Manahawkin Lake Dam dam
Manahawkin Lake Dam
Manahawkin Lake Dam, located in Manahawkin, New Jersey, is a crucial structure managed by the local government for recreational purposes. Completed in 1929, this Earth dam stands at a height of 12 feet and spans a length of 900 feet, holding a storage capacity of 127 acre-feet. The dam is situated on Mill Creek, within Ocean County, New Jersey, and is regulated by the state agency NJDEP, with regular inspections conducted to ensure its safety and compliance with state regulations.
Despite its historical significance and recreational value, Manahawkin Lake Dam has been assessed to be in poor condition with a significant hazard potential. The last inspection in September 2021 revealed the dam's vulnerability, prompting the need for risk management measures and the preparation of an Emergency Action Plan (EAP). With a drainage area of 19.7 square miles and a surface area of 54 acres, any failure of the dam could lead to severe consequences, underscoring the importance of regular maintenance and monitoring to safeguard the surrounding community.
As a focal point of the Stafford Township, Manahawkin Lake Dam serves not only as a recreational spot but also as a critical infrastructure in need of attention and mitigation strategies to address its current condition. With the collaboration of state agencies and local authorities, efforts are underway to ensure the long-term safety and resilience of this dam, balancing the need for recreation with the imperative of public safety in the face of potential climate-related challenges.
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 Manahawkin Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Westecunk Creek At Stafford Forge Nj | 18 cfs | → |
| East Branch Bass River Near New Gretna Nj | 7 cfs | → |
| Cedar Creek At Lanoka Harbor Nj | 73 cfs | → |
| Oswego River At Harrisville Nj | 26 cfs | → |
| West Branch Wading River Near Jenkins Nj | 17 cfs | → |
| Mcdonalds Branch In Lebanon State Forest Nj | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Manahawkin Lake Dam.
Boat launches
- Shore Avenue Ship Bottom
- West 75th Street 99, Harvey Cedars
- West 81st Street 99, Harvey Cedars
- North Shore (Blue) Trail Burlington County
- Lake Trail Burlington County
- Scotts Landing Road 1099, Galloway Township
Track Manahawkin 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.
About Manahawkin Lake Dam
Where does the data for Manahawkin 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 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 Manahawkin Lake Dam.