Dam Report

Contoocook River Dam dam

New Hampshire, USA Contoocook River Hazard Significant
Today high
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Tonight low
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Dam height
15ft
Hazard rating
Significant
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Contoocook River Dam -- None dam
Contoocook River Dam None · Contoocook River
About this dam

Contoocook River Dam

The Contoocook River Dam, located in Jaffrey, New Hampshire, was completed in 1861 and serves primarily for recreational purposes. This concrete dam stands at a height of 15 feet and has a length of 98 feet, providing a storage capacity of 60 acre-feet. The dam is owned by the Local Government and is regulated by the NHDES Dam Bureau, with state permitting, inspection, and enforcement in place to ensure its safety and integrity.

With a significant hazard potential and a moderate risk assessment score, the Contoocook River Dam is a vital structure for managing water resources in the area. The dam controls the flow of the Contoocook River, with a maximum discharge capacity of 3500 cubic feet per second. Despite its age, the dam has not been rated for its condition, and its Emergency Action Plan (EAP) is not up-to-date, raising concerns about emergency preparedness in case of a critical event.

As a key feature in the local water management system, the Contoocook River Dam plays a crucial role in providing recreational opportunities, regulating water flow, and mitigating flood risks. With ongoing monitoring and maintenance efforts, the dam continues to serve the community while facing challenges related to aging infrastructure and emergency response readiness. Enthusiasts of water resources and climate will find the Contoocook River Dam an intriguing case study in the intersection of infrastructure, environmental management, and public safety.

StateNone
River / streamContoocook River
NID IDNH00733
Owner typeLocal Government
Primary purposeRecreation
Dam typeConcrete
Year built1861
Dam height15 ft
Dam length98 ft
Max storage60 AF
Normal storage15 AF
Surface area5.0 ac
Drainage area21.2 sq mi
Hazard potentialSignificant
ConditionNot Rated
Last inspectionWed, 28 Nov 2018 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 Contoocook River Dam -- inflows here typically show up in storage 24-72 hours later.

Track Contoocook River 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 Contoocook River Dam

Where does the data for Contoocook River 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 Significant 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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