About & Methodology
Every number traceable to an official government gauge.
What this site is
Reservoir Bench republishes the official daily record for nine major Western US reservoirs in one fast, citable place: current surface elevation, storage, percent full, and recent changes, with full daily history downloadable as CSV. It is built for people who want the number and its source, not commentary.
Sources and update cadence
Colorado River system reservoirs (Lake Mead, Lake Powell, Lake Mohave, Lake Havasu, Flaming Gorge, Blue Mesa, Navajo): the Bureau of Reclamation RISE API daily elevation and storage result series. California reservoirs (Shasta, Oroville): the California DWR CDEC JSON data service, daily elevation (sensor 6) and storage (sensor 15). The site rebuilds daily; each page shows the as-of date of its newest reading. Reclamation and DWR occasionally revise recent values, and those revisions flow through at the next rebuild.
Percent-full methodology
Percent full = latest storage ÷ a fixed published capacity. Capacity figures are taken from the government operations reports listed below — the same bases Reclamation and DWR use in their own daily reporting (for Lake Mead, 26,120,000 acre-feet at elevation 1,219.6 ft, the bottom of the exclusive flood-control space). Agencies also publish other capacity figures (total capacity including flood-control and dead storage, or live-storage bases in narrative reports), so percentages you see elsewhere may differ by a few points.
| Reservoir | Gauge series | Capacity basis (AF) | Capacity source |
|---|---|---|---|
| Lake Mead | USBR RISE items 6123 (elevation) / 6124 (storage) | 26,120,000 | USBR Lower Colorado River Daily Report |
| Lake Powell | USBR RISE items 508 (elevation) / 509 (storage) | 23,314,000 | USBR Lower Colorado River Daily Report |
| Lake Mohave | USBR RISE items 6133 (elevation) / 6134 (storage) | 1,873,648 | USBR Lower Colorado River Daily Report |
| Lake Havasu | USBR RISE items 6128 (elevation) / 6129 (storage) | 570,253 | USBR Lower Colorado River Daily Report |
| Flaming Gorge Reservoir | USBR RISE items 341 (elevation) / 337 (storage) | 3,749,000 | USBR Lower Colorado River Daily Report |
| Blue Mesa Reservoir | USBR RISE items 78 (elevation) / 76 (storage) | 827,472 | USBR Lower Colorado River Daily Report |
| Navajo Reservoir | USBR RISE items 612 (elevation) / 613 (storage) | 1,696,000 | USBR Lower Colorado River Daily Report |
| Shasta Lake | CDEC SHA sensors 6 (elevation) / 15 (storage) | 4,552,000 | CDEC daily reservoir storage summary |
| Lake Oroville | CDEC ORO sensors 6 (elevation) / 15 (storage) | 3,424,753 | CDEC daily reservoir storage summary |
What this site does not do
No forecasts, no predictions, no water-supply or investment advice, and no invented statistics. If a value is missing from the source record it renders as "—", never as zero. Explanatory pages (shortage tiers, post-2026 process) cite the governing USBR documents directly.
Citing this site
All underlying data is US-government public domain. You are welcome to cite or quote any page with attribution and a link to reservoirbench.com. Contact: contact@reservoirbench.com.