Current Water Supply Conditions and Outlook
January 27, 2015
Our overall water supply situation and outlook remains good.
Last week, 2.93 inches and 3.65 inches of precipitation were recorded in our Cedar and South Fork Tolt River watersheds, respectively. We have closely monitored snowpack and hydrology throughout the winter season and we are holding water levels in our mountain storage reservoirs above normal levels for this time of the year while staying within reservoir flood management levels. High stream flows from last week’s warm, heavy rainstorm were captured in our reservoirs on both the Cedar and South Fork Tolt Rivers as part of winter season flood management. Chester Morse Lake is at elevation 1557.6 feet, about 2.5 feet higher than last week, and about 6.3 feet above its long term average (based on the years 1989 to 2005). South Fork Tolt Reservoir is at elevation 1762.6 feet, about 3.3 feet higher than last week, and about 8.5 feet above its long term average. Stream flows below SPU facilities on the Cedar and South Fork Tolt Rivers will continue to be held above guaranteed normal minimum flow levels.
Snow accumulations in the Cascade Mountains are well below normal for this time of the year. Snowpack is about 21 percent of normal in both the Cedar River and the South Fork Tolt River watersheds. Although last week’s warm heavy rains have resulted in the melting of some of our snowpack, we have about two months of winter left for snow to accumulate. We are therefore carefully watching how the snowpack builds throughout the remaining part of the snow season.
Water consumption for the previous seven days averaged approximately 103 mgd. That is more than the 101 mgd consumed during the same period last year, and less than the average of 115 mgd used during the same period over the years 1999-2008.
Sockeye and Chinook salmon completed spawning in the mainstem Cedar River by the end of December. Juvenile sockeye and Chinook salmon have begun to emerge from redds spawned early in the spawning period and these young fish will use the river margins to rear. Cedar River Coho salmon peak spawning is usually in December. Cedar Coho will continue to spawn in the Cedar River through the end of February. Young coho, steelhead and trout that emerged in 2014, are rearing in the Cedar at this time.
Tolt summer-run steelhead move into the upper reaches of the South Fork Tolt River during the summer and fall where they wait to spawn during the following winter and spring. At this time, early spawning steelhead in the population have begun to construct redds. These early redds will start to produce emerging fry in April. Adult summer steelhead will continue to spawn into the month of April so protection against redd scour and juvenile stranding are important. Young steelhead and coho that emerged in 2014 are currently rearing in the South Fork Tolt.
View Current Water Supply Graphs (pdf)