FIRST DAY OF WMA DROUGHT EXERCISE: Afternoon Potomac flow and demand update (Monday 2020-11-16)

Our afternoon report appears below. Note that an ACTUAL test release from Little Seneca Reservoir has been approved by the CO-OP General Managers and is planned to be initiated tomorrow morning at 10 AM at a rate of 400 million gallons per day (MGD) and continued for 12 hours. Due to this release, flow in Seneca Creek will be elevated between approximately 10 AM on November 17 and 6 AM on November 18.

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RECENT CONDITIONS – ACTUAL

Potomac River Flows:
Little Falls gage flow 2020-11-15: 11052 MGD (17100 cfs)
Little Falls gage flow 2020-11-16: 8467 MGD (est., based on recently available real time data) (13100 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2020-11-15: 9630 MGD (14900 cfs)
Point of Rocks flow 2020-11-16: 6980 MGD (est., based on recently available real time data) (10800 cfs)

Today's estimated production* (2020-11-16):
FW estimated production: 158 MGD
WSSC estimated production: 153 MGD
Washington Aqueduct estimated production: 113 MGD
Total estimated production: 424 MGD
*Based on CO-OP daily demand forecasting models. FW includes the LW purchase and excludes Falls Church. Washington Aqueduct includes Falls Church

Tomorrow's estimated production* (2020-11-17):
FW estimated production: 151 MGD
WSSC estimated production: 148 MGD
Washington Aqueduct estimated production: 115 MGD
Total estimated production: 413 MGD
*Based on CO-OP daily demand forecasting models. FW includes the LW purchase and excludes Falls Church. Washington Aqueduct includes Falls Church

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Recommended (SIMULATED) operations for this afternoon (2020-11-16 A.M.):

Fairfax Water:
Keep Potomac withdrawal rate (SIMULATED) as steady as possible.

WSSC Water:
Keep Potomac withdrawal rate (SIMULATED) as steady as possible.

Little Seneca Reservoir
There are no water supply releases at this time.

Washington Aqueduct:
Maintain 75 MGD of withdrawals at Little Falls (SIMULATED).

Loudoun Water:

The following values (SIMULATED) are provided under the protocol developed to satisfy the Virginia Water Protection permit # 10-2020, Part I. 2. f (p. 10), and Part I.J.10

QPR, obs = 683 MGD (1057 cfs) (SIMULATED)

QPR, WS = 0 MGD (SIMULATED)

QPR = 9630 MGD (SIMULATED)

North Branch reservoirs (USACE, Baltimore District):

There are no water supply releases at this time.

Note: Flow levels (SIMULATED) have dropped to a level that has triggered enhanced monitoring, per the drought operations manual of the Water Supply Coordination Agreement. When adjusted flow at Little Falls (adjusted flow is gage flow plus upstream withdrawals) less the environmental flow is less than twice the Washington metropolitan area withdrawals, the water suppliers will begin reporting yesterday’s and today’s withdrawals and this morning’s reservoir storage volumes. ICPRB asks that communications be sent by 7:30 am and updates sent by 1:00 pm. Reporting can be submitted through www.icprbcoop.org, by email to coop@icprb.org, or by telephone by leaving a message with the CO-OP operations number at 301-274-8132. Thank you for your contribution to the monitoring efforts.

ICPRB CO-OP Drought Operations Team (Alimatou, Cherie, Heidi, and Sarah)

"# Net Potomac Withdrawals Actual and Forecast" "# 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" "# Total Annual Average Assumptions: FW = 138.82; WSSC = 158.43; WA = 120.72; LW = 23.86" "# Start Date = 2021-02-04" "# Stop Date = 2021-05-15" "# Time Zone = Eastern Standard Ttime (EST)" "# Units = million gallons per day (mgd)" DateTime,FW_POT,WSSC_POT,WA_GF,WA_LF,LW_POT,LW_FW,FW_OC,WSSC_PA,LW_BR 2021-02-03,73.36,95.49,107.17,0,5.97,12.42,69.41,72.85, 2021-02-04,77.64,98.36,101.29,0,6.56,12.42,70.21,72.78, 2021-02-05,69.42,93.04,95.63,0,5.32,12.42,70.21,72.58, 2021-02-06,74.14,92.97,100.46,0,4.89,13.07,70.19,72.39, 2021-02-07,74.58,92.93,107.67,0,6.04,13.07,70.36,72.21, 2021-02-08,70.39,92.53,111.21,0,5.08,13.07,71.55,72.36, 2021-02-09,67.96,103.65,113,0,5.28,13.07,70.07,64.68, 2021-02-10,78.45,92.59,105.71,0,4.98,13.07,69.53,62.36, 2021-02-11,64.26,92.05,101.38,0,4.48,13.07,71.27,65.24, 2021-02-12,64.53,92.29,97.29,0,4.86,13.07,70.5,60.63, 2021-02-13,64.91,93.55,101.79,0,5.11,13.07,70.39,68.2, 2021-02-14,74.4,93.3,104.13,0,5.14,13.07,71.55,64.23, 2021-02-15,65.04,93.21,100.96,0,5.07,13.07,71.92,62.93, 2021-02-16,82.84,91.08,112.83,0,4.78,13.07,71.57,71.88, 2021-02-17,49.97,91.45,107.29,0,4.84,13.07,70.21,71.84, 2021-02-18,55.38,91.54,62.47,0,5.61,13.07,70.75,66.39, 2021-02-19,59.16,92.32,103.49,0,5.33,13.07,64.61,57.61, 2021-02-20,57.43,92.57,101.64,0,4.35,13.07,68.35,65.64, 2021-02-21,69.89,101.42,109.73,0,5.88,13.07,69.99,70.53, 2021-02-22,63.37,96.59,125,0,12.42,8.19,70.21,64.89,6.78 2021-02-23,58.8,92.07,123.38,0,6.32,13.07,76.42,64.6, 2021-02-24,57.59,92.04,117.83,0,13.07,8.14,71.86,66.53,6.14 2021-02-25,57.34,91.43,132.67,0,4.81,13.07,71.99,63.88, 2021-02-26,57.72,92.12,126.92,0,4.25,13.07,72.3,63.79, 2021-02-27,54.28,91.5,119.88,0,4.19,13.07,72.8,66.57, 2021-02-28,52,90.98,107.92,0,6.87,13.07,72.09,63.37, 2021-03-01,61.96,130.56,116.38,0,6.62,13.07,72.24,18.4, 2021-03-02,61.98,154.71,110.92,0,7.05,13.07,71.55,0, 2021-03-03,79.93,159.92,120.71,0,6.94,13.07,72.15,0, 2021-03-04,80.18,157.2,107.52,0,6.79,13.07,72.2,0, 2021-03-05,81.26,140.33,104.12,0,6.02,13.07,72.15,15.6, 2021-03-06,85.04,93.54,100.1,0,6.25,13.07,72.13,64.15, 2021-03-07,94.21,99.37,105.87,0,7.66,13.07,66.16,58.79, 2021-03-08,82.36,94.17,109.08,0,7.56,13.07,75.44,58.88, 2021-03-09,89.09,94.08,109.41,0,7.7,13.07,72.07,63.49, 2021-03-10,87.66,93.94,109.64,0,7.57,13.07,71.98,57.06, 2021-03-11,88.77,93.9,109.48,0,7.55,13.07,71.98,57.48, 2021-03-12,85.83,94.02,105.06,0,6.39,13.07,71.6,63.66, 2021-03-13,86.66,93.6,100.09,0,6.33,13.07,71.52,64, 2021-03-14,55.19,91.94,113.29,0,7.48,13.07,72.27,60.22, 2021-03-15,82.59,91.98,62,0,7.2,13.07,71.73,60.21, 2021-03-16,83.52,92.76,108.9,0,6.61,13.07,72.43,57.95, 2021-03-17,78.64,92.19,106.7,0,6.41,13.07,71.1,55.17, 2021-03-18,81.08,93.29,105.52,0,6.38,13.07,69.21,50.21, 2021-03-19,79.77,92.72,102.76,0,5.65,13.07,71.38,47.65, 2021-03-20,82,93.47,98.47,0,5.85,13.07,73.42,52.84, 2021-03-21,86.27,93.51,105.06,0,7.37,13.07,73.42,60.66, 2021-03-22,79.57,91.41,108.39,0,6.46,13.07,73.81,64.95, 2021-03-23,80.52,92.56,106.82,0,6.71,13.07,73.81,58.74, 2021-03-24,59.99,91.79,115.29,0,6.84,13.07,72.41,50.96, 2021-03-25,57.58,91.53,114.08,0,7.05,13.07,71.91,51.75, 2021-03-26,56.7,91.2,110.96,0,7.3,11.04,71.99,59.1, 2021-03-27,57.72,91.62,111.54,0,7.61,11.04,72.15,58.95, 2021-03-28,54.43,91.77,121.08,0,8.97,11.04,72.2,59.02, 2021-03-29,52.8,92.74,121.42,0,8.14,11.04,72.15,58.71, 2021-03-30,50.85,92.13,117.38,0,8.03,11.04,72.13,58.97, 2021-03-31,57.27,92.46,112,0,11.21,11.04,66.16,52.91, 2021-04-01,52.62,93.51,114.96,0,11.25,11.04,75.44,47.34, 2021-04-02,55.56,92.75,115.17,0,10.63,11.04,72.07,48.25, 2021-04-03,50.66,93.45,105.63,0,10.96,11.04,71.98,57.41, 2021-04-04,56.82,93.33,112.04,0,12.55,11.04,71.98,56.57, 2021-04-05,65.36,90.39,118.71,0,12.53,11.04,71.6,58.92, 2021-04-06,71.1,90.35,106.57,0,12.8,11.04,71.52,62.24, 2021-04-07,72.19,90.22,116.42,0,11.72,11.04,71.55,61.3, 2021-04-08,70.93,89.71,121.67,0,7.77,14.82,71.73,63.49, 2021-04-09,58.63,89.64,127.04,0,6.39,14.82,72.43,56.54, 2021-04-10,52.38,89.4,109.96,0,6.75,14.82,71.1,54.48, 2021-04-11,62.34,103.35,122.43,0,8.36,14.82,69.21,55.63, 2021-04-12,69.89,101.35,109.28,0,7.41,14.82,71.38,54.09, 2021-04-13,70.13,87.63,109.83,0,7.85,14.82,73.42,55.71, 2021-04-14,97,98.57,120.92,0,7.91,14.82,69.67,62.14, 2021-04-15,74.87,91.59,114.46,0,7.92,14.82,73.81,52.16, 2021-04-16,96.42,91.66,108.29,0,7.18,14.82,73.04,58.74, 2021-04-17,75.41,100.08,113.79,0,7.3,14.82,71.82,58.88, 2021-04-18,71.23,95.97,109.46,0,8.82,14.82,75.72,59.1, 2021-04-19,77.56,101.96,125.46,0,8.85,14.82,77.54,52.59, 2021-04-20,72.51,102.15,124.21,0,8.94,14.82,76.79,47.14, 2021-04-21,67.22,99.6,119.5,0,11.04,14.65,74.84,56.21,6.83 2021-04-22,72.71,88.24,125.88,0,8.44,14.82,71.92,66.73, 2021-04-23,69.49,97.33,117.29,0,6.85,14.82,71.69,63.08, 2021-04-24,72.44,92.57,120.67,0,7.6,14.82,74.22,63.47, 2021-04-25,64.07,92.11,96.5,0,9.28,14.82,75.71,61.88, 2021-04-26,71.11,92.52,118.17,0,9.35,14.82,73.99,62.44, 2021-04-27,79.34,98.53,126.25,0,9.7,14.82,72.39,68.52, 2021-04-28,86.6,98.83,127.42,0,9.52,14.82,74.79,68.81, 2021-04-29,80.64,103.15,136,0,9.44,14.82,80.95,66.09, 2021-04-30,74.02,95.83,144.88,0,15.26,11.52,73.76,62.66, 2021-05-01,78.9,90.97,117.63,0,14.82,10.16,74.16,62.57,6.3 2021-05-02,83.9,106.14,121,0,16.21,11.52,74.18,62.36, 2021-05-03,82.24,99.12,125.29,0,15.68,11.52,74.04,56.17, 2021-05-04,72.01,103.78,128.04,0,16.07,11.52,73.42,54.64, 2021-05-05,73.65,98.23,126.63,0,15.22,11.52,74.38,54.08, 2021-05-06,71.24,91.46,92.75,0,15.46,11.52,72.29,57.96, 2021-05-07,76.42,97.65,124.42,0,14.64,11.52,70.87,61.82, 2021-05-08,56.58,96.64,123,0,15.21,11.52,69.67,55.89, 2021-05-09,63.09,90.65,109.33,0,16.85,11.52,69.96,51.45, 2021-05-10,84.6,101.07,123.92,0,16.59,11.52,73.04,51.26, 2021-05-11,69.56,103.42,125.88,0,17.18,11.52,75.42,51.22, 2021-05-12,85.14,105.09,139.96,0,17.21,11.52,73.72,50.84, 2021-05-13,74.5,105.1,137.46,0,17.2,11.52,77.07,55.11, 2021-05-14,89.85,102.18,136.33,0,16.36,11.52,75.98,55.63,