RCW 90.54.020 requires that perennial rivers and streams shall be retained with base flows necessary to provide for preservation of wildlife, fish, scenic, aesthetic, and other environmental values and navigational values. Under this provision, base flows for stream management units of a basin are established which describe discharge rates at stream measurement stations in each unit. The following subsections, WAC 173-559-030(1) through (4), establish these requirements for WRIA 59:
Table 1 Stream Management Units
Stream Management Unit and Control Station Number | Control Station Location by River-Mile, and Sec- tion Township and Range | Stream Management Reach | |
Upper Colville River | 32.1 | Colville River | |
No. 12.4080.00 | Sec. 31, T. 33 N., | from confluence | |
R. 40 E.W.M. | with Stensgar | ||
Creek to | |||
confluence of | |||
Sheep Creek | |||
and Deer Creek. | |||
Lower Colville River | 5.0 | Colville River | |
No. 12.4090.00 | Sec. 29, T. 36 N., | from confluence | |
R. 38 E.W.M. | with Lake | ||
Roosevelt to | |||
confluence with | |||
Stensgar Creek. |
Table 2 Base Flows in the Colville River basin
(in Cubic Feet Per Second)
Month | Day | Upper Colville (12.4080.00) | Lower Colville (12.4090.00) |
Jan. | 1 | 30 | 80 |
15 | 30 | 80 | |
Feb. | 1 | 30 | 80 |
15 | 38 | 100 | |
Mar. | 1 | 47 | 124 |
15 | 59 | 157 | |
Apr. | 1 | 76 | 200 |
15 | 76 | 200 | |
May | 1 | 49 | 200 |
15 | 32 | 135 | |
Jun. | 1 | 20 | 90 |
15 | 17 | 70 | |
Jul. | 1 | 15 | 55 |
15 | 13 | 43 | |
Aug. | 1 | 11 | 33 |
15 | 11 | 33 | |
Sep. | 1 | 14 | 40 |
15 | 18 | 49 | |
Oct. | 1 | 22 | 60 |
15 | 27 | 70 | |
Nov. | 1 | 35 | 84 |
15 | 43 | 100 | |
Dec. | 1 | 43 | 100 |
15 | 36 | 90 |
Figure 1 BASE FLOW HYDROGRAPH FOR SELECTED STATIONS
Wash. Admin. Code § 173-559-030
Order DE 77-6, § 173-559-030, filed 7/22/77.