Dam Report

Mamaroneck Reservoir Dam dam

New York, USA Mamaroneck River Hazard High
Today high
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Tonight low
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Dam height
19ft
Hazard rating
High
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Mamaroneck Reservoir Dam -- None dam
Mamaroneck Reservoir Dam None · Mamaroneck River
About this dam

Mamaroneck Reservoir Dam

The Mamaroneck Reservoir Dam, located in Mamaroneck, New York, is a concrete dam completed in 1928 with a primary purpose of flood risk reduction along the Mamaroneck River. Standing at a height of 19 feet and a length of 185 feet, the dam has a storage capacity of 241 acre-feet and a maximum discharge rate of 4240 cubic feet per second. The dam is state-regulated by the New York State Department of Environmental Conservation, with regular inspections and enforcement to ensure its safety and functionality.

Despite its age, the Mamaroneck Reservoir Dam is facing some challenges, with a poor condition assessment and a high hazard potential. The dam's condition was last assessed in December 2018, and it is in need of maintenance and potential rehabilitation to improve its overall safety. The dam has an emergency action plan in place, but there are concerns about its effectiveness in meeting current guidelines. With a moderate risk level assigned, there is a need for continued risk management measures to address any potential vulnerabilities and ensure the dam's resilience in the face of climate change and extreme weather events.

For water resource and climate enthusiasts, the Mamaroneck Reservoir Dam represents a crucial piece of infrastructure that plays a vital role in flood risk reduction in the region. As efforts are made to address its current condition and potential risks, the dam serves as a reminder of the ongoing challenges faced in managing water resources and adapting to changing environmental conditions. With continued oversight and maintenance, the Mamaroneck Reservoir Dam will remain a key asset in protecting communities and ecosystems from the impacts of flooding and ensuring the sustainable management of water resources in the area.

StateNone
River / streamMamaroneck River
NID IDNY00111
Owner typeLocal Government
Primary purposeFlood Risk Reduction
Dam typeConcrete
Year built1928
Dam height19 ft
Dam length185 ft
Max storage241 AF
Normal storage18 AF
Surface area18.0 ac
Drainage area15.2 sq mi
Hazard potentialHigh
ConditionPoor
Last inspectionMon, 09 Nov 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 Mamaroneck Reservoir Dam -- inflows here typically show up in storage 24-72 hours later.

Track Mamaroneck 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 Mamaroneck Reservoir Dam

Where does the data for Mamaroneck 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.