DESCRIPTION
This summer (2018), Chelan County Natural Resources Department (CCNRD) will install a culvert under SR 207 to improve fish access to floodplain habitat. An 18' diameter culvert will be installed approximately 0.5 mile north of Coles Corner to provide fish access to 13 acres of off-channel rearing and high flow refuge habitat. SR 207 will be closed with a detour via Chumstick Highway for 2-4 days sometime after Labor day. If you have questions about this project, keep reading the project background information below, see the project files attached to this web site, and/or contact Jennifer Hadersberger, (509) 860-1022.
Project Background
In 2011, an alternatives analysis was completed to evaluate stream habitat enhancement projects near river mile 4 in Nason Creek. Nason Creek river mile 4 is located just downstream from the intersection of Hwy 2 and Coles Corner. The alternatives analysis evaluated background information and existing site conditions to identify the following alternatives to enhance instream and floodplain connection processes near RM 4 on Nason Creek:
1. SR 207 Relocation
2. Installation of a causeway to reconnect the mainstem to the floodplain
3. Two large bridges to reconnect the mainstem to the floodplain
4. Installation of one or two culverts under SR 207 to reconnect the mainstem to the floodplain
5. Engineered log jams in the mainstem of Nason Creek
6. No action alternative
Following completion of the Alternatives Analysis in Febuary 2012, the Regional Technical Team requested more information about the feasibility of SR 207 relocation and the biological benefit of reconnecting 77 acres of floodplain habitat. CCNRD worked with USFS, WSDOT, and other stakeholders to evaluate the feasibility of SR 207 re-location. SR 207 relocation is estimated to cost 10-20+ million and that level of funding was not available at this time. In addition, the feasibility study indicated that avalanches may present a safety hazard in the vicinity of the proposed re-location route.
Therefore, CCNRD secured funds from Bonneville Power Administration to implement alternative #4 from the list above which was the second choice alternative of the Regional Technical Team during their February 2012 review. This alternative would reconnect 13 acres of floodplain by installing a culvert under SR 207.
Another project was developed at this location through feedback on the alternatives analysis and further review of the USBR Kahler Reach Assessment. In 2014, 0.6 acres of floodplain fill were removed near RM 4.6 to improve floodplain connectivity within this reach.