SR 520 Bridge Replacement and HOV Program - Evans Creek mitigation

WSDOT provided wetland mitigation at the confluence of Bear Creek and Evans Creek in Redmond. This work was part of the Medina to SR 202: Eastside Transit and HOV Project

Site map of Evans Creek mitigation

WSDOT, the city of Redmond and local watershed groups identified the Evans Creek mitigation site as an important wetland habitat area. The mitigation work performed here strengthens the local natural environment by improving the quality of wetland habitat. The improvements mitigate for a loss in wetlands resulting from construction of the Eastside project.


Project overview

Through the environmental review process, WSDOT works to avoid, minimize and mitigate for all project effects. While we have avoided and minimized construction impacts to the greatest practical extent, the Eastside highway project resulted in the loss of approximately 6.3 acres of wetlands in the project area. To mitigate for the loss, WSDOT provided improvements at the Evans Creek site. 

WSDOT provided wetland mitigation of approximately 32 acres near the city of Redmond. This mitigation occurred on land that was previously farmed. WSDOT will monitor this site and collect data on plants, wildlife, soil and water for up to 10 years to ensure the site is compatible with and contributes to the local ecosystem. 

The project team worked with resource agencies and tribes to identify the Evans Creek site. WSDOT worked with the agencies and tribes through project design and continued to engage with these stakeholders during work on the site.


Ecological benefits of the mitigation project

A view of Evans Creek, looking eastEvans Creek and Bear Creek contain Cedar River, Issaquah and North Lake Washington Chinook salmon populations. In fact, Bear Creek has the highest abundance of Chinook salmon of all Northwest tributaries.

The Evans Creek mitigation site will support a variety of wetland plants and wildlife. Native plants will provide better habitat than the non-native reed canarygrass that had taken over this area, and will improve water quality and benefit salmon and other species.

Native wetland plants include dogwood, salmonberry, willow, and native wetland grasses. Other native plant species include black cottonwood, red alder, Western red cedar, and Sitka spruce. The project also incorporated habitat enhancing features such as large and small woody debris.


Project timeline

Work on the site began in summer 2012, and was completed in late 2013. WSDOT will monitor the site until 2024.