The Channel Migration Potential (CHAMP) layer contains stream networks of Western Washington (and much of Western Oregon) with associated data and information important for assessing channel migration activity. It also features information on channel characteristics such as stream flow and physical dimensions. This data layer’s main feature is a classification of channel migration potential based on channel confinement and erosion potential. The layer was derived from existing statewide geospatial datasets and classified according to channel migration measurements by the High Resolution Change Detection (HRCD) project for the Puget Sound Region (Washington Department of Fish and Wildlife, 2014). While the layer identifies the potential for channel migration, it does not predict channel migration rates. Thus, this data layer should be used to screen and prioritize stream reaches for further channel migration evaluation. The tool helps plan and prioritize floodplain management actions such as Channel Migration Zone mapping, erosion risk reduction, and floodplain restoration. The background, use, and development of the CHAMP layer are fully described in Ecology Publication 15-06-003 (full report citation and URL below). That report also describes visual assessment techniques that should be used along with the CHAMP layer to assess channel migration potential. Legg, N.T. and Olson, P.L., 2015, Screening Tools for Identifying Migrating Stream Channels in Western Washington: Geospatial Data Layers and Visual Assessments: Washington State Department of Ecology Publication 15-06-003, 40 p. https://fortress.wa.gov/ecy/publications/SummaryPages/1506003.htmlThe tool developers would like to thank the following people for their contribution to this work: • Brian D. Collins (University of Washington) • Jerry Franklin (Washington Department of Ecology) • Christina Kellum (Washington Department of Ecology) • Matt Muller (Washington Department of Fish and Wildlife) • Hugh Shipman (Washington Department of Ecology) • Terry Swanson (Washington Department of Ecology) This project has been funded wholly or in part by the United States Environmental Protection Agency under Puget Sound Ecosystem Restoration and Protection Cooperative Agreement Grant PC-00J27601 with Washington Department of Ecology. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.Generally, this data layer should be used to screen and prioritize stream reaches for further channel migration evaluation. The data resolution does not allow one to predict channel migration. The classification identifies stream segments for further examination, and those that likely require limited attention or analysis. The potential uncertainty involved in the classification approach is a reason for the visual assessment techniques (described below in Ecology Publication 15-06-003) being described along with the CHAMP data layer.

Ecology created SMA_Jurisdiction_Streams (also known as SMA_Arcs_Adopt) by selecting appropriate flowlines from the National Hydrographic Dataset "NHDFlowline.lyr" as maintained by the Department of Ecology in conjunction with the USGS. This dataset can be used with linear referencing and is synchronized with the March 2019 version of NHD.The original official list of streams that meet the 20 cubic feet per second (cfs) mean annual flow criteria found in state rule at WAC 173-18 HAS BEEN SUPERSEDED by lists contained in Ecology-approved shoreline master programs.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. Streams and rivers westof the Cascades crest with a mean annual flow of 1,000 cfs or greater, and eastof the Cascades crest with either a mean annual flow or 200 cfs or more orthe portion downstream from the first 300 square miles of drainage areas are classified as shorelines of statewide significance.

Points on streams and rivers where SMA jurisdiction begins as published in Chapter 173-18 WAC. This layer will not be updated. It is slowly becoming outdated as cities and counties update their list of SMA streams in their shoreline master program. See WAC 173-18-044 posted at http://apps.leg.wa.gov/wac/default.aspx?cite=173-18-044.Point locations were originally compiled for Ecology in 1972 by the US Geological Survey, Water Resources Division, Tacoma, WA, and released in STREAMS OF WASHINGTON UNDER THE REQUIREMENTS OF THE SHORELINE MANAGEMENT ACT OF 1971. Points were determined using multiple-regression techniques based on streamflow and basin precipitation records. Ecology has occasionally updated point locations, and added and subtracted points since 1972.

Streams and rivers published in Chapter 173-18-WAC. This layer will not be updated. It is slowly becoming outdated as cities and counties update their list of Shoreline Management Act streams in their shoreline master program. See WAC 173-18-044 posted at http://apps.leg.wa.gov/wac/default.aspx?cite=173-18-044.The upstream points where SMA jurisdiction begins were originally compiled for Ecology in 1972 by the US Geological Survey, Water Resources Division, Tacoma, WA, and released in STREAMS OF WASHINGTON UNDER THE REQUIREMENTS OF THE SHORELINE MANAGEMENT ACT OF 1971. Points were determined using multiple-regression techniques based on streamflow and basin precipitation records. Ecology has occasionally updated those points and added and subtracted SMA streams and portions of SMA streams since 1972.

Water bodies (lakes, wetlands, etc.) published in Chapter 173-20 WAC. These will be replaced by water body lists published in local government shoreline master programs. See Chapter 173-20-044 WAC.

Polygons representing natural waterway or channel structure locations (such as sediment ponds, litter traps, weirs, spillways, drop structures) and associated details. Includes description, asset section (for As Constructed drawings) and key attributes. This layer is intended to help identify the location of Melbourne Water's drainage assets for asset management and maintenance purposes.Waterway (Reach) layer created from original FIS 1:50K (Vicmap Hydro) streams data set which included only those waterways within catchments of greater than 60ha. Waterways (Reach) Rectification project undertaken 2001 to 2003 to review and correct the extent of the waterways reach network to ensure a complete data set exists (using the Drainage Metropolis Boundary, 50K data, 1:2500 Drainage Record Plans, Drainage Limits data, orthophotos, as constructed and/or design drawings, contour data and Melway Street Directory). Waterway (Reach) extents defined and attributes populated in GIS and Hansen (AMIS) for all records including assigning nodes and node numbers (for start / end points) and removing any reaches less than 100 metres in length that are predominantly channel assets. Waterways in extended area incorporated in 2005 using Vicmap Hydro data and aerial imagery, then updated in 2009/10 using Lidar survey data (contours). Data is maintained using Lidar survey data (contours) and 60 ha limits. Please refer to metadata for each record in dataset for specific source / accuracy information.NOTE: Whilst every effort has been taken in collecting, validating and providing the attached data, Melbourne Water Corporation makes no representations or guarantees as to the accuracy or completeness of this data. Any person or group that uses this data does so at its own risk and should make their own assessment and investigations as to the suitability and/or application of the data. Melbourne Water Corporation shall not be liable in any way to any person or group for loss of any kind including damages, costs, interest, loss of profits or special loss or damage, arising from any use, error, inaccuracy, incompleteness or other defect in this data.