Longley dam
Longley
Longley, also known as McGee Lake, is a privately owned dam located in Bishop, California. Built in 1910, this earth dam stands at a height of 27 feet and serves primarily for hydroelectric power generation and recreation purposes. It has a storage capacity of 178 acre-feet and covers a surface area of 11 acres, with a maximum discharge capacity of 300 cubic feet per second.
Managed by the Federal Energy Regulatory Commission, Longley is regulated and inspected to ensure its safety and compliance with state standards. Despite being classified as having a low hazard potential, the dam is subject to regular inspections and emergency action plans to mitigate any risks. With a moderate risk assessment rating, Longley plays a crucial role in water resource management and climate resilience efforts in the region.
The dam's location on McGee Creek in Inyo County, California, highlights its importance in providing water resources and recreational opportunities for the local community. With a history dating back over a century, Longley stands as a testament to the ingenuity of early hydroelectric infrastructure projects and continues to play a vital role in supporting sustainable water management practices in the area.
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 Longley -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Hot C A Flume Nr Mammoth Lakes Ca | 65 cfs | → |
| Mf San Joaquin R Nr Mammoth Lakes Ca | 579 cfs | → |
| Deadman C A Big Springs Nr Crestview Ca | 37 cfs | → |
| Marble Fork Kaweah R Ab Horse C Nr Lodgepole Ca | 149 cfs | → |
| Nf Willow C Nr Sugar Pine Ca | 416 cfs | → |
| Big C Div Nr Fish Camp Ca | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Longley .
Boat launches
- Florence Lake Campground
- Florence Lake Boating Site
- Lake Edison Boating Site
- Huntington Boat Ramp & Launching Site
Campgrounds
- North Lake Campground
- North Lake
- Bishop Park
- Bishop Park Campground
- Bishop Park Group Campground
- Big Trees Campground
Fishing spots
- Horton Lake
- Desolation Lake
- Lower Desolation Lake
- Little French Lake
- Bishop Creek
- Lower Golden Trout Lake
Paddle runs
- Dam Outlet At South Lake To Habeggers Rv Park
- Headwaters To Inlet At South Lake
- Headwaters To Wilderness Boundary
- Northwest Boundary Of Nf/Kings Canyon Np To Hot Springs Area
- Hot Springs Area To West End Of Blarney River
- Outlet Of Martha Lake (Boundary Extend 0.25 Mile On Each Side Of River) To Northwestern Boundary Of Kings Canyon National Park
Track Longley 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 Longley
Where does the data for Longley 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 Low 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 Longley .