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River and stream shorelines

The current official list of streams that meet the 20 cfs criteria is found in state rule at WAC 173-18. The WAC 173-18 stream list WILL BE SUPERCEDED by lists contained in Ecology-approved shoreline master programs. WAC 173-18-044, adopted February 2, 2007 states:

Each local government master program shall include a list of streams constituting shorelines of the state within the jurisdiction of the master program that complies with the requirements of RCW 90.58.030 (2)(d). When such master program is approved by the department, subsequent to the effective date of this provision, the list within the master program shall be the official list for that jurisdiction and shall supersede the list contained herein.

View shoreline data on interactive mapping site:

Visit Ecology's Digital Atlas and click on SMA streams under the "Jurisdiction" layer for a graphic display of streams meeting this criteria.

You can download the current WAC 173-18 streams list AND the proposed list from Ecology's GIS Data site. Look for "shoreline management act" in the alphabetized subject list on that web page.

Spreadsheet of "Proposed" list of streams available:

Ecology's "proposed" list of streams is based on the results of three USGS stream flow studies with corrections based on locally supplied flow data. This list, as a spreadsheet is available here (.xls). The spreadsheet lists the specific point at which every stream or river in the state flows at 20 cubic feet per second mean annual flow, as predicted by the USGS studies, as corrected. The spreadsheet also lists the points at which streams and rivers are determined to be Shorelines of Statewide Significance according to the criteria provided by RCW 90.58.030(c), (d), and (e). Local governments should use the spreadsheet list as a starting point for establishing the preliminary boundaries of shoreline jurisdiction.

Click here to view three regional USGS stream flow studies.

For more information

Rule: WAC 173-18 - list of streams that meet the 20 cfs mean annual flow criteria

Visit Ecology's Digital Atlas and click on SMA streams under the "Jurisdiction" layer for a graphic display of streams meeting this criteria.

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