Wash. Admin. Code § 173-507-020

Current through Register Vol. 24-23, December 1, 2024

Section 173-507-020 - Establishment of instream flows

(1) Instream flows are established for stream management units with monitoring to take place at certain control stations as follows:

STREAM MANAGEMENT UNIT INFORMATION
Control Station No. Stream Management Unit Name	Control Station by River Mile and Section, Township and Range	Affected Stream Reach Including Tributaries
12.1330.00 So. Fk. Skykomish River	51.6 28-27-10E	From confluence with N. Fk. Skykomish River to headwaters.
12.1381.50 Sultan River	5.1 17-28-8E	From mouth to headwaters.
12.1411.00 Skykomish River	25.0 12-27-6E	From mouth to headwaters, excluding So. Fk. Skykomish River and Sultan River.
12.1430.00 No. Fk. Snoqualmie	2.2 26-24-8E	From mouth to headwaters.
12.1445.00 Snoqualmie River	40.0 19-24-8E	From Snoqualmie Falls to headwaters, excluding No. Fork Snoqualmie River.
12.1485.00 Tolt River	8.7 31-26-8E	From mouth to headwaters.
12.1490.00 Snoqualmie River	23.0 9-25-7E	From confluence with Harris Creek to Snoqualmie Falls, excluding Tolt River.
12. Snoqualmie River	2.5 26-27-6E	From mouth to confluence with Harris Creek, including Harris Creek.
12.1554.00 Pilchuck River	1.9 18-28-6E	From mouth to headwaters.
12.1508.00 Snohomish River	20.4 16-27-6E	From influence of mean annual high tide at low base flow levels to confluence with Skykomish River and Snoqualmie River, excluding Pilchuck River.

(2) Instream flows established for the stream management units in WAC 173-507-020(1) are as follows:

INSTREAM FLOWS IN THE SNOHOMISH RIVER BASIN (in Cubic Feet per Second)
Month	Day	12.1330.00 So. Fk. Skykomish	12.1411.00 Skykomish	12.1430.00 No. Fk.* Snoqualmie	No. Fk.** Snoqualmie
Jan.	1	900	2200	260	200
	15	900	2200	260	200
Feb.	1	900	2200	260	200
	15	900	2200	260	200
Mar.	1	900	2200	260	200
	15	900	2200	300	200
Apr.	1	1100	2650	300	200
	15	1250	3250	300	200
May	1	1250	4000	300	200
	15	1250	4900	300	200
June	1	1250	4900	300	200
	15	1250	4900	300	200
July	1	1250	3250	300	200
	15	950	2170	195	140
Aug.	1	650	1450	130	100
	15	450	1000	130	100
Sept.	1	450	1000	130	100
	15	450	1000	130	100
Oct.	1	550	1300	130	130
	15	700	1700	165	165
Nov.	1	900	2200	210	200
	15	900	2200	260	200
Dec.	1	900	2200	260	200
	15	900	2200	260	200
- - - - - - - - - - - -

*

Normal year flows must be maintained at all times unless a critical condition is declared by the director. The director, or his designee, may authorize, in consultation with the state departments of fisheries and wildlife, a reduction in instream flows during a critical condition period. At no time are diversions subject to this regulation permitted for any reason when flows fall below the following critical year flows, except where a declaration of overriding considerations of public interest is made by the director.

**	Critical year flows represent flows below which the department believes substantial damage to instream values will occur.

Month	Day	12.1381.50 Sulton	12.1445.00 Snoqualmie (above Falls)	12.1485.50 Tolt River*	Tolt River**
Jan.	1		1550	280	190
	15		1550	280	190
Feb.	1		1550	280	190
	15		1550	280	190
Mar.	1		1550	280	190
	15		1550	280	190
Apr.	1		1550	280	190
	15		1550	280	190
May	1		1550	280	190
	15		1550	280	190
June	1		1550	280	190
	15		1550	280	165
July	1		1550	280	140
	15		1100	240	120
Aug.	1		770	170	120
	15		600	120	120
Sept.	1		600	120	120
	15		600	120	120
Oct.	1		820	190	185
	15		1100	280	190
Nov.	1		1550	280	190
	15		1550	280	190
Dec.	1		1550	280	190
	15		1550	280	190
- - - - - - - - - - - -

*

Normal year flows must be maintained at all times unless a critical condition is declared by the director. The director, or his designee, may authorize, in consultation with the state departments of fisheries and wildlife, a reduction in instream flows during a critical condition period. At no time are diversions subject to this regulation permitted for any reason when flows fall below the following critical year flows, except where a declaration of overriding considerations of public interest is made by the director.

**	Critical year flows represent flows below which the department believes substantial damage to instream values will occur.

Month	Day	12.1490.00 Snoqualmie (Carnation)	12. Snoqualmie (mouth)	12.1554.00 Pilchuck R.	12.1508.00 Snohomish R.
Jan.	1	2500	2800	300	6000
	15	2500	2800	300	6000
Feb.	1	2500	2800	300	6000
	15	2500	2800	300	6000
Mar.	1	2500	2800	300	6000
	15	2500	2800	300	6000
Apr.	1	2500	2800	300	6000
	15	2500	2800	300	6500
May	1	2500	2800	300	7200
	15	2500	2800	300	8000
June	1	2500	2800	300	8000
	15	2500	2800	300	8000
July	1	1850	2180	220	5700
	15	1300	1550	160	4000
Aug.	1	950	1080	120	2800
	15	700	800	85	2000
Sept.	1	700	800	85	2000
	15	700	800	85	2000
Oct.	1	1050	1200	130	2900
	15	1650	1850	200	4000
Nov.	1	2500	2800	300	6000
	15	2500	2800	300	6000
Dec.	1	2500	2800	300	6000
	15	2500	2800	300	6000

(3) Instream flow hydrographs, as represented in the document entitled "Snohomish River instream resource protection program," shall be used for definition of instream flows on those days not specifically identified in WAC 173-507-020(2).

(4) All consumptive water rights hereafter established shall be expressly subject to the instream flows established in WAC 173-507-020(1) through (3).

(5) At such time as the departments of fisheries and/or wildlife and the department of ecology agree that additional stream management units should be defined, other than those specified in WAC 173-507-020(1), the department of ecology shall identify additional control stations and management units on streams and tributaries within the basin and shall set instream flows where possible for those stations as provided in chapters 90.22 and 90.54 RCW.

Wash. Admin. Code § 173-507-020

Statutory Authority: Chapters 43.21B, 43.27A, 90.22 and 90.54 RCW. 88-13-037 (Order 88-11), § 173-507-020, filed 6/9/88. Statutory Authority: Chapters 90.22 and 90.54 RCW. 79-10-003 (Order DE 79-8), § 173-507-020, filed 9/6/79.