Monitoring Reports

During periods of drought, the Cooperative Water Supply Operations on the Potomac (CO-OP) helps manage the Washington metropolitan area water supply system by coordinating withdrawals from the Potomac River and off-river reservoirs and recommending releases from upstream reservoirs when forecasted flow in the river is not sufficient to meet expected needs. These needs include water demands and an environmental flow-by of 100 million gallons per day (MGD) on the Potomac River at Little Falls dam near Washington, D.C.

Initiation of daily Potomac flow and demand update (Tuesday, 2025-09-02)

Submitted by admin1 on Tue, 09/02/2025 - 12:34

Situational Awareness (Tuesday, 2025-09-02):
CO-OP is initiating daily drought monitoring and reporting today because Potomac River flow at the US Geological Survey’s gage at Point of Rocks, Maryland, has fallen below 2,000 cubic feet per second (cfs), CO-OP's daily monitoring threshold.

Suspending Drought Monitoring - Daily Potomac flow and demand update (Tuesday, 2024-11-19)

Submitted by hmoltz on Tue, 11/19/2024 - 13:56

Situational Awareness (Tuesday, 2024-11-19)
Today, CO-OP is suspending its daily drought monitoring and reporting. This phase of CO-OP’s drought response is triggered when daily Potomac River flow at the USGS’s Point of Rocks gage falls below 2000 cubic feet per second (cfs). Yesterday’s flow rose above that threshold. According to the Middle Atlantic River Forecast Center predictions, the average basin rainfall may be up to 0.5 inches over the next 3 days. We will continue to monitor conditions closely and we will resume daily drought monitoring if needed. 

Daily Potomac flow and demand update (Monday, 2024-11-18)

Submitted by snummer on Mon, 11/18/2024 - 13:57

Situational Awareness (Monday, 2024-11-18)
While the daily average flow at Point of Rocks has just crossed the 2000 cfs drought monitoring threshold (at 2020 cfs), ICPRB’s CO-OP Section will continue daily monitoring for the time being to ensure that the flow at Point of Rocks will remain above said threshold for an extended period of time. No appreciable rainfall is expected in the basin over the next 24 hours according to the Middle Atlantic River Forecast Center predictions. Over the next 3 days, the average basin rainfall may be around 0.25 inches. 

Daily Potomac flow and demand update (Sunday, 2024-11-17)

Submitted by admin1 on Sun, 11/17/2024 - 13:17

Situational Awareness (Sunday, 2024-11-17)
The current flow at Point of Rocks is 2,090 cfs, but yesterday's daily average flow remains below the 2,000 cfs drought monitoring threshold. The Middle Atlantic River Forecast Center forecasts steady or gradually receding river levels, with 0.2 inches of rain expected in the next 24-72 hours and 0.7 inches over the week.

Special Conditions
None

Daily Potomac flow and demand update (Friday, 2024-11-15)

Submitted by hmoltz on Fri, 11/15/2024 - 13:20

Situational Awareness (Friday, 2024-11-15)
Approximately 0.26 inches of rain has fallen in the basin over the past 24 hours.  According to the Middle Atlantic River Forecast Center predictions, the next 24 hours may see 0.2 inches of rain. The week-long outlook expects a total of approximately 0.7 inches of rain in the basin.

Special Conditions
None

Daily Potomac flow and demand update (Tuesday, 2024-11-12)

Submitted by admin1 on Tue, 11/12/2024 - 13:06

Situational Awareness (Tuesday, 2024-11-12)
Potomac River flow has steadied in response to the recent rainfall, and a modest amount of rain is again expected in the coming days. According to the Middle Atlantic River Forecast Center, average cumulative precipitation is predicted to be around 0.2 inches over the next three days and 0.3 inches over the next week.

Special Conditions
None

Recent basin-wide average precipitation (above Little Falls):

Daily Potomac flow and demand update (Monday, 2024-11-11)

Submitted by snummer on Mon, 11/11/2024 - 13:16

Situational Awareness (Monday, 2024-11-11)
Over the past 24 hours, approximately 0.2 inches of rain fell across the basin. According to the Middle Atlantic River Forecast Center predictions, the next 72 hours may see 0.2 inches of rain. The week-long outlook expects a total of approximately 0.3 inches of rain in the basin.

Special Conditions
None