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. We also thank MWCOG for suggesting a severe drought scenario, and for organizing the conference call of the Drought operations Technical Committee. We intend to follow up on the issues raised during that call, and will include a summary of the call in our upcoming report on the exercise.
This year's exercise simulated one of the lowest flow periods in our region's history, the week of August 21st through 27th, 1930. In our exercise scenario, the year was 2022, and Loudoun Water was a full member of CO-OP. Simulated releases from the North Branch reservoirs began in mid-July, and were augmenting flows throughout the exercise week. ICPRB's flow prediction tools were run using 1930 flows, altered by simulated reservoir releases and simulated 2022 withdrawals. It became clear to us as we devised each days' operations strategy that Loudoun Water’s participation in CO-OP was of considerable benefit in helping ensure that the Little Falls 100 MGD flow-by is met even when flow fluctuations are predicted to cause short-term deficits. A 20 MGD shift of demand from the river to Quarry A provided reductions in Potomac River withdrawals comparable to reductions provided by shifts to the Patuxent and the Occoquan reservoirs. This allowed CO-OP to better respond to the river's variability within a 24 to 36 hour time period. Concurrently, participation in CO-OP operations allowed Loudoun Water to make withdrawals from the river and benefit from the flexibility of the CO-OP systems approach.
If you have any observations or feedback on the exercise that should be included in the report, please send them along.
Cherie, Sarah, and Karin
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Drought exercise simulation day: August 27 2022.
SIMULATED Daily Flows:
Little Falls gage flow 08/26: 180 MGD (280 cfs)
Little Falls gage flow 08/27: 190 MGD (est., based on most recently available real time data) (290 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 08/26: 580 MGD (900 cfs)
Point of Rocks flow 08/27: 640 MGD (est., based on recently available real time data) (980 cfs)
Today's estimated demand (08/27/22) P.M.:
ACTUAL WSSC P.M. estimated demand: 160 MGD
ACTUAL FW P.M. estimated demand: 145 MGD
ACTUAL Aqueduct P.M. estimated demand: 142 MGD
SIMULATED LW total estimated demand: 31 MGD
SIMULATED LW WTP estimated demand: 15 MGD
Tomorrow's estimated demand (08/28/22):
ACTUAL WSSC estimated demand: 160 MGD
ACTUAL FW estimated demand: 160 MGD
ACTUAL Aqueduct estimated demand: 145 MGD
SIMULATED LW total estimated demand: 34 MGD
SIMULATED LW WTP estimated demand: 15 MGD