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Watershed Characterizations
A watershed characterization is a science-based examination of the features of a watershed, and how those features interact to affect the watershed's natural environment. Characterization studies provide baseline science for policymakers to use when making regulatory and land-use decisions -- for example, the data may be used to identify which areas of a watershed have the best chance of being restored, or which areas are most vulnerable to development.

Methodology to a Watershed-Based Approach to Federal and State Clean Water Act Regulations

September 2013
Complete Document

Individual Sections:
Part 1   Landscape Characterization
Part 2   Characterize Condition of Ecological Processes in Study Area
Part 3   Characterize Natural Resources in Study Area
Part 4   Assess Potential Sites within Context of Landscape
Part 5   Potential Uses of Watershed Characterization Results
May 2012

Individual Sections:
Part 1   Landscape Characterization
Part 2   Characterize Condition of Ecological Processes in Study Area
Part 3   Characterize Natural Resources in Study Area
Part 4   Assess Potential Sites within Context of Landscape
Part 5   Potential Uses of Watershed Characterization Results

How watershed characterizations help protect watersheds, water quality and aquatic resources from impacts of growth  (PDF)

Watershed Characterization Studies

Deschutes Watershed

Henderson Inlet Watershed

Nisqually Watershed

Appendices (LPK files):  Appendix E Floodplain  |  Appendix E Riparian  |  Appendix E Wetlands

Totten-Eld Inlets

Watershed Characterizations Funding History

In 2006, the Board of Thurston County Commissioners approved a $40,000 grant from the former Puget Sound Action Team (now the Puget Sound Partnership) to conduct a Watershed Characterization (a land cover/land-use description) of the Henderson Inlet. The work was funded as a pilot to assess the feasibility of a watershed based National Pollutant Discharge Elimination System (NPDES) permit. The overall goal is to take a watershed approach to natural resource management.

The completion of the Henderson Inlet Watershed Characterization resulted in additional grant funding to complete characterizations of all Puget Sound drainages in Thurston County.

In 2008, the Environmental Protection Agency (EPA)  awarded Thurston County a $623,059 grant to complete a detailed landscape description of areas experiencing rapid environmental change, including Totten and Eld Inlets; Deschutes Watershed; and Nisqually Watershed.. The project involved using highly sophisticated satellite imaging data to create an inventory of land cover, which was then used to create a list of priority natural-resource sites (such as wetlands, floodplains and riparian zones).

The total project cost was approximately one million dollars. The match to the EPA grant funds consisted of current activities within the Environmental Health Department; Storm and Surface Water Utility Fees collected from Thurston County property owners; and a $70,000 grant from the Washington State Department of Ecology to monitor Yelm and Thompson creeks stream flow, groundwater levels, and precipitation.

The expenditure of funds exceeded the project cost by approximately $50,000 and delayed completion of the project by one year because Thurston County embarked on an extensive Peer Review. The reviewers included Derek Booth, PhD; David Montgomery, PhD, and Richard Horner, PhD. Their review provided valuable input and provided assurance that the Methodology and the results of Watershed Characterization met the Best Available Science threshold.