1 Water Supply Conditions Update
Steven R. Ritchie
Assistant General Manager, Water
May 18, 2026
May 18, 2026 Reservoir Storage
2 Reservoir
Current
Storage1,2,3
Maximum
Storage4
Available
Capacity
Percent of
Maximum
Storage
Normal
Percent of
Maximum
Storage5
(AF) (AF) (AF)
Tuolumne System
Hetch Hetchy 360,900 360,360 0 100.0% 76.4%
Cherry 267,400 273,345 5,945 97.8% -
Eleanor 26,710 27,100 390 98.6% -
Water Bank 570,000 570,000 0 100.0% 94.3%
Total Tuolumne Storage 1,225,010 1,230,805 6,335 99.5% - Local System
Calaveras 58,433 96,670 38,237 60.4% -
San Antonio 44,694 53,266 8,572 83.9% -
Crystal Springs 46,469 68,953 22,484 67.4% -
San Andreas 15,998 18,675 2,677 85.7% -
Pilarcitos 1,940 3,125 1,185 62.1% -
Total Local Storage 167,534 240,689 73,155 69.6% -
Total System Storage 1,392,544 1,471,494 79,490 94.6% 83.4% Total without water bank 822,544 901,494 79,490 91.2% - Other
California
Reservoirs
3 California Drought Monitor
4 Hetch Hetchy Precipitation
5 Upcountry 6-station Precipitation Index as of
May 17, 2026
12-Month Median Total: 30.92 inches
Current Year Total: 30.17 inches
6 Annual Comparison:
Bay Area 7-station Precipitation Index
as of May 17, 2026
12-Month Median Total: 23.35 inches
Current Year Total: 25.59 inches
7 Annual Comparison:
Upcountry Snowpack
8 Water Available to the City
9 California
Precipitation
Forecast
10 Total Deliveries
11