Current Water Supply Conditions and Outlook
May 27, 2015
Our current water supply outlook is good despite the low snowpack conditions we experienced in our mountain watersheds during the winter and early spring seasons.
Last week, 0.10 inches and 0.33 inches of precipitation were recorded in our Cedar River and South Fork Tolt River watersheds respectively. Snowpack in our watersheds is now essentially gone. In order to meet our normal goal of refilling our reservoirs toward the end of spring, we are relying more than usual on rainfall than snowmelt. Moving forward, we will capture spring rainfall runoff in our reservoirs to attenuate the normal drawdown of our reservoirs as we move toward the start of the peak water demand period which starts around June 1. Streamflows in both the South Fork Tolt and Cedar Rivers are being held slightly above guaranteed flows for this time of the year and are providing full protection for incubating salmon and steelhead trout.
Chester Morse Lake at the Overflow Dike is at elevation 1562.0 feet, about 0.9 feet lower than last week, and about 2.1 feet above its long term average (based on the years 1989 to 2005). Masonry Pool Reservoir at Masonry Dam is at elevation 1561.9 feet, about 0.9 feet lower than last week, and about 2.3 feet above its long term average. The South Fork Tolt Reservoir at the South Fork Tolt Dam is at elevation 1758.0 feet, about 1.5 feet lower than last week, and about 4.1 feet below its long term average. Water releases from reservoir storage are actively being managed for water supply, fish habitat, hydropower and flood management objectives for both the Cedar and South Fork Tolt Rivers.
Water consumption for the previous seven days averaged approximately 129 mgd. That is more than the 121 mgd consumed during the same period last year, and less than the average of 134 mgd used during the same period over the years 1999-2008.
View Current Water Supply Graphs (pdf)