Water Supply Forecasts
Here you can find the latest water supply forecasts from the exclusive DHSVM-WSF framework.
Archived 2024 forecasts: LINK
Forecasts are organized by state, watershed, and forecast point (click headers to sort by column). The 50% exceedance level indicates that there should be an equal chance that the actual runoff volume will be above or below the forecast value, and in general across many years and watersheds, there should be roughly a 20% chance that the total runoff will be outside of the 90-10% exceedance range.
The following forecasts are EXPERIMENTAL, provided “as is,” and available for informational purposes only, with no warranty express or implied. Mountain Hydrology LLC explicitly disclaims any liability associated with or arising from use of these data and explicitly disclaims any implied warranty of accuracy, validity, fitness for a particular purpose, non-infringement, or merchantability. Using or referencing the following data in any manner indicates your acknowledgement of these terms and your sole assumption of the entire risk associated with experimental data.
Mountain Hydrology LLC hereby releases the following table under CC-BY 4.0.
| State | Watershed | Forecast Point | Forecast Period | Issue Date | 90% Exceedance | 50% Exceedance | 10% Exceedance |
|---|---|---|---|---|---|---|---|
| CA | Yuba River | YRS (B120) | March - July | March 3, 2025 | 906 TAF | 1,303 TAF | 1,899 TAF |
| CA | Yuba River | YRS (B120) | April - July | March 3, 2025 | 526 TAF | 780 TAF | 1,204 TAF |
| CA | Tuolumne River | Hetch Hetchy | March - July | March 3, 2025 | 413 TAF | 526 TAF | 670 TAF |
| CA | Tuolumne River | Hetch Hetchy | April - July | March 3, 2025 | 375 TAF | 479 TAF | 612 TAF |
| CA | San Joaquin River | SBF (B120) | March - July | March 3, 2025 | 844 TAF | 1,077 TAF | 1,415 TAF |
| CA | San Joaquin River | SBF (B120) | April - July | March 3, 2025 | 663 TAF | 864 TAF | 1,169 TAF |
| CA | Yuba River | YRS (B120) | March - July | February 16, 2025 | 805 TAF | 1,265 TAF | 1,991 TAF |
| CA | Yuba River | YRS (B120) | April - July | February 16, 2025 | 461 TAF | 721 TAF | 1,239 TAF |
| CA | Tuolumne River | Hetch Hetchy | March - July | February 16, 2025 | 371 TAF | 512 TAF | 728 TAF |
| CA | Tuolumne River | Hetch Hetchy | April - July | February 16, 2025 | 328 TAF | 456 TAF | 655 TAF |
| CA | San Joaquin River | SBF (B120) | March - July | February 16, 2025 | 759 TAF | 1,080 TAF | 1,584 TAF |
| CA | San Joaquin River | SBF (B120) | April - July | February 16, 2025 | 579 TAF | 852 TAF | 1,290 TAF |
Probabilistic exceedance levels are just one output from DHSVM-WSF. Daily ensemble streamflow traces for each forecast point are provided as CSV files to interested parties on request or in real-time by previous arrangement. Maps of snow, soil moisture, water table depth, evapotranspiration, and many other variables can be provided on request. Written setup, calibration, validation, and forecast reports are similarly provided to contracted customers. To learn more, please contact eli.boardman@mountainhydrology.com.