Grant Lake dam
Grant Lake
Grant Lake, located in Lee Vining, California, is a key water supply resource managed by the local government. Built in 1940, this Earth-type dam stands at a height of 87 feet and has a capacity of 47,525 acre-feet. With a surface area of 1,095 acres and a drainage area of 60 square miles, Grant Lake plays a crucial role in providing water for the region.
Managed by the Department of Water Resources and regulated by the Safety of Dams agency, Grant Lake boasts a high hazard potential but is currently in satisfactory condition. Despite its age, the dam undergoes regular inspections and has a designated emergency action plan in place. With Rush Creek as its primary source, Grant Lake serves as a vital water resource for the surrounding area, supporting various water supply purposes.
The dam's location within Mono County, California, highlights its importance in water management and climate resilience efforts. With a history dating back to the early 20th century, Grant Lake continues to play a crucial role in water supply and regulation, ensuring the safety and sustainability of the region's water resources in the face of changing climate conditions.
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 Grant Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Deadman C A Big Springs Nr Crestview Ca | 33 cfs | → |
| Mf San Joaquin R Nr Mammoth Lakes Ca | 350 cfs | → |
| Hot C A Flume Nr Mammoth Lakes Ca | 60 cfs | → |
| Green Creek Near Bridgeport | 47 cfs | → |
| Robinson C At Twin Lks Outlet Nr Bridgeport | 115 cfs | → |
| Merced R A Happy Isles Bridge Nr Yosemite Ca | 848 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grant Lake.
Boat launches
Campgrounds
- Grant Lake Campground
- Aerie Crag Rv Camp
- Aerie Crag Picnic Area
- Oh Ridge
- Oh! Ridge Campground
- Lower Lee Vining
Fishing spots
Paddle runs
- Headwaters To Wilderness Boundary
- Headwaters To Walker Lake
- Sce Powerhouse To La Dept. Of Water And Power Diversion
- Saddlebag Lake Rna Boundary To State Highway 120
- Confluence With Glass Creek To Big Springs
- Headwaters Tributaries To Research Natural Area Boundary
More reservoirs
Track Grant Lake 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 Grant Lake
Where does the data for Grant Lake 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Grant Lake.