DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Wednesday 10/05/2020) - DROUGHT EXERCISE
Yesterday's basin-wide average precipitation (above Little Falls):
0 inches
(based on CO-OP's Low Flow Forecast System analysis of MARFC gridded quantitative precipitation estimates)
Daily Flows (simulated):
Little Falls gage flow 10/04: 5260 MGD (8140 cfs)
Point of Rocks gage flow 10/04: 4740 MGD (7340 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Little Falls gage flow 10/05: 4710 MGD (7280 cfs)
Point of Rocks gage flow 10/05: 3790 MGD (5870 cfs)
Today's estimated demand (10/05/20) P.M.:
WSSC P.M. estimated demand: 164 MGD
FW P.M. estimated demand: 160 MGD
Aqueduct P.M. estimated demand: 145 MGD
Total P.M. estimated demand: 469 MGD
Tomorrow's estimated demand (10/06/20):
WSSC estimated demand: 164 MGD
FW estimated demand: 150 MGD
Aqueduct estimated demand: 145 MGD
Total estimated demand: 459 MGD
Loudoun Water Broad Run Discharge:
Today's (10/05/20 A.M.): 9 MGD
Tomorrow's (10/06/20) : 9 MGD
Loudoun Water demand:
Today's (04/24/04 A.M.): 11 MGD
Tomorrow's (04/25/04) : 11 MGD
SIMULATED - Recommended operations for today (10/05/20):
No operational changes are recommended for this afternoon.
NOTE - The table below contains corrected values for reservoir storage.
Reservoirs - Usable storage as of this morning (BG) - Simulated (Note: We assume Brighton Dam rehabilitation has reduced Patuxent capacity by 4 BG.)
Facility %Full Current Reported Capacity*
WSSC’s Patuxent reservoirs: 77% 7.83 10.20
Fairfax Water’s Occoquan reservoir: 100% 8.05 8.05
Little Seneca Reservoir: 99% 3.87 3.90
Jennings Randolph Total Reservoir: 73% 21.29 29.30
Jennings Randolph water supply**: 100% 13.10 13.10
Jennings Randolph water quality**: 50% 8.19 16.30
Savage Reservoir: 59% 3.71 6.30
*Storage and capacities for Occoquan, Patuxent and Little Seneca reservoirs are provided by Washington metropolitan area water utilities, and based on best available information. Storage and capacities for Jennings Randolph and Savage reservoirs are based on observed water levels and available US ACE water level/storage tables from 1998. ICPRB estimates that sedimentation has resulted in a loss of total available storage in Jennings Randolph Reservoir of 1.6 BG in recent years, and this loss is not reflected in the numbers above.
** ICPRB's initial estimate. Final accounting of Jennings Randolph water supply versus water quality storage will be provided at a later date by the US ACE.