Monitoring Reports

Stream flows in the Potomac basin continue to slowly decline. The National Weather Service (NWS) quantitative prediction forecast indicates that less than 1/10 inch of rain will fall in the basin over the next seven day period.

Daily Flows:
Little Falls gage flow 2017-09-22: 1351 MGD (2090 cfs)
Little Falls gage flow 2017-09-23: 1254 MGD (est., based on recently available real time data) (1940 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

The 7-day forecast calls for dry conditions throughout the Potomac basin. Flows in the river are at typical levels for this time of year.

Daily Flows:
Little Falls gage flow 2017-09-21: 1293 MGD (2000 cfs)
Little Falls gage flow 2017-09-22: 1338 MGD (est., based on recently available real time data) (2070 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Point of Rocks flow 2017-09-21: 1377 MGD (2130 cfs)
Point of Rocks flow 2017-09-22: 1280 MGD (est., based on recently available real time data) (1980 cfs)

Flow at Point of Rocks is currently elevated because of two water quality releases made by the Corps last weekend from Jennings Randolph Reservoir. NWS forecasts indicate that dry conditions will persist for the next week.

Daily Flows:
Little Falls gage flow 2017-09-20: 1260 MGD (1950 cfs)
Little Falls gage flow 2017-09-21: 1254 MGD (est., based on recently available real time data) (1940 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Flow at Point of Rocks is currently at about 2000 cfs, CO-OP's trigger for daily drought monitoring. But the likely cause of this rise in flow is the Corps' AVF release on Saturday, Sep 16th. National Weather Service (NWS) forecasts indicate that dry conditions will continue in the basin for the next 7 days.

Daily Flows:
Little Falls gage flow 2017-09-19: 1267 MGD (1960 cfs)
Little Falls gage flow 2017-09-20: 1280 MGD (est., based on recently available real time data) (1980 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Potomac River flow at Point of Rocks is hovering around 2000 cfs, the trigger for CO-OP daily drought monitoring. It should be noted that flows in the river are not particularly low for this time of year - 2000 cfs is close to the median flow at Point of Rocks in mid-September. The National Weather Service forecast calls for little rain over the next seven days.

This concludes the 2017 Washington Metropolitan Area (WMA) Drought Exercise - thank you for your support of WMA drought preparedness!
Actual daily drought monitoring continues, so suppliers please continue to submit your withdrawal data every morning.

DROUGHT EXERCISE - Afternoon Potomac flow and demand update (Wednesday 8/13/2017) - DROUGHT EXERCISE
NOTE: In our twice daily reports for the 2017 exercise we will be reporting ACTUAL basin flows and system withdrawals, and SIMULATED recommended operations.

Over the past 24 hours, accumulations of rain of up to an inch were recorded in scattered areas, in the northwestern portion of the basin. According to the Middle Atlantic River Forecast Center's quantitative precipitation forecasts, between zero and 1/2 of an inch is expected over the next 72 hours, mainly in the northern portion of the basin.

Little rain fell on the basin over the past 24 hours. According to the Middle Atlantic River Forecast Center's quantitative precipitation forecasts, between zero and 3/4 of an inch of rain is expected throughout the basin over the next 72 hours.

There was no significant rainfall in the basin over the last 24 hours. The National Weather Service predicts basin-wide average accumulations of approximately 1 to 3 inches over the next 2 days and significant rises in flow at the Point of Rocks and Little Falls gages over the next week.

Up to 0.25 inch of rain fell in western portions of the basin over the the past 24 hours. The Middle Atlantic River Forecast Center predicts 0.75 to 2 inches of rain over the next 3 days.