Release 2026-09.11a01267
Readings through Sep 2026. Forecasts Oct 2026 to Sep 2028. Built 2026-10-22 10:35.
A newer release exists: 2026-09.5cdfad9c.
Outlook scenario: NOAA CPC issue 2026-10, water year 2027, 121.9 % of normal precipitation.
| File | What it holds | Size |
|---|---|---|
| wells_forecast_outlook.csv | Every map well, one column per month, under NOAA's outlook. ft below ground. | 2.2 MB |
| wells_forecast_normal.csv | The same under a normal year (100 % of normal precipitation). | 2.2 MB |
| wells_forecast.parquet | Both tables in long format. | 1.4 MB |
| wells.geojson | Wells as points: attributes and the forecasts at months 12 and 24. | 3.6 MB |
| surface_now.tif | Kriged depth surface at the latest readings. GeoTIFF, EPSG:4326. | 7 KB |
| surface_outlook.tif | Forecast surface under NOAA's outlook, one band per month. | 0.1 MB |
| surface_normal.tif | Forecast surface in a normal year, one band per month. | 0.1 MB |
| surface_normal_low.tif | A normal year's deepest month. | 7 KB |
| gsa_summary.csv | Per GSA: average depth now and a year ago, forecasts, RMS wells below MT, plan rule. | 28 KB |
| subbasin_summary.csv | Per subbasin: average depth now and a year ago, forecasts. | 3 KB |
| README.md | What each file holds. | 2 KB |
| CITATION.cff | Citation metadata. | 289 bytes |
| LICENSE.txt | The licence. | 558 bytes |
Cite
Gray, W. (2026). Central Valley Groundwater Map and Forecast, release 2026-09.11a01267 (readings through Sep 2026) [Data set]. CC BY 4.0. https://groundwater-map-175591637760.us-west1.run.app/release/2026-09.11a01267
Licence: CC BY 4.0 (cite Gray, W.). Share and adapt for any purpose with credit. Input data keeps its own terms:
- Groundwater levels: California DWR, Periodic Groundwater Level Measurements (data.cnra.ca.gov, public domain); USGS CVHM2 observations
- Precipitation and temperature: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed monthly
- Evapotranspiration: OpenET ensemble v2.1 (https://etdata.org), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); sampled at the wells
- Vegetation (NDVI): NASA MODIS MOD13A2 v061 (Didan, K., doi:10.5067/MODIS/MOD13A2.061), via NASA AppEEARS
- Crop cover: USDA NASS Cropland Data Layer
- River flows: USGS NWIS. Project flows and water-year indices: California DWR CDEC. Allocations: U.S. Bureau of Reclamation (CVP) and California DWR (SWP)
- GSA boundaries (i03) and groundwater basins (i08 Bulletin 118, critically overdrafted basins): California DWR, data.cnra.ca.gov, Creative Commons Attribution (http://www.opendefinition.org/licenses/cc-by)
- Ground elevation: USGS 3DEP 1/3 arc-second DEM and DWR surveyed station elevations. Data available from U.S. Geological Survey, National Geospatial Program. Recharge soils: Soil Survey Staff (2020). Gridded National Soil Survey Geographic (gNATSGO) Database for the Conterminous United States. USDA Natural Resources Conservation Service. https://nrcs.app.box.com/v/soils. Canals: (c) OpenStreetMap contributors (ODbL)
- NOAA outlook scenario: NOAA Climate Prediction Center long-lead outlooks. Disadvantaged communities: California DWR i16 (2023), CC BY. Domestic wells: DWR Well Completion Reports; dry wells: DWR Dry Well Reporting System
The model at this release
Typical error at a well on held-out quiet years: 4.8 ft at 1 month, 6.2 at 6, 7.0 at 12. Full results in release.json.