Seattle – Water managers have begun slowly filling the
reservoir at Howard Hanson Dam at the headwaters of the Green River. As is
typical, the Army Corps of Engineers slowly begins annual spring fill of the
reservoir in late February, allowing water levels to rise within Howard Hanson
Dam’s reservoir.
The process takes roughly three months to refill the
reservoir. The current plan targets a maximum pool elevation of 1,167 feet
above sea level. A 1,167 foot elevation pool has been the spring refill target
since 2007.
Water stored during the spring refill of the reservoir
will be used to augment downstream flows to help endangered species of fish,
including Chinook and steelhead. Project managers believe that the regulated
downstream flows will aid spawning and other life-cycle events for the fish.
Additionally, some of the stored water will be used to provide water supply to
the City of Tacoma and its water supply partners.
Snowpack in the Green River Basin is near average
conditions and the water supply outlook for the spring is for average to above
average runoff based on the current snowpack and wet basin soils following well
above average precipitation over the last few months. This year’s favorable
water supply outlook is in sharp contrast to last year, which experienced
record low spring runoff in the basin and presented challenging refill
conditions.
The Corps operates the Howard Hanson Dam project, which
provides flood risk management to the Green River valley, low-flow augmentation
to the Green River for environmental benefits, and water supply to the City of
Tacoma and its water supply partners.
For more information call Tanya King, U.S. Army Corps of
Engineers, Seattle District, public affairs at 206-764-3750 or email at Tanya.m.king@usace.army.mil
Current reservoir information is available on line at: http://www.nwd-wc.usace.army.mil/nws/hh/www/index.html
Release no. 16-009