Steven R. Ritchie
Assistant General Manager, Water
September 18, 2023
Water Supply Conditions Update
September 18, 2023 Reservoir Storage
Storage as of:
Reservoir
Current
Storage1,2,3
Maximum
Storage4
Available
Capacity
Percent of
Maximum
S
torage
Normal
Percent of
M
aximum
Storage5
(AF) (AF) (AF)
Tuolumne System
Hetch Hetchy 351,700 360,360 8,660 97.6% 82.8%
Cherry 250,300 273,345 23,045 91.6% -
Eleanor 25,790 27,100 1,310 95.2% -
Water Bank 570,000 570,000 0 100.0% 99.6%
Total Tuolumne Storage 1,197,790 1,230,805 33,015 97.3% - Local System
Calaveras 90,731 96,670 5,939 93.9% -
San Antonio 51,493 53,266 1,773 96.7% -
Crystal Springs 49,643 68,953 19,310 72.0% -
San Andreas 14,741 18,675 3,934 78.9% -
Pilarcitos 2,722 3,125 403 87.1% -
Total Local Storage 209,330 240,689 31,359 87.0% -
Total System Storage 1,407,120 1,471,494 64,374 95.6% 81.8% Total without water bank 837,120 901,494 64,374 92.9% - 2 Water bank storage reported by HHWP for 09/17/2023
3 Local storage i s the date's 8AM storage val ue taken from USGS data 5The ratio of median storage for this day over maximum storage capacity. Median storage for this day is based on historical storage data from years 1991 - 2020 18-Sep-2023
1 Upcountry storage is the date's 8AM storage value taken from USGS data 4 Hetch Hetchy maximum storage is with drum gates activated. Cherry and Eleanor maximum storage is with flashboards in. All maximum storages taken from rating curve.
Other
California
Reservoirs
California Drought Monitor
Hetch Hetchy Precipitation
5 Upcountry 6-station Precipitation Index as of
September 17, 2023
Avg Annual Total: 36.68 inches
YTD Total: 61.90 inches
Avg Annual Total: 36.68 inches
YTD Total: 61.94 inches
Bay Area 7-station Precipitation Index
as of September 17, 2023
Avg Annual Total: 22.80 inches
YTD Total: 44.32 inches
Avg Annual Total: 22.80 inches
YTD Total: 44.32 inches
Upcountry Snowpack
Water Available to the City
Tuolumne River Water Available
to the City
National
Precipitation
Forecast
Total Deliveries