Seattle Public Utilities Mami Hara, General Manager/CEO

managingRiverTitle

Compliance Summary

The Cedar River Instream Flow Management Program, as specified by the Instream Flow Agreement for the Cedar River (Agreement), includes provisions for a guaranteed mean daily flow regime. This regime includes guaranteed minimum levels below which stream flows shall not be allowed to drop and supplemental flows that are expected to be provided according to specific frequency targets described in the Agreement. The table and graphs below summarize compliance with minimum flow specifications and supplemental flow targets from 2000 through 2013.

Cedar River Instream Flow Compliance Monitoring
HCP years 1- 13 (2000-2013)

Instream Flow Parameter Target Actual
Years in which normal flows met or exceeded at all times ≥ 90% of all years 100% of all years
Years in which critical flows implemented ≤ 10% of all years 0% of all years
2500 acre ft. normal summer water block (June 17 - Aug. 4) ≥ 90% of all years 100% of all years
3500 acre ft. supplemental summer water block (June 17 - Aug. 4) ≥ 63% of all years 86% of all years
Early fall flow augmentation (Sept. 16 - Sept. 30) ≥ 90% of all years 100% of all years
Late Winter/Spring Supplemental Flow (Feb. 11 to Apr. 14) Flow ≥ 378 cfs at least 70% of days in all normal years Target met or exceeded in 11 of 13 years. See graph below.
Fall High Normal Supplemental Flow (Oct. 8 to Dec. 30) See graph below Performance exceeding all targets. See graph below.


Flow-compliance-graph-winter-spring


Flow-compliance-graph-fall