Hemlock Lake Dam dam
Hemlock Lake Dam
Hemlock Lake Dam, located in Andover, New Jersey, is a privately-owned earth dam built in 1951 primarily for recreation purposes. The dam stands at a height of 20 feet and stretches 250 feet in length, with a storage capacity of 22 acre-feet. Situated on the Pequest River-TR, the dam serves as a vital water resource for the surrounding area and covers a surface area of 10 acres, with a drainage area of 0.6 square miles.
Despite its significant hazard potential and poor condition assessment, Hemlock Lake Dam is regulated and inspected by the New Jersey Department of Environmental Protection (NJDEP) to ensure public safety and environmental compliance. The dam has a history of periodic inspections, with the most recent assessment conducted in December 2020. Although the dam lacks an Emergency Action Plan (EAP) meeting guidelines and updated emergency contacts, it remains a crucial structure for water management in the region.
Water resource and climate enthusiasts will find Hemlock Lake Dam to be a fascinating example of human intervention in water infrastructure for recreational purposes. As a privately-owned earth dam with a historical significance dating back to the mid-20th century, the dam's condition and regulatory oversight provide valuable insights into the challenges and responsibilities associated with managing water resources in a changing climate. The dam's location on the Pequest River-TR adds to its importance in the local ecosystem, making it a focal point for discussions on water conservation and disaster preparedness.
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 Hemlock Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Pequest River At Huntsville Nj | 15 cfs | → |
| Musconetcong River At Outlet Of Lake Hopatcong Nj | 14 cfs | → |
| Eb Paulins Kill Near Lafayette Nj | 11 cfs | → |
| Green Pd Bk Bl Picatinny Lk At Picatinny Ars Nj | 2 cfs | → |
| Green Pond Brook At Picatinny Arsenal Nj | 2 cfs | → |
| Paulins Kill At Blairstown Nj | 58 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Hemlock Lake Dam.
Boat launches
- Jefferson Lake Road Sussex County
- Dell Avenue 9, Netcong
- West Shore Drive Stillwater Township
- Mcdade Recreational Trail Delaware
- Poxono Access Area In Nj
- Kittatinny Access Area
Track Hemlock 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 Hemlock Lake Dam
Where does the data for Hemlock 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 Hemlock Lake Dam.