Dam Report

Deans Reservoir Dam dam

Connecticut, USA Copps Brook Hazard High
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Tonight low
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Dam height
15ft
Hazard rating
High
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Deans Reservoir Dam -- None dam
Deans Reservoir Dam None · Copps Brook
About this dam

Deans Reservoir Dam

Deans Reservoir Dam, located in Stonington, Connecticut, is a historic masonry dam completed in 1888 with a primary purpose of water supply. The dam stands at a height of 15 feet and has a storage capacity of 90 acre-feet, serving as a vital resource for the surrounding community. Situated on Copps Brook, the dam plays a crucial role in maintaining water levels and ensuring a stable water supply for residents in the area.

Owned by a public utility, Deans Reservoir Dam is regulated by the Department of Energy and Environmental Protection (DEEP) in Connecticut, with regular inspections and enforcement to ensure its safety and functionality. Despite being classified as having a high hazard potential, the dam is currently assessed to be in fair condition as of the last inspection in August 2020. With a spillway width of 24 feet and a surface area of 35 acres, the dam is equipped to manage water flow and mitigate potential risks.

As a key component of the water supply infrastructure in New London County, Deans Reservoir Dam serves as a critical resource for the region. With its rich history dating back over a century, the dam continues to play a vital role in water management and conservation efforts. Climate and water resource enthusiasts will find Deans Reservoir Dam to be a fascinating example of how historic structures can still contribute to modern-day water supply needs while adhering to stringent regulatory standards and safety measures.

StateNone
River / streamCopps Brook
NID IDCT00614
Owner typePublic Utility
Primary purposeWater Supply
Dam typeMasonry
Year built1888
Dam height15 ft
Dam length220 ft
Normal storage90 AF
Surface area35.0 ac
Drainage area5.3 sq mi
Hazard potentialHigh
ConditionFair
Last inspectionThu, 06 Aug 2020 00:00:00 GMT

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.
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Deans Reservoir Dam -- inflows here typically show up in storage 24-72 hours later.

Track Deans Reservoir 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.

FAQ

About Deans Reservoir Dam

Where does the data for Deans Reservoir 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.

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