Spokane County Water Resources is managing a study to investigate methods to increase surface water stream flow in WRIAs 55 and 57 during low flow summer months. Flows in the Spokane River and the Little Spokane River are largely controlled by snowmelt in the watersheds with peak flow generally occurring in the spring to early summer and low flows occurring in late summer. Human demand for water peaks during the summer when river flows are the lowest.
This work is funded by the Washington State Department of Ecology through grants for Water Resource Inventory Areas (WRIA) 55 and 57.
Surface Water Base Flows
Wetland restoration, surface water storage, and groundwater recharge may provide ways to augment surface water base flows in the WRIAs. Wetland restoration may provide a way to slow runoff in the 2 watersheds, recharge underlying aquifers, and increase streamflows during summer low flow periods. Increasing existing or creating new surface water storage (e.g. lakes, reservoirs, or wetlands) could capture surface water runoff from upland areas and allow for delayed release during summer months. Additionally, altering groundwater recharge areas in both WRIAs may provide a way to increase stream flows during low flow periods.