Waterlevel & Dam

The waterlevel of Manchaug Pond is of utmost importance to the health of this lake ecosystem, the quality of life for year-round and seasonal residents and tourists, the safety of property and residences along the shoreline and downstream, and the maintenance of water in-lake and downstream flow feeding dependent fisheries, drinking water sources, water-dependent businesses. Key to maintaining the proper waterlevel is the Manchaug Pond Dam which is now owned, operated, and maintained by the Town of Sutton.


Frequently Asked Questions:

  • What are  the waterlevel goals?
    • April 1st:  Achieve FULL. Refill of the lake from the winter drawdown occurs in February and March in order to bring the waterlevel to full or just above as required by Mass DEP (Massachusetts Department of Environmental Protection) and Mass Wildlife (Mass. Department of Fish and Wildlife) for healthy fisheries during spawning months.
    • Spring/Summer: Maintain FULL as much as possible for connectivity to coldwater fishery stream and healthy fisheries in coves, wetlands and along shore as required by Mass Wildlife. This is dependent on rainfall and evaporation.
    • Early October/ Columbus Day Weekend: Winter DRAWDOWN begins.
    • Mid-Late January: Reach greatest low of drawdown.
    • Late January-Early February: End winter drawdown.
  • Who owns the Manchaug Pond Dam?   The Town of Sutton owns the dam while the Manchaug Pond Foundation holds the deed to the flow-rights of Douglas and Sutton.
  • Who operates and maintains and operates the dam?  The care and operation of the dam is executed by the dam owner.
  • Will another flashboard be added to the dam spillway?  No, the current number of flashboards are for normal operation and to get us to “full.”
  • Who decides if the gate is open or closed?  The dam caretaker makes that determination with input from the Manchaug Pond Foundation. Many variables are considered from the weather forecast, to the presence/absence of snow cover in the watershed and ice cover on the lake, to runoff and saturated soils or lack of in the surrounding watershed, to conditions downstream at Stevens Pond and in the Mumford and Blackstone Rivers. Whatever the situation, you have a voice in the Manchaug Pond Foundation who works closely with the town. Waterlevel issues affect public safety, the health of the lake ecosystem, needs of shoreline properties, public access and recreation, flood prevention, drinking water wells and septic systems, control of invasive aquatic species, and more.
  • Why is the dam low-level gate open … or closed?  Possible reasons include winter lake-level drawdown, maintaining spring/summer season FULL, a rain or a storm event in the forecast, the low-level gate needs to be flushed, dam maintenance to be performed, or downstream work on the Steven’s Dam or a change in downstream water needs.
  • Is the dam safe?  Yes, the dam undergoes regular inspections both informal as part of its daily operation and formal by an outside inspector as part of the requirements of the Massachusetts Office of Dam Safety.
  • Who can I contact with a question or concern?  Ask it here! Manchaug Pond Foundation fields questions and concerns of the property owners and the user-community serving as the liaison with local and state regulating agencies.

Manchaug Pond Foundation

April 18, 2017, Public Boat Ramp

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THE WATERLEVEL:
What’s happening at the pond!

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2018

~ December: Manchaug continues to serve as a reservoir preventing flooding on lake and downstream in the Mumford and Blackstone Rivers.  Dam owner continues to monitor and is maintaining 100% flow out the low-level gate in order to address the extraordinary amount of precepitation this fall season.

~ November 28: Dam caretaker reports waterlevel has come down more than 7 inches from last Wednesday to Monday with greater drop expected.

Officially, 2018 is recorded as the wettest meteorological fall ever for the area. (Period from September 1 – November 30 with records dating back to the late 1800’s at the Massachusetts based Blue Hill Meteorological Observatory.)

~ November 21:  This afternoon‘s update from the dam owner finds the waterlevel has only gained 1/4″ since Monday with watershed run-off down  an estimated 20%.

Gate is open 100%.  Expectation is with no to little precipitation the lake can be lowered fast for drawdown to resume. High water downstream in the Mumford River is being monitored but Stevens is handling Manchaug’s outflow.

In this morning’s communication, the dam owner reports gate is wide open, 4 dry days coming up, and the promise the lake will get to the lower level.

With unprecedented amounts of rainfall this fall, the lake is serving it’s purpose well as a reservoir to store and gradually drain off the excess water.    Shoreline resident are dealing with the higher waterlevel late in the season but no flooding is occuring at Manchaug Pond.  Downstream flooding concerns  must be taken into the equation, docks and other periphery on lake are secondary concerns at best. 

~ November 17:  The situation here in the watershed and downstream is as follows with the Manchaug Pond low-level gate remaining 100% open:

  • Flooding between Manchaug and Stevens Ponds;
  • Stevens is down a little with significant flow out and over their dam;
  • Manchaug village center is at capacity to flooding;
  • Mumford River at capacity;
  • Blackstone River at capacity.
  • Comparisons between precipitation received in 2017 and 2018:
    Month 2017 2018
    July 4.72 4.2
    Aug 2.18 4.82
    Sept 2.07 8.18
    Oct 8.24 4.08
    Nov. thu 17th 0.72 6.72
    Total 17.42 29.94
  • Watershed saturation: The ground was less saturated from August and September in 2017 than 2018 as July 16, 2017 we had .56″ and July 17, 2018 we had 3.82″. The rest of the month 1″.  By October 23, 2017 we realized .56″ and by October 30, 2018 we had 8.24″.  On the 2 occurrences sited the ground was not saturated. Saturated watershed soils = increased runoff filling Manchaug Pond.
  • Last November, we had 1.89″ for the month. This year, 6.72″ by the 17th.

~ Mid-November: Communication with dam owner continues, meeting as recently as November 14th.  Shared goal remains to lower waterlevel ASAP and resume drawdown.

~ November:  Above average rainfall and runoff from a saturated watershed has brought the waterlevel up to summer levels.  The dam owner, who manages both Manchaug and Stevens Ponds, is working to bring both waterlevels down  so the winter drawdown can resume. Flow from Manchaug is being increased as Stevens Dam and downstream concerns allows. Manchaug Pond Foundation is in communication expressing concern and has requested gate 100% open and  flashboards out.

Aerial View of Manchaug Pond Dam – November 2018

~ Winter drawdown began October 9th.  Make arrangements and adjustments for your boats and docks as the waterlevel goes down.  This year we are well over the full mark going into the drawdown.

~ October 6: Water continues to flow over the flashboards. Flow may be obstructed by debris at low-level gate.

~ October 2:  The increased flow out the low-level gate is to bring the level down with the additional rain and runoff.  Drawdown will begin as planned after the Columbus Day weekend.

~ August-September: Periodic rain brought us to “full.”  With good control of the dam, full continues to be maintained with water going over the flashboards at both Manchaug and Stevens Pond dams.

~ July 11: Hot dry weather with little significant rainfall continues to cause evaporation and a lowering of the waterlevel of Massachusetts lakes and ponds. The dam operator reports normal operations of both the Manchaug and Stevens dams with minimal outflows by design for a healthy Mumford River system.

~ July 1: Heavy rains have brought the waterlevel up closer to full in spite of the week’s temperatures in the 90’s.

~ June 26th: Low-level gate is closed. By design it does allow a minimal continuous flow for the health of the downstream river system habitat as required by the Department of Environmental Protection (MassDEP).

~ June 18th:  Waterlevel down 4.5″ due to evaporation, high temperatures and lack of rainfall.

~ April 30:  As of this morning we are 1″ over full!  The dam caretaker will continue to monitor regulating the flow as needed with the spring’s periodic rainfall.

~ April 1: Refill occurred in March as required by the Massachusetts Department of Environmental Protection.

~ March:   The beginning of the month saw no ice, the dam’s low level gate closed and the spillway flashboards ready for refill to accommodate the drier summer season.

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Drawdown allows for the desiccation, freezing and physical disruption of plants, roots, and seed beds around the shoreline.

Winter Lake-level Drawdown & Refill

WHEN?

Winter Drawdown:

October:  The annual drawdown of the waterlevel begins about Columbus Day. The water level will drop at a rate of approximately one to two inches per day, to achieve an approximate total level of 5.5 to 6 ft. below full with the process completed by-enlarge December 1st but reaching its lowest point in early January. This is a gradual drawdown with timing to allow for amphibians, reptiles and other aquatic organisms to move to deeper water before ice formation and substrate freezing and to provide fall recreational opportunities.

Lake Refill:

March-April: Lake refill must be achieved by April 1st to provide a stable pool elevation and habitat for spring spawning and connectivity with the watershed in-flowing cold water fishery stream.*

WHY?

Flood Control:

The lower winter waterlevel provides storage capacity for runoff from unusually high precipitation and snow-melt events.

Dam Maintenance:

With the upstream face of the dam exposed, inspection and maintenance can be performed as needed which would include re-pointing and facing of the concrete.

Invasive Species Control:

Since 1990, the Manchaug Pond Foundation and its parent organization, the Manchaug Pond Association, has worked with the dam owner to employ lake-level drawdown as the best option for controlling aquatic invasive species.  2018 both the Sutton and Douglas Conservation Commissions issued Order of Conditions  (DEP file numbers 303-0866 and 143-0956) which mandates drawdown and other physical/mechanical means of management as the first-line of defense in the control of invasives.

Lycott Environmental’s Lee Lyman, a pioneer in the management of ecological systems, first recommended tweeking the timing of our annual drawdown to both protect native species and to control unwanted invasives.   Providing the weather conditions are conducive, historically the water level  has been drawn down during the middle of September and no later than mid October and at a rate of approximately one to two inches per day to minimize impacts to downstream environments and to allow certain aquatic organisms such as fresh-water mussels, crayfish, turtles and amphibians to migrate to deeper portions of the water body to overwinter and brought back in March and April.

Drawdown allows for the desiccation, freezing, and physical disruption of plants, roots, and seed beds around the shoreline. In addition to reducing the growth of non-native invasive weeds such as Fanwort and Variable Milfoil, Manchaug Pond Foundation notes successful control of Asian Clam at the state public access boat ramp.   A look at Manchaug Pond’s bathymetry  shows how lake-level drawdown can be an effective method for aiding in the management of aquatic vegetation in the shallow shoreline areas of lakes and ponds.Manchaug Pond Foundation

THE DAM

Purpose:

While the waters of Manchaug Pond Reservoir are no longer needed in the manufacturing processes of downstream textile mills, today the importance of the 380 acre reservoir and its dam are no less important and are found to be farther reaching:

  • provides required minimum, continual flow in the Mumford River supporting aquatic species;
  • supplies storage capacity to attenuate flooding concerns on-lake and downstream;
  • provides and enhances fisheries and wetlands;
  • ensures connectivity with in-flowing coldwater fishery streams;
  • allows year-round recreational opportunities benefiting tourism;
  • provides higher quality of life in this corner of the Blackstone Valley and Commonwealth.

Operation & Maintenance:

Visual inspections of the dam are made with daily water surface elevations and precipitation levels recorded and necessary adjustments made to the low-level gate and flashboards/stoplogs in compliance with the Conservation Commission and Mass DEP orders.

Annual maintenance includes cutting of the grass-covered earthen embankment twice a year. Re-pointing with concrete of the upstream stepped-face’s stone-masonry wall is done as needed. In compliance with Massachusetts Office of Dam Safety regulations, a Phase I Inspection/Evaluation is conducted every other year by an outside engineering firm.

In 2006 the low-level gate mechanism was replaced with steel construction and the operator’s platform renovated.

Repairs to the spillway box culvert were made in the years 2005, 2008, 2009, and 2013.

2015 new flashboards/stoplogs were installed.

2006  Repairs to low-level gate
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Overall Structure & Construction

Manchaug Pond Foundation Waterlevel & Dam

2010 Aerial of Dam with Torrey Road at crest.

Originally constructed in 1836 by downstream textile mill owners, its primary purpose was to impound the pond creating a reservoir to provide the mills with a continuous flow through the year.  In 1960, extensive improvements were made which included widening and raising the dam crest, constructing the downstream earthen embankment, replacing the overflow spillway, expanding the low-level outlet, and accommodating Torrey Road.

Today, Manchaug Pond Dam stretches 330 feet long, 28 feet high, and 36 feet wide with Torrey Road at its crest and sits in the town of Sutton, Massachusetts, U.S.A. at Latitude 42.09048 N   Longitude 71.76630 W. The upstream side of the dam is a stepped-face stone-masonry wall made up of large stone blocks with joints mortared with concrete. The downstream slope is a grass/vegetation covered earth slope constructed in 1960’s.

  • Manchaug Pond Foundation Dam

    Dam viewed from Holt Road

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    Upstream side made of stone-masonry

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  • Looking south toward low-level gate

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  • Earthen downstream side

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Spillway

The overflow spillway was constructed in 1960 when extensive improvement were made to the dam.
Primarily a reinforced- concrete box culvert, it extends from the upstream side through the center of the day to the downstream side measuring approximately 10 feet. wide by 9.35 feet high.

2016: On February, 26th, new flashboards installed made of thick, red oak. Two flashboards were significantly damaged by a beaver in 2015.

  • Manchaug Pond Foundation Waterlevel & Dam

    Spillway with cage on upstream side

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    Spillway/culvert box opening with flashboards.

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    Culvert box of spillway as seen from upstream

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    Water flow over spillway flashboards

Low-level Gate

The low-level outlet is comprised of a hand-operated gate which opens to a 2 ft. by 2ft. stone conduit through the dam structure enlarging to a 2-ft. by 3-ft. high reinforced-concrete outlet on the downstream side of the earthen embankment, added during the 1960 construction.


Sources:
Drawdown Performance Standards for the Protection of Fish and Wildlife Resources. Approved September 23, 2002, Massachusetts Division of Fisheries & Wildlife.