Project Title : Chehalis Basin (WRIA 22/23) In-Stream Flow Recommendations

Project Location : Water Resource Inventory Area No. 22/23

Description :

This project has the goal of gathering flow data in the Chehalis Basin to:

Prepare flow exceedance probability hydrographs for the fifteen minimum instream flow control sites for which we do not currently have enough flow data to prepare one,

Determine if existing minimum instream flows established in 1976 are being met at the twenty-five control points that are not currently gauged,

Compare actual instream flows to flows recommended in several Instream Flow Incremental Methodology (IFIM) studies that have been, or are near, completion, and

Recommend "Natural Resource Base Flows" for the purposes of meeting the watershed planning goals established in the "Watershed Planning Act" (RCW 90.82).

The following main stem segments and tributaries will be addressed in this project:

Description	Base Flows set 3-10-76 in Ch. 173-522 WAC	Closed	WDF IFIM * = 2001 study underway	Hydrograph Available
Chehalis R.-Elk Creek to headwaters	Y	-	*	Y
Elk Creek	Y	-	-	Y
South Fork Chehalis River	Y	Y	-	-
Chehalis River -- Elk Cr. to Newaukum R.	Y	-	Y (RM 90) upstream of confluence with S Fork Chehalis R.	-
S Fork Newaukum R	Y	Y	Y	Y
N Fork Newaukum R	Y	Y	Y	Y
Newaukum R	Y	Y	Y	Y
Salzer Cr.	Y	Y	-	Y
Skookumchuck R.	Y	Y	*	Y
Chehalis R (Grand Mound) - Newaukum to Prairie Cr.	Y	-	-	Y
Black River	Y	Y	*	Y
Cedar Cr.	Y	-	-	-
Porter Cr.	Y	-	-	Y
Chehalis R (Porter) - Prairie Cr. to Porter Cr.	Y	-	-	Y
Cloquallum Cr.	Y	-	Y	Y
E Fork Satsop R.	Y	-	-	Y
Decker Creek	Y	-	-	-
M Fork Satsop R.	Y	-	-	-
Satsop R	Y	-	*	Y
Chehalis R. - below Satsop R.	Y	-	-	-
Wynoochee R.	Y	Y	-	Y
Wiskah R.	Y	-	Y (RM 20.5)	-
E Fork Wishkah R.	Y	-	-	-
W Fork Hoquiam R.	Y	-	*	-
M Fork Hoquiam R.	Y	-	-	-
E Fork Hoquiam R.	Y	-	-	-
Humptulips R.	Y	-	*	Y
Elk River	Y	-	-	-
Johns R.	Y	-	-	-
Newskah Creek	Y	-	-	-
Charley Creek	Y	-	-	-
-	-	-	-	-

BACKGROUND

A Water Resources Management Program (hereafter referred to as the "1975 Management Program") for the Chehalis River Basin (WRIA 22/23) was completed in November 1975, revised in November 1976, and reprinted in September 1980. This 1975 management program established priorities for water use and established the primary goal to "protect and fully utilize the basin surface and groundwater resources for the greatest benefit to the people of the state of Washington." The 1975 Management Program recognized the limitation of available surface waters, established priorities among the many beneficial uses and used those priorities to allocate water accordingly. The first two priorities are provided below. For a full description of the priorities see page 6 of the1975 Management Program.

Priority I

"This management policy will not affect the existing water rights. Existing water rights have highest priority in use. Priority has been established by the date of filing of the original application with the department."

Priority II

"The second priority use category is the flow necessary to maintain base flows for preservation or wildlife, fish, scenic, aesthetic, and other environmental values. Consistent with the fundamental policy of this state, water rights issued after the effective date of this policy shall not impair maintenance of base flows in the stream."

Several important points about "management" of the water resource in the Chehalis Basin were made under the section on Establishment of Base Flows on page 7 of the 1975 Management Program:

"It is a fundamental policy of this state that "perennial rivers and streams of this state be retained with base flows necessary to provide for preservation of wildlife, fish ""

" flow levels be established and enforced "

"The base flows shall be controlled at specific designated control stations and shall extend to the influence of mean annual high tide at low base flow levels."

"Water right permits and certificates issued in the future will not allow appropriation of surface water from the Chehalis River and its tributaries below the base flow levels as established through this policy. Existing water rights are not affected by base flow restrictions."

"The stream flow levels will be monitored by the department. When and where the flows fall below the base flow, future water right holders will be notified and diversion will be regulated progressively in order of priority and filing date until established base flow is resumed."

Minimum Instream flows (called "base flows") were established for 31 control points in the Chehalis Basin (WRIA 22/23) in 1976 under Chapter 173-522 WAC. However, neither the Department of Ecology nor anyone else has "monitored" stream flow levels sufficiently to determine if the minimum instream flows established in 1976 are being met. Currently, there are 14 actively monitored flow gages in the entire Chehalis Basin. Five of those are on the Wynoochee River and three are on the Skookumchuck River. The remaining five active flow gages are not sufficient to manage water resources in the Chehalis Basin as envisioned in the 1975 Management Program. There is enough flow data on record to prepare flow exceedance probability hydrographs for sixteen of the 31 control points (Caldwell, 1999). Fifteen of the 31 control points do not have sufficient site-specific flow data to prepare flow exceedance probability hydrographs. Twenty-five of the 31 control sites are not adequately gauged to determine if existing minimum in-stream flows are being met at any time of the year.

The purpose of this grant is to gather flow data in the Chehalis Basin to:

Prepare flow exceedance probability hydrographs for the fifteen minimum instream flow control sites for which we do not currently have enough flow data to prepare one,

Determine if existing minimum instream flows established in 1976 are being met at the twenty-five control points that are not currently gauged,

Compare actual instream flows to flows recommended in several Instream Flow Incremental Methodology (IFIM) studies that have been, or are near, completion, and

Recommend "Natural Resource Base Flows" for the purposes of meeting the watershed planning goals established in the "Watershed Planning Act" (RCW 90.82). The development of "natural resource base flows" are not intended to supercede the existing minimum in-stream flows that are used only to determine at what flow level water rights get issued or regulated. These "natural resource base flows" will not be used for any regulatory activity, but they will establish the level of flow the Chehalis Basin Partnership will use for developing management plan actions.

Conduct Flow Study (Step B in Ecology process)

Task 1

1.1 Measure flows during 2002 (possibly validated by additional flow measurements in 2003 if time allows) at 15 control stations where minimum in-stream flows (base flows) were set in the 1976 rule and we don't have flow data.

1.2 Measure flows during 2002 (possibly validated by additional flow measurements in 2003 if time allows) at 10 additional locations where minimum in-stream flows were set in 1976, and we have enough flow data to develop flow exceedance probability hydrographs but where current flow data is unavailable.

Deliverable(s): Flow Data on a minimum of 25 of the 31 control points established in the 1976 minimum instream flow WAC.

Due Date(s): May 2003

Task 2

2.1 Correlate 2002/2003 flow data from USGS or other existing flow stations in the Chehalis Basin with flow data collected under Task 1.1 and 1.2 described above. Develop flow exceedance probability hydrographs using this correlated data.

2.2 Compare the flow exceedance probability hydrographs developed in Task 1.3 to existing minimum in-stream flows set in 1976.

2.3 Compare the flow exceedance probability hydrographs developed in Task 1.3 and existing minimum in-stream flows set in 1976 to the recommended flows developed under all IFIM studies carried out in the Chehalis Basin.

Deliverable(s): flow exceedance probability hydrographs for 15 sub-basins; comparison of these flow exceedance probability hydrographs to 1976 instream flows and results of IFIM studies within the Chehalis Basin.

Due Date(s): May 2003

Task 3

3.1 Develop recommended voluntary "natural resource base flows" (i.e. flow levels that we want to see in the river during summer/fall low flow months) for all the control points established in the 1976 rule and any additional locations determined to be important to our planning process. The "natural resource base flows" developed should be intended to adequately meet the needs of fish (i.e. they will be biologically based) but must also be hydrologically achievable with a high degree of certainty.

3.2 Develop recommendation on whether or not additional sub-basins in the Chehalis should be closed to further appropriation based on the comparison of "natural resource base flows" established under this effort with existing river flows, minimum in-stream (base) flows established in 1976, and recommended flows under IFIM studies.

Deliverable(s): recommended natural resource base flows; recommended closures of additional sub-basins.

Due Date(s): May 2003

Develop Instream Flow Recommendations (Step C in Ecology process)

Task 1

1.1 Review recommendations developed under Task 3 with the Chehalis Basin Partnership Steering/Technical Committee

1.2 Review recommendations developed under Task 3 with the full Chehalis Basin Partnership.

1.3 Reach consensus on instream flow recommendation.

Deliverable(s): Consensus agreement on appropriate instream flows.

Due Date(s): June 2003

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