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| Station House Lofts, downtown aquifer dig, 3/2017 / credit Bob Yoder |
Downtown Redmond and Marymoor Village lies over a shallow, sandy aquifer from which the City gets 40% of our drinking water. Jessica Alakson, the City geological scientist gave Council a brief report on actions the City is taking to protect the aquifer from development of 1-2 stories of underground parking garages.
The aquifer is mapped by "Critical Area Recharge Areas" (C.A.R.A.). One day, Redmond Town Center will be redeveloped with 12-story buildings and one or two levels of underground parking. Town Center is in the high priority C.A.R.A. Type 1 zone. The proposed "Nelson Village" is in the C.A.R.A. Type 1 zone, as well.
Ms. Alakson said excavating the sandy aquifer artificially lowers the ground water-table. Water will be purchased from Cascade Water Alliance if water table significantly drops. [When water levels drop significantly, it's my understanding the developer may have to pay for the difference.]
Jessica stated "Temporary Construction Dewatering" will be amended to include the following limitations within the Critical Aquifer Recharge Area (CARA):
· Limit rate to 5,500 gallons per minute; and · Limit cumulative duration to a maximum of 1 year; and · Limit depth to a maximum of 9 feet below season high groundwater elevation.
Council member Jeralee Anderson asked Jessica how long it takes to recharge the aquifer? Jessica said if it's raining heavily, less than a month. The average recharge time is 2-4 months. Ms. Anderson asked how many projects would be vested from the more restrictive regulations. Jessica said hardly any.
No decisions were made.
-- Bob Yoder, 7/6/2022
Source: Council Committee of the Whole, Public Works, Presiding Officer CM Malissa Stewart
"The Challenge And Need for De-watering" (a summary of all my posts on Redmond's water.) BY
What about leaving it as a lovely wetland?
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