KOLOA — Thanks to a federal and state partnership, Kauai’s bridges will be getting some critical repairs.
The Central Federal Lands Highway Division of the Federal Highway Administration, in cooperation with the Hawaii Department of Transportation, is developing four bridge projects on the island, and 10 statewide, to be developed through this peer-to-peer partnership.
• Koloa Bridge 7E
One roadwork project that began in May on Kaumualii Highway (State Route 50) near milepost 7 involves rehabilitating Bridge 7E, about 800 feet west of Tree Tunnel, or Maluhia Road, in the Koloa District. A temporary two-lane bypass road was constructed on the mauka side of the highway for the duration of the construction.
The project aims to improve mobility for highway users, address existing structural deficiencies and meet current design standards for roadway width, load capacity, barrier railing and transitions. The estimated cost is $3.9 million, and completion is scheduled for February 2018, according to the state department.
The two existing culvert structures, which convey flows of an intermittent stream, will be replaced with a longer and wider single-cell box culvert with no change in highway alignment.
The new structure will continue to carry two travel lanes (one in each direction) with a 44-foot-wide section consisting of 12-foot-wide lanes, two 8-foot-wide shoulders, and 2-foot-wide crash-tested railings.
Construction is progressing through December to include the final bridge deck, retaining walls, and grading and gravel placement at the bridge approaches. Traffic will remain on the temporary bypass until the replacement has been completed.
• Hanapepe River Bridge
A proposed project on Kaumualii Highway, the coastal perimeter road serving the Westside looks to improve the safety and reliability of the Hanapepe Bridge, crossing the Hanapepe River near Hanapepe Bay. The existing three-span structure will be replaced with a longer and wider bridge to accommodate two 12-foot travel lanes, two 8-foot shoulders and two 5-foot sidewalks for improved safety and reliability.
The estimated construction cost is $23 million for a scheduled duration of 24 months. A Multiple Award Task Order Contract has been awarded, and construction of a temporary bypass bridge by Hawaiian Dredging is anticipated in early 2018 before the main project can begin.
• Kapaa Stream Bridge
The proposed project in the Kawaihau District on Kuhio Highway (Route 56) near milepost 10 would improve the Kapaa Stream Bridge through rehabilitation or replacement. The project also proposes to improve the highway intersection at Mailihuna Road, which would include roadway widening, lighting, signage, pavement markings, drainage, walkway and traffic signal installation. On-going design activities support developing a roundabout configuration at the intersection.
Right-of-way acquisition is underway with affected landowners and utility agencies. The estimated construction cost is $11.7 million for the replacement bridge and $2.4 million for the roundabout. Construction is anticipated to begin in early 2018 for a duration of 22 months. The construction schedule may be updated as the project progresses through design and permitting.
• Wainiha Stream Bridges
The last project will be Kuhio Highway (Route 560) on the North Shore in the Hanalei District between milepost 6.4 and 6.7, near the mouth of Wainiha Stream before it feeds into Wainiha Bay. The proposed project will replace three temporary bridges with permanent structures. The original bridges were replaced with prefabricated, modular steel bridges after Bridge #2 suffered permanent damage, and #1 (the southernmost bridge) and #3 (the northernmost bridge) were determined to be structurally deficient.
There are three load-restricted bridges that cross Waioli, Waipa, and Waikoko streams that must be crossed to access the Wainiha Stream bridges. These bridges may be unable to accommodate construction loads, so alternatives such as temporary bridges or supplemental supports will be studied to provide construction access. Preparation of the final environmental assessment is also in process.
The project is estimated to cost between $20 to $25 million. Construction is anticipated to begin after all necessary permits and approvals are secured, and bridge work is expected to last for approximately two years.