pond exceeded
the capacity of the sluice gate for long enough to completely fill the pond so that water spilled
over the dam crest. This occurred on November 30 when 2.17in of rain fell and again on
December 5 when 0.87in fell. The November 30 event caused pond level to rise to a level just
over 2ft above the dam spillway as the discharge of the Mill River reached 2,350cfs at the
Lamont Bridge gage station. This event transported considerable bedload sediment into the
bottom of the pond and was ultimately responsible for adding more sediment to the pond than
was removed during this first redistribution.
Figure 6. Pond water level hydrograph during the drawdown period. The pond filled to spilling twice during the
period in response to rain events, 2.17in on November 30 and 0.87in on December 5.
Turbidity was measured using a Campbell Scientific OBS500 Smart Turbidity Meter with
ClearSensorTM technology. Both backscatter and side scatter measurements are made and
recorded by a Campbell Scientific CR1000 every 15 minutes. We have found that the side
scatter results correlate well with direct suspended sediment measurements so only side scatter
results are included in this report.
Figure 7. Plot showing turbidity and pond level during the fall drawdown period. The two yellow bands show
the period of sediment redistribution. Figure A shows turbidity values as a 1hour moving average
while figure B turbidity is expressed as average value over 24 hours.
B A
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There are occasional spurious results in the turbidity record when the readings spike to a high
value. These measurements could be due to debris or fish passing by the measurement window
at the time of the measurement. We have elected to not delete these spikes from the record but to
instead use average values to minimize the impact of the spikes. In figure 7A, a moving average
of 4 measurements is reported. Since measurements are made every 15minutes, these can be
considered an hourly moving average. In figure 7B the values are simple daily averages. The
daily average takes away a lot of the noise in the measurements but it is possible that the noise is
real given the episodic nature of the distribution operations and the sudden channel bank collapse
that sometimes occurs.
Downstream turbidity values, as measured at the Lamont Bridge gage station, generally
increased during the drawdown period (figure 7). This was due to 3 factors. Suspended
sediment was released during sediment redistribution operations as the bulldozer moved
sediment into the stream channel. It was also released as a result of stream erosion into the pond
bottom. This erosion rate is influenced by both the water level upstream of the dam and the
discharge of the Mill River. Finally suspended sediment and bed load sediment was brought into
the pond system during high flow events. The Christmas day storm is a good example as the
pond had been returned to full level prior to this event, yet this storm caused the highest 24hr
average turbidity measured during the project.
The net effect of sediment redistribution operations on turbidity is relatively small. The average
turbidity for the entire fall drawdown period (November 13 – December 18) was 34 NTU. If you
compare the periods when active sediment redistribution was occurring to those when it was not
but the pond was still drawn down you find no significant difference for the first redistribution
(32 NTU prior, 26 NTU during, and 33 NTU after). Average turbidity during the second
redistribution was higher 61 NTU but still fairly low compared to the natural event on December
25 when turbidity averaged 91 NTU.
High turbidity impacts are partially a function of discharge. High discharge during periods of
high turbidity helps keep the sediment in suspension maintaining its transport through the
system. Thus, the high turbidity associated with the December event would not be expected to
deposit suspended sediment in the channel. Sediment redistribution in the fall, rather than the
summer, benefits from the higher discharges that generally occur late in the fall. Discharge
during the drawdown period November 13 – December 18, averaged 140cfs with a median value
of 100cfs (figure 8). A major rain event on November 30 produced 2.17in of rain at the Dam
Monitoring Station. This caused pond level to rapidly rise to over 2ft above the crest of the dam
with discharge rising to 2,350cfs. This was the second highest flow recorded during 2020.
Maximum turbidity reached 425 NTU (1hr moving average) just before the peak in the
hydrograph (figure 9). This high flow was responsible for transporting large volumes of bedload
sediment into the pond, negating the sediment clearing efforts during sediment redistribution #1.
Thus, sediment redistribution #2 was conducted during the same drawdown.
Bedload sediment is released from the pond into the downstream channel whenever pond level is
lowered more than about 5ft. This sediment accumulates in the splash pool and in the
downstream channel mostly above the Lamont Bridge. The bedload sediment released from the
pond is a fine to medium sand that is distinctly different from the native gravel bed. A reference
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reach has been established just upstream of the Lamont Bridge where observations are made
using a web cam mounted on the bridge. Once every hour during daylight, the camera points to
the reference section and takes a photograph. These observations are augmented by photographs
Figure 8. Hydrograph showing discharge of the Mill River at the Lamont Bridge gage station during the Fall
drawdown period. Yellow areas indicate when sediment redistribution operations were in progress.
taken by observers who occasionally check the site. Photographs taken during the first
redistribution (11/22) show a light coating of fine sand covering the bottom gravel at the
reference site (figure 10A). By November 27,
considerable sand had accumulated in the
splash pool and some was moving down the
channel (figure 10B). By November 29, most
of the stream bottom in the area of the
reference station had been covered with a
layer of fine to medium sand (figure 10 C and
D). The storm on November 30 moved a lot
of bed load sediment. It scoured the reference
site, but by December 11 more sand had
moved back in (figure 10E). Upstream of the
dam, a lot of sand was deposited on the pond
bottom near the inlet as the entire pond was
filled with water during this event. Within a
couple of days, inflow to the pond was low
enough that the open sluice gate could handle
all the flow and the pond redrained, leaving a series of depositional fluvial dune features exposed
near the pond entrance (figure 10F).
Figure 9. Turbidity peaks during the rising limb of the
hydrograph of the November 30 rain event
11
Lamont Bridge Reference Site 11/22/20
Splash pool 11/27/20
Lamont Bridge 11/29/20 Lamont Bridge reference site 11/29/20
Lamont Bridge reference site 12/11/20
Upstream pond bottom bar 12/11/20
Figure 10. Photos of sediment accumulation during the November 13 – December 18, pond drawdown.
A B
C D
E
F
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An interesting sidenote on this event. During an inspection (November 30) of the gage stations
just prior to the storm, large schools of tadpoles were observed packed along the left bank of the
Mill River immediately upstream from the Lamont Bridge (figure 11). An equal number were
observed after the event indicating that 2,350cfs was not enough to wash them all downstream.
Figure 11. Cluster of tadpoles found adjacent to the left bank of the Mill River just upstream of the Lamont Bridge
on November 30, 2020, immediately prior to the 2.17in rain event.
Analysis of Sediment Redistribution 1
A bulldozer was used to redistribute sediment during the period between November 17 and
November 24. A drone mission was flown just prior to the beginning of operations to establish
base line conditions. A DEM (figure 12) was created from the air photos taken by the drone
using photogrammetry methods based on structure from motion techniques (PIX4D).
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Figure 12. DEM of the pond bottom created from drone acquired air photos taken on November 17, 2020.
Black and white hillshade that extends beyond the limits of the pond bottom is based on slope
(darker = steeper).
Redistribution operations were completed on November 24, but weather and the Thanksgiving
break prevented the flying of the post redistribution drone flight until December 4. This was
after a major rain event on November 30 caused the flow in the Mill River to peak at a discharge
over 2,000cfs. This event transported a large volume of bed load into the pond with much of it
being deposited near the entrance of the river into the pond.
The December 4 DEM (figure 13) looks quite similar to the November 17 DEM (figure 12) as
the storm essentially erased the changes in the pond bottom accomplished during the sediment
redistribution. The bedload sediment transported into the pond was deposited in the form of
fluvial dunes near the upstream end of the pond (figure 14), raising the surface of the pond
bottom, in some areas, higher than it was prior to sediment redistribution.
14
Figure 13. DEM of the pond bottom created from drone acquired air photos taken on December 4, 2020.
Black and white hillshade that extends beyond the limits of the pond bottom is based on slope
(darker = steeper). Note depositional features near the upstream end of the pond.
15
Figure 14. Closeup of December 4 DEM showing the sedimentary structures (fluvial dunes) deposited
during the November 30 storm event.
Normally there is a net loss of sediment from the pond bottom as a result of sediment
redistribution operations. That was likely true in this case, however, the storm that immediately
followed, added significant amounts of sediment so the net effect in this case was a gain in
sediment. The amount of gain was quantitatively determined by a mathematical analysis of the
DEMs.
Subtracting the post redistribution DEM from the pre redistribution DEM results in an elevation
model that shows the changes in elevation at each pixel location (figure 15). From this we can
observe where sediment was removed and where it accumulated. Areas covered by water create
spurious values and are excluded from this analysis. The red polygon shows the areas included
in the analysis.
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Figure 15 Model showing the difference in elevation determined by subtracting the December 4 DEM from the
November 17 DEM. Removal of sediment is represented by the blue colors (negative values) and the
reds indicate accumulation of sediment. Yellow areas show no change.
Figure 15 shows that there was some net removal of sediment in the central part of the pond near
the pond inlet (blue area). This is the area where sediment usually accumulates so is one of the
areas targeted during the sediment redistribution. Some of the redistributed sediment was moved
eastward from this area to fill in a low spot in the pond bottom (red “v”). The area of sediment
structures near the entrance to the pond is shown in red indicating net deposition here even
though it was an area targeted during the redistribution. The storm was also responsible for the
addition of approximately 0.5m of sediment on the point bar just east of the upper part of the
island. This is an area of perennial deposition as the flow of water around the island is forced to
make a more than 90˚ turn, causing sediment deposition on the inside of the turn.
Integrating the pixels in the elevation change model allows us to quantitatively summarize
changes in sediment volume in the pond. Since changes in the elevation of the pond bottom are
not uniform, the integration was done separately for gain and loss areas. Of course, the purpose
of the redistribution is to lower the pond bottom in shallow areas and put that sediment in deeper
areas or where it is more likely to be carried away by the current. Therefore, in a normal
redistribution, loss areas will be greater than gain areas and overall, there will be a loss of
sediment volume from the operations area. The high flow event on November 30, after
redistribution operations were completed, reversed the impact of the redistribution such that,
overall there was a net gain in sediment volume. Looking at the results on an area basis, only
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about 20% of the pond bottom in the operations area experienced a lowering of the surface while
40% saw increased elevations due to deposition. The remaining area 40% saw no significant
change in elevation (for the purposes of this study a D elevation of ±5cm is considered no
change). In terms of volume, those areas that experienced loss of sediment lost a total of 626m3
while those areas that experienced sediment gain, gained 1,316m3, for a net gain in sediment of
690m3. Since it was immediately apparent that there was more sediment in the pond a second
sediment redistribution operation was conducted as soon as possible.
Analysis of Sediment Redistribution 2
Sediment redistribution operations began on December 15 and ended on December 18. There
was a significant snowfall event (12in) on December 17 that prevented any immediate post
redistribution drone flight. The only data available to evaluate the effectiveness of this operation
is the drone flight on December 4 that can be used as a pre-operation flight and the drone flight
on January 22 (figure 16) that can be used as a post-operation dataset. However, that means the
pre-redistribution DEM was done 11 days before the start of sediment redistribution operations
and although the pond was in a low stage condition throughout most of that period, it briefly
filled on December 6 in response to just under 1in of rain (figure 6). Worse, the post sediment
redistribution DEM was created from data collected a full 5 weeks after redistribution operations
were completed and the largest discharge event of the year occurred during that period. Also, the
pond was filled during most of that period. Despite this, an elevation difference model (figure
17) was constructed by subtracting the January 22, DEM from the December 4, DEM. This
model shows the net effect of both sediment redistribution operations and deposition associated
with the storm events.
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Figure 16. DEM of the pond bottom created from drone acquired air photos taken on January 22, 2021. Black and
white hillshade that extends beyond the limits of the pond bottom is based on slope (darker = steeper).
Note similar depositional features as shown in figure 12.
Analysis of the elevation change model (figure 17) was impacted by the relatively high stage of
the lowered pond on January 22. Water levels were high enough to flood the low spots at the
southern end of the model (next to the athletic field). This problem was exacerbated by snow
and ice that made determining the exact location of the shoreline difficult. This resulted in the
analysis area for this sediment redistribution being smaller than for the first redistribution.
Integrating raster cells in the elevation model that show sediment loss indicates that
approximately 17% of the pond bottom experienced a loss of sediment with a total volume loss
of 421m3. This is most likely the result of sediment redistribution operations where sediment
was moved to the stream channel and that sediment was then transported out of the pond system.
In contrast, approximately 45% of the pond bottom experienced sediment gain with a total
volume gain of 1,100m3. This sediment was largely brought into the pond during the December
25 storm event. This left about 38% of the pond showing no significant change in bottom
elevation. This is a conservative value as cells were classified as having no change if the
difference in elevation was less than ±5cm. This is greater than the resolution of the DEMs
because there is considerable compaction of the sediment as it dries out.
19
Figure 17. Elevation difference model created by subtracting the January 22 DEM from the December 4 DEM. The
red polygon marks the extent of the analysis area. Water levels were higher on January 22 and water
flooded a narrow channel at the southern end of the pond.
The net result of the analysis of elevation changes between December 4 and January 22 is that
the pond experienced a net gain of 679m3. It was quite evident after the December 25 event
there was a need for a third sediment redistribution. Not only was the pond still filled with
sediment (net addition of over 1,300m3) but the high flows did considerable damage to the
flashboards on the dam and moved a number of large logs to the area of the sluice gate.
December 25 Storm Event
The pond was refilled on December 18, after Sediment Redistribution 2. A combination of
snowmelt (high temperature of 62˚F) and 1.5in of rain on December 24 and 25 resulted in the
highest discharge measured during 2020. The hydrograph at the USGS Clement St gage station
(#01171500) shows a brief spike in discharge at over 4,000cfs (figure 18). This is preceded by a
downward spike when discharge dropped to near 2,000cfs. It is likely that this was caused by
the formation of an ice jam on the Mill River just upstream of the Clement St gage station. The
resulting blockage to streamflow caused the sudden drop in discharge. The ice jam then failed
causing the sudden release of a large volume of water that briefly drove the discharge above
4,000cfs. A similar record is seen at the Lamont Bridge Station.
20
Figure 18. Hydrographs of the December 25 event from both the upstream USGS Clement St bridge and the Lamont
Bridge gage stations.
Figure 19. Turbidity was highest on the rising limb of the hydrograph. The secondary peak during the afternoon is
likely associated with a sudden
The high discharge was accompanied by high turbidity values with the moving average
increasing to over 350NTU during the rising limb of the hydrograph. Like the December 1
event, the maximum turbidity occurred prior to the peak in the hydrograph suggesting a limited
volume of fine grain material available for transport.
21
The high discharge of water over the crest of the dam, damaged the flashboards and the water
level in the pond dropped in response. Pond level remained low after the event until the
flashboards were replaced in the spring. Pond level was lowered for the final sediment
redistribution on January 20th (figure 20). During the redistribution, logs transported from
upstream, probably during the December 25th event, became lodged in the sluice gate preventing
it from operating properly. Thus, the pond remained largely drained throughout the spring. This
allowed for significant sediment removal by erosion of the stream flowing across the pond
bottom.
Figure 20. Pond hydrograph showing water level relative to the elevation of the crest of the dam.
Sediment Redistribution 3
Immediately after the December 25 rain/snowmelt event it was apparent that a third sediment
redistribution would be required to remove new sediment added to the pond. Pond level was
lowered on January 20 and a drone flight was flown on January 22 in preparation for the
bulldozer to begin moving sediment on January 25. Operations were completed on January 30th
and the final drone flight was flown later that day. However, the pond was unable to be filled
due to the logs in jammed in the sluice gate. There followed a long period when the level of the
partially filled pond varied considerably both because of the clogged sluice gate and the damaged
flashboards (figure 21). The flashboards were repaired in late May and the pond was essentially
restored to a normal level as leakage through the partially clogged sluice gate was fairly small.
However, during low flow periods pond level dipped slightly below the dam crest for short
periods of time (figure 21). The logs clogging the sluice gate were finally cleared on October 13.
22
Figure 21. Pond level after the third sediment redistribution was unstable until the flashboards were repaired in May
and the sluice gate was cleared in October. Drawdown in December was associated with the 2001
sediment redistribution.
The January 2021 drawdown revealed the full extent of bedload sand deposited on the pond
bottom near the inlet during the December 25 event. Drone flights and DEMs documented the
thickness and location of these deposits which formed a series of bars, scour holes and fluvial
dunes (figure 22 and 23). These deposits are made up of medium to coarse sand with some
pebbles.
Figure 22. January 22 DEM showing the sand features on the pond bottom. Red arrows show the inferred current
direction when these features were formed. Note the similarity to features formed during the November
30 event shown in figure 14.
23
Figure 23. Closeup of the scour holes and fluvial dunes deposited during the December 25 event. These sediments
are composed of medium to coarse sand.
Analysis of Sediment Redistribution 3
This was the only sediment redistribution of the three, that was completed without a storm
disrupting operations and adding more sediment to the pond bottom. The drone flights could be
completed in a timely manner, so unlike the previous two redistributions, the results provide a
clear picture of the effect of the operation. A comparison of the pre-redistribution DEM (figure
16) to the post-redistribution DEM (figure 24) shows how bulldozer operations concentrated on
moving the bedload sand deposited on the pond bottom during the December 25 event. This
sediment was moved to three different locations. Some was moved eastward, forming a lobe of
sediment partially filling a low area of the pond bottom (figure 24). Some was used to fill the
trough in front of the upstream edge of the island. This sediment was piled higher than the
normal pond elevation with the expectation that it would be eroded during subsequent high flow
events. This part of the island is protected from erosion by riprap and there is normally a deep
scour hole that forms in front of it. Finally, most of the material was pushed into the stream
channel that along the north and east sides of the pond. Some of this sediment was moved
downstream by the stream and some went to narrowing the channel (figure 25). The narrowing
caused a reduction in the cross-sectional area of the stream channel and that caused an increase
24
in stream velocity that, in turn, increased the competence of the stream to transport more
sediment downstream. Sediment lost from the system during redistribution is mainly due to river
transport of this sediment added to the stream channel.
Figure 24. DEM of pond bottom after sediment redistribution on January 30, 2021. Compare with pre-redistribution
shown in figure 16.
An elevation difference model was constructed by subtracting the January 30 DEM from the
January 22 DEM. This model (figure 26) shows where sediment was removed (lower surface)
and where it was accumulated (higher surface). The analysis area (shown by the red polygon in
figure 26) is limited to areas not covered by water. Areas where sediment was removed were
determined by querying the elevation difference model to determine all cells with values greater
than 0.05m (0.05m was used to allow for subsidence due to shrinkage associated with the drying
out of the pond bottom). The resulting raster of 0s and 1s was then used as a screen to identify
the cells that were integrated to determine the total amount of sediment that was excavated. In
this redistribution, a total volume of 1,424m3 was excavated from an area of 4,333m2 (19% of the
analysis extent).
25
Figure 25. Orthophoto showing the extent of the stream channel on January 22. Red line shows the channel as it
existed on January 30, immediately after sediment redistribution operations were completed. The
narrowing represents sediment moved into the stream channel from redistribution operations.
Figure 26. Model showing elevation changes as a result of sediment redistribution operations in January. The blue
areas show where sediment was removed and the red areas show where it was accumulated. The red
polygon marks the analysis extent.
26
A similar methodology was used to determine the volume and area where sediment was
accumulated. The analysis shows a total of 1,122m3 of sediment was accumulated over an area
of 6,483m2 (29% of the analysis extent). This is primarily the sediment that was piled at the
edge of the channel and in front of the island. The net effect of this redistribution, as calculated
within the analysis area, was a loss (export) of 302m3 of sediment.
Conclusion
Sediment redistribution during 2020 was a complex of 3 different operations done over several
months with 2 major flow events mixed in (Table 2). It is really not possible to fully analyze the
first two operations without drone data from just before and just after the work was done. It is
likely that each, at least for a short time, resulted in a net loss of sediment that was then partially
erased by sediment brought in during the two storms that occurred after each operation was
completed.
Table 2 Summary of Sediment Redistribution Operations
Sediment Loss Sediment Accumulation Net Change
Operation Vol (m3) Area (m2) Vol (m3) Area (m2) Vol (m3)
1 626 4,847 1,316 9,780 690 gain
2 421 3,611 1,100 9,375 679 gain
3 1,424 4,333 1,122 6,483 302 loss
The analysis of the final redistribution is robust and shows a net loss of just over 300m3 of
sediment. While it is not possible to definitely say that the material lost from the analysis area
was exported from the pond, it is likely. In fact, it may be that even more sediment is exported
than the reported net change as there is likely channel erosion in the downstream area of the
pond bottom, just upstream of the dam. This is especially apparent during periods when the
pond stage drops below -8ft. During the operation to clear the sluice gate of debris, the pond
briefly drained completely and during that time, a knickpoint was observed to form and migrate
upstream. This resulted in considerable transport of sediment out of the pond.
Sediment released from the pond accumulates in the splash pool and in the downstream channel
between the dam and the Lamont Bridge (see Appendix 1 for photos). However, that sediment is
generally present for a relatively short period of time and is cleaned out by subsequent high flow
events, especially when discharge exceeds 1000cfs. No significant sediment accumulations have
been observed in the Mill River diversion channel below the Rt 66 bridge nor in downstream
sections of the Mill River below the Rt 10 dam. It is apparent that the vast majority of sediment
released from Paradise Pond is being transported through the lower part of the Mill River system
all the way to the Oxbow.
Paradise Pond Sediment Management
Report
2020
APPENDIX
Reference Section Photo Library
2
PHOTO 1
Under the Lamont Bridge
December 25, 2020. Note staff gage completely under water. The staff gage is located on the
second left side post from the front of the photo. The two pipes on the second right side post
hold gage station sensors. River flow is from right to left. Photo by G. Hartwell.
PHOTO 2
Under the Lamont Bridge
January 1, 2021. The first set of posts is behind the photographer. This photo shows the second
set of posts with the staff gage on left and pipes for sensors on right. Debris from Dec 25.
3
Photo 3
Upstream side of the Lamont Bridge
December 26, 2020. Debris piled up on the upstream side of the Lamont Bridge from the
December 25 flow event. Double pipes on left post hold gage station sensors.
Photo 4
Paradise Pond dam
December 26, 2020. Splashboard damage on dam crest from December 25 event.
4
Photo 5
Left bank of splash pool
December 26, 2020. Red line shows high water mark on the left bank from December 25
hydrologic event. Maximum discharge was over 4,000cfs.
Photo 6
Splash pool below Paradise Pond dam.
March 18 2021. Sediment filled splash pool. Damaged splashboard at top of dam is visible in
lower right of the photo.
5
Photo 7
Lamont Bridge reference section
March 18, 2021. View of stream reference section from the Lamont Bridge looking upstream to
the dam. Note sediment filled channel and partially drawn down pond. A large amount of
sediment was released from the pond during the extended partial drawdown after the damage
from the December 25 event.
Photo 8
Under the Lamont Bridge, upstream
March 18, 2021. Sediment filled channel under the Lamont Bridge. Double pipes hold sensors
for the gage station.
6
The following sequence of photos was collected from the web cam located on the Lamont
Bridge. The camera is programmed to tilt downward and collect a photo from the reference
section hourly during daylight hours. This sequence documents changes in bed load sand
through the prolonged drawdown during the spring of 2021.
Photo 9 April 14, 2021
Photo 10 May 20, 2021
7
Photo 11 June 16, 2021
Photo 12 July 23, 2021
8
Photo 13 August 21, 2021
Photo 12 September 15, 2021
a
prepared by
prepared for
Trustees of the Smith College
Facilities Management
126 West Street
Northampton, MA 01063
February 2021
Freshwater Mussel Monitoring in the Mill River for the
Paradise Pond Sediment Management Project: 2016-2020
biodrawversity
Biodrawversity LLC
206 Pratt Corner Road
Leverett, MA 01054
REPORT
NHESP File Number: 10-27790
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
1
INTRODUCTION
From 2016 to 2020, Biodrawversity LLC collected baseline
data (2016 and 2017) and implemented annual monitor-
ing (2017 to 2020) of the mussel community and aquatic
habitat in the Mill River downstream from Paradise Pond in
Northampton, Massachusetts. Qualitative odonate (drag-
onfly and damselfly) surveys were also conducted in these
areas in 2017. This research was completed as part of the
Paradise Pond Sediment Management Protocol Project (“Proj-
ect”) that is being conducted by Smith College. One of the
goals of the Project is to facilitate the export of accumu-
lated sediment from Paradise Pond via natural streamflow
to avoid costly dredging and to potentially improve down-
stream habitat. Recent management efforts have focused
on redistributing fine sediment within Paradise Pond to put
it nearer the dam, and then to open the dam’s sluice gates
during high-flow events to allow the river to transport sedi-
ment downstream. Once it passes downstream from the
dam, the sediment will likely be widely dispersed in the Mill
River downstream to the Oxbow, or deposited on the river’s
floodplain. Smith College is studying the transport and fate
of this sediment.
The Massachusetts Natural Heritage and Endangered
Species Program (NHESP) required baseline data collection
and long-term monitoring of mussels to determine the po-
tential effects (beneficial or adverse) of sediment release
on state-listed mussels living downstream from Paradise
Pond, and if adverse effects on mussels are documented, to
evaluate alternate approaches. State-listed mussel species
that have historically been documented in the lower Mill
River and the nearby Oxbow include Ligumia nasuta (East-
ern Pondmussel; Special Concern), Strophitus undulatus
(Creeper; Special Concern), Alasmidonta heterodon (Dwarf
Wedgemussel; Endangered), and Lampsilis cariosa (Yellow
Lampmussel; Endangered). NHESP also required a baseline
qualitative survey of odonates in the same general areas of
the mussel survey to determine species composition of the
odonate community, with focus on state-listed species that
have been documented in the Mill River. Target state-listed
species included Boyeria grafiana (Ocellated Darner), Gom-
phus abbreviatus (Spine-crowned Clubtail), Gomphus ven-
tricosus (Skillet Clubtail), and Neurocordulia yamaskanensis
(Stygian Shadowdragon).
Mussel monitoring Site 1 in the Mill River in Northampton, Massachusetts.
Ligumia nasuta (Eastern Pondmussel)
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
2
This annual report, which is revised each year to in-
clude the newest annual monitoring, summarizes the qual-
itative and quantitative baseline mussel study (2016 and
2017) and annual mussel monitoring (2017 to 2020). The
odonate data were described in the 2017 annual report
and are omitted from this annual report.
METHODS
The objective of the freshwater mussel study was to obtain
data on mussel presence, density, shell length distribution,
and habitat using a combination of quantitative (quadrats)
and qualitative (timed searches) survey methods at five lo-
cations in the Mill River (Figure 1). Mussel survey locations
overlap with the sediment monitoring sites that are being
studied by Dr. Robert Newton of Smith College.
1. Qualitative Mussel Survey
Timed qualitative surveys were conducted at five locations
(Figure 1). Sites 1-4 were surveyed qualitatively in 2016,
and Site 5 was partially surveyed in 2016 and 2017, and
fully surveyed from 2018 to 2020. Surveys were completed
using a combination of snorkeling, SCUBA diving, and wad-
ing. Biologists recorded the shell length, shell condition,
location, and habitat of state-listed species encountered
during these surveys, and also recorded counts (or general
abundance) of co-occurring species. Shell condition refers
to the degree of shell erosion (e.g., loss of periostracum
or other damage); for each mussel, biologists subjectively
assign a numeric score ranging from 0.0 (no shell erosion)
to 1.0 (severe loss of periostracum or other damage) and
these scores are averaged for all individuals in a sample to
produce an index of shell condition ranging from 0 to 1.
These qualitative surveys determined that mussel densities
in areas between Paradise Pond and Route 10 (i.e., Sites 3,
4, and 5) were considered too low for the quantitative sam-
pling described below.
2. Quantitative Mussel Survey
Quantitative sampling was initially conducted at two lo-
cations downstream from Route 10 (Figures 2 and 3) be-
tween September 25-27, 2016. Quantitative sampling was
repeated at these same two sites in 2017 (May 23-25), 2018
(June 18-20), 2019 (June 4-6), and 2020 (June 3-5). Study
plots spanned the width of the river and were 50 meters
in length. A total of 120 quadrats (size = 1.0m2) were sam-
pled within each plot, arranged along 12 transects with 10
quadrats per transect. Qualitative surveys at these loca-
tions showed that the primary target species (L. nasuta)
was more common in shallow and intermediate depths
close to the shoreline, and therefore each plot was divided
into three longitudinal strata and the quadrat density was
Mussel monitoring Site 2 in the Mill River in Northampton, Massachusetts.
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
3
N
Site 1 Mill RiverParadise P
o
n
d
OxbowSite 2
Site 3
Site 4
Site 5
Hulberts Pond
Hulberts Pond sedimentmonitoring site(not used formussel survey)
Figure 1. Qualitative mussel survey sites (5) in the Mill River from Paradise Pond
to the Oxbow.
(40 quadrats per strata;double quadrat densityin Strata 1 and 3
N
Strata 1Strata 2Strata 3
Figure 2. Site 1 for the quantitative mussel sampling, showing stratification for
quadrat sampling.
Strata 1Strata 2Strata 3
(40 quadrats per strata;double quadrat densityin Strata 1 and 3
N
Figure 3. Site 2 for the quantitative mussel sampling, showing stratification for
quadrat sampling.
doubled in strata 1 and 3. Strata 2 occupied the middle half
of the channel, and were therefore approximately twice as
large as strata 1 and 3. Quadrat allocation included four
transects (40 quadrats) in strata 1 and 3, and four transects
(40 quadrats) in strata 2.
Biologists recorded the numbers of uncommon mus-
sel species (i.e., all species except for Elliptio complanata))
at the surface of the sediment in the entire 1.0m2 quadrat,
and recorded the number of E. complanata at the surface of
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
4
the sediment in a randomly selected quarter of each quad-
rat. The different method for E. complanata was meant to
reduce the survey time, as this species can be too abundant
to count efficiently. Biologists also excavated and sieved
the top 10 centimeters of sediment from a randomly select-
ed quarter of each quadrat, and recorded the number of
individuals of each species that were found buried. Counts
for surface mussels versus buried mussels were recorded
separately. Biologists record the shell length and shell con-
dition of all state-listed species.
For each quadrat, biologists recorded water depth, the
presence and percent cover of different types of substrate,
substrate embeddedness, qualitative estimate of flow ve-
locity, and percent cover of submerged aquatic vegetation
and woody debris. Raw data can be provided upon request
(MS Excel file) but are too cumbersome to include with this
written report. Substrate type and percent cover were es-
timated visually using the following categories: clay, silt,
sand, gravel, cobble, and riprap. Embeddedness was visual-
ly estimated for quadrats that contained coarse and gravel
and cobble, using the five ratings described in Platts et al.
(1983):
<5 percent of surface covered by fine sediment
5-25 percent of surface covered by fine sediment
25-50 percent of surface covered by fine sediment
50-75 percent of surface covered by fine sediment
>75 percent of surface covered by fine sediment
3. Analysis
Mussel density (mussels/m2) and population size estimates
(with 90% confidence intervals) of each species were com-
puted for each plot. The density and population estimates
were computed in two ways: (1) all quadrats weighted
equally, and (2) using the stratification described above,
where quadrats are not weighted equally because of the
double density of quadrats in strata 1 and 3. Shell length
and condition data are summarized as a means of demon-
strating age structure (inferred from length-frequency dis-
tributions), recruitment, and mussel health.
RESULTS
1. Qualitative Mussel Survey
From 2016 to 2020, eight mussel species were found dur-
ing qualitative surveys (Tables 1, 2). Of the potential state-
listed species in the study area, L. nasuta were found only at
Site 1 and Site 2, and S. undulatus were found only at Site 5.
No L. cariosa or A. heterodon were found. Other uncommon
species found included Margaritifera margaritifera at Site 5,
one dead Alasmidonta undulata at Site 2, and Pyganodon
cataracta at Sites 1 and 2. Lampsilis radiata was relatively
more common, and E. complanata was by far the most nu-
merous. It is also important to note that some species were
detected during quantitative sampling at some sites (not
during qualitative sampling), including S. undulatus at Sites
1 and 2, M. margaritifera at Site 1, A. undulata at Sites 1 and
2, and Anodonta implicata at Site 2.
Highest densities of mussels were found at Site 1 and
Site 2 (Table 2). Several hundred E. complanata were ob-
served at these two sites, compared to only four live at sites
3–5 combined. E. complanata was numerous along stable
banks and also throughout the channel, whereas other
Transect and quadrat at Site 2.
Sieved materials from a quadrat along the shoreline of Site 2, with mix of trash
and three L. nasuta.
Site 5 between Route 20 and the Paradise Pond Dam.
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
5
mussel species were found primarily along stable banks
and were uncommon or absent in the middle half of the
channel. No mussels, live or dead, were found at Site 3.
Only three L. radiata shells were found at Site 4.
In 2018, 185 L. radiata were found during a longer du-
ration (nearly 10 person-hours) qualitative survey at Site 5,
along with 14 M. margaritifera, five S. undulatus, and two
E. complanata (Table 2). Similar numbers were observed
during the qualitative survey in 2019: 120 L. radiata (and
33 shells), 20 M. margaritifera, and four S. undulatus. The
2020 qualitative survey at Site 5 was generally consistent
with the 2019 and 2018 results, except with fewer L. radiata
(73 live, 41 shells); 22 M. margaritifera and two S. undulatus
were also found. These qualitative survey data suggest a
declining L. radiata population at Site 5. The few S. undu-
latus found at Site 5 are large and in poor condition. The
M. margaritifera population at Site 5, though small, appears
to be stable. Historic data suggest that mussels are nearly
absent within and upstream from Paradise Pond (one live
M. margaritifera was found upstream in 2016).
2. Quantitative Mussel Survey
From 2016 to 2020, eight species were detected during
quantitative sampling, including five species at Site 1 and
seven species at Site 2. Anodonta implicata was detected
for the first time in 2020. Tables 3 and 4 summarize density
and population size estimates for species at each site, giv-
ing equal weight to all of the quadrats (disregarding strati-
fication). Tables 5 and 6 show the same statistics that were
computed based on the stratified design, with double den-
sity of quadrats in strata 1 and 3. Raw data can be provided
upon request. Density estimates were computed for each
strata at each site, and the overall population estimate was
the sum of the population estimates for each of the three
strata. Tables 7 and 8 more clearly contrast the population
estimates derived from these two different methods, for all
five years. The population estimates based on the stratified
design are probably more accurate.
Latin Name (abbreviation)Common Name Status
Alasmidonta undulata (AlUn)Triangle Floater
Anodonta implicata (AnIm)Alewife Floater
Elliptio complanata (ElCo)Eastern Elliptio
Lampsilis radiata (LaRa)Eastern Lampmussel
Ligumia nasuta (LiNa)Eastern Pondmussel Special Concern
Margaritifera margaritifera (MaMa)Eastern Pearlshell
Pyganodon cataracta (PyCa)Eastern Floater
Strophitus undulatus (StUn)Creeper Special Concern
Table 1. Mussel species documented in the Mill River for the Paradise Pond Sedi-
ment Management Project, from 2016 to 2020.
Site 5
Site 1 Site 2 Site 3 Site 4 2016 2017 2018 2019 2020
Start Latitude 42.30068 42.30462 42.30656 42.31018 42.31326 42.31557 42.31326 42.31326 42.31326
Longitude -72.65159 -72.64765 -72.64631 -72.64060 -72.64072 -72.64101 -72.64072 -72.64072 -72.64072
End Latitude 42.30170 42.30597 42.30725 42.31173 42.31599 42.31630 42.31630 42.31630 42.31630
Longitude -72.65097 -72.64644 -72.64534 -72.63952 -72.64098 -72.64079 -72.64079 -72.64079 -72.64079
Survey Date 9/9/2016 9/8/2016 9/8/2016 9/8/2016 9/9/2016 6/12/2017 5/14/2018 6/1/2019 5/19/20
Duration (person-hrs)2.0 3.3 2.0 2.0 2.0 2.0 10.0 10.0 11.0
Mean Depth (ft)2.50 2.80 2.50 0.50 1.25 ~3-4 3.0 3.0 3.0
Max Depth (ft)5.00 6.00 4.50 1.50 3.00 ~12.0 ~12.0 ~12.0 ~12.0
Flow Velocity <0.1 m/s <0.1 m/s <0.1 m/s Variable Variable Variable Variable Variable Variable
Dominant Substrate(s)*Cl-Si-S-G Cl-Si-S-G-W Si-RR S-G-RR Si-S-G-C S-G-C-B-BR S-G-C-B-BR S-G-C-B-BR S-G-C-B-BR
Species Counts**
L. nasuta 7 20 0 0 0 0 0 0 0
S. undulatus 0 0 0 0 1 0 5 4 2
M. margaritifera 0 1 0 0 1 (1)18 14 20 22
A. undulata 0 0 (1)0 0 0 0 0 0 0
P. cataracta 1 6 0 0 0 0 0 0 0
L. radiata 10 27 0 0 (3)10 (25)2 (1)185 (26)120 (33)73 (41)
E. complanata 100s 100s 0 0 1 1 2 0 0
Table 2. Locations, survey effort, habitat, and mussel counts for qualitative mussel surveys in the Mill River, 2016 to 2020.
*Substrate Abbreviations: Cl = Clay, Si = silt, S = sand, G = gravel, C = cobble, B = boulder, BR = bedrock, RR = riprap, W = wood/detritus
**Number in parentheses indicates shell counts.
***Site 5 survey areas: 2016 = Route 20 to the walking bridge. 2017 = walking bridge to the Paradise Pond dam, 2018-2020 = Route 20 to the Paradise Pond dam.
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
6
Table 4. Density and population estimates for each species at Site 2. Data ana-
lyzed without stratification. Species abbreviations as in Table 1.
Species
Statistic LaRa LiNa StUn AlUn PyCa AnIm ElCo ALL
Year: 2016
Mean Density 0.09 0.22 0.00 0.00 0.05 0.00 1.93 2.29
St. Dev.0.53 0.84 0.00 0.00 0.39 0.00 3.11 3.16
Estimate 105 249 0 0 58 0 2,223 2,635
90% CI (Lower)13 104 0 0 -9 0 1,688 2,091
90% CI (Upper)197 394 0 0 124 0 2,759 3,180
Year: 2017
Mean Density 0.04 0.53 0.01 0.03 0.03 0.00 3.63 4.26
St. Dev.0.24 1.43 0.09 0.16 0.16 0.00 4.58 5.01
Estimate 48 604 10 29 29 0 4,178 4,897
90% CI (Lower)7 358 -6 2 2 0 3,390 4,035
90% CI (Upper)89 849 25 56 56 0 4,967 5,759
Year: 2018
Mean Density 0.00 0.23 0.01 0.00 0.08 0.00 3.70 4.03
St. Dev.0.00 0.87 0.09 0.00 0.31 0.00 6.98 7.04
Estimate 0 222 8 0 79 0 3,515 3,824
90% CI (Lower)0 98 -5 0 36 0 2,522 2,822
90% CI (Upper)0 345 21 0 123 0 4,508 4,825
Year: 2019
Mean Density 0.01 0.58 0.03 0.01 0.04 0.00 14.80 15.47
St. Dev.0.09 1.56 0.18 0.09 0.20 0.00 20.58 20.79
Estimate 8 546 32 8 40 0 14,060 14,693
90% CI (Lower)-5 324 6 -5 11 0 11,132 11,736
90% CI (Upper)21 768 57 21 68 0 16,988 17,651
Year: 2020
Mean Density 0.03 0.56 0.01 0.01 0.07 0.01 6.40 7.08
St. Dev.0.16 2.34 0.09 0.09 0.40 0.09 10.53 10.61
Estimate 24 530 8 8 63 8 6,080 6,721
90% CI (Lower)1 197 -5 -5 6 -5 4,582 5,212
90% CI (Upper)46 864 21 21 121 21 7,578 8,230
Table 3. Density and population estimates for each species at Site 1. Data ana-
lyzed without stratification. Species abbreviations as in Table 1.
Species
Statistic LaRa LiNa AlUn PyCa MaMa ElCo JUV*ALL
Year: 2016
Mean Density 0.18 0.03 0.00 0.00 0.00 5.13 0.00 5.35
St. Dev.0.77 0.37 0.00 0.00 0.00 11.92 0.00 12.02
Estimate 174 32 0 0 0 4,877 0 5,083
90% CI (Lower)65 -20 0 0 0 3,182 0 3,373
90% CI (Upper)283 84 0 0 0 6,572 0 6,792
Year: 2017
Mean Density 0.14 0.20 0.00 0.00 0.00 11.83 0.00 12.18
St. Dev.0.37 1.00 0.00 0.00 0.00 24.98 0.00 25.37
Estimate 135 190 0 0 0 11,242 0 11,566
90% CI (Lower)81 48 0 0 0 7,689 0 7,958
90% CI (Upper)188 332 0 0 0 14,794 0 15,174
Year: 2018
Mean Density 0.03 0.35 0.00 0.00 0.00 7.47 0.77 8.62
St. Dev.0.18 1.06 0.00 0.00 0.00 10.66 2.03 10.78
Estimate 32 333 0 0 0 7,093 728 8,186
90% CI (Lower)6 182 0 0 0 5,577 440 6,653
90% CI (Upper)57 483 0 0 0 8,610 1,017 9,718
Year: 2019
Mean Density 0.02 0.33 0.01 0.00 0.01 17.83 0.00 18.19
St. Dev.0.13 1.11 0.09 0.00 0.09 23.35 0.00 23.62
Estimate 16 309 8 0 8 16,942 0 17,282
90% CI (Lower)-2 151 -5 0 -5 13,620 0 13,922
90% CI (Upper)34 466 21 0 21 20,263 0 20,642
Year: 2020
Mean Density 0.08 0.35 0.01 0.01 0.00 9.77 0.00 10.21
St. Dev.0.43 1.33 0.09 0.09 0.00 12.43 0.00 12.67
Estimate 71 333 8 8 0 9,278 0 9,698
90% CI (Lower)10 143 -5 -5 0 7,510 0 7,896
90% CI (Upper)133 522 21 21 0 11,047 0 11,500
*tiny juvenile mussels, species not determined
Site 1, Year 2016: Three species were detected. Based on
the stratified design, we estimate population sizes of 4,190
E. complanata, 158 L. radiata, and 25 L. nasuta. E. compla-
nata comprised 95.8 percent of the mussel community at
this site. All mussels were relatively less common along the
left bank (strata 1); we estimated 225 E. complanata (90%
confidence limit: 87–363) and no other species in strata 1.
In contrast, we found three species and estimated 3,338
mussels (90% confidence limit = 2,161–4,514) in strata 3.
Strata 2 had intermediate densities of E. complanata and
few L. radiata. L. nasuta were only detected in Strata 3.
Site 1, Year 2017: The same three species were detected
at Site 1 in 2017. Based on the stratified design, we esti-
mate population sizes of 9,415 E. complanata (more than 2x
higher than the 2016 estimate), 126 L. radiata (slightly low-
er than the 2016 estimate), and 230 L. nasuta (much higher
than the 2016 estimate of 25 mussels). See Table 5 for the
90% confidence intervals associated with these popula-
tion estimates. E. complanata comprised 96.4 percent of
the mussel community at this site. As in 2016, all mussels
were relatively less common along the left bank (strata 1).
E. complanata were exceptionally common along the right
bank (strata 3), and more than double the density that was
estimated for strata 3 in 2016. Strata 2 (center channel) had
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
7Table 5. Density and population estimates by strata for each species encountered at Site 1, 2016 to 2020. Species abbreviations as in Table 1.Year: 2016Year: 2017Year: 2018Year: 2019Year: 2020StatisticLaRaLiNaElCoALLLaRaLiNaElCoALLLaRaLiNaElCoJUV*ALLLaRaLiNaAlUnMaMaElCoALLLaRaLiNaAlUnPyCaElCoALLStrata 1Strata 1Strata 1Strata 1Strata 1Mean Density0.000.000.900.900.030.002.402.430.000.603.400.904.900.000.650.000.0018.7019.350.000.230.000.006.006.23St. Dev.0.000.002.122.120.160.004.034.070.001.354.492.125.300.001.590.000.0021.5421.380.000.530.000.007.026.99Estimate002252256060060601508502251,2250163004,6754,838056001,5001,55690% CI (Lower)008787-4033934206255987882059003,2793,452022001,0451,10390% CI (Upper)0036336317086187002381,1413631,5680266006,0716,223091001,9552,009Strata 2Strata 2Strata 2Strata 2Strata 2Mean Density0.100.001.701.800.100.402.703.200.000.134.501.406.030.030.000.000.0310.8010.850.050.000.030.008.408.48St. Dev.0.630.002.852.860.301.524.995.310.000.655.812.655.520.160.000.000.1610.0510.080.220.000.160.009.9610.00Estimate450765810451801,2151,4400311,1253501,50660062,7002,713130602,1002,11990% CI (Lower)-2904334771036328210-117481781,148-400-42,0482,059-20-401,4551,47090% CI (Upper)11901,0971,143803571,7982,0590731,5025221,8641700173,3523,3662701702,7452,767Strata 3Strata 3Strata 3Strata 3Strata 3Mean Density0.450.1012.8013.350.300.2030.4030.900.100.3314.500.0014.930.030.330.030.0024.0024.380.180.830.000.0314.9015.93St. Dev.1.130.6318.1718.150.520.8236.5037.140.301.0214.710.0015.290.161.000.160.0031.7632.370.712.180.000.1616.7316.98Estimate113253,2003,33875507,6007,72525813,62503,7311114611010,80010,969793710116,7057,16690% CI (Lower)39-162,0222,16142-35,2345,3185152,67102,740-730-707,0957,191-41170-74,7535,18590% CI (Upper)186664,3784,5141081039,96610,132451484,57904,7233026330014,50514,7461626260308,6579,148All StrataAll StrataAll StrataAll StrataAll StrataTotal Estimate158254,1904,3731262309,4159,771252635,6005756,4631830911618,17518,5199142861110,30510,841*tiny juvenile mussels, species not determined
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
8Table 6. Density and population estimates by strata for each species encountered at Site 2, 2016 to 2020. Species abbreviations as in Table 1.Year: 2016Year: 2017Year: 2018Year: 2019Year: 2020StatisticLaRaLiNaPyCaElCoALLLaRaLiNaStUnAlUnPyCaElCoALLLiNaStUnPyCaElCoALLLaRaLiNaStUnAlUnPyCaElCoALLLaRaLiNaStUnAlUnPyCaAnImElCoALLStrata 1Strata 1Strata 1Strata 1Strata 1Mean Density0.130.580.131.502.330.051.150.000.050.082.804.130.400.000.132.703.230.001.250.000.000.1013.3014.650.001.680.000.000.180.033.705.58St. Dev.0.651.360.652.823.040.222.080.000.220.273.534.691.080.000.334.564.800.002.320.000.000.3012.6312.500.003.850.000.000.680.167.868.53Estimate38173384506981534501523840123810003167580603750030399043950503005381110167390% CI (Lower)-1367-13231461-21830-22565873300103794950195006300834220203000-5498100990% CI (Upper)8827888669934325070324311151602170053971111705550054497253680802001052017222336Strata 2Strata 2Strata 2Strata 2Strata 2Mean Density0.100.000.033.703.830.000.100.000.000.005.906.000.030.030.133.803.980.030.230.100.030.0319.2019.600.080.000.030.030.030.0013.5013.65St. Dev.0.630.000.163.783.730.000.630.000.000.005.515.730.160.160.404.964.960.160.890.300.160.1616.1616.490.270.000.160.160.160.0012.5112.52Estimate550142035210405500032453300663195099486830885760588023088804050409590% CI (Lower)-350-9149615710-3500024592483-4-45629672-5-26-5-54503459720-5-5-503077312190% CI (Upper)14503625742636014500040314117171757127113162013754202070177163430202020050235069Strata 3Strata 3Strata 3Strata 3Strata 3Mean Density0.050.080.000.600.730.080.330.030.030.002.202.650.280.000.004.604.880.000.250.000.000.0011.9012.150.000.000.000.000.000.002.002.00St. Dev.0.220.350.001.451.550.350.920.160.160.003.623.981.010.000.0010.0710.110.000.740.000.000.0029.0129.360.000.000.000.000.000.006.416.41Estimate1523018021823988806607956900115012190138000654566830000001100110090% CI (Lower)-2-506797-526-5-503794853004975630320002408249600000018718790% CI (Upper)325002933385016920200941110513400180318740243000106821086900000020132013All StrataAll StrataAll StrataAll StrataAll StrataTotal Estimate1081955126653019384988232347455333175663277530198580308381629516958235038860862606868
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
9
Table 7. Comparison of unstratified versus stratified population estimates for each species encountered at Site 1, from 2016 to 2020. Differences in the statified vs.
unstratified estimates are due to the unequal weighting of quadrats in the stratified design.
Unstratified Stratified
Species 2016 2017 2018 2019 2020 2016 2017 2018 2019 2020
L. radiata 174 135 32 16 71 158 126 25 18 91
L. nasuta 32 190 333 309 333 25 230 263 309 428
A. undulata 0 0 0 8 8 0 0 0 11 6
P. cataracta 0 0 0 0 8 0 0 0 0 11
M. margaritifera 0 0 0 8 0 0 0 0 6 0
E. complanata 4,877 11,242 7,093 16,942 9,278 4,190 9,415 5,600 18,175 10,305
Juveniles 0 0 728 0 0 0 0 575 0 0
All 5,083 11,566 8,186 17,282 9,698 4,373 9,771 6,463 18,519 10,841
Table 8. Comparison of unstratified versus stratified population estimates for each species encountered at Site 2, from 2016 to 2020. Differences in the statified vs.
unstratified estimates are due to the unequal weighting of quadrats in the stratified design.
Unstratified Stratified
Species 2016 2017 2018 2019 2020 2016 2017 2018 2019 2020
L. radiata 105 48 0 8 24 108 38 0 8 23
L. nasuta 249 604 222 546 530 195 498 175 580 503
S. undulatus 0 10 8 32 8 0 8 6 30 8
A. undulata 0 29 0 8 8 0 23 0 8 8
P. cataracta 58 29 79 40 63 51 23 63 38 60
A. implicata 0 0 0 0 8 0 0 0 0 8
E. complanata 2,223 4,178 3,515 14,060 6,080 2,665 4,745 2,775 16,295 6,260
All 2,635 4,897 3,824 14,693 6,721 3,019 5,333 3,019 16,958 6,868
intermediate densities of E. complanata and few L. radiata,
and unlike in 2016, L. nasuta were detected in strata 2 (all
juveniles found by excavation, 12-15 mm in length, found
in transects 5 [3] and 7 [1]).
Site 1, Year 2018: The same three species were detected as
in 2016 and 2017. In addition, many juvenile mussels (10-
18 mm) were detected that could not be reliably identified,
so these were treated separately in the density and popu-
lation size calculations. Based on the stratified design, we
estimated a population size of 5,600 E. complanata, which
is much lower than the 2017 estimate of 9,415 and com-
parable to the 2016 estimate of 4,190. We estimated 25 L.
radiata, which is much lower than the 2016 (158) and 2017
(126) estimates. We estimated 263 L. nasuta, which is slight-
ly higher than the 2017 estimate of 230, and much higher
than the 2016 estimate of 25. We estimated 575 juvenile
mussels that we could not identify; these were likely mostly
E. complanata based on proportions of the three species
found in this study area. See Table 5 for the 90% confidence
intervals associated with these population estimates. E.
complanata comprised more than 90 percent of the mussel
community at this site. As in previous years, mussels were
relatively less common along the left bank (strata 1), except
that a large proportion of L. nasuta and juvenile mussels
were found in strata 1 for the first time. E. complanata were
exceptionally common along the right bank (strata 3). The
center channel (strata 2) had intermediate densities of E.
complanata, many juvenile mussels, few L. nasuta, and no
L. radiata.
Site 1, Year 2019: In addition to the three species that
were detected from 2016 to 2018, two additional species
were detected at Site 1 for the first time: M. margaritifera
(1) and A. undulata (1). Based on the stratified design, we
estimated a population size of 18,175 E. complanata, which
is almost 2x higher than estimates from any of the previous
years, and almost 3.3x higher than the 2018 estimate (Table
7). Most of this increase was due to much higher numbers
near the shoreline (strata 1 and 3). We estimated 18 L. ra-
diata in 2019, which is lower but consistent with the 2018
result, and consistent with a downward trend from 2016 to
2019 (158, 126, 25, 18). We estimated 309 L. nasuta, up from
earlier estimates (263 in 2018, 230 in 2017, and 25 in 2016).
See Table 5 for the 90% confidence intervals for these pop-
ulation estimates.
E. complanata comprised more than 98 percent of the
mussel community at this site. As in previous years, mus-
sels were relatively less common along the left bank (strata
1), except that a large proportion of L. nasuta were found
in strata 1 for the second consecutive year. E. complanata
were exceptionally common along the right bank (strata 3).
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
10
The center channel had intermediate densities of E. compla-
nata; just two individuals of other species were detected in
strata 2, including one L. radiata and one M. margaritifera.
Site 1, Year 2020: Based on the stratified design, we esti-
mated a population size of 10,305 E. complanata, which is
considerably lower than the 2019 estimate but more con-
sistent with the estimates in previous years (though higher)
(Table 7). We estimated 91 L. radiata in 2020, higher than
the 2018 and 2019 estimates and closer to the 2016 and
2017 estimates, and opposing the downward trend ob-
served over the previous four years (158, 126, 25, 18, and
91 for 2016-2020, respectively). We estimated 428 L. nasuta,
up from the 2019 estimate and consistent with the previ-
ous trend of an increasing population size (25, 230, 263,
309, and 428 for 2016 to 2020, respectively). A. undulata
were detected again in 2020 for the second consecutive
year, P. cataracta was detected at Site 1 for the first time,
and M. margaritifera was not detected in 2020 after it was
found in 2019. See Table 5 for the 90% confidence intervals
for these population estimates. As in previous years, mussel
densities were highest along the right bank (strata 3).
Site 2, 2016: Four species were detected. Based on the
stratified design, we estimate population sizes of 2,665 E.
complanata, 108 L. radiata, 195 L. nasuta, and 51 P. cata-
racta. E. complanata comprised 88.3 percent of the mussel
community at this site. All mussels were relatively less com-
mon along the right bank (strata 3), where we estimated
218 mussels (90% confidence limit: 97–338). In contrast, we
estimated 2,104 mussels (90% confidence limit = 1,571–
2,636) in strata 2, although these were mostly E. compla-
nata (2,035) and L. radiata (55). L. nasuta were not found
in strata 2. Four species were found in strata 1, including
relatively high numbers of L. nasuta (population estimate
= 173; 90% confidence interval = 67–278) but intermediate
or low numbers of other species and a total of 698 mussels
(90% confidence interval = 461–934).
Site 2, 2017: Six species were detected at Site 2 in 2017,
two more (S. undulatus and A. undulata) than in 2016.
Based on the stratified design, we estimate population siz-
es of 4,745 E. complanata (much higher than 2016), 108 L.
radiata (lower than 2016), 498 L. nasuta (higher than 2016),
23 P. cataracta (lower than 2016), as well as 8 S. undulatus
and 23 A. undulata. See Table 6 for the 90% confidence in-
tervals associated with these estimates. As in 2016, E. com-
planata comprised 89.0 percent of the mussel community
at this site. Mussels were least dense along the right bank
(strata 3), most dense in the center channel (strata 2), and
of intermediate density along the left bank (strata 1) (Table
6). Generally, more species were detected near the banks,
and the high density of mussels in strata 2 was comprised
mostly of E. complanata.
Site 2, 2018: Four species were detected during quantita-
tive sampling at Site 2 in 2018, two fewer than in 2017. Nei-
ther A. undulata nor L. radiata were detected in 2018. Based
on the stratified design, we estimate population sizes of
2,775 E. complanata, approximately ~2,000 lower than the
2017 estimate. We estimated 3,109 mussels overall, down
from the 2017 estimate of 5,333, but identical to the 2016
estimate. See Table 6 for the 90% confidence intervals as-
sociated with these population estimates. The population
L. nasuta from Site 1.
S. undulatus from Site 5.
A. undulata from Site 1.
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
11
estimate of 175 L. nasuta was low compared to the 2017
estimate of 498, but similar to the 2016 estimate of 195. E.
complanata comprised 92.0 percent of the mussel com-
munity at this site. Data indicate a possible shift in mussel
distribution and density in the channel, with an increase in
mussel density along the right bank (strata 3), moderate
decrease along the left bank (strata 1), and a large decrease
in the center channel (strata 2) (Table 6). Generally, more
species were detected near the banks, and L. nasuta den-
sity was much higher along both banks.
Site 2, 2019: Six species were detected during quantita-
tive sampling at Site 2 in 2019, the same as 2017 and two
higher than in 2018. Based on the stratified design, we es-
timate population sizes of 16,295 E. complanata, almost 6x
higher than the 2018 estimate and more than 3.4x higher
than the 2017 estimate (Table 6). This also resulted in a far
higher estimate for the total number of mussels (all spe-
cies)—16,958, compared to 3,019, 5,333, and 3,019 for
2016 to 2018, respectively. E. complanata comprised 96.1
percent of all mussels. The population estimate of 580 L.
nasuta in 2019 was higher than the 2018 estimate of 175,
but consistent with the 2017 estimate of 498. Estimates for
the other four species have been low in all four years. Gen-
erally, more species were detected near the banks, and L.
nasuta density was much higher along both banks. E. com-
planata density was high across the entire channel.
Site 2, 2020: Seven species were detected during quanti-
tative sampling, including the same six from 2019 and, for
the first time, A. implicata. Based on the stratified design,
we estimate 6,260 E. complanata, almost one-third the esti-
mate of 16,295 from the previous year, but more consistent
with results from 2016 to 2018 (Tables 6, 8). E. complanata
comprised 91.1 percent of all mussels. The population es-
timate of 503 L. nasuta in 2020 was consistent with previ-
ous results. Estimates for the other species were low and
generally consistent among all five years. More species and
individuals were detected near the right bank (Strata 1) or
middle of the channel (Strata 2). Only E. complanata was
found in Strata 3, whereas a fair proportion of L. nasuta had
been found in Strata 3 in all prior years.
Rare Species Data: Table 9 summarizes shell length and
shell condition data for the two state-listed species, L. na-
suta and S. undulatus, collected during both quantitative
and qualitative sampling. These data are summarized for
each year for L. nasuta, and for all years combined for S.
undulatus because so few were found. For all years com-
bined (sample size = 223) L. nasuta ranged in length from
11.0 to 111.0 mm, with an average length of 55.5 mm and
a shell condition index of 0.17. Considering the difficulty of
detecting juvenile L. nasuta, the high proportion of small
mussels suggests strong recruitment in this population,
with notable young cohorts in 2017 and 2020. L. nasuta
were found at an average depth of 1.3 ft, in a mix of clay,
silt, sand, and gravel substrates, often among vegetation
and woody debris. Too few S. undulatus were found for a
meaningful length analysis, but the 19 individuals ranged
in length from 52.0 to 89.0 mm (average = 68.5). They gener-
ally had moderately to highly eroded shells (shell condition
index = 0.60), particularly the individuals found at Site 5.
Ligumia nasuta S. undulatus
(all years combined)Statistic 2016 2017 2018 2019 2020 ALL
Total Measured 36 34 41 63 49 223 19
Average Shell Length (mm)68.2 46.2 52.5 61.4 47.5 55.5 68.5
Standard Deviation 19.6 23.2 18.4 18.9 22.7 21.8 -11.51
Min Length (mm)15.5 12.0 23.0 25.0 11.0 11.0 52.0
Max Length (mm)99.0 91.0 88.9 111.0 107.0 111.0 89.0
Shell Condition 0.15 0.04 0.12 0.23 0.22 0.17 0.60
Length Class Counts
< 20.0 mm 2 4 0 0 12 18 0
20.0 - 29.9 mm 1 10 2 2 2 17 0
30.0 - 39.9 mm 0 0 14 5 1 20 0
40.0 - 49.9 mm 1 3 7 11 5 27 0
50.0 - 59.9 mm 3 4 4 10 14 35 4
60.0 - 69.9 mm 11 6 3 19 9 48 8
70.0 - 79.9 mm 10 6 8 4 4 32 3
80.0 - 89.9 mm 4 0 3 6 1 14 4
90.0 - 99.9 mm 4 1 0 4 0 9 0
> 100.0 mm 0 0 0 2 1 3 0
Table 9. Summary of L. nasuta and S. undulatus shell length and shell condition, for all individuals measured from 2016 to 2020.
Freshwater Mussel Monitoring in the Mill River for the Paradise Pond Sediment Management Project: 2016-2020
12
DISCUSSION
The annual quantitative surveys conducted from 2016 to
2020 followed the same study design, and were completed
by same personnel, yet yielded variable density and popu-
lation size estimates, especially for E. complanata (Tables
7 and 8). At both Sites 1 and 2, E. complanata population
size estimates were far higher in 2019 than in the other
four years of sampling. We are not certain why E. compla-
nata densities were so much higher in 2019. Results were
generally more consistent for the other species. L. radiata
may have declined from 2016 to 2019 at both Sites 1 and 2,
but then increased in 2020. L. nasuta populations have re-
mained either steady or have increased from 2016 to 2020,
and there is continued evidence of juvenile recruitment in
the L. nasuta population. The qualitative survey conducted
at Site 5 documented a much larger L. radiata population
in this reach than was previously known, but the numbers
of live L. radiata detected has steadily dropped from 2018
to 2020, while shell counts indicate high mortality in this
reach. At Site 5, S. undulatus are scarce and possibly declin-
ing, and M. margaritifera counts have been low but consis-
tent.
With five years of quantitative monitoring now com-
pleted, we are gaining a better understanding of popula-
tion sizes and trends for each species. However, data are
rather variable. Several factors are likely to contribute to
the year-to-year differences, possibly related to timing of
the surveys and survey conditions. The 2016 survey was
completed in September, and the 2017 to 2020 surveys
were completed in the spring (late May to mid-June). Time
of year and streamflows strongly influence monitoring re-
sults, and therefore surveys have been consistent from 2017
to 2020 to reduce variability. Quantitative surveys should
occur only from late May to mid-June when river discharge
is below 100 cfs. This should control for key variables such
as water clarity, water temperature, water depth, and flow
conditions, and also for the behavior of each species.
The objective of long-term mussel monitoring is to de-
termine if, and to what extent, sediment released during
sluice experiments affect mussel populations downstream
from Paradise Pond. A sluice experiment is defined as the
opening of the sluice gate at the Paradise Pond Dam dur-
ing high-flow events to allow the river to transport accumu-
lated sediments from the impoundment to downstream
areas. Dr. Robert Newton is studying the export and fate
of sediment released during sluice experiments. One sluice
experiment was conducted in late September of 2015, but
little sediment was transported. In 2016, Smith College ex-
perimented with redistributing sediment within the Para-
dise Pond impoundment during an extended drawdown
to increase the amount of sediment closer to the dam,
which may increase sediment export during subsequent
sluice experiments. Baseline data on the freshwater mussel
community was conducted in September 2016 and again
in May 2017; both of these are considered baseline datas-
ets because no sluice experiments were conducted during
the intervening period.
Two activities were conducted in Paradise Pond in 2019.
First, a sluice experiment was conducted on April 20, after
about one inch of rain had fallen. The gate was fully opened
at 10:56 AM, at a starting flow of 368 cfs. Flow peaked at 843
cfs between 3:15 PM and 4:15 PM. The gate was closed the
following afternoon when flows reached 309 cfs; the gate
had been open for almost 28 hours. From November 1 to
November 20, 2019, Smith College conducted a sediment
redistribution project in Paradise Pond, which began with
a pond drawdown followed by use of a bulldozer to redis-
tribute sediment. The sluice gate was operated to control
downstream sediment release. Prior to refilling the pond,
an experiment was completed to determine sediment re-
lease rate when the pond was completely drained. On No-
vember 19, the pond was allowed to completely drain, with
sluice gate open, and approximately 1,120m3 of sediment
was washed downstream and accumulated in the splash
pool in ~40 minutes. A high flow event on December 14
moved most of that accumulated sediment from the splash
pool to downstream areas.
Smith College continued with sediment redistribution
three times in 2020 and early 2021; these all began with a
pond drawdown and use of a bulldozer to redistribute sedi-
ment. These were completed during the weeks of Novem-
ber 16, December 14, and January 25, each lasting approxi-
mately five days. Two high-flow events transported some
of this material downstream from the dam, including a No-
vember 30-December 1 storm (2+ inch rain) and a Decem-
ber 25 storm (1+ inch rain accompanied by snowmelt). The
latter event smashed the flashboards that, to date, have not
been repaired and therefore the pond has remained in par-
tial drawdown for the winter.
Quantitative mussel surveys will be repeated at sites
1 and 2 in 2021; this is the core element of the long-term
monitoring program. The qualitative survey will also be
repeated at Site 5. These surveys will continue to build a
robust dataset that will help to understand effects of sedi-
ment releases on mussels.
Impact of Sediment Redistribution on
Macroinvertebrates in the Mill River
(2018-2021)
Marney Pratt 2/28/22 Smith College Department of Biological Sciences
1
Contents
Executive Summary ....................................................................................................................................... 2
Introduction .................................................................................................................................................... 2
Methods .......................................................................................................................................................... 4
Environmental Conditions ......................................................................................................................... 4
Macroinvertebrate Sampling ...................................................................................................................... 4
Data analysis .............................................................................................................................................. 7
Results ............................................................................................................................................................ 8
Environmental Conditions ......................................................................................................................... 8
Sediment Types ........................................................................................................................................ 11
Macroinvertebrate Density ....................................................................................................................... 12
Functional Feeding Groups ...................................................................................................................... 14
Discussion .................................................................................................................................................... 20
Conclusion ............................................................................................................................................... 21
Literature Cited ............................................................................................................................................ 21
Acknowledgements ...................................................................................................................................... 22
APPENDIX .................................................................................................................................................. 24
2
Executive Summary
• Macroinvertebrates are commonly used as bioindicators of human impacts on freshwater
ecosystems
• The impact assessed in this report is whether redistributing sediment in the early winter (Nov-Dec)
as part of Smith College’s Sediment Management Protocol in Paradise Pond affects
macroinvertebrates in the Mill River.
• A Before-After-Control-Impact design (or BACI design) can be used to assess impacts. In this
study, an interaction between year and location is a possible indication of an impact of the
sediment redistribution that took place in the winters during 2019-2021.
• There were no interactions between year and location that would indicate an impact of winter
sediment redistribution on the macroinvertebrates downstream of Paradise Pond. Thus, it is
recommended that redistributing the sediment in the winter is the best policy to reduce impact on
the macroinvertebrates downstream of the pond.
• There was consistently greater macroinvertebrate density downstream of Paradise Pond, which is
assumed to be a general impact of the pond increasing temperature and/or nutrients just
downstream of the pond.
• Macroinvertebrates, especially gathering collectors, increased in density both upstream and
downstream of Paradise Pond in 2020 and this may be an impact of reduced human activity during
the Covid-19 pandemic lockdown.
Introduction
Aquatic macroinvertebrates are useful bioindicators of potential impacts of how Smith College is
managing the sediment in Paradise Pond because many macroinvertebrates are very sensitive to
environmental impacts (Merritt et al. 2019). A common way to asses an impact on organisms in a river is
to use a Before-After-Control-Impact design (or BACI design)(Strayer and Smith 2003). A BACI design
has at least one sample before (Before sample) and after (After sample) an impact and has sample at a site
that is likely to be affected by the impact (Impact sample) as well as for a sample that should not be
affected by the impact (Control sample). In this report, I concentrate on the potential impact from the
redistribution of sediment in Paradise Pond in the early winter (November – December) of 2019 and 2020
on the macroinvertebrates in the Mill River in Northampton, MA. The “Impact” site is the rocky riffle
habitat downstream of Paradise Pond, while the “Control” site is a rocky riffle habitat upstream of the
pond (Figure 1). Since the last sediment redistribution happened in July 2016, and previous analyses
determined that things recovered by fall of 2017 (Pratt 2020), the samples taken in 2018 and 2019 are
assumed to be fairly typical and serve as the “Before” samples while 2020 and 2021 are the “After”
samples since they happened after each round of winter sediment redistribution in November 2019 and
December 2020.
When sediment was redistributed in Paradise Pond in the summer (July 2016), there was a small, short-
lived impact on the macroinvertebrates downstream of the pond (Pratt 2020). Longer-term monitoring has
shown that the typical situation is for there to be greater overall macroinvertebrate density downstream
compared to upstream of Paradise Pond. But after moving sediment in the summer, there were fewer
macroinvertebrates downstream than normal in the fall other than one gathering collector flathead mayfly,
Stenacron interpunctatum, which increased substantially. Gathering collectors eat organic material from
softer sediments, so an influx of fine sediment from redistribution in Paradise Pond may have benefitted
3
this mayfly while many other organisms were negatively impacted. It was hypothesized that by shifting
the sediment redistribution to the winter that any fine sediment released would be cleared out by winter
storms while the macroinvertebrates are mostly in a dormant state and would therefore have less of an
impact.
Figure 1. Location of sampling sites in the Mill River in Northampton, MA. The Impact site is the site
downstream of Paradise Pond, and the Control site is the site upstream of Paradise Pond. (Image from Google
Maps)
4
Methods
Environmental Conditions
Macroinvertebrate samples were collected in late May to early June (=Summer samples) as well as mid-
September to early October (=Fall samples)(Table 1). To understand the environmental conditions
leading up to when samples were taken, I calculated some environmental variables for the 2 months
before and during samplings for each season: April 15 to June 15 for Summer, and August 15 – October
15 for Fall in each year from 2018-2021.
Daily precipitation in millimeters as well as maximum and minimum temperature in Celsius were
downloaded from the from the NOAA Global Historical Climatology Network for the Amherst, MA
station (NOAA station: USC00190120) using the rnoaa package in R (Chamberlain 2020). Total
precipitation was calculated by summing the daily precipitation values for each 2-month period in each
year. Accumulated Degree Days (ADD) was calculated as the sum of the estimated average daily temp
(mean of the minimum and maximum daily temperature in Celsius) above 0℃ for each 2-month period in
each year.
River discharge in cubic feet per second (cfs) data were downloaded from the Mill River USGS National
Water Information System station in Northampton, MA (USGS site number: 01171500) using the
dataRetrieval package in R (De Cicco et al. 2018). The typical discharge for the 2-month period was
determined using the median (since discharge values were not at all normally distributed), and the
maximum discharge over the 2-month period was used to determine the result of the strongest storms in
that 2-month period.
Macroinvertebrate Sampling
Aquatic macroinvertebrates were sampled in 0.5 m x 0.5 quadrats from riffle habitats (areas with a rocky
bottom, shallow depth, rippled water surface, and relatively fast water flow) by kick-sampling using D-
nets (LaMotte D-net, 30 cm wide base, 500 micron mesh). Nets were placed downstream with the
opening facing upstream. One to two quadrats were sampled in each of five different subsampling areas
(called microhabitats here) within each location. When two quadrats were sampled within a microhabitat
on the same date, they were combined into one sample. The percent cover of organic debris (dead leaves
and sticks), sandy sediment, and larger rocks was estimated within each quadrat. Larger rocks were
picked up and any organisms found on the rocks were picked or rubbed off and placed in a tub of river
water. Once all larger rocks were cleaned off and placed outside of the quadrat, the substratum was
disturbed by kicking the bottom for 30 seconds to 1 minute making sure that the D-net caught anything
disturbed by the kicking. The contents of the net were rinsed into the tub of water.
The riffle sites upstream (42.319451, -72.654336) and downstream (42.315514, -72.64108) of Paradise
Pond (Figure 1) were sampled on 2-3 different days in the summer and fall (Table 1). Location
coordinates were taken with the built-in GPS sensor on a Vernier LabQuest 2 Interface (accuracy: half of
data points fall within a circle with radius of 2m). Because five microhabitats were sampled on three
different days in each location for a particular season and year, there were usually 15 samples for each
location in each year and season. One exception was in the Fall of 2018, when because of logistical and
time constraints all microhabitat samples were combined on the same date resulting in three samples from
each location. While there are fewer separate sampled for Fall of 2018, note that a similar total area was
sampled in each location (Table 1). Another exception was in the Fall of 2021, when weather conditions
made it unsafe to sample the upstream location on a third date. Thus, there were only 10 samples taken for
the upstream location in the Fall of 2021.
5
After collection, samples were taken back to lab, sieved down to 500 microns, and all macroinvertebrates
were sorted out and preserved in 70% ethyl alcohol. Most macroinvertebrates were identified using
identification keys (Peckarsky 1990; Merritt et al. 2019) down to genus or even species whenever
possible, however, some were only identified to family or occasionally just to order when identifications
were particularly difficult (such as for segmented worms and midge larvae). A complete list of organisms
found and their overall abundance in each location is given in Appendix A. Each organism was also
assigned to a functional feeding group (Stream Biomonitoring Unit Staff 2012; Merritt et al. 2019) as
indicated in Appendix A.
6
Table 1. Information for macroinvertebrates sampled in riffles upstream and downstream of Paradise
Pond in the Mill River, Northampton, MA. Each sample was from a particular microhabitat where one to
two 0.5 m x 0.5 m quadrats were used and then combined together at the microhabitat level (expect for
Fall 2018 when all microhabitat samples were combined for a particular sample date). The total area
sampled is the area of all quadrats, and the total number of organisms was the sum of all organisms
sampled for a combination of location, season, and year; and the organism density was the total number of
organisms divided by the area sampled.
Year Season Location Dates Number of Samples
Total Area Sampled (m2)
Total # Organisms
Organism Density (#/m2)
2018
Summer Downstream 05/29, 06/05, 06/07 15 7.50 2,350 313.3
Upstream 05/31, 06/06, 06/08 15 7.50 1,282 170.9
Fall Downstream 09/17, 09/25, 10/11 3 7.00 1,335 190.7
Upstream 09/24, 10/02, 10/04 3 7.75 265 34.2
2019
Summer Downstream 05/28, 06/03, 06/04 15 7.50 4,096 546.1
Upstream 05/30, 05/31, 06/05 15 7.50 1,467 195.6
Fall Downstream 09/17, 09/23, 09/26 15 7.50 1,608 214.4
Upstream 09/16, 09/24, 10/03 15 7.50 908 121.1
2020
Summer Downstream 06/06, 06/07, 06/09 15 3.75 8,926 2,380.3
Upstream 06/05, 06/07, 06/08 15 7.50 9,118 1,215.7
Fall Downstream 09/18, 09/20, 09/26 15 7.50 8,445 1,126.0
Upstream 09/19, 09/25, 09/27 15 7.50 2,868 382.4
2021
Summer Downstream 06/03, 06/08, 06/11 15 6.25 5,348 855.7
Upstream 06/02, 06/07, 06/10 15 6.25 1,710 273.6
Fall
Downstream 09/23, 09/28, 09/29 15 4.00 3,791 947.8
Upstream 09/22, 09/30 10 5.00 485 97.0
7
Data analysis
A BACI sampling design can detect a possible impact when there is an interaction between the sampling
location (in this case, Downstream site = Impact, and Upstream site = Control) and the sample that
happened before and after the impact where the impact we are most interested in was the sediment
redistribution that happened in Paradise Pond in the early winter of 2019 and 2020 (in this case, 2018 &
2019 = Before, 2020 & 2021 = After). Macroinvertebrate life cycles do vary a lot seasonally, so there is a
potentially substantial confounding seasonal effect. Thus, I generally analyzed the summer and fall data
separately. For the analyses in this report, I removed the crayfish recorded because their high mobility
makes it hard to know the true number within a quadrat. I also aggregated most of the macroinvertebrates
at the genus level but harder to identify organisms were identified to family (such as the Chironomidae
family of midges) or higher taxonomic levels (most worms were identified to phylum or class except for
the flatworm Girardia). A list of all the taxa included is in an Appendix at the end of this report
(Appendix A).
Functional Feeding Groups: Aquatic biologists categorize macroinvertebrates into functional feeding
groups (FFG) to better understand the ecology of a river ecosystem. The FFG’s in this report included:
scrapers (scrape periphyton off rocks and other surfaces), gathering collectors (gather or deposit feeds on
fine particulate organic matter in the sediment or on surface films), filtering collectors (filter feed or
suspension feed on fine particulate matter suspended in the water), shredders (chews live plant or dead
plant matter including more coarse particulate organic matter), and predators (ingest whole or partial
animals).
In addition to looking for possible impacts on each FFG separately, I also used the substrate stability ratio
which is the ratio of the scrapers and filtering collectors to the gathering collectors and shredders. Since
scrapers and filtering collectors generally prefer to be attached to rocks, while gathering collectors and
shredders prefer sand and organic debris such as decaying leaves, this ratio may indicate the relative
importance of rocky habitats to softer sediments. If sediment redistribution brings in more sediment, you
might expect the substrate stability ratio to decrease because gathering collectors and shredders would
likely do better with more sandy sediment and organic debris.
Impact on macroinvertebrates was assessed by calculating the density of all the macroinvertebrates as
well as each FFG separately. Density was calculated by counting the total number of organisms (all
macroinvertebrates or a specific FFG) in a sample and dividing that by the total sample area (m2).
Relative abundance of each FFG was also calculated by counting the total number of a particular FFG in a
sample and dividing that by the total of all macroinvertebrates in the same sample.
Statistical Analysis:
All statistical analyses were performed in R version 4.1.0 (R Core Team 2021)). In most ANOVA
models, the design was unbalanced (the number of observations was not equal in all of the interaction
cells), so I used type III sum of squares for the 2-way ANOVA full factorial models. For all ANOVA
models, post-hoc pairwise comparisons were made for terms that were significant using the Tukey HSD
adjustment. When the interaction term was significant, then interpreting main effects is problematic, so
pairwise comparisons were generally only made among the interaction pairwise groups. Main effects
were only interpreted when interaction terms were not significant. When the interaction was not
significant, a reduced model was performed using type II sum of squares and just main the effects, and
post-hoc pairwise comparisons were made for significant main effects with more than two levels using the
Tukey HSD adjustment. Anova models were performed using the lm function from the stats package (R
Core Team 2021), type II and III sum of squares were calculated with the Anova function from the car
8
package (version 3.0-12, Fox and Weisberg 2019), and post-hoc pairwise comparisons were performed
with the emmeans function from the emmeans package version 1.7.2 (Lenth 2022) using the Tukey
adjustment. In all analyses of density and substrate stability ratio, the values were log transformed before
analysis to better fit the assumption of normal residuals.
To understand the relationship between precipitation and proportion of sediment type, regression models
using the lm function from the stats package in R were performed to fit a quadratic polynomial (method =
y ~ poly(x, 2)). The value for the precipitation was the total precipitation in millimeter for the two months
before and including sampling (April 15 – June 15 for the Summer sampling, August 15 – October 15 for
the Fall sampling). Precipitation data were downloaded from the from the NOAA Global Historical
Climatology Network daily values from the Amherst, MA station (NOAA station: USC00190120) using
the rnoaa package in R (Chamberlain 2020). Since there was only one precipitation value for each
sampling time (each season in each year), I used the median percent cover of the sediment type for each
location in each season and year in the analysis. The regression was performed for each sediment type
(rock, sand, and organic debris) separately but with all seasons, years, and both locations used in one
model.
Results
Environmental Conditions
The air temperature over the 2-month period before and during summer sampling, as assessed by
Accumulated Degree Days (ADD), was within the interquartile range (IQR, which is the middle 50% of
data) in all years except 2020 where it was lower than usual (Figure 2). In the fall, the ADD was typical
in 2019 and 2020, but higher than normal in 2018 and 2021. Precipitation was within the IQR in 2018-
2020, but higher than normal in 2021 in the summer (Figure 2). In the fall, precipitation was typical in
2020, but higher than normal in 2018 and 2021 and lower than normal in 2019.
The median discharge of the Mill River for the 2-month period before and during sampling was within the
IQR in all years except for 2018 when it was slightly lower than normal in the summer (Figure 3). In the
fall, the median discharge was a little lower than the IQR in 2019 and 2020, but much higher than normal
in 2018 and 2021. The maximum river discharge in the summer was all within or just slightly above the
IQR for all years, while it was just below the IQR in 2019 and 2020 and much higher than normal in 2018
and 2021 in the fall (Figure 3).
9
Figure 2. (a) Accumulated Degree Days (ADD) and (b) total precipitation (mm) for the 2 months before and
during sampling in the late spring - early summer (April 15 to June 15, Summer) and the late summer – early fall
(August 15 – October 15, Fall). ADD was calculated as the sum of the estimated average daily temp (mean of the
minimum and maximum daily temperature in Celsius) above 0℃. Blue (precipitation) and red (ADD) points
represent the measurement for the 2-month period for each year and season, and the boxplot shows the median
(thick horizontal line), mean (X), and interquartile range (upper and lower hinge of box, IQR) for the long-term
(1938-2021). Whiskers represent the distance from the box hinge to the maximum or minimum value or no farther
than 1.5*IQR from the nearest hinge, and points outside of the whiskers are interpreted as outliers. Points to the
right of the box are the measures for each year from 2018-2021 and are labeled with the year they represent.
(a)
(b)
10
Figure 3. (a) Median and (b) maximum river discharge in cubic feet per second (cfs) for the 2 months before and
during sampling in the late spring - early summer (April 15 to June 15, Summer) and the late summer – early fall
(August 15 – October 15, Fall). Blue points represent the measurement for the 2-month period for each year in
each season and the boxplot shows the median (thick horizontal line), mean (X), and interquartile range (upper and
lower hinge of box, IQR) for the long-term (1938-2021). Whiskers represent the distance from the box hinge to
the maximum or minimum value or no farther than 1.5*IQR from the nearest hinge, and points outside of the
whiskers are interpreted as outliers. Points to the right of the box are the measures for each year from 2018-2021
and are labeled with the year they represent.
(a)
(b)
11
Sediment Types
Most of the sediment was rock for the location upstream (Median = 79%, IQR = 24%) as well as the
downstream (Median = 80%, IQR =17%) of Paradise Pond. Sand typically made up a little less than a
quarter of the substratum (upstream: Median = 17%, IQR = 20%; downstream: Median = 15%, IQR =
15%), while organic debris such as leaves and sticks generally made up less than 5% of the substratum
(upstream: Median = 2%, IQR = 5%; downstream: Median = 3%, IQR = 4%). There was some variation
in the proportion of the sediment over time between the locations and seasons (Figure 5). Notably, there
was generally more organic debris in the fall, and the overall pattern among years was similar between the
two locations with the following exceptions: (1) summer 2020 there was less rock and more sand
upstream, (2) summer 2021 there was less sand and organic debris and more rock upstream, and (3) fall
2018 there was more sand and less rock and organic debris upstream.
Since the pattern among years and seasons was reasonably similar between the two locations, it suggested
factors that would affect the whole river could show relationship with percent cover of sediment. All three
sediment types showed a non-linear relationship with the total precipitation over two months with the
highest percent cover of rock and the lowest percent cover of sand and organic debris occurring between
200-300 mm of rain over a two-month period (Figure 6). There was a significant but weak quadradic
polynomial relationship for rock (R2 = 0.51, P = 0.01), but no significant relationship between sand (R2 =
0.20, P = 0.24) or organic debris (R2 = 0.19, P = 0.26) and precipitation.
Figure 4. Proportion of different sediment types (rock, sand, and organic debris) for the riffle locations downstream
and upstream relative to Paradise Pond in the Mill River, Northampton, MA in the summer and fall from 2018-
2021. Percent cover was measured in a total of 15-30 quadrats (0.5 m x 0.5 m) in each location in each year and
season (see Table 1 for sampling dates).
12
Figure 5. Effect of two months of precipitation on percent cover of different sediment types in the Mill River,
Northampton, MA. Each point represents the median percent cover measured in 15-30 quadrats (0.5 m x 0.5 m)
sampled in each location during (Upstream and Downstream relative to Paradise Pond) in a particular year and
season (see Table 1 for sampling dates), and precipitation was summed for the 2 months before and during
sampling in the summer (April 15 to June 15) and the fall (August 15 – October 15). The curve represents a best fit
quadratic polynomial with 95% confidence interval shown in gray.
Macroinvertebrate Density
The density of macroinvertebrates (log of the number of organisms per meter squared) was not
significantly affected by the interaction between year and location in the summer (F3,112 = 1.3, P = 0.27) or
the fall (F3,83 = 2.4, P = 0.07). In both seasons, the density of macroinvertebrates was greater downstream
than upstream, and greater in 2020 than all other years (Table 2, Figure 7).
13
Table 2. Results from a full-factorial 2-way ANOVA comparing the log of macroinvertebrate density (#/m2) with
year and location as fixed effects for the summer and fall sampling season. The years included were 2018-2021,
and the locations were riffles upstream and downstream of Paradise Pond. Values shown include the type II sum of
squares (SS(II)), degrees of freedom (df), F-value, and P-value. Significant P-values are in bold red. (D =
Downstream, U = Upstream)
Season Term SS (II) df F-value P-value Post-hoc Comparisons
Summer
Year 62.3 3 48.9 <0.0001 2020 > (2018, 2019, 2021)
Location 19.8 1 46.6 <0.0001 D > U
Residuals 48.8 115
Fall
Year 45.7 3 17.5 <0.0001 2020 > (2018, 2019, 2021)
Location 33.5 1 38.4 <0.0001 D > U
Residuals 75.0 86
Figure 6. Changes in macroinvertebrate density (number of organisms per meter squared) over time in years for
the summer and fall in a riffle downstream and upstream of Paradise Pond in the Mill River, Northampton, MA.
Points represent the density from a microhabitat sample and horizontal lines represent the median of 3-15 samples
within a year for a location. The y-axis is log10 scaled. See Table 1 for sample sizes and dates and Table 2 for
statistical results.
14
Functional Feeding Groups
The overall relative abundance not taking location, year, or season into account was greatest for the
collector gatherers (45%) followed by scrapers (31%) and collector filterers (19%). Predators only made
up 3% and shredders 1.3% of the overall sample (<1% were not able to be assigned to a functional
feeding group). The pattern of functional feeding group relative abundance varied through time and with
season, but the upstream and downstream locations showed similar patterns overall (Figure 8).
Figure 7. Relative abundance of different functional feeding groups over time in years for the summer and fall in
the riffle locations upstream and downstream of Paradise Pond in the Mill River, Northampton, MA. Relative
abundance is the number of a functional feeding group divided by the total number of all organisms in the sample.
See Table 1 for sampling dates and sizes.
Substrate Stability Ratio. The log of the substrate stability ratio had a significant interaction between year
and location in the summer (Table 3), but the only difference between locations occurred in 2019 when
the ratio was greater downstream than upstream (Figure 9). The ratio was also greater in 2018 and 2019
compared to 2020 and 2021 in the summer (Figure 9). In the fall, the log of the substrate stability ratio
did not have a significant interaction between year and location (F3,83 = 0.1, P = 0.96), but there was a
main effect of location as well as year (Table 3). Overall, the substrate stability ratio was greater
downstream compared to upstream, and lower in 2020 compared to all other years in the fall (Figure 9).
15
Table 3. Results from a full-factorial 2-way ANOVA comparing the log of the substrate stability ratio with year
and location as fixed effects for the summer and fall sampling season. The years included were 2018-2021, and the
locations were riffles upstream and downstream of Paradise Pond. Values shown include the sum of squares (SS),
degrees of freedom (df), F-value, and P-value. Results with Intercept and Year x Location interaction terms are
type-III models, results with only main effects are type-II models. Significant P-values are in bold red. (D =
Downstream, U = Upstream)
Season Term SS df F-value P-value Post-hoc Comparisons
Summer
Intercept 20.3 1 43.0 <0.0001
Year 48.9 3 34.5 <0.0001
Location 0.1 1 0.3 0.62
Year x Location 4.1 3 2.9 0.04 D > U in 2019
(2018, 2019) > (2020, 2021)
Residuals 52.9 112
Fall
Year 64.8 3 11.1 <0.0001 2020 < (2018, 2019, 2021)
Location 9.3 1 4.8 0.03 D > U
Residuals 167.2 86
Figure 8. Substrate stability ratio over time in years for the summer and fall in the riffle locations upstream and
downstream of Paradise Pond in the Mill River, Northampton, MA. Points represent the substrate stability ratio
(number of scrapers and filtering collectors divided by the number of gathering collectors and shredders) from a
microhabitat sample and horizontal lines represent the median of 3-15 samples within a year for a location. The y-
axis is log10 scaled. The thicker brackets represent a significant difference among years where 2018 & 2019 had a
greater ratio than 2020 & 2021 in the summer. The thin bracket indicates a significant difference between locations
in the summer of 2019. See Table 1 for sample sizes and dates and Table 3 for additional statistical results.
16
Gathering Collectors. The interaction between year and location was not significant for the log density of
gathering collectors in the summer (F3,112 = 1.3, P = 0.27) or the fall (F3,83 = 0.4, P = 0.73). The density of
gathering collectors was greater downstream than upstream in the summer, but not quite different in the
fall (Table 4, Figure 10). There was a significant main effect of year on gathering collector density in the
summer and the fall (Table 4). In the summer, there was the greatest density of gathering collectors in
2020, intermediate density in 2021, and the lowest density in 2018 and 2019 (Figure 10). In the fall, the
density of gathering collectors was greater in 2020 than in 2018, 2019, and 2021 (Figure 10).
Scrapers. The interaction between year and location was not significant for the log density of scrapers in
the summer (F3,112 = 2.1, P = 0.10) but was significant for the fall (Table 4). The density of scrapers was
greater downstream than upstream in the summer and the fall (Table 4, Figure 10). There was a
significant main effect of year on scraper density in the summer with greater density in 2020 compared to
all other years (Table 4). In the fall, the only significant difference between locations and years was in
2020 when scrapers were more abundant downstream (Table 4).
Filtering Collectors. The interaction between year and location was not significant for the log density of
filtering collectors in the summer (F3,112 = 1.9, P = 0.13) or the fall (F3,83 = 0.4, P = 0.73). There was a
significant main effect of location for both seasons with greater filtering collector density downstream
than upstream (Table 4, Figure 10). There was also a significant main effect of year on filtering collector
density in both seasons, but while post-hoc comparisons found that the density was greater in 2020 than in
2021 in the summer, there were no significant pairwise comparisons for years in the fall (Table 4, Figure 10). Predators. The interaction between year and location was not significant for the log density of predators
in the summer (F3,112 = 1.1, P = 0.32) or the fall (F3,83 = 1.4, P = 0.25). There was a significant main effect
of location for both seasons with greater predator density downstream than upstream (Table 4, Figure 10). There was also a significant main effect of year on predator density only in the summer, with greater
density in 2020 than in 2021 (Table 4, Figure 10).
Shredders. The interaction between year and location was not significant for the log density of shredders
in the summer (F3,112 = 1.2, P = 0.37) or the fall (F3,83 = 0.5, P = 0.70). There was a significant main effect
of location for both seasons with greater shredder density downstream than upstream (Table 4, Figure 10). There was also a significant main effect of year on shredder density, with greater density in 2020 than
in all other years in the summer and greater density in 2020 and 2021 compared to 2019 in the fall (Table
4, Figure 10).
17
Table 4. Results from full-factorial 2-way ANOVA tests comparing the log density (#/m2) of different functional
feeding groups (FFG) with year and location as fixed effects. The years included were 2016-2019, and the
locations were riffles upstream and downstream of Paradise Pond. Values shown include the sum of squares (SS),
degrees of freedom (df), F-value, and P-value. Results with Intercept and Year x Location interaction terms are
type-III models, results with only main effects are type-II models. Significant P-values are in bold red. (D =
Downstream, U = Upstream)
FFG Season Term SS df F-value P-value Post-hoc Comparisons
Gathering Collectors
Summer
Year 164.3 3 85.5 <0.0001 2020 > 2021 > (2018, 2019)
Location 8.6 1 13.4 0.0004 D > U
Residuals 73.7 115
Fall
Year 174.5 3 21.1 <0.0001 2020 > (2018, 2019, 2021)
Location 10.3 1 3.7 0.06
Residuals 237.0 86
Scrapers
Summer
Year 39.9 3 27.8 <0.0001 2020 > 2019 > (2018, 2021)
Location 16.2 1 34.0 <0.0001 D > U
Residuals 55.0 115
Fall
Intercept 46.7 1 31.8 <0.0001
Year 51.9 3 11.8 <0.0001
Location 3.3 1 2.2 0.14
Year x Location 20.5 3 4.7 0.005 D > U in 2020
D in 2020 > everything else
Residuals 121.6 83
Filtering Collectors
Summer
Year 16.8 3 3.3 0.02 2020 > 2021
Location 49.1 1 29.1 <0.0001 D > U
Residuals 193.9 115
Fall
Year 19.0 3 2.8 0.04 none
Location 73.9 1 32.6 <0.0001 D > U
Residuals 194.8 86
Predators
Summer
Year 10.1 3 3.0 0.04 2020 > 2021
Location 34.9 1 30.6 <0.0001 D > U
Residuals 131.3 115
Fall
Year 2.6 3 1.0 0.40
Location 40.5 1 45.9 <0.0001 D > U
Residuals 75.8 86
18
FFG Season Term SS df F-value P-value Post-hoc Comparisons
Shredders
Summer
Year 40.7 3 14.3 <0.0001 2020 > (2018, 2019, 2021)
Location 18.2 1 19.1 <0.0001 D > U
Residuals 109.4 115
Fall
Year 20.1 3 5.1 0.003 (2020, 2021) > 2019
Location 5.3 1 4.0 0.05 D > U
Residuals 112.5 86
19
Figure 9. The effect of location and year on the density of various functional feeding groups for the summer and
the fall in a riffle downstream and upstream of Paradise Pond in the Mill River, Northampton, MA. Points represent
the density (number individuals per meter squared) of a particular functional feeding group from a microhabitat
sample and horizontal lines represent the median of 3-15 samples within a year for a location. The y-axis is log10
scaled and note the maximum is not the same for each graph. See Table 1 for sample sizes and dates and Table 4
for additional statistical results.
20
Discussion
The most important question to answer was whether moving sediment redistribution in Paradise Pond to
the late fall/early winter (November – December) would reduce the impact on the Mill River downstream
of the pond. When sediment was redistributed in Paradise Pond in the summer (July 2016), there was a
measurable impact on the macroinvertebrates downstream of the pond (Pratt 2020). In particular, one
gathering collector, the flathead mayfly Stenacron interpunctatum, increased substantially downstream of
the pond in the fall of 2016 while many other macroinvertebrates decreased. The impact was short-lived
as things went back to the typical situation by fall of 2017, but there was a measurable impact. In this
current report, I analyzed data from 2018-2021. Both 2018 and 2019 samples were long enough after the
July 2016 sediment redistribution and occurred before the winter sediment redistributions in 2019 and
2020 to serve as good “Before” years, while 2020 and 2021 could both be considered “After”. By using
the location upstream of Paradise Pond as a “Control” site and downstream as the “Impact” site, I can test
for an interaction between year and location to help discover any potential impacts from sediment
redistribution.
Importantly, there were few to no interactions between location and year in the samples from 2018-2021
which suggests little to no impact of winter sediment redistribution. The riffle sampling area downstream
of Paradise Pond almost always had greater density of overall macroinvertebrates as well as each of most
of the functional feeding groups, but this was true in all years and suggests a general impact of the
presence of the pond rather than an impact of sediment redistribution. There is evidence from other
studies that other areas just downstream of a small dam are affected by the conditions created by the
presence of an impoundment. Small dams that create impoundments like Paradise Pond can increase
water temperatures downstream and increase the quality of food for some macroinvertebrates from an
increase in organic material that gets released into the area downstream (Singer and Gangloff 2011). In a
review of the effects of small impoundments on stream conditions and macroinvertebrates, most studies
found an increase in water temperature, a decrease in dissolved oxygen, and small increases in nutrients
such as phosphates and nitrates just downstream of small dams (Mbaka and Mwaniki 2015). They also
reported that some studies found an increase, some found a decrease, and others found no change in
macroinvertebrate abundance downstream of small dams. It is not known why macroinvertebrate density
is higher downstream of Paradise Pond, but it seems likely that it is a general effect of Paradise Pond
influencing the temperature of the water and nutrients or food abundance or quality released from the
impoundment. Detailed water quality and environmental testing including the temperature, dissolved
oxygen levels, nutrient load, and food availability need to be done over a long time to see if this is the
case.
When sediment was redistributed in the summer, the difference in macroinvertebrate density downstream
and upstream of Paradise Pond was less pronounced possibly because there was an overall negative effect
of the sediment released from the pond on the macroinvertebrates downstream of Paradise Pond (Pratt
2020). Fine sediment noticeably built up in the downstream location after the July 2016 sediment
redistribution but was mostly cleared out by the next summer sampling time. There was still a noticeable
lack of difference between the upstream and downstream macroinvertebrates in the summer of 2017, but
it may take the macroinvertebrates a summer of reproduction and population growth to recover. By the
fall of 2017 the norm of greater macroinvertebrate density downstream was restored. In contrast to
summer sediment redistribution, when sediment was redistributed in the winter, it is assumed that any
buildup of sediment downstream of the pond generally got cleared out by winter storms while the
macroinvertebrates are more dormant. Because there was no clear detectable impact of winter sediment
redistribution on the macroinvertebrates, it is recommended that moving sediment in the early winter is
the best policy to reduce impacts on the Mill River downstream of Paradise Pond.
21
Another interesting result found in the 2018-2021 samples was the large increase in macroinvertebrate
density and lower substrate stability ratio in 2020 (noting that sometimes 2021 showed a similar but
usually weaker trend). The increase in density in 2020 was also seen for most of the functional feeding
groups but was especially pronounced for the gathering collectors. About 2/3rd of the samples in the
summer of 2020 had over 1000 gathering collectors per meter squared (especially chironomid midges).
The decrease in substrate stability ratio can be explained by the relatively large increase in gathering
collectors relative to the other functional feeding groups. Because this increase in density occurred in the
riffles downstream and upstream of Paradise Pond, this indicates an impact on the Mill River in general
rather than an impact of sediment redistribution or the pond itself. The precipitation and discharge over
the two months prior to sampling in 2020 were fairly typical (Figure 2, Figure 3), but the air temperature
(as measured by Accumulated Degree Days – ADD) was a little cooler before the summer 2020 sampling
(Figure 2). It is possible that there was something about the cooler temperature that benefited the
macroinvertebrates in the river. There may also be other impacts further upstream of both sampling
locations that benefited the macroinvertebrates. Maybe there was increased organic matter as food for the
gathering collectors and other functional feeding groups, but there was similar or lower sand and organic
debris (the preferred substrates for gathering collectors and shredders) in the summer of 2020 downstream
and more of all functional feeding groups downstream. The nutrient and food levels available for each
functional feeding group was not measured directly, so it is hard to know how food availability might
have changed over time. It is important to keep in mind that there was another notable thing about 2020
which was the impact of the Covid-19 pandemic lockdown on humans. Reduced air and water pollution
occurred in 2020 while humans were in pandemic lockdown because of reduced travel and economic
activities (Rume and Islam 2020; Facciolà et al. 2021). It is not clear how changes in human activity
during the lockdown would benefit the macroinvertebrates specifically beyond some improvements in air
and water quality, but it is an interesting idea to test with further research.
Conclusion
The samples taken from upstream and downstream of Paradise Pond in 2018-2021 show no evidence of
impact from winter sediment redistribution in the pond. The results from assessing the impact of the
summer sediment redistribution led to the prediction that winter sediment redistribution should have less
impact. It is reassuring that the data from 2018-2021 support this new strategy of moving sediment in the
winter to lower the impact on macroinvertebrates. The question why the macroinvertebrate density, and
especially the density of gathering collectors, increased so much in 2020 remains. Additional monitoring
will be needed to determine if cooler late spring, early summer temperatures may cause an increase in
macroinvertebrate density in general. Measuring nutrient levels would also be beneficial in helping
interpret results of additional macroinvertebrate monitoring. If over the long-term 2020 stands out as an
exceptional year, it could suggest that the changes in human activity during the Covid-19 pandemic
lockdown may be the ultimate cause of the increased macroinvertebrate density. More research is needed
to understand what changes in human activity caused the increases in macroinvertebrate density.
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project.org/package=emmeans.
Mbaka JG, Mwaniki MW. 2015. A global review of the downstream effects of small impoundments on stream
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Merritt RW, Cummins KW, Berg MB, editors. 2019. An introduction to the aquatic insects of North America. Fifth
edition. Dubuque, IA: Kendall Hunt Publishing Company.
Peckarsky BL, editor. 1990. Freshwater macroinvertebrates of northeastern North America. Ithaca: Comstock Pub.
Associates.
Pratt M. 2020. Impact of sediment redistribution on macroinvertebrates in the Mill River (2015-2019).
Northampton, MA: Smith College.
R Core Team. 2021. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for
Statistical Computing. http://www.R-project.org/.
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https://www.sciencedirect.com/science/article/pii/S2405844020318089.
Singer EE, Gangloff MM. 2011. Effects of a small dam on freshwater mussel growth in an Alabama (U.S.A.)
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Acknowledgements
The funding for the research presented in this report was provided by Smith College Facilities Management, the
Department of Biological Sciences, and the Summer Undergraduate Research Fellowship Program. The data were
collected with the help of many Smith College students from the Bio 131 courses in the fall semesters and by
Summer Undergraduate Research Fellowship (SURF) students in the summer of 2018 (Renee Halloran, Lyric
Williams, and Sasha Clapp), 2019 (Sasha Clapp, Andrew Turgeon, Samikshya Dhami), and 2021 (Britney Danials,
Tess Goldmann, Kelly McKenna, Claire Jordan, Lucy Grant). Special thanks to Denise Lello who helped collect
data in her sections of Bio 131 in the fall semesters. During the covid-19 pandemic lockdown in 2020, many people
helped with outside collecting including Henry Renski, Sasha Clapp, Windy Pearman, June Ariens, Claire Jordan,
Claire Lord, Sawyer Blake, and Adriana Grow. Julie Dubreuil helped sort, count, and ID macroinvertebrates from
the summer 2020 samples.
23
24
APPENDIX
Appendix A. Total number of different taxa found in the Mill River in Northampton, MA for the
locations Downstream and Upstream of Paradise Pond summed for all years and seasons (2018-2021).
Most organisms were identified to genus, but some were only identified to family, order, or even phylum.
FFG = functional feeding group, scr = scraper, cf = collector filterer, cg = collector gatherer, sh =
shredder, prd = predator, prc = piercer.
Taxon Downstream Upstream FFG
Chironimidae* 8,445 6,891 cg
Cheumatopsyche 3,522 523 cf
Stenonema 3,156 1,069 scr
Stenacron 2,151 833 cg
Segmented Worms 2,001 807 cg
Leucrocuta 1,843 1,153 scr
Hydropsyche 1,730 488 cf
Hydropsychidae 1,466 132 cf
Neophylax 1,412 1,165 scr
Chimarra 1,289 82 cf
Stenelmis 1,269 249 scr
Psephenus 933 466 scr
Apatania 716 740 scr
Ephemerella 646 257 cg
Isonychia 476 155 cf
Ferrissia 386 434 scr
Optioservus 366 120 scr
Agapetus 339 255 scr
Antocha 305 251 cg
Taeniopteryx 293 66 sh
Glossosoma 197 118 scr
Pycnopsyche 172 98 sh
Lebertia 142 47 prd
Perlesta 141 58 prd
25
Taxon Downstream Upstream FFG
Acroneuria 133 26 prd
Girardia 128 0 prd
Baetis 122 214 cg
Dannella 122 131 cg
Rhyacophila 121 61 prd
Acentrella 100 149 cg
Plauditus 97 104 cg
Drunella 96 40 scr
Sperchon 96 40 prd
Psychomyia 93 4 cg
Philopotamidae 84 49 cf
Dolophilodes 72 52 cf
Procloeon 71 111 cg
Ceraclea 70 1 cg
Epeorus 65 72 scr
Leuctra 63 15 sh
Caecidotea 58 21 cg
Simulium 52 8 cf
Torrenticola 49 18 prd
Nematomorpha 42 12 prd
Chironimidae* 40 14 prd
Polycentropus 35 22 cf
Sphaerium 35 6 cf
Paraleptophlebia 32 20 cg
Paragnetina 30 11 prd
Chironimidae* 28 110 cf
Goera 24 17 scr
Nigronia 24 13 prd
Sperchonopsis 23 12 prd
26
Taxon Downstream Upstream FFG
Alloperla 21 14 cg
Rhagovelia 20 0 prd
Cernotina 19 28 prd
Glossosomatidae 19 22 scr
Tipulidae 19 0
Gammarus 18 4 cg
Oecetis 18 2 prd
Polycentropodidae 18 15 cf
Hemerodromia 14 1 prd
Helicopsyche 13 4 scr
Clinocera 12 5 prd
Eurylophella 12 8 cg
Prostoma 12 1 prd
Climacia 11 0 prd
Corydalus 10 5 prd
Neureclipsis 10 5 cf
Claassenia 9 1 prd
Culicidae 9 1 cf
Hygrobates 9 3 prd
Simuliidae 9 1 cf
Teloganopsis 9 0 cg
Hemiptera 8 1 prd
Neoleptophlebia 8 2 cg
Beloneuria 7 1 prd
Bivalvia 7 0 cf
Oulimnius 7 4 scr
Attaneuria 6 1 prd
Perlodidae 6 0 prd
Torleya 6 3 cg
27
Taxon Downstream Upstream FFG
Aturus 5 0 prd
Bezzia 5 7 prd
Boyeria 5 2 prd
Mideopsis 5 3 prd
Siphlonurus 5 2 cg
Trichoptera 5 3 cf
Wormaldia 5 2 cf
Argia 4 0 prd
Fingernail Clams 4 0 cf
Hydroptilidae 4 9 scr
Leptoceridae 4 2 cg
Chironimidae* 4 1 sh
Neoperla 4 0 prd
Prosimulium 4 0 cf
Agnetina 3 0 prd
Empididae 3 1 prd
Ephydridae 3 0 cg
Pteronarcys 3 0 sh
Rhithrogena 3 34 scr
Sialis 3 2 prd
Sweltsa 3 1 prd
Testudacarus 3 0 prd
Atractides 2 0 prd
Attenella 2 5 cg
Curculionidae 2 1 sh
Gammaridae 2 1 cg
Habrophlebiodes 2 0 scr
Hansonoperla 2 1 prd
Heterocloeon 2 1 scr
28
Taxon Downstream Upstream FFG
Insecta 2 1
Microcylloepus 2 1 scr
Nematoda 2 0 cg
Ophiogomphus 2 3 prd
Perlidae 2 2 prd
Protzia 2 1 prd
Tipula 2 0 sh
Anthopotamus 1 0 cg
Baetidae 1 2 cg
Blephariceridae 1 1 scr
Carabidae 1 0 prd
Ceratopogonidae 1 2 prd
Collembola 1 0 cg
Diphetor 1 0 cg
Diptera 1 0
Hetaerina 1 0 prd
Hydra 1 0 prd
Hydroptila 1 4 scr
Isoperla 1 1 prd
Iswaeon 1 2 scr
Lara 1 0 sh
leeches 1 3 prd
Lepidoptera 1 0 sh
Leptophlebia 1 0 cg
Limnephilidae 1 0 sh
Mystacides 1 1 cg
Neohermes 1 0 prd
Petrophila 1 7 scr
Physa 1 2 cg
29
Taxon Downstream Upstream FFG
Planorbidae 1 0 scr
Platyhelminthes 1 0 prd
Plecoptera 1 0
Pseudocloeon 1 0 cg
Psychomyiidae 1 0 cg
Sciaridae 1 1
Sigara 1 0 prd
Suwallia 1 1 prd
Trombidiformes 1 2 prd
Blepharicera 0 27 scr
Neotrichia 0 4 scr
Plectrocnemia 0 4 cf
Chironimidae* 0 2 scr
Ameletus 0 1 scr
Atherix 0 1 prd
Caenis 0 1 cg
Centroptilum 0 1 cg
Cinygmula 0 1 scr
Crambidae 0 1 sh
Diploperla 0 1 prd
Liodessus 0 1 prd
Psychoda 0 1 cg
*Note that the family Chironomidae is listed more than once because some were identified lower than
family and were in different functional feeding groups. So here they are summed by family and FFG.
Paradise Pond Dam Upstream Station - USGS gauging station at Clement Street bridge - www.waterdata.usgs.gov/ma/nwis/uv?01171500
Maintenance Activity Log Downstream Station - Smith Mill River & Paradise Pond Monitoring Stations - http://pond.smith.edu
Paradise Pond Sediment Management Plan - DEP file # 246-0725 - Expires Sept. 2024 Paradise Pond, Smith College, Northampton, MA
Waterfront Resource Maintenance Activity - DEP file # 246-0715 - 11/12/22 Paradise Pond, Smith College, Northampton, MA
Maintenance activity
1: Erosion & Sediment Controls X 7: Flashboard repair
2: Bank Maintenance & Erosion Repair 8: Exercising of Low-Level Outlet Sluice Gate
3: Rodent Control 9: Dam Inspection
4: Maintenance of existing structures 10: Vegetation Management
X 5: Partial Drawdowns 11: Pond Maintenance Dredging - SPECIAL ACTIVITY
X 6: Floating Debris Removal X 12: Other Sediment redistribution within Pond (year 3 of 5 year permit)
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU
Stage Observations/notes
11/11/20 12:49 PM Check Flow 31.3 39 0% 0.25 1 0.92 Planning partial drawdown Fri, 11/13. Sediment redistribution starting on
Tue, 11/17/20
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/13/20 6:22 AM Check Flow 32.7 47 0% 0.25 1 0.96
6:52 AM Open gate to 50%40F, overcast, drizzle - padlock missing
7:22 AM Check flow 32.7 214 50% -0.05 7 1.55
7:44 AM Check Flow " 209 50% -0.26 4 1.53
8:59 AM Check Flow 32.7 198 50% -1.23 3 1.50
10:04 AM Check Flow 32.7 187 50% -2.52 6 1.46
10:55 AM Operate gate 20%
11:52 AM Check Flow 32.7 49 20% -5.65 27 0.96 40F, overcast, drizzle
1:30 PM Check Flow 33.5 47 20% -6.16 29 0.95 41, overcast, light rain
2:10 PM Operate gate 18%
2:38 PM Check Flow 34.3 38 18% -6.29 33 0.92 42F
3:37 PM Check Flow 34.3 38 18% -6.13 24 0.92 42F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/14/20 8:36 AM Check Flow 36.6 40 18% -4.93 2 0.92 44F, partly sunny (received 0.1 inch rain yesterday)
9:35 AM Check Flow "" 18% -4.88 1 0.92 45F, mostly cloudy
9:50 AM Operate gate 30%
10:13 AM Operate gate 19%
10:31 AM Check Flow 36.6 44 19% -5.24 7 0.94 46F, mostly cloudy
1:14 PM Check Flow " 40 19% -5.28 5 0.93 "
4:59 PM Check Flow 35.8 40 19% -5.40 3 0.93 43F, clear
5:23 PM Check Flow " 40 19% -5.42 3 0.93 42F
6:48 AM Check Flow " 40 19% -5.49 4 0.92 36F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/15/20 5:13 AM Check Flow 32.7 36 19% -6.22 7 0.91 26F, clear
6:19 AM Operate gate 18%
6:40 AM Check Flow 32.0 32 " -6.38 17 0.89 25F, clear
9:26 AM Check Flow " 33 " -6.34 7 0.90 31, partly sunny
5:03 PM Check Flow 30.5 31 " -6.54 10 0.89 49F, overcast - rain in the forecast
5:20 PM Check Flow " 31 " -6.56 12 0.89 50F
5:30 PM Operate gate 17%
6:31 AM Check Flow 30.5 28 17% -6.37 9 0.88 50F, raining
9:18 PM Check Flow 50.8 33 17% -5.23 16 0.90 57F, 0.37 in. rain
9:32 PM Operate gate 25%
9:54 PM Check Flow 50.8 57 25% -4.88 16 0.99 59F, 0.48 in. rain
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/16/20 6:10 AM Check flow 137 76 25% -0.28 5 1.05 0.53 in. rain yesterday, Pond nearly full
6:40 AM Operate gate 100% Beaver present. Trouble opening gate.
7:32 AM Check flow 136 264 100% -0.52 14 1.70
7:52 AM Check flow " 263 100% -0.66 10 1.70
8:19 AM Check flow 132 261 100% -0.81 8 1.69
9:19 AM Check flow 127 256 100% -1.32 18 1.68 47F, partly sunny
9:38 AM Check flow 127 254 100% -1.54 7 1.67 49F
10:44 AM Check flow 121 243 100% -2.53 11 1.64
11:46 AM Check flow 116 228 100% -4.01 24 1.59 49F, mostly cloudy
12:30 PM Operate gate 55% Scouring
12:31 PM Check flow 111 206 55% -6.38 287 1.52
1:16 PM Check flow 106 130 55% -5.38 111 1.27
1:18 PM Operate gate 70%
2:34 PM Check flow 100 154 70% -6.73 276 1.35 Scouring
2:35 PM Operate gate 60%
2:56 PM Check flow 100 120 60% -6.26 102 1.23
2:57 PM Operate gate 57%
3:12 PM Check flow 100 116 57% -5.73 100 1.22
3:18 PM Check flow 96.1 115 57% -5.52 48 1.21
3:23 PM Operate gate 65%
4:36 PM Check flow 93.3 140 65% -5.89 45 1.30
4:50 PM Operate gate 62%
5:45 PM Check flow 90.5 127 62% -6.24 40 1.26
6:10 PM Operate gate 58%
6:35 PM Check flow 86.4 112 58% -6.06 37 1.20
7:01 PM Check flow 86.4 113 58% -5.80 29 1.21
7:24 PM Check flow 83.8 113 58% -5.69 24 1.21 44F
8:43 PM Check flow 79.9 113 58% -5.69 20 1.21 40F
9:32 PM Check flow 78.6 112 58% -5.67 19 1.20
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/17/20 4:06 AM Check flow 65.5 92 58% -7.00 41 1.13 Pond stage bottomed at -7.5 and came up
4:30 AM Operate gate 40%
5:45 AM Check flow 63.2 38 40% -4.79 10 0.92 31F, clear
6:05 AM Operate gate 34% Opened gate to 100% for about 20 min. Noted audible sudden increase of
flow passing 48% open.
6:50 AM Check flow 62.1 83 34% -7.04 39 1.09
7:05 AM Operate gate 32%
7:15 AM Met w/contractor SedRed 1 Walked Pond bottom with contractor. Witnessed install of vertical control.
Watched start of sediment redistribution. Photographed and videoed
during first 20 minutes of work
8:30 AM Met w/Greg de Wet
and Bob Newton
Reviewed survey sequencing and helped Bob finish survey after Greg left
for class.
11:20 AM Operate gate 31% With Professor Bob Newton, opened gate to 67% until scour visible.
Closed gate to 25% after 5 minutes. Left gate at 31% at 11:45
12:29 PM Check flow 54.7 72 31% -6.52 28 1.05 45F, mostly cloudy, actively redistributing sediment into river all morning
2:21 PM Check flow 52.7 71 31% -6.30 31 1.05 44F, overcast
2:30 PM Operate gate 30%
3:35 PM Installed padlock
3:45 PM Check flow 52.7 71 30% -6.33 29 1.05
6:40 PM Check flow 50.8 66 30% -6.31 18 1.03
7:26 PM Check flow 49.8 66 30% -6.34 19 1.03
7:40 PM Operate gate 26% Close to 20%, 6 min., build small head, open to 55%, close to 26%
8:02 PM Check flow 49.8 78 26% -6.48 29 1.07 Stage falling
8:15 PM Operate gate 24%
8:32 PM Check flow 48.8 56 24% -6.19 16 0.98 35F, mostly clear
9:09 PM Check flow 48.8 53 24% -5.88 11 0.98 34F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/18/20 7:23 AM Check flow 44.2 57 24% -5.19 2 1.00 27F, sunny - active sediment redistribution into river
8:28 AM Check flow 44.2 57 24% -5.28 1 0.99 27F, sunny & breezy
10:02 AM Check flow 43.3 56 24% -5.53 19 0.99 28F, sunny & breezy
11:48 AM Check flow 42.5 55 24% -5.71 46 0.99 29F, sunny & breezy
12:22 PM Check flow 42.5 54 24% -5.79 44 0.98 30F, sunny & breezy
2:53 PM Check flow 41.6 54 24% -6.10 54 0.98 32F, sunny & breezy
4:39 PM Check flow 40.7 50 24% -6.33 47 0.96 29F, clear
5:15 PM Operate gate 22%
5:47 PM Check flow 40.7 44 22% -6.21 40 0.94 28F, clear
6:22 PM Check flow 39.9 45 22% -6.03 32 0.94 27F, clear
7:27 PM Check flow 39.9 46 22% -5.88 29 0.95
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/19/20 8:10 AM Check flow 35.8 44 22% -5.98 5 0.94 25F, mostly sunny - actively dosing river (web cam)
8:24 AM Check flow 35.8 43 22% -6.01 5 0.94 25F, mostly sunny - grading mid-pond (web cam)
9:04 AM Check flow 35.8 43 22% -6.10 20 0.94 27, mostly sunny
10:25 AM Operate gate 21%
11:00 AM Check flow 35.8 40 21% -6.21 36 0.93 36F, mostly sunny - actively dosing river (web cam)
11:56 AM Check flow 35.0 41 21% -6.18 46 0.93
2:36 PM Check flow 35.0 41 21% -6.19 76 0.93
3:35 PM Operate gate 20%
5:06 PM Check flow 35.0 39 20% -6.14 28 0.92 41F
6:05 PM Check flow 35.0 39 20% -6.10 18 0.92 40F
8:49 PM Check flow 34.3 39 20% -6.01 15 0.92 41F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/20/20 8:29 AM Check flow 34.3 39 20% -5.79 10 0.92 47F, partly sunny
9:27 AM Check flow 34.3 39 20% -5.79 5 0.92 49F, partly sunny
4:38 PM Check flow 34.3 39 20% -5.77 7 0.92 60F, mostly cloudy
6:32 PM Check flow 34.3 38 20% -5.75 129 0.92 49F
9:28 PM Check flow 34.3 38 20% -5.68 4 0.92 41F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/21/20 10:07 AM Check flow 33.5 38 20% -5.87 72 0.92 56F, partly sunny - high turbidity from frequent right bank collapse
5:25 PM Check flow 32.7 37 20% -6.11 94 0.91 49F, overcast
6:05 PM Operate gate 19%
6:41 PM Check flow 32.7 35 19% -6.08 77 0.90 48F
8:59 PM Check flow 32.7 35 19% -5.97 62 0.90 46F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/22/20 9:10 AM Check flow 31.3 33 19% -6.03 117 0.90 35F, partly sunny
10:24 AM Check flow 31.3 33 19% -6.06 120 0.90 39F, partly sunny
10:45 AM Operate gate 18%
5:04 PM Check flow 30.5 31 18% -5.92 91 0.89 41F, overcast - rain in forecast
8:52 PM Check flow 29.8 31 18% -5.97 118 0.89 41F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/23/20 6:29 AM Check flow 35.8 33 18% -5.32 125 0.93 41F, raining
6:52 AM Operate gate 25%
7:31 AM Check flow 38.2 54 25% -5.26 45 0.98 41F, raining (0.37 inches)
7:58 AM Check flow " 54 25% -5.24 35 0.98 41F, raining
8:26 AM Check flow 41.6 55 25% -5.1 77 0.99 41F, raining
8:35 AM Operate gate 35%
10:12 AM Check flow 47 83 35% -6.63 116 1.09 45F, raining (0.6 inches)
10:18 AM Check flow 47.9
10:20 AM Operate gate 28%
11:07 AM Check flow 47.9 61 28% -5.88 127 1.01 44F, light rain (0.71 inches)
11:17 AM Check flow 52.7 62 28% -5.73 127 1.01
11:47 AM Check flow " 64 28% -5.37 115 1.02 44F, rain ended (0.72 inches) blue sky approaching from West
12.39 PM Check flow 53.7 66 28% -4.8 157 1.03
12:45 PM Operate gate 32%
2:06 PM Check flow 58.9 78 32% -4.58 150 1.07 44F, mostly sunny
3:04 PM Check flow 60 86 32% -4.75 194 1.11 44F, sunny
3:35 PM Check flow 64.4 86 32% -4.77 209 1.11 43F, sunny
4:27 PM Check flow 70.1 86 32% -4.75 238 1.11 41F, clear
5:26 PM Check flow 73.7 86 32% -4.57 266 1.11 40F
6:40 PM Check flow 77.4 89 32% -4.19 238 1.12 38F
7:20 PM Operate gate 36%
7:32 PM Check flow 78.6 104 36% -3.95 191 1.17 38F, clear
8:51 PM Check flow 79.9 104 36% -3.95 212 1.17 38F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/24/20 5:20 AM Check flow 65.5 97 36% -4.99 136 1.15 29F, clear
6:30 AM Check flow 63.2 94 36% -5.36 128 1.14 30F
7:03 AM Check flow 63.2 93 36% -5.54 124 1.13 31F
8:19 AM Operate gate 30% Walked Pond before operating gate. Significant channel scour (in Pond)
compared to Thursday 11/19, at end of day
8:37 AM Check flow 60 78 30% -6.04 163 1.08 35F
8:55 AM Check flow 60 75 30% -5.83 170 1.06 36F
9:22 AM Check flow 58.9 76 30% -5.68 150 1.07 39F, mostly sunny
10:52 AM Check flow 57.8 78 30% -5.50 170 1.07 40F, mostly sunny
11:28 AM Check flow 56.8 77 30% -5.48 158 1.07 42F
1:26 PM Check flow 53.7 76 30% -5.64 137 1.07 43F, clear
3:41 PM Check flow 52.7 70 30% -6.07 116 1.05 43F, clear - Pond stage graph flat lined at 6.07 for an hour
3:53 PM Operate gate 25% Hatfield Equipment finished Sed Red. Dozer off site.
4:26 PM Check flow 51.7 57 25% -5.90 103 0.99 42F, clear
4:57 PM Check flow " 58 25% -5.64 92 1.00 38F
5:21 PM Check flow 50.8 59 25% -5.45 94 1.00 34F
9:04 PM Check flow 47.9 61 25% -4.89 86 1.01 29F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/25/20 7:29 AM Check flow 43.3 57 25% -5.52 120 1.00 31F, overcast
7:53 AM Check flow " 57 25% -5.58 121 0.99 31F, overcast
10:21 AM Check flow 42.5 55 25% -5.91 125 0.99 34F, overcast
11:00 AM Operate gate 23%
12:27 PM Check flow 41.6 50 23% -5.9 119 0.97 39F, overcast
3:20 PM Check flow 40.7 51 23% -5.86 102 0.97 41F, overcast
3:45 PM Operate gate 21%
5:37 PM Check flow 40.7 46 21% -5.52 84 0.95 40F, overcast
6:54 PM Check flow 40.7 46 21% -5.36 72 0.95 39F, light rain
8:37 PM Check flow 39.9 47 21% -5.23 104 0.95 38F, drizzle
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/26/20 5:12 AM Check flow 43.3 49 21% -4.75 98 0.96 38F, raining
6:00 AM Check flow " 50 21% -4.55 76 0.97 39F, raining
6:17 AM Check flow 47 50 21% -4.49 83 0.97 "
6:30 AM Operate gate 28%
7:17 AM Check flow 64.4 78 28% -4.33 96 1.07 "
8:17 AM Check flow 76.1 78 28% -4.01 106 1.08 40F, raining (0,57 inches)
8:31 AM Check flow " 79 28% -3.77 109 1.08 40F, rain diminishing (0.58 inches)
8:50 AM Operate gate 50% Opened gate 100% for 15 min. closed to 50% by 9:09 AM
9:22 AM Check flow 82.5 178 50% -4.66 105 1.43 41F, raining (0.59 in.)
9:41 AM Check flow " 161 50% -5.20 86 1.37 41F, raining (0.61 in.)
10:21 AM Check flow 91.9 147 50% -6.52 421 1.33 42F
10:30 AM Operate gate 38%
10:47 AM Check flow " 122 38% -6.75 241 1.24 42F, raining (0.68 in.)
12:24 PM Check flow 132.0 123 38% -4.32 316 1.24 44F, rain stopped (0.72 in.)
12:50 PM Operate gate 75%
1:02 PM Check flow " 186 75% -3.77 217 1.46 45F, drizzle
1:27 PM Check flow 160.0 218 75% -4.17 506 1.56 45F, drizzle
2:21 PM Check flow 176.0 214 75% -4.67 225 1.55 45F, drizzle
3:42 PM Check flow 188.0 219 75% -4.26 146 1.56 46F, rain stopped (0.74 in.)
4:53 PM Check flow 194.0 225 75% -3.64 139 1.58 46F, fog
5:08 PM Operate gate 100%
5:52 PM Check flow 188.0 234 100% -3.34 100 1.61 46F
6:56 PM Check flow 188.0 236 100% -3.24 138 1.61 46F
8:02 PM Check flow 184.0 234 100% -3.25 106 1.61 45F, drizzle (0.75 in.)
9:07 PM Check flow 180.0 234 100% -3.39 227 1.61 45F
9:17 PM Check flow 169.0 234 100% -3.42 227 1.61 45F
9:30 PM Operate gate 75%
9:45 PM Check flow " 229 75% -3.53 188 1.59 45F, clearing
9:50 PM Check flow " 224 75% -3.55 200 1.58 45F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/27/20 4:29 AM Check flow 129 178 75% -7.16 393 1.43
4:50 AM Operate gate 45%
6:46 AM Check flow 121 141 45% -4.13 217 1.30 41F, overcast
7:18 AM Check flow 116 142 45% -3.90 204 1.31 41F
7:51 AM Check flow " 142 45% -3.70 197 1.31 41F
8:23 AM Check flow 113 143 45% -3.60 276 1.31 42F
8:55 AM Check flow " 143 45% -3.54 223 1.31 42F
9:55 AM Check flow 108 143 45% -3.52 180 1.31 43F
12:04 PM Check flow 103 141 45% -3.78 163 1.30 47F
12:20 PM Check flow 100 140 45% -3.85 180 1.30 49F
4:07 PM Check flow 93.3 132 45% -5.11 289 1.27 51F
4:45 PM Operate gate 38%
5:24 PM Check flow 89.1 116 38% -5.50 291 1.22 49F
8:09 PM Check flow 85.1 115 38% -5.55 201 1.21 46F
9:03 PM Check flow 83.8 114 38% -5.73 234 1.21 46F
9:11 PM Check flow " 114 38% -5.76 234 1.21 46F
9:20 PM Check flow 82.5 114 38% -5.76 179 1.21 45F
9:30 PM Operate gate 30%
10:00 AM Check flow " 86 30% -5.34 175 1.10 45F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/28/20 1:02 PM Check flow 65.5 92 30.0% -3.95 200 1.13 51F, partly sunny
3:35 PM Operate gate 26%
4:09 PM Check flow " 74 26% -4.24 29 1.06 49F, partly sunny
5:39 AM Check flow 63.2 75 26% -3.88 311 1.06 46F
9:21 PM Check flow 61 76 26% -3.54 175 1.07 35F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/29/20 8:04 AM Check flow 54.7 74 26% -3.92 268 1.06 30F, clear
8:21 AM Check flow " 74 26% -3.95 293 1.06 32F
9:25 AM Check flow " 74 26% -4.05 245 1.06 38F
10:22 AM Operate gate 24%
5:33 PM Check flow 51.7 67 24% -3.69 421 1.03 39F, clear
8:38 AM Check flow 50.8 62 24% -3.73 424 1.01 34F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
11/30/20 7:48 AM Check flow 47.9 60 24% -3.99 372 1.01 33F, overcast. 1" to 2" rain in today's forecast
8:01 AM Check flow " " 24% -4.00 385 1.01
9:40 AM Operate gate 23.5%Opened gate to 100% for about 10 minutes to drop stage to -5.5. Gate at
23.5% at 10:08. Rain started about 10:06
10:28 AM Check flow 47.9 53 23.5% -5.36 291 0.98 38F, raining
11:01 AM Check flow " 55 23.5% -5.28 360 0.99 "
11:33 AM Check flow " 56 23.5% -5.15 286 0.99 39F, raining (0.11 in.)
12:22 PM Check flow 51.7 56 23.5% -4.93 375 0.99 41F, raining (0.15 in.)
2:46 PM Check flow 61 68 23.5% -3.75 401 1.04 51F, raining (0.65 in.)
2:58 PM Operate gate 50%
3:10 PM Operate gate 100%
4:01 PM Check flow 87.8 220 100% -4.51 211 1.56 51F, raining (1.27 in.)
4:27 PM Check flow 119 216 100% -4.76 256 1.55 54F, raining (1.37 in.)
5:18 PM Check flow 178 221 100% -4.43 3 1.57 59F, raining (1.53 in.) - Pond filling
6:54 PM Check flow 266 245 100% -1.86 86 1.64 61F, raining (1.75 in.)
7:18 PM Check flow 919 263 100% -0.36 202 1.70 61F, raining (1.93 in.)
7:30 PM Check flow " 355 100% 0.28 292 1.96 60F, raining (1.96 in.)
8:53 PM Check flow 1450 1612 100% 1.52 1 4.44 62F, raining (2.15 in.)
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/1/20 8:18 AM Check flow 761 859 100% 0.85 15 3.13
Peak flow at USGS ~2,200 cfs, ~ midnight. Rain ended ~10:15 PM on
11/30. (2.17 in. total rain)
8:40 AM Check flow " 817 100% 0.80 15 3.04
9:02 AM Check flow " 791 100% 0.77 13 2.99 57F, mostly cloudy
11:49 AM Check flow 550 613 100% 0.55 8 2.61 59F, mostly cloudy
1:03 PM Check flow 515 565 100% 0.49 10 2.49 58F, mostly cloudy
1:24 PM Check flow 473 552 100% 0.46 7 2.46 57F, mostly cloudy
2:39 PM Check flow 431 505 100% 0.40 7 2.35 55F, partly sunny
3:32 PM Check flow 410 480 100% 0.35 5 2.29 53F
4:51 PM Check flow 387 446 100% 0.30 5 2.20 49F
6:00 PM Check flow 358 420 100% 0.25 5 2.13 48F, mostly clear
6:50 PM Check flow 340 397 100% 0.21 5 2.08 45F
7:28 PM Check flow 319 388 100% 0.20 5 2.05 44F
9:15 PM Check flow 305
9:18 PM Check flow 293 358 100% 0.13 5 1.97 42F
9:30 PM Operate gate 75%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/2/20 8:19 AM Check flow 199 261 75% -0.37 2 1.69 35F, mostly cloudy
9:30 AM Check flow 192 254 75% -0.50 1 1.67 37F, partly sunny
10:25 AM Check flow 188 251 75% -0.59 1 1.66 40F
11:00 AM Operate gate 100%
12:02 PM Check flow 182 248 100% 0.83 1 1.65 41F
12:41 PM Check flow 178 243 100% 0.93 1 1.64 42F
2:01 PM Check flow 173 235 100%
2:37 PM Check flow 173 234 100% -1.19 1 1.61 39F
3:44 PM Check flow 169 228 100% -1.36 2 1.59 40F
6:28 PM Check flow 164 221 100% -1.85 3 1.57 38F
8:54 PM Check flow 156 215 100% -2.50 4 1.55 40F
9:10 PM Operate gate 65%
9:24 PM Check flow 156 208 65% -2.64 6 1.53 40F
9:33 PM Check flow " 195 65% -2.63 4 1.49 40F
9:43 PM Check flow " 194 65% -2.62 4 1.48
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/3/20 5:18 AM Check flow 141 185 65% -3.80 7 1.45 32F, clear
5:30 AM Operate gate 58%
5:40 AM Check flow " 173 58% -3.89 7 1.41 32F, clear
6:51 AM Check flow 137 171 58% -3.81 5 1.41 32F, clear
7:33 AM Check flow 136 171 58% -3.82 4 1.41 32F, clear
7:44 AM Check flow "" " -3.83 "" 33F, clear
8:00 AM Operate gate 60%
8:10 AM Check flow " 174 60% -3.87 3 1.42 34F
9:17 AM Check flow 132 174 60% -4.09 4 1.42 37F
10:30 AM Check flow 132 171 60% -4.40 5 1.41 42F
11:03 AM Check flow " 170 60% -4.52 7 1.41 44F
1:58 PM Operate gate 50%
2:23 PM Check flow 129 144 50% -4.99 11 1.31 51F
4:35 PM Check flow 125 151 50% -3.95 2 1.34 44F, clear
5:54 PM Check flow 125 153 50% -3.73 2 1.34 38F
6:47 PM Check flow 124 153 50% -3.66 1 1.35
9:09 PM Check flow 121 153 50% -3.62 1 1.35 42
9:21 PM Check flow 122 153 50% -3.62 1 1.35 42F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/4/20 7:16 AM Check flow 113
7:23 AM Check flow 113 144 50% -4.81 3 1.31 35F, overcast
8:10 AM Operate gate 45%
9:41 AM Check flow 113 133 45% -4.46 1 1.28 47F
10:34 AM Check flow 111 134 45% -4.28 0 1.28 49F, some sun
12:18 PM Check flow 111 135 45% -4.11 0 1.28 52F
4:47 PM Check flow 109 136 45% -4.12 0 1.29 51F, mostly cloudy
7:04 PM Check flow 108 135 45% -4.22 0 1.28 49F
8:41 PM Check flow 106 134 45% -4.33 0 1.28 48F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/5/20 8:27 AM Check flow 109 132 45% -4.71 6 1.27 40F, raining (0.25 in.)
9:02 AM Operate gate 100%
9:43 AM Check flow 116 190 100% -5.65 12 1.47 39F, raining (0.36 in.)
11:57 AM Check flow 129 178 100% -6.91 51 1.43 36F, raining (0.60 in.)
12:10 PM Check flow 129 182 100% -6.57 46 1.44 36F, raining (0.62 in.)
12:18 PM Check flow 141 184 100% -6.39 45 1.45 36F, raining (0.63 in.)
3:33 PM Check flow 226 218 100% -2.59 14 1.56 38F, raining (0.81 in.)
5:29 PM Check flow 331 242 100% -0.71 14 1.63 38F, raining (0.86 in.)
7:27 PM Check flow 387 417 100% 0.34 29 2.13 39F, rain stopped (0.86 in.)
8:24 PM Check flow 393 431 100% 0.42 29 2.16 39F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/6/20 8:07 AM Check flow 238 290 100% 0.06 9 1.78 32F, partly sunny
8:19 AM Check flow 229 288 100% 0.05 9 1.77 32F
8:37 AM Check flow " 284 100% 0.04 11 1.76 31F
8:53 AM Check flow " 282 100% 0.02 9 1.75 32F
9:25 AM Check flow 219 277 100% 0.01 14 1.74 32F
11:20 AM Check flow 206 260 100% -0.06 3 1.69 34F
1:13 PM Check flow 199 251 100% -0.15 2 1.66 35F
2:10 PM Check flow 194 248 100% -0.23 2 1.65 35F
2:17 PM Check flow 188 " " " " " "
4:55 PM Check flow 178 239 " -0.53 3 1.63 32F
8:36 PM Check flow 162 228 " -1.11 1 1.59 31F
8:48 PM Operate gate 75%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/7/20 6:09 AM Operate gate 62%
7:41 AM Check flow 134 170 62% -4.49 3 1.40 27F, clear
8:19 AM Check flow 132 170 62% -4.48 3 1.41 27F, clear
9:43 AM Check flow 131 170 62% -4.57 3 1.40 31F, clear
12:01 PM Check flow 129 167 62% -4.96 4 1.39 34F, clear
12:29 PM Check flow 127 166 62% -5.03 4 1.39 36F, clear
2:08 PM Operate gate 58%
3:45 PM Check flow 125 158 58% -5.11 279 1.36 34F, partly cloudy
4:34 PM Check flow 125 158 58% -5.12 4 1.36 32F
6:46 PM Check flow 124 156 58% -5.20 12 1.36 31F
8:48 PM Check flow 122 155 58% -5.33 5 1.35 30F
9:00 PM Operate gate 55%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/8/20 7:31 AM Check flow 114 145 55% -5.49 9 1.32 28F, overcast
8:05 AM Operate gate 50%
8:20 AM Check flow 113 133 50% -5.48 3 1.28 28F, overcast
9:05 AM Check flow 113 135 50% -5.13 0 1.28 28F, overcast
1:58 PM Check flow 109 139 50% -4.77 " 1.30 30F, overcast
4:38 PM Check flow 108 138 50% -4.99 " 1.29 "
5:43 PM Check flow " 137 50% -5.08 " " "
6:22 PM Check flow " " 50% -5.15 " " 29F
8:58 PM Check flow 106 135 50% -5.35 " 1.28 25F
9:30 PM Operate gate 47%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/9/20 7:17 AM Check flow 99 126 47% -5.34 0 1.25 25F, overcast
8:32 AM Check flow " 125 47% -5.50 9 1.25 26F, overcast
9:20 AM Check flow " 124 47.0% -5.61 0 1.24 28F, overcast
11:21 AM Check flow 97.5 123 47.0% -5.76 2 1.24 30F, bright overcast
11:50 AM Operate gate 44.0%
12:22 PM Check flow " 117 44.0% -5.50 0 1.22 32F, bright overcast
1:57 PM Check flow " 119 44.0% -5.21 0 1.23 34F, bright overcast
4:07 PM Check flow " 120 44.0% -5.10 0 1.23 35F, overcast
6:25 PM Check flow 96.1 120 44.0% -5.07 0 1.23 32F
9:08 PM Check flow 97.5 120 44.0% -5.07 0 1.23 34F
Upstream Downstm. Gate Pond Stream
GO
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/10/20 7:25 AM Operate gate 42%
8:40 AM Check flow 93.3 113 42% -5.13 1 1.21 34F, partly sunny
10:34 AM Check flow " 115 42% -4.96 0 1.21 42F, mostly sunny
11:25 AM Check flow " 115 42% -4.93 0 1.21 43F, sunny
11:43 AM Check flow "" 42% " "" 44F, sunny
1:28 PM Check flow " 116 42% -4.95 " 1.22 44F, sunny
5:17 PM Check flow 91.9 114 42% -5.06 " 1.21 39F
5:30 PM Operate gate 41%
6:01 PM Check flow " 111 41% -5.05 2 1.20 34F
6:46 PM Check flow " 112 41% -5.01 0 1.20 32F
7:27 PM Check flow 90.5 112 41% -5.00 0 1.20 31F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/11/20 6:31 AM Check flow 86.4 109 41% -5.43 1 1.19 25F
7:40 AM Operate gate 39%
8:47 AM Check flow 85.1 103 39% -5.31 0 1.17 27F, mostly sunny
9:24 AM Check flow "" " -5.21 0 " 32F
6:07 PM Check flow 87.8 104 39% -5.06 4 1.18 37F
6:34 PM Check flow 86.4 104 39% -5.06 6 1.18 36F
9:24 PM Check flow 87.8 104 39% -5.08 0 1.18 33F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/12/20 7:23 AM Check flow 85.1 103 39% -5.33 1 1.17 36F, drizzle
9:51 AM Check flow 85.1 103 39% -5.49 0 1.17 37F, overcast
12:21 PM Check flow 83.8 101 39% -5.64 8 1.16 39F, drizzle
1:17 PM Check flow "" 39% -5.68 5 1.16 "
1:30 PM Operate gate 37%
4:30 PM Check flow " 99 37% -5.02 22 1.15 40F, drizzle
6:19 PM Check flow 85.1 99 37% -4.87 9 1.16 40F, drizzle (0.03 in.)
9:07 PM Check flow " 101 37% -4.69 57 1.16 40F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/13/20 7:20 AM Check flow 99 106 37% -3.19 0 1.18 41F, drizzle (0.04 in. yesterday, 0.08 in. so far today)
7:27 AM Operate gate 50%
7:51 AM Check flow " 139 50% -3.20 4 1.30 41F, drizzle stopped
8:17 AM Check flow 102 145 50% -3.40 3 1.32 41F
8:35 AM Check flow " 144 50% -3.59 0 1.32 42F
8:51 AM Check flow " 143 50% -3.77 4 1.31 42F
9:26 AM Check flow 105 141 50% -4.04 0 " 43F
9:56 AM Check flow " 139 50% -4.30 1 1.30 43F
11:02 AM Check flow 106 136 50% -4.79 1 1.29 47F, overcast
11:17 AM Check flow 108 135 50% -4.85 1 1.28 47F
1:17 AM Check flow 109 132 50% -5.28 4 1.27 55F, overcast
4:17 PM Check flow 106 130 50% -5.42 4 1.27 52F, breaks of sunshine
5:23 AM Check flow 106 130 50% -5.54 8 1.27 48F
5:37 PM Operate gate 48%
7:04 PM Check flow 105 128 48% -5.63 9 1.26 42F
7:18 PM Operate gate 46%
7:50 PM Check flow " 122 46% -5.53 11 1.24
8:39 PM Check flow 103 124 46% -5.40 5 1.25 38F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/14/20 7:13 AM Check flow 97.4 116 46% -6.53 122 1.22 33F, overcast
7:17 AM Check flow 93.3 " " " "" "
7:30 AM Operate gate 40%
8:18 AM Check flow 93.3 104 40% -5.77 64 1.17 34F, snowing
10:19 AM Check flow 91.9 109 40% -5.03 120 1.19 33F, light snow
10:31 AM Check flow "" 40% -4.98 131 " "
11:51 AM Check flow 90.5 109 40% -4.83 71 " "
1:44 PM Check flow 91.9 110 40% -4.73 61 1.20 34F, overcast
9:27 PM Check flow 94.7 111 40% -4.45 224 1.20 33F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/15/20 7:50 AM Check flow 86.4 108 40% -4.73 47 1.19 30F, clear
8:30 AM Check flow SedRed
2 " 107 40% -4.92 72 1.19
Dozer returned to Pond today to redistribute remaining soft sediment and
new sediment brought in by 2200 cfs event on Nov 30
12:02 PM Check flow 83.8 105 40% -5.29 218 1.18 33F, clear
3:37 PM Operate gate 37%
4:44 PM Check flow 81.2 96 37% -5.48 182 1.15 31F, clear
6:44 PM Check flow 78.6 96 37% -5.27 189 1.15 29F
8:56 PM Check flow 77.4 96 37% -5.28 194 1.15 28F
9:15 PM Operate gate 35%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/16/20 6:59 AM Check flow 66.6 89 35% -5.19 119 1.12 17F, clear
7:30 AM Check flow 64.4 88 35% -5.28 141 1.11 16F, clear
8:17 AM Check flow 63.2 87 35% -5.45 "" "
8:50 AM Operate gate 30%Dozer continued working in middle Pond and point bar East of island.
Frost appears to help dozer work in soft sediments.
11:20 AM Check flow 60 75 30% -5.07 186 1.07 19F, overcast
1:20 PM Check flow "" " -5.15 297 1.06 22F, overcast
3:50 PM Check flow 66.6 " " -5.18 217 " 23F, overcast
7:23 PM Check flow 67.8 79 " -4.56 661 1.08 24F, overcast
9:32 PM Check flow " 80 " -4.34 612 1.08 24F, snowing
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/17/20 8:08 AM Check flow 48.8 88 30% -6.48 156 1.11 20F, snowing (12" on the ground)
8:50 AM Operate gate 20%
9:18 AM Check flow 47.9 73 20% -5.51 165 1.05 21F, snowing
9:42 AM Check flow " 63 20% -4.76 155 1.02 21F, snowing
10:36 AM Check flow " 65 20% -3.99 168 1.02
10:59 AM Operate gate 25%Opened gate to 100% for 3 minutes before closing to 25%
12:06 PM Check flow " 76 25% -5.35 150 1.07 22F, snow ending (15" accumulation)
12:28 PM Check flow " 71 25% -5.27 185 1.05 22F, sun coming out
2:22 PM Check flow 50.8 64 25% -4.80 194 1.02 25F, mostly sunny
3:00 PM Operate gate 23.5%
3:48 PM Check flow 51.7 56 23.5% -4.32 325 0.99 25F, mostly sunny
4:22 PM Check flow 54.7 59 23.5% -4.16 355 1.00 24F
4:45 PM Operate gate 27%
5:23 PM Check flow 56.8 73 27% -4.00 360 1.06 24F
6:23 PM Check flow 58.9 76 27% -3.92 328 1.07 25F
7:44 PM Check flow 60 79 27% -3.68 375 1.08 25F
8:18 PM Check flow 62.1 " " -3.57 353 " "
8:30 PM Operate gate 28.5%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/18/20 8:02 AM Check flow 85.1 84 28.5% -0.72 203 1.10 23F, overcast
8:50 AM Check flow 82.5 85 28.5% -0.59 185 1.10
9:17 AM Check flow 83.8 84 28.5% -0.52 188 1.10
9:30 AM Operate gate 22%
9:58 AM Check flow " 52 22% -0.42 212 0.97
10:36 AM Check flow " 50 22% -0.25 194 0.96 24F
1:17 PM Check flow 86.4 114 22% 0.19 251 1.21 30F, clear
1:50 PM Operate gate 16.1%Gate closed to 16.1% is as far as it would go. Opened to about 52%
which is as far as it would go. Lot's of leaf debris and one log shot out
when opened to 52%. Contacted Rodney Hunt - Engineer will visited site
next Tue or Wed to consult.
4:22 PM Check flow 87.8 109 " 0.21 248 1.19 27F, clear
9:44 AM Check flow 76.1 99 " 0.19 263 1.16 15F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/19/20 7:58 AM Check flow 72.5 114 16.1% 0.26 271 1.21 4F, clear (ice effects stream flow note on USGS site - stream flow report
from 10:30 PM last night)
8:46 AM Check flow ice 115 " 0.27 275 1.21
1:23 PM Check flow " 104 " " 295 1.18
5:19 PM Check flow " 107 " 0.24 297 1.18 25F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/20/20 10:13 AM Check flow 70.1 93 16.1% 0.26 311 1.13 24F, overcast
12:44 PM Check flow 72.5 98 " 0.27 281 1.15 27F, overcast
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/21/20 8:31 AM Check flow 72.5 87 16.1% 0.23 396 1.11 31F, overcast
4:35 PM Check flow 73.7 89 " 0.22 369 1.12 34F, overcast
8:46 PM Check flow " 88 " 0.19 379 1.11 30F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/22/20 7:33 AM Check flow 72.5 85 16.1% 0.18 363 1.10 29F, fog
10:00 AM Gate inspection &
operation
6.7%Met Rob Kibler, Head of Engineering from Rodney Hunt to operate / test
gate. Managed to get it closed to 6.8% open, using a combination of
motor and hand crank. Will use grapple hook and water jet to break up
debris when grounds staff returns to work - week of Jan 4.
4:48 PM Check flow " 85 6.7% 0.23 354 1.10 39F, overcast
9:06 PM Check flow " 84 " 0.23 373 " 39F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/23/20 7:57 AM Check flow 68.9 81 6.7% 0.23 474 1.09 24F, clear
9:19 AM Check flow " 80 " " 441 1.08 31F, clear
1:44 PM Check flow " 79 " " 419 " 41F, partly cloudy
8:36 PM Check flow 67.8 77 " " 524 1.07 27F, partly cloudy
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/25/20 8:08 AM Check flow 2890 NR 6.7% 2.90 181 NR 60F, raining (.86 in. + significant snow melt) (NR - Not Reporting)
8:30 AM Check flow 2720 " " 2.97 219 " 59F, raining (.89 in.)
9:46 AM Check flow 3240 " " 3.02 297 " 57F, raining (.98 in.)
10:19 AM Check flow 3200 " " 3.09 152 " 57F, raining (1.01 in.)
11:55 AM Check flow 2800 " " 2.83 144 " 56F, raining (1.11 in.)
12:43 PM Check flow 2380 " ""
1:22 PM Check flow 2120 " " 2.53 558 " 53F, raining (1.30 in.)
2:28 PM Check flow 1980 " " 2.34 55 " 53F, raining (1.39 in.)
5:06 PM Check flow 1830 2828 " 2.06 45 6.07 53F, raining (1.47 in.)
5:17 PM Check flow 1770 NR " 2.07 47 NR 52F, light rain
6:19 PM Check flow 1790 2806 " 2.05 46 6.05 50F, overcast (1.47 in. rain)
8:52 PM Check flow 1510 2128 " 1.65 45 5.18 45F, clearing
1:40 PM on 12/25/2020
Afternoon on 21/27/2020
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/26/20 9:49 AM Check flow 558 629 6.7% 0.39 6 2.64 32F, partly cloudy
11:50 AM Check flow 554 576 " 0.31 7 2.52 31F, partly cloudy
12:27 PM Check flow 511 565 " 0.30 5 2.49 30F, partly cloudy
7:33 PM Check flow 358 450 " 0.11 6 2.21 30F, partly cloudy
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/27/20 8:10 AM Check flow 259 346 6.7% -0.14 1 1.94 23F, mostly sunny
8:20 AM Check flow 251 345 " -0.15 1 1.93 "
5:15 PM Check flow 241 308 " -0.25 0 1.83 32F, mostly clear all day. High of 37. Sever damage to flash boards.
Large debris dam against Lamont bridge. A result of Christmas day high
flow. No flow coming from sluice even though it is 6.7% open
5:53 PM Check flow 241 306 " -0.25 1 1.82
7:34 PM Check flow 236 302 " -0.27 0 1.81 29F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/28/20 9:08 AM Check flow 197 270 6.7% -0.37 1 1.72 30F, overcast
7:38 PM Check flow 192 262 " -0.39 0 1.69 37F, mostly cloudy
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
12/31/20 9:34 AM Check flow 173 237 6.7% -0.45 0 1.62 40F, light rain (0.2 in.)
10:28 AM Check flow 176 240 " -0.44 0 1.63 40F
1:25 PM Check flow 182 248 " -0.41 0 1.65 39F
3:18 PM Check flow 178 245 " -0.42 1 1.64 39F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/4/21 10:37 AM Check flow 141 205 6.7% -0.58 2 1.52 2" snow overnight - Planning debris dam clean up at Lamont Bridge
4:28 PM Check flow 136 201 " -0.59 2 1.50 38F, snowmelt = .07 in. rain
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/14/21 1:00 PM Observe site 6.7%Debris Dam against Lamont Bridge was cleared by Grounds Crew earlier
this week. Flashboards severely damaged.
1:10 PM Check flow 76 n/a " -0.90 0 n/a
Lightly snowing 34F. Jay Lucey, Leon Chartier present to help clear and
operate gate
1:10 PM Operate gate 100%
After many attempts to open w/ electric power and some hand cranking
gate operated smoothly. (opening & stalling within less than 1%).
2:02 PM Operate gate 40% Closed gate to 40% after about 30 minutes at 100%
3:20 PM Check flow 76 143 " -1.86 0 1.31
5:22 PM Check flow 77.4 143 " -2.00 0 1.31 33F, drizzle (0.05 in.)
9:15 PM Operate gate 36%Gate would not go below 36%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/15/21 8:44 AM Check flow 73.7 134 36% -1.69 0 1.28 32F, overcast, rain in forecast for late evening
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/16/21 9:28 AM Check flow 167 293 36% -0.71 18 1.79 36F, rain tapering (1.26 in. since 1:00 AM)
1:03 PM Check flow 261 353 " -0.40 9 1.96 40F, clearing sky (1.31 in. rain total)
8:51 PM Check flow 368 436 " -0.13 5 2.18 37F, mostly clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/19/21 8:10 AM Check flow 108 156 36% -1.23 0 1.36 37F, partly sunny
5:31 PM Check flow 102 151 36% -1.27 0 1.34 34F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/20/21 12:22 PM Operate gate 40.0%Lowering stage in prep for pre-SedRed survey tomorrow
12:39 PM Check flow 96 149 " -1.36 0 1.33 35F, partly sunny
1:46 PM Check flow 94.7 146 " -1.40 0 1.32 31F, overcast
5:02 PM Check flow 93.3 141 40.0% -1.44 0 1.30 30F, partly clear
5:15 PM Operate gate 45.5%Trouble going from 40% to 45.5%
8:44 PM Check flow 91.9 147 45.5% -1.90 0 1.33 24F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/21/21 5:30 AM Check flow 70.1 USGS site report is time stamped 5:30 at 7:18 am (ice)
7:18 AM Check flow 70.1 132 45.5% -4.79 6 1.27 20F, mostly clear
7:58 AM Operate gate 38.0%
8:34 AM Check flow " 105 " -5.54 14 1.18 USGS time stamp still 5:30 am
7:02 AM Check flow " 118 " -2.80 0 1.23 28F
7:14 PM Operate gate 41.0%
7:56 PM Check flow " 125 " -2.63 0 1.25 28F
9:25 PM Operate gate 44.0%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/22/21 7:44 AM Check flow ice 133 44.0% -3.23 0 1.28 22F, mostly clear
8:16 AM Check flow "" " -3.31 "" 24F, partly sunny
9:30 AM Survey Pond Survey Pond bottom. Total station & drone. Bob, Jon, Tracey
5:48 PM Check flow " 128 " -4.18 " 1.26 37F, mostly cloudy
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/23/21 8:55 AM Check flow 87.8* 124 44.0% -4.82 0 1.25 *USGS station time stamp 6:45 am. (ice), 24F, partly sunny
10:50 AM Check flow 82.5 121 44.0% -5.41 4 1.23 24F, clear
12:13 PM Operate gate 40.0%
12:50 PM Check flow 79.9 108 " -5.62 5 1.19 25F, clear
6:43 PM Check flow 73.7 75 " -4.31 0 1.06 21F, clear
9:00 PM Check flow 71.3 97 " -2.53 0 1.21 19F, clear
9:15 PM Operate gate 42%
Opened to 75% then closed to 42%. Ran without stalling in both
directions
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/24/21 10:55 AM Check flow ice 180 42.0% -6.67 5 1.44
22F, clear - Overnight pond drained completely . Current stage would
normally cause very high turbidity.
6:20 PM Check flow " 126 " -2.93 0 1.25 22F, clear (steady rise in stage through the day)
6:49 PM Check flow " 129 " -2.84 0 1.26 21F, clear
8:04 PM Check flow " 132 " -2.55 0 1.27 20F, clear
8:20 PM Operate gate 36.0%Opened to 80% then closed to 36%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/25/21 6:30 AM Check flow -3.20 Checked via mobile device. Pond stage only
7:40 AM Operate gate SedRed 3 40.0%Opened gate 100% for about 30 minutes then closed to 40%. No trouble.
Dozer on site
8:27 AM Check flow ice 206 " -5.10 0 1.52 18F, clear
10:01 AM Check flow " 198 " -5.83 0 1.50 23F, clear
12:41 PM Check flow " 130 " -5.30 7 1.27 29F. clear
2:30 PM Operate gate 40.0%Opened 100% - 10 min. - closed gate to 40%
3:25 PM Check flow still rising Checked via mobile device. Pond stage only
3:34 PM Operate gate 45%
4:50 PM Check flow " 115 " -3.93 0 1.21 31F, clear
7:18 PM Check flow " 117 " -3.66 0 1.22 29F, clear
7:35 PM Operate gate 48%Opened gate to 60% then closed to 48%
9:00 PM Check flow " 142 " -4.20 0 1.31 27F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/26/21 6:00 AM Check flow -6.25
Stage dropped to -6.00 at midnight, was steady for 4 hours then dropped
to -6.8 around 6:00 am, came up to around -6.2 and is falling down now.
Turbidity spike at 6:00 am of 25, but was down below 10 by 7:30 am.
10:17 AM Check flow ice 118 48.0% -6.38 4 1.22 26F, mostly cloudy
12:51 PM Check flow " 109 " -6.06 1 1.19 30F, overcast
5:14 PM Check flow " 114 " -5.57 1 1.21 26F, light snow
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/27/21 7:03 AM Check flow ice 114 48.0% -6.21 0 1.21
27F, overcast, 3" snow yesterday evening & overnight. Remarkably low
turbidity for current Pond depth.
9:09 AM Check flow " 116 " -6.14 1 1.20 28F, flurries
9:56 AM Check flow " 110 " -5.75 0 1.20 29F, flurries
10:41 AM Check flow " 116 " -5.81 0 1.22 30F, light flurries
12:28 PM Check flow " 113 " -5.84 0 1.21 32F, overcast
4:25 PM Check flow " 110 " -5.86 14 1.20
33F, overcast - dozer was redistributing sediment into the river for much
of the afternoon
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/28/21 9:10 AM Check flow ice 104 48.0% -5.90 0 1.18 28F, overcast
9:56 AM Check flow "" " -5.93 0 1.17
4:20 PM Check flow " 103 " -5.85 13 1.17
26F, clear - dozer distributed sediment (course sand) directly to the river.
Highest turbidity spike today was 18 NTU's.
4:52 PM Check flow " " " -5.80 8 1.17 25F, clear
6:28 PM Check flow "" " -5.68 2 1.17 21F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/29/21 4:23 PM Check flow ice ice 48.0% -5.78 10 1.39
17F, clear - Turbidity spikes in the 100's while dozer was redistributing
sediment directly to the river. Dwstr CFS unreliable due to ice.
6:00 PM Check flow "" " -5.97 7 1.38 15F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/30/21 8:43 AM Check flow ice ice 48.0% -7.87 85 1.59 6F, clear - Turbidity spike of 250 just after midnight.
9:41 AM Check flow "" " -7.55 46 " 12F, clear
10:10 AM Check flow "" " -7.36 10 1.58 15F, clear
2:49 PM Check flow "" " -6.27 14 1.53 21F, clear
8:37 PM Check flow "" " -7.24 21 1.51 11F, clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
1/31/21 10:46 AM Check flow ice ice 48.0% -7.03 17 1.52 9F, hazy sun
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/1/21 8:20 AM Check flow ice ice 48.0% -7.11 85 1.66 19F, snowing
11:00 AM Check flow "" " -7.58 106 1.68 23F, flurries
2:22 PM Check flow "" " -7.25 124 1.68 23F, snowing
5:05 PM Check flow "" " -7.38 120 1.75 25F, snowing
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/2/21 8:28 AM Check flow ice ice 48.0% -7.25 144 ice 31F, 10" snow
1:24 PM Check flow "" " -6.72 69 "
6:00 PM Check flow "" " -6.42 4 " 35F, overcast
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/3/21 7:33 AM Check flow ice ice 48.0% -6.21 1 ice 29F, overcast
12:54 PM Check flow "" " -6.07 9 " 34F, overcast
3:29 PM Check flow "" " -5.95 3 " 35F, overcast
5:02 PM Check flow "" " -5.91 1 " 34F, overcast
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/10/21 10:06 AM Check flow ice ice 48.0% -6.21 0 ice
20F, clear. Pond stage has ranged from -8 to -4 with no gate operation
since Jan 25.
1:52 PM Check flow "" " -3.67 0 ice 30F, mostly sunny
5:24 PM Check flow "" " -2.70 0 ice 27F, mostly clear
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/13/21 11:35 AM Check flow ice ice 48.0% -3.58 0 ice 19F, hazy sunshine
1:19 PM Check flow "" " -3.36 0 " 24F, hazy sunshine
2:26 PM Check flow "" " -3.22 0 " 27F, hazy sunshine
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/16/21 10:12 AM Check flow ice ice 48% -1.33 19 ice 34F, 0.7 in rain since early am
10:46 AM Check flow "" " -1.25 20 " 35F, rain stopped (0.77 in rain)
11:21 AM Check flow "" " -1.19 20 " 36F
1:20 PM Operate gate 100%
2:09 AM Check flow "" " -2.00 28 " 38F
3:25 PM Check flow "" " -3.44 45 " 38F
5:56 PM Check flow "" " -5.80 33 " 37F
6:11 PM Check flow "" " -5.63 32 " 37F
9:26 PM Check flow "" " -3.76 19 " 32F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/17/21 6:44 AM Check flow ice ice 100% -7.18 58 ice 21F, clear
3:47 PM Check flow "" " -6.37 10 " 29F, clear - Pond stage has ranged between -7.5 & -4 during the last 12
hours. Turbidity spikes of 70 and 40 ntu's
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/18/21 12:15 PM Check flow ice ice 100% -5.77 424 ice 26F, overcast. With gate still at 100% open pond stage has dropped to 9'
resulting in significant scouring up stream of the gate. A site visit at 8:00
(when stage was at about -9' the top of the gate is visible and within a few
feet from the gate course sediment was visible. Presumably this occurred
while the gate was partially open. Leaving gate at 100% until this area is
clear of sediment.
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/19/21 4:01 PM Check flow ice ice 100% -8.62 142 ice 29F, light snow. Average stage for last 24 hours below -8
8:22 PM Check flow ice ice 100% -8.24 116 ice 29F, snow stopped
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/24/21 2:10 PM Check flow ice ice 100% -6.58 5 ice 49F, partly sunny - Pond stage has been fairly steady just below -6 for 48
hrs. Average stage on 2/22 was below -8 for about 6 hours.
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
2/25/21 11:25 AM Check flow ice ice 100% -3.63 X ice 40F, snow melt probable reason for stage rise - Turbidity sensor not
reporting. Much sediment visible in the plunge pool and downstream.
5:07 PM Check flow " " " -3.18 X " 39F, mostly sunny
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/1/21 7:33 AM Check flow ice ice 100%-3.49 8 ice 35F, raining (.13 in) Pond stage was about -5.25 about 20 hrs ago
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/2/21 10:37 AM Check flow ice ice 100% ice ice ice Equipment frozen (12F this morning, very windy)
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/4/21 12:36 PM Check flow ice ice 100% ice ice ice
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/12/21 n/a Deployed custom
made 5 pronged
grapple hook to clear
gate
ice 100% Dropped grapple hook into Pond directly upstream of gate in attempt to
remove debris obstructing gate operation and flow. Strong current pulled
grapple through and after a short duration struggle to pull it back through,
it was released and passed through into the plunge pool.
3/13/21 n/a Retrieved grapple
and redeployed
ice 100% Installed 3 lines on grapple. One upstream and two to each side. Dropped
grapple into Pond upstream of gate and worked it left and right with little
results.
3/16/21 n/a Redeployed grappled
w/ 3 lines
ice Operated grapple with 2 laborers from grounds with some success. Pulled
up several small branches, one stub log. Bent one hook. Ran out of time.
Brought grapple to weld shop, added hook reinforcement.
3/18/21 n/a Redeployed grapple
w/ 4th line (chain) and
come-along winch
ice Operated grapple with 2 laborers from grounds. Bent several hooks on
submerged left side training wall at Gate. Returned to weld shop.
Removed one bent & cracked hook. Added reinforcing ring.
3/23/21 n/a Deployed custom
water jet to clear clog
ice 100%Operated custom water jet at gate from row boat. Some materials did pass
through. Ran out of time.
3/24/21 9:08 AM
Redeployed grapple
w/ 3 lines. Two at
bottom, 1 from stem.99 _
100% to
35% to
100%,
multiple
times
__ _
Noticed upstream station reporting again. Operated grapple with 2
laborers from grounds. Made more progress. Several good size logs
passed and one good gusher of finer organic materials. However,
apparently other material advanced into partial clog. Gate closed to only
33.9%. Flow diminished but some flow still passing through clog.
3/26/21 6:17 PM Check flow 122 175 100%
_235 1.42 Sunny, windy, 73F. Received .25 in. rain in last 24 hrs
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/29/21 6:54 AM Check flow 330 414 100%_660 2.12 Pond spilling. 0.7" rain yesterday. 41F
12:52 PM " 246 332 " "_1.90 Turbidity not reporting, 42F, partial clearing, windy
4:55 PM Operate gate 33.7% Closed gate to 34.2%. Cranked further closed to 33.7%
5:34 PM Check flow 197
8:41 PM " 178
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
3/31/21 6:54 AM Check flow 113 159 33% _ 0 1.37 42F, overcast
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
4/27/21 7:30 AM Clear gate clog
From boat attempted to free compacted debris just upstream and possible
within the sluice using a newly acquired pike pole. We retrieved grapple
but were unsuccessful at removing the clog. Gate will only close to 30%
open. didn't improve the clog
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
4/28/21 4:50 AM Check flow 77.4 117 30% -1.32 0 1.22 Flashboards still as they were following the 2020 Christmas day storm
5:03 AM Operate gate 100%Initiating partial drawdown for installation of new fall protection anchors
and flashboard repair
6:00 AM Check flow 77.4 208 100% -2.54 1 1.53 48F
7:10 AM Check flow 77.4 172 100% -3.85 2 1.15 48F
7:17 AM Operate gate 45%
7:30 AM Remove debris from
dam crest
Smith grounds crew removed tree trunks and large branches from dam
crest (about 1 hour activity)
8:43 AM Check flow 77.4 78 45% -2.89 3 1.07 51F
8:47 AM Operate gate 65%
AM & PM Install fall protection Evan Fall Protection - drilled holes & installed anchors w/2 part epoxy
12:04 PM Operate gate 60%
PM Remove damaged
flashboards
Smith carpentry started removal of flashboards & pins. Will continue
tomorrow, weather permitting.
3:20 PM Operate gate 55%
5:30 PM Check flow 82.4 100 55% -4.35 3 1.16 73F
6:47 AM Check flow 81.2 103 55% -3.72 3 1.17 70F, light rai
6:50 PM Operate gate 62%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
4/29/21 6:22 AM Check flow 86.4 130 62% -6.18 5 1.27 54F
7:02 AM Operate gate 58%
8:25 AM Check flow 86.4 125 58% -5.60 4 1.25 55F
1:55 PM Check flow 97.5 136 58% -4.04 18 - 58F, received 1/2" rain in last 3 hours (not raining now)
2:00 PM Operate gate 100%Anticipating higher flows soon
3:08 PM Check flow 119 195 100% -4.14 12 1.49 58F, started raining again around 3:00.
3:41 PM Check flow 116 194 100% -4.27 12 1.48 58F, 0.69 in. rain today so far - currently raining
5:30 PM Check flow 173 196 100% -4.09 12 1.49 57F, 0.86 in. rain, currently raining
6:00 PM Operate gate 32%Closed gate - stalled at 32% open, but with persistent clog flow through
gate is significantly lower than it would be without the clog
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
4/30/21 noon Check flow 500 cfs
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/3/21 8:01 AM Check flow 124 175 30.2% -1.70 1 1.42 55F, overcast, potential occasional showers predicted.
8:45 AM "122 175 " -1.70 1 " 56F
3:53 PM "121 169 " -1.71 2 1.40 68F, overcast no rain so far
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/4/21 8:12 AM Check flow 171 232 30.2% -1.57 2 1.60 50F, 0.51 in. rain in last 12 hrs.
8:58 AM "188
10:23 AM "212
9:54 PM "210 266 " -1.50 2 1.71 53F, rain stopped around 8:00 am.
5:31 PM "188 245 " -1.55 2 1.64 59F, overcast - rain predicted overnight into tomorrow
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/5/21 10:24 AM Check flow 1000 1123 30.2% -0.36 16 3.63 51F, 1.1" rain since 9 pm yesterday. Peak flow ~1,250 cfs at 3:00 am
5:05 PM "601 644 " -0.90 7 2.67 54F, raining
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/6/21 4:15 PM Check flow 269 323 30.2% -1.39 3 1.87 62F, sunny day
4:18 PM "258
5:19 PM "248 316 " -1.40 3 1.85 62F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/10/21 10:03 AM Check flow 231 289 30.2% -1.45 2 1.77 50F, 0.48 rain btw mid-night & 4:00 am. Overcast
2:44 PM "234 291 " -1.45 3 1.78 60F, mostly cloudy
4:59 PM "222 274 " -1.48 2 1.73 60F
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/11/21 7:05 AM Check flow 156 30.2%
7:20 AM Operate gate 100%
8:32 AM Check flow 152 217 " -2.16 1 1.56 51F, clear
9:25 AM "150 209 " -2.2 2 1.53 52F
10:32 AM "145 204 " -2.23 2 1.52 55F
3:00 PM "145 199 " -2.29 2 1.50 59F, partly cloudy
3:20 PM "145 198 " -2.30 1 1.50 58F
4:42 PM "145 198 " -2.34 2 1.50
58F - Incoming flow is just below sluice capacity w / clog. Spillway has
stopped spilling.
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/12/21 7:52 AM Check flow 121 178 100% -4.88 6 1.43 49F, mostly sunny
Flashboard repair
8:41 AM " 122 177 " -4.98 5 1.43 51F
9:10 AM Operate gate 85.0%
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/13/21 6:55 AM Check flow 105 85.0%
7:05 AM Operate gate 50.0%Flashboards replaced. Started refilling Pond.
3:48 PM Check flow 103 112 " -0.47 5 1.20 67F
4:10 PM Operate gate 29.6%Pond Spilling. Gate stalled at 30.3%. Hand cranked to 29.6%
5:21 PM Check flow 103 140 " 0.22 3 1.30 Bob recalibrated stage reading around 3:50 pm
Scheduled sluice gate inspection with Bob Newton using GoPro camera
at 2:00 PM tomorrow.
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
5/14/21 7:07 AM Check flow 93.3 146 29.6% 0.25 192 1.32 42F, clear
Will schedule diver to clear gate debris jam.
Upstream Downstm. Gate Pond Stream
Date Time Specific Activity Flow - cfs Flow - cfs Position Stage NTU Stage Observations/notes
10/13/21 9:00 AM Diver on site 29.6%
Diver cleared gate debris jamb with assistance from Facilities operations
group and systematic opening and closing the gate. Jamb cleared after
several hours. No draw down.
12:30 PM Gate closed 0%