Dam Report

Bow Lake Dam dam

New Hampshire, USA Isinglass River Hazard High
Today high
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Tonight low
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Dam height
24ft
Hazard rating
High
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Bow Lake Dam -- None dam
Bow Lake Dam None · Isinglass River
About this dam

Bow Lake Dam

Bow Lake Dam, located in Strafford, New Hampshire, is a state-owned earth dam built in 1832 with a primary purpose of recreation. Standing at a height of 24 feet and stretching 400 feet in length, the dam impounds the Isinglass River, creating a surface area of 1171 acres and a maximum storage capacity of 22,380 acre-feet. Despite its age, the dam remains state-regulated and regularly inspected by the New Hampshire Department of Environmental Services Dam Bureau.

The dam's spillway, with a width of 20 feet, is uncontrolled, and its high hazard potential and poor condition assessment highlight the need for ongoing maintenance and risk management measures. The dam's risk assessment indicates a moderate risk level, emphasizing the importance of emergency preparedness and adherence to guidelines in case of a potential breach. With the dam situated in a picturesque setting and offering recreational opportunities, ongoing efforts to ensure its structural integrity and safety are crucial for both water resource management and climate resilience in the region.

In conclusion, Bow Lake Dam serves as a vital recreational asset while also posing significant risks that require proactive management and oversight. As a historic structure with a high hazard potential, the dam's condition assessment, last conducted in 2016, underscores the need for continued monitoring and maintenance to mitigate potential threats. By prioritizing safety measures and risk management strategies, stakeholders can ensure the long-term sustainability of Bow Lake Dam and safeguard the surrounding environment and communities from potential water resource challenges.

StateNone
River / streamIsinglass River
NID IDNH00055
Owner typeState
Primary purposeRecreation
Dam typeEarth
Year built1832
Dam height24 ft
Dam length400 ft
Max storage22,380 AF
Normal storage17,276 AF
Surface area1,171.0 ac
Drainage area14.3 sq mi
Hazard potentialHigh
ConditionPoor
Last inspectionWed, 18 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 Bow Lake Dam -- inflows here typically show up in storage 24-72 hours later.

Track Bow Lake 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 Bow Lake Dam

Where does the data for Bow Lake 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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