Afternoon Potomac flow and demand update (Friday 09/10/2010)

Submitted by admin1 on Fri, 09/10/2010 - 14:00

The Jennings Randolph water supply release, which started at 8:30 AM today (September 10), is currently visible at the USGS stream gage in Luke, MD. The USGS did a rating curve adjustment that resulted in an increase of 71 MGD (110 cfs) at Point of Rocks from this morning's reading. We are watching for the arrival of the Little Seneca release at Little Falls. Past tests have indicated that the time of travel is approximately 29 hours, which would imply the arrival to be at 1:00 PM.

The 24-hour observed precipitation shows that up to 0.1 of an inch fell on a small portion of the basin. The 48-hour forecast still shows that there is a 50% chance of up to 0.25 of an inch of precipitation to occur between Saturday and Sunday.

Daily Flows:
Little Falls gage flow 09/09: 260 MGD (410 cfs)
Little Falls gage flow 09/10: 280 MGD (est., based on most recently available real time data) (431 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 09/09: 690 MGD (1070 cfs)
Point of Rocks flow 09/10: 690 MGD (est., based on recently available real time data) (1070 cfs)

Today's estimated demand (09/10/10) P.M.:
WSSC P.M. estimated demand: 210 MGD
FW P.M. estimated demand: 205 MGD
Aqueduct P.M. estimated demand: 175 MGD
Total P.M. estimated demand: 590 MGD

Tomorrow's estimated demand (09/11/10):
WSSC estimated demand: 205 MGD
FW estimated demand: 205 MGD
Aqueduct estimated demand: 160 MGD
Total estimated demand: 570 MGD

Recommended operations for today (09/10/10):

Fairfax Water:
Begin preparing for a load shift to Occoquan Reservoir.

WSSC:
Keep Potomac withdrawals as steady as possible.

Seneca (release date, time, amount in MGD):
No new releases are currently scheduled.

Aqueduct:
Great Falls withdrawal target: per operational preference.
After the arrival of the Little Seneca test release at Little Falls, we will request that Little Falls pumping shift from approximately 65 MGD to 125 MGD.

Information on the release provided by the Baltimore COE appears in the table below:
Date: JR water quality: JR water supply: Savage: Total:
Sept. 10 95 cfs 274 cfs 55 cfs 435 cfs

Tags
PM Report
Enhanced Operations