Thurston County facilities are now open to the public with restrictions, including maintaining physical distancing of at least six feet at all times and, per the Washington State Secretary of Health’s face covering order wearing a cloth face covering or mask. If you come to county facilities, please be prepared for potentially long wait times or lines due to distancing guidelines. We continue to encourage residents to access county services online, by phone, by email, or through the use of drop boxes located outside of county buildings.
The availability of remote services vary by office and department.

Click here for office and department contact information
Click here for information on COVID-19

Green Cove Creek Drainage Basin Plan

Green Cove Creek Comprehensive Drainage Basin Plan, December 1998, adopted by the City of Olympia and Thurston County

Note: The basin plan on this Web page has been divided into several PDFs to make it easier for viewers to find information.  

Although the PDFs are generally about 25-35 pages long, they still take time to load because the PDFs were created by scanning a paper-version of the document (as opposed to simply converting a Word document to a PDF).

Instead of waiting to view the files through this web site, a better choice is to right-click the underlined hyperlink and then "save target" (ie., save the file) to your own computer and open it from there. Use the magnifying glass in Adobe to zoom in.


Section 1 (PDF)
  • Resolution 11869
  • Determination of Nonsignificance
  • Executive Summary
  • Vicinity Map
  • Acknowledgements
  • Table of Contents
  • Chapter 1 Introduction
  • Chapter 2 Basin Characterization
Section 2 (PDF)
  • Chapter 3 Hydrology
  • Chapter 4 Water Quality

Section 4 (PDF)
  • Chapter 6 Problem Identification and Prioritization
  • Chapter 7 Analysis of Alternatives to Reduce Future Peak Flows in Green Cove Creek
  • Chapter 8 Recommended Plan
  • Chapter 9 Recommended Plan Implementation
  • References
  • Appendix A: Regulatory Authority for Basin Plan Measures
  • Appendix B: Regional Nonstructural Management Program
  • Appendix C: Soils Description
  • Appendix D: Green Cove Basin Wildlife
  • Appendix C: Habitat Survey Data