Lock 4 - Stillwater dam
Lock 4 - Stillwater
Lock 4 - Stillwater, also known as Stillwater Dam, is a concrete gravity dam located in Stillwater, New York. Built in 1955, this dam serves the primary purpose of hydroelectric power generation on the Hudson River. With a height of 5 feet and a length of 820 feet, Lock 4 has a storage capacity of 3,150 acre-feet and a maximum discharge of 200,000 cubic feet per second. It is regulated by the Federal Energy Regulatory Commission and is inspected regularly to ensure its safety and functionality.
The dam features an uncontrolled spillway with a width matching its length, and is equipped with four slide (sluice gate) outlet gates. The hazard potential of Lock 4 is deemed significant, while its risk assessment rates it as moderate. While the condition assessment is not available, emergency action preparedness measures have been put in place, with the last revision of the Emergency Action Plan occurring in January 2021. Lock 4 - Stillwater continues to play a critical role in water resource management and climate resilience efforts in the region, showcasing the importance of sustainable hydroelectric infrastructure for a greener future.
Enthusiasts and experts in water resources and climate will find Lock 4 - Stillwater to be an intriguing subject of study, with its unique design, operational features, and role in renewable energy production. As a key player in the hydroelectric sector, this dam exemplifies the intersection of engineering, environmental stewardship, and regulatory oversight. With its rich history and ongoing maintenance efforts, Lock 4 stands as a testament to the vital importance of responsible water resource management in the face of evolving climate 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 Lock 4 - Stillwater -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Hudson R Above Lock 1 Nr Waterford Ny | 9,390 cfs | → |
| Hudson River At Lock 1 Near Waterford Ny | 8,410 cfs | → |
| Mohawk River At Cohoes Ny | 4,520 cfs | → |
| Hudson River At Green Island Ny | 13,600 cfs | → |
| Hoosic River Near Eagle Bridge Ny | 1,040 cfs | → |
| Glowegee Creek At West Milton Ny | 37 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lock 4 - Stillwater .
Boat launches
- Hudson River Road 951, City Of Mechanicville
- Us 9 Round Lake
- Lock One Road Town Of Halfmoon
- Saratoga Lake State Boat Launch
- Flightlock Road Town Of Waterford
- Outlet Road Town Of Ballston
Campgrounds
- Lake Lauderdale Campground
- Moreau Lake State Park
- Rustic Barn Campground
- Corinth
- Cherry Plain State Park
- Cherry Plain State Park Campgrounds
Track Lock 4 - Stillwater 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 Lock 4 - Stillwater
Where does the data for Lock 4 - Stillwater 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 Lock 4 - Stillwater .