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Watersheds, rivers and streams

General Information

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King County Watersheds

Normative Flow Studies

Relating Flow Regimes to Ecological Outcomes

Picture of Snoqualmie Valley The Normative Flow Studies project seeks to enhance our understanding of the relationship between river and stream flow patterns with ecological parameters. This understanding will be used to develop a stream assessment methodology and analytical tools that will help King County to evaluate the effects of management actions (such as water reuse, stormwater management, and flood hazard management) in protecting or restoring a flow regime that supports ecosystem health and salmon conservation goals.

Project Goals and Objectives

In order to promote salmon conservation and ecosystem integrity within King County, the Normative Flow Studies project seeks to develop and employ Normative Flow concepts to influence policies and programs and optimize management actions that affect or respond to river and stream flow conditions. In support of this goal, the project has the following objectives:
  • Develop a valid and defensible river and stream assessment method, employing and testing Normative Flow concepts, for use in King County rivers and streams
  • Develop new analytical tools (e.g, models, databases, etc.) and/or adapt existing tools to support the assessment method
  • Provide analytical tools to Water Resource Inventory Areas (WRIAs) and other interested parties for consideration and use as needed to fill gaps in technical programs
  • Develop and employ educational tools that improve understanding of Normative Flow analysis and its relevance to policy and program development and implementation
  • Apply the assessment method to evaluate the efficacy of current or proposed flow regimes for ecosystem and conservation objectives
  • Formulate flow management recommendations based upon the assessment and analytical methods
  • Use the flow management recommendations to inform technical, regulatory (e.g, permitting), and policy decisions specific to King County
  • Monitor and evaluate the effectiveness of management actions based upon Normative Flow concepts to develop and implement corrections in analysis and actions as a result

Project Products

Visit the Normative Flow Studies Project Products page for more information about the conceptual foundation of the Normative Flow Studies project, the development of hydrological and biological indicators of flow alteration in King County’s lowland stream systems, and efforts to understand the ecological consequences of flow management actions at the river scale through the Middle Green River Flow Investigation.

Science Review Team and Project Partners

Visit the Science Review Team and Project Partners page for more information about the team of nationally-known scientists providing technical guidance and peer review for the project, along with information about tribal, state, and federal agency participation in the Normative Flow Studies project.

Related Information

Visit the Normative Flows Links page to find out more about efforts to link flow regimes to ecological parameters and native species sustainability in other parts of the United States and around the globe.

For information about the Normative Flow Studies, please contact Curtis DeGasperi, Hydrologist, WLR Science, Monitoring and Data Management Section.