Dam Report

Webster Lake Dam dam

New Hampshire, USA Chance Pond Brook Hazard High
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Tonight low
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Dam height
14ft
Hazard rating
High
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Webster Lake Dam -- None dam
Webster Lake Dam None · Chance Pond Brook
About this dam

Webster Lake Dam

Webster Lake Dam, located in Franklin, New Hampshire, is a concrete buttress dam completed in 1873 with a primary purpose of recreation. Standing at a height of 14 feet and a length of 133 feet, the dam has a storage capacity of 2650 acre-feet and serves as a vital component for managing water resources in the area. The dam regulates Chance Pond Brook and has a spillway width of 99 feet to control maximum discharge levels.

Despite being classified with a high hazard potential, Webster Lake Dam is currently rated in fair condition, with the last inspection conducted in May 2020. The New Hampshire Department of Environmental Services Dam Bureau oversees the regulation, permitting, inspection, and enforcement of the dam, ensuring its safety and compliance with state standards. With a moderate risk assessment rating of 3, the dam is equipped with emergency action plans and protocols to mitigate any potential risks and ensure public safety. Water resource and climate enthusiasts can appreciate the historical significance and functional importance of Webster Lake Dam in managing water levels and providing recreational opportunities in the Merrimack region of New Hampshire.

StateNone
River / streamChance Pond Brook
NID IDNH00410
Owner typeState
Primary purposeRecreation
Dam typeConcrete
Year built1873
Dam height14 ft
Dam length133 ft
Max storage2,650 AF
Normal storage1,100 AF
Surface area612.0 ac
Drainage area19.0 sq mi
Hazard potentialHigh
ConditionFair
Last inspectionMon, 11 May 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 Webster Lake Dam -- inflows here typically show up in storage 24-72 hours later.

Track Webster 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 Webster Lake Dam

Where does the data for Webster 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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