The current watershed planning effort was initiated in late 1998 when
funding was provided by the Washington Legislature under House Bill 2514
(RCW 90.82). Spokane County is the Lead Agency
and one of the initiating governments in completing these watershed
planning efforts for the Middle Spokane and Little Spokane watersheds.
Components of watershed planning include a required water quantity element
and optional water quality, habitat, and instream flow elements. Beyond the
required analysis of water quantity, the Planning Unit for WRIA 55 and 57 also
accepted the optional component of analyzing instream flow. In October 1, 2001,
application was made to Ecology for additional funds to study instream flows.
A scope of work was developed and Golder
Associates was retained in the Fall of 2000. The final Level 1
Technical Assessment was completed in June 2003. The Level 2 Data
Analysis was started in April 2002 using the MIKE suite of computer programs,
which includes dynamically linked climatic, surface water, and groundwater
modules. The Level 2 Technical Assessment: Watershed Simulation Model report
was completed in February 2004.
An instream flow study for the Little Spokane River was completed in December 2003 (Golder, December 2003).
An instream flow study on parts of the Spokane River done in cooperation with Avista Corporation was
completed in June 2004 (NHC and Hardin-Davis, 2004).
A preliminary screening of potential Multi-purpose storage projects for both WRIAs by Golder Associates Inc
was presented to the Planning Unit in July 2004. The Planning Unit asked Golder to investigate three projects further.
The final Multi-purpose Storage Assessment was completed in December 2004 (Golder, December 2004).
The MIKE SHE model Scenario Analysis final report was completed in early spring 2005 (Golder, March, 2005)
The WRIA 55/57 Watershed Plan was approved by the Planning Unit on July 6, 2005.
The WRIA 55/57 Watershed Plan was adopted by the Commissioners of Pend Oreille,
Spokane, and Stevens counties on January 31, 2006.