Dam Report

Long Sault North dam

New York, USA St. Lawrence River Hazard High
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Dam height
25ft
Hazard rating
High
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Long Sault North                                                  -- None dam
Long Sault North None · St. Lawrence River
About this dam

Long Sault North

Long Sault North is a state-owned hydroelectric dam located on the St. Lawrence River in Massena, New York. Built in 1958 by Chas. T. Main, this Earth-type dam stands at a height of 25 feet and stretches 4300 feet in length. With a maximum storage capacity of 803,000 acre-feet and covering a surface area of 37,500 acres, the dam plays a crucial role in hydroelectric power generation and navigation in the region.

Managed by the Federal Energy Regulatory Commission, Long Sault North has a high hazard potential and is subject to regular state inspections. Despite its age, the dam's condition assessment is currently unavailable, signaling a need for further evaluation to ensure its safety and structural integrity. With a drainage area of 300,000 acres and a normal storage capacity of 750,000 acre-feet, this dam remains a significant water resource management structure in the St. Lawrence River watershed.

As a key component of New York's water infrastructure, Long Sault North serves as a vital source of renewable energy and contributes to the region's economic development. With its high risk potential and complex regulatory oversight, the dam underscores the importance of effective risk management and emergency preparedness in safeguarding water resources and addressing the impacts of climate change on water infrastructure systems.

StateNone
River / streamSt. Lawrence River
NID IDNY00678
Owner typeState
Primary purposeHydroelectric
Dam typeEarth
Year built1958
Dam height25 ft
Dam length4,300 ft
Max storage803,000 AF
Normal storage750,000 AF
Surface area37,500.0 ac
Drainage area300,000.0 sq mi
Hazard potentialHigh
ConditionNot Available
Last inspectionWed, 30 Sep 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 Long Sault North -- inflows here typically show up in storage 24-72 hours later.

Track Long Sault North in the Snoflo app

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FAQ

About Long Sault North

Where does the data for Long Sault North 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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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

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