This project will improve Chiwawa Loop Road (93300), which is a Rural Major Collector (FFC 07) that serves as the main access to the northern area of the City of Plain from the City of Leavenworth. Chiwawa Loop is also the beginning access point for thousands of acres of National Forest Service land and the Thousand Trails Preserve. The beginning of the project will connect to Chiwawa Loop II (CRP 559) at Wending Lane, which was constructed in 2008 and will end at Sumac Lane.
The existing roadway had deteriorating pavement and narrow pavement width. There were unnecessary horizontal curves, a poor intersecting road alignment, a partial fish barrier, drainage deficiencies, obstacles within the clear zone, and a hill with a vertical grade over 10%.
The project addressed the deficiencies listed above by upgrading the structural integrity of the deteriorating pavement and roadway base so it could be maintained at a low life cycle cost. In addition to a new roadway base and surfacing, this project also widened the road from 22-feet to 30-feet, improve roadway geometrics, replaced and added guardrail, constructed a fish passable drainage structure, and made improvements to the roadside and clear zones. In addition, coordination with the local irrigation and water district allowed them to replace their deficient systems and flow grades, while improving the roadway alignment and grade.
Chelan County's efforts in providing these great benefits for the public were recognized at CRAB's annual State Road Design Conference by awarding to the county 1st Place in the 2018 Statewide Project Design Competition.