# Central Valley Groundwater Map and Forecast: release 2026-09.11a01267

Readings through 2026-09. Forecast 2026-10 to 2028-09 (months 1-24, the tested range). Built 2026-10-22 10:35.
Licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Input data keeps its own terms (DWR, PRISM, OpenET, NASA MODIS, USGS, USDA NASS CDL, CDEC, Reclamation).

## 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

## Files

- `wells_forecast_outlook.csv`, `wells_forecast_normal.csv`: one row per map well, one column per forecast month, ft below ground. Outlook = NOAA outlook: CPC issue 2026-10, water year 2027, central run at 121.9 % of normal precipitation. Normal = 100 % of normal precipitation. Header lines (#) explain the flags.
- `wells_forecast.parquet`: the same two tables in long format (site_code, scenario, month, depth_ft).
- `wells.geojson`: the wells as points with their attributes and the forecasts at months 12 and 24.
- `surface_now.tif`: the kriged depth surface at the latest readings. `surface_outlook.tif`, `surface_normal.tif`: one band per forecast month. `surface_normal_low.tif`: a normal year's deepest month. GeoTIFF, EPSG:4326, ft below ground, NaN outside the forecast area.
- `gsa_summary.csv`, `subbasin_summary.csv`: the kriged average now and a year ago, the forecasts, RMS wells below their MT and the plan rule (GSAs).
- `release.json`: the release's metadata, its model's test results and file hashes. `SHA256SUMS`: checksums.

## The model

A statistical model trained on DWR monitoring-well readings: a graph neural network blended with gradient-boosted trees. No pumping input. Months 1-12 are tested on held-out years; months 13-24 on year 2 of three held-out periods. A kriged cell is about 5.7 by 4.4 km; it is the area's level, not a well's. Test results for this release are in release.json (`model`).