WINTER ACCUMULATION CONTEXT
El Niño / La Niña
NOAA ENSO discussion ↗ENSO shifts seasonal odds. It does not determine Sierra snow totals or spring flooding.
Flood alerts that matter.
Important official Corcoran flood news by email. No routine reports.
Checking your alert preference…
SAWTELLE TIKI CLUB · TULARE BASIN, CALIFORNIA
Winter snow.
Spring water.
Corcoran Flood Watch · Sierra snowpack & spring runoff
LOCAL GROUND.
BIG-PICTURE
perspective.
Esri satellite mosaic · acquisition dates vary · not a current flood imageBIG-PICTURE
perspective.
36° N / 119° W
THE SOUTHERN SAN JOAQUIN VALLEY
THE SOUTHERN SAN JOAQUIN VALLEY
01 THE BASIN02 THE LEVEES03 THE NEIGHBORHOODPUBLIC SOURCES · DATED OBSERVATIONS
Checking the NWS feed…
THE SEASONAL WATER WATCH · SIERRA TO TULARE BASIN
The Sierra. The snowmelt. Next spring.
This watch follows the water stored in Sierra snowpack and the spring runoff it may produce for the Kings, Kaweah and Tule river systems. Reservoir storage, operations, diversions and levees influence how much reaches the Tulare Lake basin—and what that could mean for Corcoran.
Loading dated snowpack and runoff sources…
01 / ACCUMULATESierra snowWinter snowfall stores water in the mountains.
02 / RELEASESpring meltWarming controls the timing and pace of runoff.
03 / ROUTERivers & reservoirsStorage, releases and diversions change the flow downstream.
04 / WATCHTulare BasinLake storage and levee conditions shape local consequences.
THE WATER THAT MAY COME DOWN
Spring runoff, basin by basin.
Checking the seasonal runoff forecast…
Projected April–July runoff compared with the source average for the same season.
Line = average (100%)Shared scale: 0–200% · not today’s river flow
Forecast volumes & uncertainty
| River | Forecast median | Source average | 90%–10% exceedance range |
|---|
Volumes in acre-feet. The percentage compares the median seasonal forecast with the bulletin’s average; it is not a flood probability. The source’s historical averaging period is not specified here.
Monthly outlook chart & data
Dark line: monthly median. Shaded band: 90% to 10% exceedance values from the model ensemble.
| Month | Median volume | 90%–10% exceedance range |
|---|
Read the runoff range correctly
A 90% exceedance value is exceeded by about 90% of model traces; a 10% value is exceeded by about 10%. These are streamflow volumes, not probabilities of flooding. The guidance is raw model output and has not been reviewed by a hydrologist. Monthly medians should not be added to estimate the seasonal median.
A spring-water outlook, not a Corcoran flood-depth forecast. These volumes do not specify reservoir releases or the amount that will enter Tulare Lake. No lake elevation, levee overtopping or property flooding is inferred.
THE WINTER THAT BUILDS THE SNOWPACK
California’s monthly & seasonal outlook.
Green/brown on precipitation maps means wetter/drier category odds, not rainfall amounts or flood probability. EC means equal chances—not a prediction of normal conditions. Temperature and snow levels affect whether winter precipitation is stored as snow. Tap the map for its full-size legend.
01 / A LITTLE BASIN MATH
What if spring sends more water?
SCHEMATIC CROSS-SECTIONNOT A SURVEY OR FLOOD MAP
Water changes with your assumptions. No inundation boundary or levee overtopping is calculated.
250,000acre-feet retained
÷100,000assumed acres
=2.5 ftaverage added depth
02 million acre-feet
These are adjustable examples, not measured starting conditions. Runoff, routing, pumping, evaporation, gates and changing surface area determine actual storage and water levels.
The lakebed is not one flat bowl. Separate storage cells, uneven ground and levees control how water collects. A terrain elevation, a lake water level and a river gauge stage are different measurements.
Explore published lake-cell elevation & storage tables
2024 cell tables hosted by the State Water Board. Separate cells are not the whole lake. These tables do not show today's water level, inundation extent or levee condition.
02 / THE LAY OF THE LAND
From the lakebed to Corcoran.
Pan and zoom; tap a point to query USGS ground elevation. Gold lines: USACE levee alignments. Blue: FEMA high-hazard zones. Purple: mapped 0.2%-annual-chance or levee-related zones. These are not forecast flooding. Open USGS map ↗
Corcoran overview. John Muir is a public school landmark; no residence is identified.
Loading official map layers…
Current flood footprint: not verified. No current Corcoran inundation forecast has been obtained. Snowpack, reservoir observations and runoff guidance do not determine where water will reach. Levee lines show mapped alignments; current heights and condition are unverified.
How to interpret these scenarios
The slider is an assumed absolute water-surface elevation in feet. It is not a lake observation, river-gauge stage, flood probability, inundation model, or evacuation boundary. A simple subtraction cannot account for levees, connectivity, drainage, reservoir releases, or subsidence.
USGS returns terrain elevation, not finished-floor height. The personal estimate has an unverified vertical datum and date. Compare elevations only after confirming compatible vertical datums and a current survey. A positive difference does not establish flood protection.
USGS elevation service · FEMA official flood maps · NOAA National Water Prediction Service
OFFICIAL WARNINGS · SEPARATE FROM THE SEASONAL OUTLOOK
Corcoran flood alerts
Official alerts cover current conditions and remain separate from the spring runoff assessment.
UPSTREAM CONDITIONS
How full are the reservoirs?
Storage is a volume in acre-feet, not a flood elevation at Corcoran. Values are provisional; reservoir operations and routing matter.
SIERRA → RESERVOIRS → VALLEY FLOOR
Where the spring water comes from
Follow the rivers from the foothill reservoirs toward the Tulare Lake bottom. Tap a reservoir to see how full it is.
Mapped river channelsSelected managed channels / bypass
Pine Flat ↓
Kings River → lower Kings branches and canals → lake bottom. The north fork / Fresno Slough route can also carry water toward the San Joaquin.
Lake Kaweah ↓
Kaweah River → distributaries, including St. Johns River and Cross Creek → lower-basin channels toward the lake bottom.
Lake Success ↓
Tule River → valley-floor channels → eastern Tulare Lake bottom.
Lake Isabella ↓
Kern River → Bakersfield and managed channels. In very wet conditions, flood routing can connect north toward Tulare Lake.
The amount reaching the lake depends on releases, diversions, recharge, canals and levees. Reservoir storage is not the amount destined for Corcoran. Only selected channels are shown; gaps do not mean a river ends there. The lake-bottom label is a location, not a shoreline or predicted flood extent.
Loading mapped river channels…
River routes & official sources
Snowmelt supplies the four main river systems. Managed diversions can move water away from the lakebed; for example, DWR used the Kern River Intertie to divert floodwater into the California Aqueduct in 2023. The map does not show current releases or channel capacity.
USGS river geometry ↗Tulare Basin hydrology ↗DWR: Kern flood diversion ↗State Water Board hydrology exhibit ↗Public reservoir locations: CDEC PNF, TRM, SCC and ISB station metadata, checked November 15, 2026. River geometry retrieval date appears above. Existing levee and FEMA layers remain in the Corcoran map.
Water storedUnfilled capacity
Graphics show a share of published reservoir capacity—not verified seasonal flood-control space or a measure of flood safety.
THE RECORD
Weekly dated reports
Each report preserves its generation date and source dates. Missing observations are identified; reports do not assign a flood-risk score.