As of May 16, 2022, all new and redevelopment construction
projects, both private and public, must comply with the 2021 King
County Surface Water Design Manual.
2021 King County Surface Water Design Manual
Burien's
surface water features (lakes, wetlands, streams, and Puget Sound) are a
significant part of our natural beauty and rich heritage. Spawning
salmon, meandering streams, and clean water are important natural
resources that must be managed wisely to protect their value. With this
in mind, the City of Burien has taken steps to preserve and restore the
natural environment through managing the stormwater runoff created by
new and redevelopment projects within the City.
Through the end of
2016, the City required construction projects to meet standards set in
the 2009 King County Surface Water Design Manual. In order to comply
with the City’s current NPDES Stormwater Permit from the Washington
Department of Ecology, the City adopted the updated 2016 King County
Surface Water Design Manual, which became effective for all new
development and redevelopment projects submitting applications beginning
January 1, 2017. This Surface Water Design Manual contains the
requirements and standards for designing stormwater management systems
in the City of Burien. As part of the permit approval process for
certain types of permits for proposed projects, Burien requires the
construction of surface water and stormwater management systems to
mitigate the impacts on natural and existing man-made drainage systems.
Changes from 2016 Manual
The most significant change to the new King County manual is the
addition of Low Impact Development (LID) BMPs (called Flow Control BMPs
in the manual), which will be required for nearly all development
projects within the City. These BMPs include facilities such as
bioretention (rain gardens), permeable pavements, dispersion, and onsite
infiltration.
As described in the 2021 King County Surface Water
Design Manual, existing site conditions shall be considered historic
site conditions. Historic site conditions are those that existed on the
site prior to any development in the Puget Sound region (ref. BMC.
13.10.140). Historic site conditions shall be assumed to be forest
cover.
For
current and past projects still utilizing the 2016 King County Surface
Water Design Manual, information regarding the 2016 manual is available
here: 2016 King County Surface Water Design Manual.
More information
Please direct your comments or questions to Heungkook Lim at (206) 248-5516, or [email protected].
Updated September 29, 2022