Data View (Password Protected)

This page lists data types stored in the database and allows them to be querried by date and formatted into a table, a graph, or a CSV file.

Potomac Basin Precipitation Monitoring

This map displays precipitation totals from the previous day. Cumulative daily values are averaged by Potomac basin sub-watershed and computed by CO-OP's Low Flow Forecast System based on gridded multi-sensor precipitation estimates provided by the Middle Atlantic River Forecast Center.

Washington metropolitan area actual and forecasted withdrawals comma-separated variable output (Password Protected)

This file lists 30 days of actual withdrawals, replaces missing values with forecasted values, and then lists 14 days of forecasted withdrawals. The withdrawals included are:

  • FW_POT = Fairfax Water Corbalis Plant withdrawal from the Potomac, no Loudoun Water purchase water
  • WSSC_POT = Washington Subburban Sanitary Commission withdrawal from the Potomac
  • WA_GF = Washington Aqueduct withdrawal from Great Falls on the Potomac
  • WA_LF = Washington Aqueduct withdrawal from Little Falls on the Potomac
  • LW_POT = Loudoun Water Trap Rock Plant withdrawal from the Potomac
  • FW_OC = Occoquan off-Potomac withdrawal by Fairfax Water
  • WSSC_PA = Patuxent off-Potomac withdrawal by WSSC
  • LW_FW = Loudoun Water purchase water to add to Fairfax Water Potomac withdrawal
  • LW_BR = Loudoun Water Broad Run wastewater return flow

Washington metropolitan daily average estimated withdrawals comma-separated variable output

This file lists 30 days of daily average estimated withdrawals based on the 2020 water supply and reliability study and then extends those values for 14 days of forecasted withdrawals. The withdrawals included are the same as described above.

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. An archive of monitoring e-mails is provided here