(SIMULATED CONDITIONS AND OPERATIONS:) Natural flow in the river has continued to rise, due to the arrival today of the North Branch reservoir release, and flow at Little Falls is currently at 263 cfs (170 MGD). Because of the improvement in flow conditions, Washington Aqueduct will be shifting a portion of its withdrawal back to its Great Falls intake this afternoon.
The National Weather Service estimates that 0.25 to 2.0 inches of rain fell in some areas in the western portion of the basin this morning. Operational recommendations have changed from this morning's email.
THE FLOWS, DEMANDS, AND DISCHARGES REPORTED BELOW REFLECT ACTUAL CONDITIONS:
The National Weather Service estimates that 1 to 2 inches of rain fell in some areas in the western portion of the basin this morning, and it predicts that the western portion of the basin will receive up to 1/2 inch of additional rain over the coming 24 hours.
An ACTUAL release from Little Seneca Reservoir of 125 MGD was initiated today at approximately 11 AM. The duration of the release will be 12 hours.
THE FLOWS, DEMANDS, AND DISCHARGES REPORTED BELOW REFLECT ACTUAL CONDITIONS:
There are no significant changes in this afternoon's weather and flow forecasts, and operational recommendations remain the same as reported in this morning's email.
Daily Flows:
Little Falls gage flow 08/21: 1670 MGD (2580 cfs)
Little Falls gage flow 08/22: 1620 MGD (est., based on most recently available real time data) (2500 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 08/21: 1740 MGD (2690 cfs)
Point of Rocks flow 08/22: 1860 MGD (est., based on recently available real time data) (2880 cfs)
The weather and flow forecasts and operational recommendations remain the same as reported in this morning's email.
Daily Flows:
Little Falls gage flow 08/20: 1820 MGD (2820 cfs)
Little Falls gage flow 08/21: 1680 MGD (est., based on most recently available real time data) (2600 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 08/20: 2080 MGD (3220 cfs)
Point of Rocks flow 08/21: 2040 MGD (est., based on recently available real time data) (3160 cfs)
Due to a combination of the recent rainfall and yesterday's USGS rating curve revision, flow at Point of Rocks is now at 3,270 cfs (2,114 MGD). The Little Falls gage is currently showing 2,900 cfs (1,875 MGD). Over the last 24 hours the majority of the basin received between 0.25 and 1.25 inches of rain. A few isolated areas received up to 1.75 inches of rain. We are, therefore, discontinuing daily monitoring. Thank you for continuing to participate in the basin's cooperative drought operations efforts.
Trace amounts of rain fell in a localized area near Goose and Seneca creeks yesterday. There was no other precipitation in the basin. The MARFC 72-hour and 5-day forecasts indicate a chance of rain across the entire basin. Predicted amounts range from trace to one inch.
Some precipitation fell in the basin yesterday, though still mainly in the eastern portion. These areas received trace amounts to a quarter of an inch of rain. The Middle Atlantic River Forecast Center's 72-hour and five-day forecasts show a chance of 0.5 to 1 inch of rain across most of the Potomac basin is possible.
Flow at Point of Rocks has been below 2,000 cfs for a couple of days. Some precipitation fell in the basin yesterday, though mainly in the eastern portion. These areas received trace amounts to one inch of rain. The Middle Atlantic River Forecast Center's 72-hour forecast shows a chance of 0.1 to 0.25 inches of rain. The five-day forecast shows between 0.25 and 0.75 inches is possible.
This concludes CO-OP's 2012 Drought Exercise. We'd like to thank everyone who contributed their time and effort to make the exercise possible. We especially thank staff from Fairfax Water, Loudoun Water, Washington Aqueduct, and WSSC, who sent us data every day, including weekends, and responded to our frequent telephone calls about simulated changes in operations. We'd like to thank the Corps' Baltimore District Office staff for taking our call each morning on simulated North Branch reservoir releases, and for preparing a table of simulated Jennings Randolph and Savage storages.