Comprehensive Flood Hazard Management Plan

PUBLIC MEETINGS

April 5-7, 2010

Rochester, Montesano, and Chehalis

What is the Chehalis River Basin Flood Authority?

• Authorized by the Washington State Legislature Spring 2008

• Established by intergovernmental agreement among the member governments

• Established to “develop or participate in the development of flood hazard mitigation measures throughout the basin”

Who are the Flood Authority Members?

• Grays Harbor County• Lewis County• Thurston County• Confederated Tribes

of the Chehalis

• City of Aberdeen• City of Centralia• City of Chehalis• City of Montesano• City of Oakville• Town of Bucoda• Town of Pe Ell

What has the Flood Authority Accomplished?

• Funding studies to aid development of solutions to flood problems:– Evaluating upstream storage facilities– Developing a LiDAR digital elevation

model for the basin– Developing a hydraulic model for the lower basin– Conducting an economic analysis to value

flood protection and ecosystem services

What has the Flood Authority Accomplished?

• Evaluated floodplain regulations in the basin• Funded an assessment of flood warning

systems in the basin• Coordinating with Corps projects• Considering options for establishing a

Flood District for future project funding• Developing a Draft Comprehensive

Flood Hazard Management Plan

What are the Future Plans of the Flood Authority?

• Continue to fund existing projects and studies• Fund the development of an Early

Warning System• Adopt the Draft Comprehensive Flood Hazard

Management Plan• Form a Flood District for future funding

of flood projects

What is a Comprehensive Flood Hazard Management Plan?

• An examination of the cause and effect of flood related problems leading to the development and implementation of feasible solutions

• Focuses on managing the hazards associated with flooding

• Considers both non-structural and structural alternatives

Why did the Flood Authority Develop a Flood Plan?

• Provide a basin-wide evaluation of flood problem areas and potential projects to address the problems

• Develop basin-wide goals for addressing flood problems

• Develop basin-wide criteria for evaluating future projects

• Identify a range of projects to address flood problems in various areas of the basin

• Identify strategies for funding future projects and establishing a flood district

• Based on Flood Plans prepared by member jurisdictions

• Solicited information from:– Flood Authority members and jurisdictions– Public involvement – Agency coordination

How was the Flood Plan Developed?

What is in the Flood Plan?

• Goals • Basin characteristics• Previous studies• Regulatory overview• Basin flood characteristics• Flood problem areas• Mitigation alternatives• Funding options• Recommended actions

What are the Flood Problem Areas?

What are the Flood Problem Areas?

What Types of Mitigation Actions are Recommended?

• Non-structural Measures– Public information

• Provide educational materials such as flood proofing guidance– Regulation

• Improve floodplain regulations, develop floodplain conservation easement programs

– Planning and data collection• Improve hydraulic modeling, study woody debris and stream gravels

– Reduce damage to existing structures• Develop home elevation and buyout programs

– Emergency response and preparedness• Develop early warning system

– Natural resource protection projects• Protect and restore riparian areas

What Types of Mitigation Actions are Recommended?

• Structural Measures– Floodplain protection

• Twin Cities levees, PUD storage facilities– Bank protection

• Bank stabilization and protection– Conveyance capacity

• Widen or deepen channels, open channel migration zone

How will the Flood Plan be Used?

• Provides a project start list for a Flood District• Recommended actions can be incorporated into

the Corps General Investigation Feasibility Study• Flood Plan meets federal and state guidelines;

therefore, projects could be eligible for federal and state funding

What Are the Next Steps?

• Public comments will be incorporated into a revised Flood Plan

• Flood Authority plans to adopt the Flood Plan in June

• Flood Authority will recommend that member jurisdictions adopt the Flood Plan as part of their individual plans and as part of the Flood District formation process

What Can You Provide?

• Comments on the Flood Plan• Specific comments about:

– Flood problem areas– Recommended actions

• Open question and comment period• Listening posts• Comment forms

Questions and Comments?

Contact Information

www.lewiscountywa.gov/chehalis-river-basin-flood-authority

seaston@esassoc.com