Skip Top Navigation

WSDOT and Wetlands

fish rearing and over wintering habitat
The creation of fish rearing and over wintering habitat on Harris Creek was part of a WSDOT wetland mitigation effort near Carnation, Washington.

Technical Information

Looking for specific technical information or resources? The Assessment Toolbox and the Mitigation Toolbox provide links, templates and guidance for wetland practitioners.  Narrative information on other wetland topics can be found on the left hand side of this page.   

What are wetlands?  

Wetlands are transitional areas between land and water. Wetlands are saturated with water or covered by shallow water at least part of most years. Only specially adapted plants can thrive in these wet, saturated soil conditions.  

Obvious wetlands include swamps, marshes, and bogs. Less obvious wetlands may only hold water for a few weeks in the spring. The U. S. Environmental Protection Agency and the U.S. Army Corps of Engineers provide a more technical definition for wetlands they regulate. These wetlands can only be reliably identified by a qualified wetland biologist.

Why are wetlands important?  

Wetlands provide ecological and economic benefits to the state because they:

  • protect and preserve drinking water supplies;
  • provide a natural means of flood and storm damage protection;
  • provide essential brooding, spawning, rearing, feeding, nesting, and wintering habitats for fish and wildlife; 
  • provide special vegetation communities; 
  • serve important functions for surface and groundwater supplies of the state; and 
  • provide outdoor training and educational resources.

Why do we protect wetlands?

Federal, state and local authorities regulate wetlands because of their importance. As a public works agency, WSDOT must obtain appropriate approvals and permits from regulatory agencies when projects cause damage to wetlands.

How does WSDOT protect wetlands? 

WSDOT’s Environmental Policy supports sound environmental protection practices in the planning, design, construction, operation, and maintenance of Washington’s transportation systems and facilities. The Transportation Decision-Making Process is a sequence of events that model efficient project delivery. The decision-making process incorporates mitigation sequencing to avoid and minimize impacts to wetlands. Compensation for unavoidable impacts is constructed and monitored until it is determined to be successful by regulating agencies.

Wetland Monitoring Internship  

In partnership with the The Evergreen State College (TESC), WSDOT offers the Wetland Ecology and Monitoring Techniques internship each summer. Graduate and undergraduate students from a variety of academic and experiential backgrounds are encouraged to apply. Information regarding the next internship is typically available in November of the preceeding year. You may also contact Doug Littauer for information via e-mail or phone (360-570-2579).  

How is WSDOT accountable for unavoidable adverse effects to wetlands?

In addition to annual monitoring reports on each site, we report on our progress in the Gray Notebook