Antrim Sewage Lagoons dam
Antrim Sewage Lagoons
The Antrim Sewage Lagoons in Hillsborough, New Hampshire, are owned and regulated by the local government and fall under the jurisdiction of the NHDES Dam Bureau. Completed in 1978, these earth dams serve a primary purpose of wastewater management and have a storage capacity of 19.4 million gallons. The lagoons cover a surface area of 2.63 acres and have a maximum dam height of 13 feet.
Despite being classified as having a significant hazard potential, the Antrim Sewage Lagoons are in satisfactory condition as of the last assessment in July 2016. Regular inspections are conducted, with the most recent one in April 2020, and the facility meets state permitting and inspection requirements. While the lagoons do not have a spillway, they are designed to effectively manage wastewater and mitigate any potential risks associated with their operation.
Water resource and climate enthusiasts interested in the intersection of infrastructure and environmental impact would find the Antrim Sewage Lagoons an intriguing case study. With a high risk assessment rating and a history dating back to the late 1970s, this facility showcases the importance of proper maintenance and regulatory oversight in managing water resources effectively.
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.
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.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
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.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Antrim Sewage Lagoons -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| North Branch River Near Antrim | 61 cfs | → |
| Contoocook River Near Henniker | 782 cfs | → |
| Nubanusit Bk Blw Macdowell Dam Nr Peterborough Nh | 31 cfs | → |
| Contoocook River At Peterborough | 118 cfs | → |
| Piscataquog River Bl Everett Dam | 8 cfs | → |
| Contoocook R Bl Hopkinton Dam At W Hopkinton | 1,080 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Antrim Sewage Lagoons.
Boat launches
- Gregg Lake Boat Launch
- Norway Pond Boat Launch
- Contoocook River (Powder Mill Pond) Boat Launch
- Franklin Pierce Lake Boat Launch
- Nubanusit Lake Boat Launch
- Zephyr Lake Boat Launch
Campgrounds
- Fox Brook Tent Site
- Camp Wanocksett
- Mt Monadnock State Park Campground
- Mile-Away Campground
- Wheelock Park Campground
- Camp Spaulding
Paddle runs
- Sewall's Island To Manchester Street Bridge
- Begins In Franklin To Sewall's Island
- First Bridge Upstream On Route 100 To Confluence With West River
- Headwaters To First Bridge Upstream On Route 100
- Headwaters To Confluence With West River (End Of Sherman Road)
- Headwaters To Crossing Of Route 100 Near Route 155
Track Antrim Sewage Lagoons 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.
About Antrim Sewage Lagoons
Where does the data for Antrim Sewage Lagoons 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Antrim Sewage Lagoons.