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Low Impact Development

In 2016, Thurston's Board of County Commissioners (BoCC) approved a project to update Thurston County's development codes to encourage the use of low impact development (LID) in new construction. This project work group included Thurston Regional Planning Council (TRPC).  LID practices retain some of a site's natural water flow and filtering by:

  • Reducing use of concrete and asphalt.
  • Retaining some trees and native vegetation already on a site.
  • Encouraging use of rain gardens (An in-ground, bowl-shaped design with special plants. The shape catches runoff so it can slowly soak into the ground. The plants help filter pollutants.) 

Work Completed
Ordinance 15355 - Adopting Code Changes for Development Codes 
Ordinance 15390 Adopting the Code Changes for UGAs
Update of Thurston County's Current Drainage Manual 
LID Project Materials on TRPC website
Map of LID Projects in Thurston County on TRPC website
Explanation of LID Integration into County Codes on TRPC website

Thurston County Codes/Titles Updated with this Project
Title 14 (Buildings & Construction)
Title 15 (Public Works)
Title 18 (Platting & Subdivisions)
Title 20 (Zoning)
Title 21 (Lacey Urban Growth Area Zoning)
Title 22 (Tumwater Urban Growth Area Zoning)
Title 23 (Olympia Urban Growth Area Zoning)


Legislative Reason for the Code Update
LID additions to code were required by Phase II Western Washington Municipal Stormwater Permit.  The County's pollution reduction activities are mandated and monitored by the U.S. Environmental Protection Agency (EPA) and by the Washington State Legislature.  Thurston County government has a clean water permit from the EPA. When the County issues building and septic permits, builds County roads, or conducts any work, it must comply with federal and state regulations. Find details on the Stormwater Management Program page.

Project Funding
This code update was funded through Stormwater Utility fees.  

Project Date 
Project kicked off in 2014. Planning Commission & public reviews ran from January through June of 2016. Public hearing hosted on June 15, 2016.  BoCC adopted updates October 2016. Updates went into effect December 2016.

Public Outreach

Meeting Date
Meeting Materials (PDFs)
​August 17, 2016 (Planning Commission Public Hearing)
Presentation (PDF)
Draft of Proposed Lacey UGA Updates (PDF)
Draft of Proposed Olympia UGA Updates (PDF)
Draft of Proposed Tumwater UGA Updates (PDF)
​June 15, 2016 (Planning Commission Public Hearing)
Meeting packet and materials 
Presentation (PDF)
Recommendation from the Planning Commission (PDF)