Seattle Hydrologic Data

Seattle Pubic Utilities contracted with Hydrosphere, Inc. to develop weekly natural inflows at four points on the Cedar River. The methods used in estimating natural flows were similar to those used by SPU in the development of the Water Resources Management Model (WRMM), and are described in a series of technical memorandums. The nine inflow points in the model are outlined in Table 8.7.

	Associated USGS Gage	Flow Represents	Calculated
Cedar 1	12115000	Cedar River near Cedar Falls	Gauged data calculated using 12111150, from 1929 to 1945 water balance using other gages was used.
Cedar 18	12115700 12115800 12116100	Gaines between USGS 12115000 and Masonry Pool	Determined via water balance
Cedar 2	12116500 12117500	Natural inflow between Masonry Dam and Landsburg	Water balance
Cedar 4		Local inflow into Lake Washington, including loss to evaporation	Water balance
Cedar 3	12117500	Natural inflow between Landsburg spawning channel
Cedar 5	12119000	Natural inflow between spawning channel and Lake Washington
Tolt 7	12147600	Headwater flows near Index
Tolt 20		Local inflows into Tolt Reservoir	Determined from river basin characteristics
Tolt 8	12148000	All Flows between reservoir and Carnation.	Determined from river basin

8.2.8 Seattle Hydrologic Data