Abstract Title

Session S-07G: Integrating Landscape Scale Assessments Into Local Planning II

Keywords

Planning Assessment & Communication

Location

Room 6E

Start Date

1-5-2014 3:30 PM

End Date

1-5-2014 5:00 PM

Description

The City of Mukilteo is experiencing high peak stream flows, ravine instability, and decreased water quality associated with development. To address these issues, the City and its project partners, City of Everett; Snohomish County Conservation District, Snohomish County Airport, the Mukilteo School District and the Department of Ecology, have developed a Stormwater Strategy Plan to prioritize and implement regional, watershed-based stormwater strategies and support the City’s stormwater comprehensive plan. Ecology’s Puget Sound Characterization (Stanley et al 2011), which establishes a framework to evaluate watershed processes, was the basis for this analysis. As part of the characterization work, Ecology and WDFW developed equations to characterize water flow processes, water quality, and habitat based on physical attributes of the landscape. Results were normalized to score watershed processes at a regional scale. This project divided the study area into project analysis units (PAUs), normalized Ecology’s results at a local scale, and used finer resolution data to evaluate watershed processes. Secondary scores, such as freshwater habitat and sediment delivery, which reflect unique City goals, were also incorporated. Each PAU had a unique score consisting of an importance score, representing the importance of key processes before development, and an intactness score, representing how intact each process is under existing conditions. The scores were used to develop a suite of relatively broad, yet distinct, stormwater management strategies designed to improve impaired processes. Specific recommendations for each PAU were then developed based on known limitations and problems, opportunities identified by others, and feasibility. The results were also used to prioritize PAUs; those with higher importance and intactness scores were given a higher priority for implementation of stormwater strategies than PAUs with lower importance and intactness scores.

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May 1st, 3:30 PM May 1st, 5:00 PM

Mukilteo Watershed-Based Stormwater Strategies Plan

Room 6E

The City of Mukilteo is experiencing high peak stream flows, ravine instability, and decreased water quality associated with development. To address these issues, the City and its project partners, City of Everett; Snohomish County Conservation District, Snohomish County Airport, the Mukilteo School District and the Department of Ecology, have developed a Stormwater Strategy Plan to prioritize and implement regional, watershed-based stormwater strategies and support the City’s stormwater comprehensive plan. Ecology’s Puget Sound Characterization (Stanley et al 2011), which establishes a framework to evaluate watershed processes, was the basis for this analysis. As part of the characterization work, Ecology and WDFW developed equations to characterize water flow processes, water quality, and habitat based on physical attributes of the landscape. Results were normalized to score watershed processes at a regional scale. This project divided the study area into project analysis units (PAUs), normalized Ecology’s results at a local scale, and used finer resolution data to evaluate watershed processes. Secondary scores, such as freshwater habitat and sediment delivery, which reflect unique City goals, were also incorporated. Each PAU had a unique score consisting of an importance score, representing the importance of key processes before development, and an intactness score, representing how intact each process is under existing conditions. The scores were used to develop a suite of relatively broad, yet distinct, stormwater management strategies designed to improve impaired processes. Specific recommendations for each PAU were then developed based on known limitations and problems, opportunities identified by others, and feasibility. The results were also used to prioritize PAUs; those with higher importance and intactness scores were given a higher priority for implementation of stormwater strategies than PAUs with lower importance and intactness scores.