Updates are required by the Washington State Department of Ecology, typically on a five-year cycle. The Manual was last updated in 2015. It made Low Impact Development Principles and Best Management Practices the preferred and commonly used approach for development.
Pierce County must update the 2015 Manual by July 1, 2021.
In addition to incorporating some minor staff and industry-requested changes, there are nine significant changes required for this update in the following areas:
- Continuous Simulation Modeling
- Replaced Hard Surfaces Redevelopment Threshold
- Equivalent Areas
- Minimum Requirement 2
- Minimum Requirement 5
- Minimum Requirement 7
- Concrete Washout Best Management Practices
- Source Control Best Management Practices
- Wetlands Guidance
Ecology Requirements:
Comment on draft changes by June 1
The draft updates are available to download below as Word documents in a track changes format. There are also two spreadsheets that summarize the changes. Please review the drafts and
submit comments, suggestions or questions by June 1.