Planning & Construction

Public Works is responsible for the improvement, maintenance, and preservation of the county’s roadways, bridges, water and sewer utilities, parks, trails, drainage systems, and solid waste. Keeping up with Thurston County’s growing population and aging infrastructure requires constant planning and construction activities.

 Construction Projects

Find information about current Public Works construction projects  by visiting our projects dashboard. Here you will find information with links to all of our current active and upcoming planned projects.

Want to know more about planned Public Works projects? Our Transportation Improvement Plan provides a great overview of our planning and project selection process, our 1-year, 6-year, and 20-year planned projects, as well as project funding information.

 County Infrastructure


Public Works is responsible for the inspection, maintenance, rehabilitation, and construction of 100 bridges in Thurston County. The Bridge Index: Summary of bridge conditions provides the most current information on Public Works bridge projects and the state of Thurston County bridges.


The county's drainage system includes culverts, storm drains, roadside ditches, and detention ponds. Visit the county's Stormwater Utility Program for more information about the county's management of stormwater. The Thurston County Drainage, Design, and Erosion Control Manual provides engineering standards for stormwater facility design.

To protect fish habitat, Public Works manages a Fish Passage Enhancement Program. Using funds from local and grant sources, our goal is to replace culverts that are barriers to fish passage.

Road Inspections

County roads are inspected annually to determine maintenance needs. Inspectors review the amount of surface cracking and potholes and give each road a rating that ranges from very good to poor/failed. These ratings help Public Works determine which roads get fixed each year. Read more about our Road Preservation Program.

 Survey monuments

Did you know that modern day property boundaries are based on surveys conducted in Thurston County during the late 1800s? Early surveyors marked out boundary lines using a combination of round brass or metal monument markers, etchings in trees, poles, carved rocks, or just about anything that would stay still. These boundaries serve as the basis for the topographical maps we use to build projects. Hikers also find them useful to estimate the amount of elevation gain or loss on trails.

There are approximately 4200 known monument markers placed around Thurston County. If you're interested in learning more about where monument markers are located around Thurston County, visit the National Geodetic Survey.

For easy reference, here is a map showing all the special flood hazard areas in the county, locations of NGS monuments within one mile of these flood areas, and flood areas within 30 miles of at least three continuously operating reference stations.

 Transportation Planning

To help Thurston County keep up with the growing population and transportation demands, Public Works conducts studies to find the best solutions for our community.