Old Marsh Pond Dam dam
Old Marsh Pond Dam
Old Marsh Pond Dam, also known as Bristol Reservoir #7, is a historic masonry dam located in East Plymouth, Connecticut. Built in 1913, this dam serves the primary purpose of water supply, with a storage capacity of 3,094 acre-feet and a normal storage capacity of 1,808 acre-feet. The dam, standing at 30 feet high and 1,200 feet long, impounds the waters of Marsh Brook and covers a surface area of 183 acres.
Managed by a public utility, Old Marsh Pond Dam is regulated by the Connecticut Department of Energy and Environmental Protection (DEEP) and undergoes regular inspections to ensure its safety and functionality. The dam has a high hazard potential but is currently assessed to be in satisfactory condition. In the event of an emergency, the dam does not have an Emergency Action Plan (EAP) prepared, highlighting the importance of ongoing risk assessment and management for this critical water resource infrastructure. With its rich history and vital role in the local water supply system, Old Marsh Pond Dam stands as a testament to the intersection of engineering ingenuity and environmental stewardship.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Old Marsh Pond Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Naugatuck River At Thomaston | 222 cfs | → |
| Burlington Brook Near Burlington | 21 cfs | → |
| Farmington River At Unionville | 576 cfs | → |
| Quinnipiac River At Southington | 33 cfs | → |
| Nonewaug River At Minortown | 19 cfs | → |
| Weekeepeemee River At Hotchkissville | 33 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Old Marsh Pond Dam.
Boat launches
- Lake Plymouth Boulevard 191, Plymouth
- Farmington River Trail Collinsville
- Batterson Park Pond
- Burr Pond
- West Hill Pond Boat Launch
- Silver Lake
Campgrounds
- Black Rock State Park
- Deep Campsite
- Windmill Hill - White Memorial
- Point Folly - White Memorial
- Camp Sequassen
- Camp Workcoeman
Fishing spots
- Great Brook Reservoir
- Lower Fulton Park Pond
- Lake Quassapaug
- Seymour Reservoir Number 4
- Reservoir Number 2
- Seymour Reservoir Number 2
Paddle runs
- Begins Below The Tailrace Of The Lower Collinsville Dam To The Route 187 Bridge
- The Confluence With The Nepaug River To A Point 0.2 Miles Below The Lower Collinsville Dam Tailrace
- New Hartford/Canton Town Line To The Confluence With The Nepaug River
- Begins Downstream Of The Borough Of Bantam, At Stoddard Road Bridge To The Confluence With The Shepaug River
- Pond Downstream Of Shepaug Reservoir Dam, Marked By Service Road Bridge To Ends In Backwaters Of Lake Lillinonah, Near Roxbury Falls
- The Hartland Headwaters To The Confluence With The Salmon Brook Main Stem
Track Old Marsh Pond Dam in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Old Marsh Pond Dam
Where does the data for Old Marsh Pond Dam come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Old Marsh Pond Dam.