KENAI, Alaska (AP) — An Alaska city plans to outsource engineering services in coordination with the U.S. Army Corps of Engineers for a project to stabilize bluffs along the Kenai River.
Kenai plans to use the Kenai Bluffs Stabilization Project to help maintain an area along the north shore of the river, the Peninsula Clarion reported Tuesday.
The project, which has been in the works for decades, aims to stabilize about 5,000 feet (1,524 meters) of the steep terrain beginning at the mouth of the waterway southwest of Anchorage.
A March 2019 feasibility study conducted by the Corps recommended a protective berm at one end of the bluff. Other options included relocating the river mouth and moving threatened structures.
The city opened a request for proposals for professional engineering services. Kenai Public Works Director Scott Curtin spoke to several potential bidders and extended the submission deadline to March 4.
Requested services include site surveys, geotechnical work, engineering studies and draft plans.
Interested bidders were asked to focus mainly on the construction of a berm at the base of the bluff, which would prevent flood tide water from washing away material collecting at the bottom of the bluff and protect the lower portion from storm damage.
Continued erosion is expected to move soil to the bottom of the bluff that will accumulate between the face and the berm, developing a more stable slope. The increased soil is expected to encourage vegetation growth that would provide further stabilization.
The Corps estimated the project would have benefits of about $824,000 and average costs of $1.62 million, resulting in a loss of about $796,000 each year.
The cost of not acting could be greater. The Corps estimated leaving the bluff unchanged would result in $39,000 in land damages, $359,000 in structure and nonstructural improvement damages and $66,000 in public infrastructure damages annually.
The damages would be in addition to an estimated annual loss of $624,000 in recreation value.
The Corps said not taking action would also likely result in 31 properties with 34 structures and 23 nonstructural improvements eventually being condemned.
Kenai City Manager Paul Ostrander said the final project cost is expected to be lower than the Corps estimate.