Dam Report

Penacook Lake Dam dam

New Hampshire, USA Rattlesnake Brook Hazard High
Today high
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Tonight low
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Dam height
9ft
Hazard rating
High
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Penacook Lake Dam -- None dam
Penacook Lake Dam None · Rattlesnake Brook
About this dam

Penacook Lake Dam

Penacook Lake Dam, located in Concord, New Hampshire, serves as a vital water supply resource for the region. Completed in 1873, this earth dam stands at 9 feet high and stretches 265 feet in length, with a storage capacity of 2210 acre-feet. The dam regulates the flow of Rattlesnake Brook and has a surface area of 360 acres, providing essential water for the community.

Despite its historical significance, Penacook Lake Dam poses a high hazard potential with a poor condition assessment, highlighting the need for regular inspections and maintenance. The dam is under the jurisdiction of the NHDES DAM BUREAU and is subject to state regulation, permitting, and enforcement. With a moderate risk assessment rating, stakeholders must prioritize risk management measures to ensure the safety and integrity of the dam for sustainable water resource management.

As a key component of the local government's water infrastructure, Penacook Lake Dam requires ongoing attention and investment to address its poor condition and high hazard potential. Climate enthusiasts and water resource advocates should monitor the dam's maintenance efforts and support initiatives to enhance its resilience in the face of changing environmental conditions. The dam's critical role in water supply underscores the importance of proactive risk management to safeguard this essential resource for the community.

StateNone
River / streamRattlesnake Brook
NID IDNH00360
Owner typeLocal Government
Primary purposeWater Supply
Dam typeEarth
Year built1873
Dam height9 ft
Dam length265 ft
Max storage2,210 AF
Normal storage1,515 AF
Surface area360.0 ac
Drainage area3.8 sq mi
Hazard potentialHigh
ConditionPoor
Last inspectionWed, 04 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 Penacook Lake Dam -- inflows here typically show up in storage 24-72 hours later.

Track Penacook 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 Penacook Lake Dam

Where does the data for Penacook 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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