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The Acre-Foot, Explained
The unit every Western reservoir is measured in — with live numbers.
- One acre-foot is the volume that covers one acre of land one foot deep: 43,560 cubic feet, about 325,851 US gallons, or about 1,233 cubic meters.
- Lake Mead currently holds 7,072,990 acre-feet (as of ) — 24 times Nevada's normal 300,000 acre-foot annual Colorado River apportionment.
Conversions
| 1 acre-foot equals | Value |
|---|---|
| Cubic feet | 43,560 |
| US gallons | 325,851 |
| Cubic meters | ≈ 1,233.5 |
| Million gallons | ≈ 0.326 |
Reservoir storage and water rights across the Western US are measured in acre-feet (AF); large reservoirs in millions of acre-feet (MAF). 1 MAF = 1,000,000 AF. Annual Lower Basin Colorado River apportionments are 2.8 MAF for Arizona, 4.4 MAF for California, and 0.3 MAF for Nevada under normal conditions (reduced under shortage tiers).
Live examples from this site
As of : Lake Mead holds 7,072,990 AF (7.07 MAF) — 27.1% of its 26,120,000 AF capacity basis. The seven tracked Colorado River system reservoirs combined: see the system page. Every reservoir page on this site shows storage in AF next to elevation in feet.