South Lake Reservoir
South Lake Reservoir
South Lake Reservoir is a man-made lake located in the Sierra Nevada mountains in California. It was built in the early 1900s to provide water to the city of Los Angeles. The lake is fed by South Fork Bishop Creek and several smaller tributaries, as well as snowmelt from the surrounding mountains. The water is then transported through a series of aqueducts and pipelines to the city. The reservoir also serves as a source of irrigation for nearby farmland and supports recreational activities such as fishing, boating, and camping. The lake's water level is heavily influenced by the snowpack in the surrounding mountains, which typically reaches its peak in April and May. In recent years, the lake has suffered from drought conditions, leading to concerns about its long-term sustainability.
Inside the reservoir
The real shoreline of this water body, with a depth model scaled so the basin holds exactly its recorded storage. Drag to orbit, scroll to zoom, and use the slider to drain and refill it. Click anywhere on the basin for the modelled depth there.
How this is built. The shoreline is the National Hydrography
Dataset polygon for this water body (“South Lake”),
matched to the dam by proximity and confirmed by comparing its area with the
National Inventory of Dams surface area.
Depth is modelled, not surveyed: the basin is shaped by distance from
shore — deep in open water, shallow in the bays — and scaled so its
volume equals the recorded storage. No national bathymetric survey exists for
US reservoirs. Treat the shoreline, area and volume as measured, and the depth
distribution as an informed approximation.
Above normal pool, water is shown rising within the normal-pool
shoreline. Where it would actually spread depends on the surrounding
terrain, which is not modelled here — a reservoir in a steep canyon barely
widens, one on flat ground can spread a long way. This is a depth and volume
figure, not an inundation map. Official inundation mapping for a dam
comes from its Emergency Action Plan.
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 South Lake Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Hot C A Flume Nr Mammoth Lakes Ca | 38 cfs | → |
| Marble Fork Kaweah R Ab Horse C Nr Lodgepole Ca | 0 cfs | → |
| Mf San Joaquin R Nr Mammoth Lakes Ca | 21 cfs | → |
| Deadman C A Big Springs Nr Crestview Ca | 19 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near South Lake Reservoir.
Boat launches
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Campgrounds
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Fishing spots
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River runs
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About South Lake Reservoir
Where does the data for South Lake Reservoir come from?
Daily storage, pool elevation, and release rates are sourced from USGS, USBR, and USACE monitoring stations. Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
Storage observations are updated daily by the operating agency. The 15-day weather forecast refreshes throughout the day. Snoflo caches and renders the most recent observation -- check the "as of" timestamp on the storage card.
What does the Hazard 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 below 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 reservoir, set a threshold, and you'll get a push the moment conditions cross.
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