1 Water Supply Conditions Update
Steven R. Ritchie
Assistant General Manager, Water
May 4, 2026
May 4, 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 355,400 360,360 4,960 98.6% 70.0%
Cherry 261,800 273,345 11,545 95.8% -
Eleanor 25,570 27,100 1,530 94.4% -
Water Bank 570,000 570,000 0 100.0% 96.2%
Total Tuolumne Storage 1,212,770 1,230,805 18,035 98.5% - Local System
Calaveras 60,021 96,670 36,649 62.1% -
San Antonio 44,708 53,266 8,558 83.9% -
Crystal Springs 46,280 68,953 22,673 67.1% -
San Andreas 15,909 18,675 2,766 85.2% -
Pilarcitos 1,953 3,125 1,172 62.5% -
Total Local Storage 168,871 240,689 71,818 70.2% -
Total System Storage 1,381,641 1,471,494 89,853 93.9% 82.0% Total without water bank 811,641 901,494 89,853 90.0% -
Other
California
Reservoirs
3 California Drought Monitor
4 Hetch Hetchy Precipitation
5 Upcountry 6-station Precipitation Index as of
May 3, 2026
12-Month Median Total: 30.92 inches
Current Year Total: 29.71 inches
6 Annual Comparison:
Bay Area 7-station Precipitation Index
as of May 3, 2026
12-Month Median Total: 23.35 inches
Current Year Total: 25.53 inches
7 Annual Comparison:
Upcountry Snowpack
8 Water Available to the City
9 10
California Precipitation Forecast
11 Upcountry Precipitation Forecast
Total Deliveries
12