Dam Report

Lake Sebago Dam dam

New York, USA Stony Brook Creek Hazard High
Today high
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Tonight low
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Dam height
30ft
Hazard rating
High
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Lake Sebago Dam -- None dam
Lake Sebago Dam None · Stony Brook Creek
About this dam

Lake Sebago Dam

Lake Sebago Dam, located in Sloatsburg, New York, is a state-owned structure primarily built for recreational purposes. Completed in 1925, this concrete dam stands at a height of 30 feet and spans a length of 1700 feet, creating a reservoir with a maximum storage capacity of 4280 acre-feet. The dam sits on Stony Brook Creek and is regulated by the New York State Department of Environmental Conservation (NYS DEC), with regular inspections and enforcement measures in place to ensure its safety.

Despite its significant recreational value, Lake Sebago Dam has been flagged with a high hazard potential and poor condition assessment, as of the last inspection in July 2020. The dam's Emergency Action Plan (EAP) has not been updated recently, raising concerns about its ability to meet safety guidelines during emergencies. Additionally, the risk assessment categorizes the dam as having a moderate risk level, indicating the need for continued monitoring and potential risk management measures to address any vulnerabilities. Enthusiasts of water resources and climate change should keep an eye on updates regarding Lake Sebago Dam to ensure the safety and sustainability of this essential infrastructure.

StateNone
River / streamStony Brook Creek
NID IDNY00772
Owner typeState
Primary purposeRecreation
Dam typeConcrete
Year built1925
Dam height30 ft
Dam length1,700 ft
Max storage4,280 AF
Normal storage3,551 AF
Surface area297.0 ac
Drainage area9.9 sq mi
Hazard potentialHigh
ConditionPoor
Last inspectionTue, 28 Jul 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 Lake Sebago Dam -- inflows here typically show up in storage 24-72 hours later.

Track Lake Sebago 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 Lake Sebago Dam

Where does the data for Lake Sebago 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.