Plans to Repair Ka‘ahakini Stream Bridge Unknown

Ka‘ahakini Stream Bridge (PC: Department of Public Works)

There are currently no plans to restore the Ka‘ahakini Stream Bridge, which was deemed structurally deficient by state and local officials last week.

The bridge, located on the outskirts of Hilo between Highway 19 and Old Māmalahoa Highway, was shut down on Oct. 30 after an inspection by the Hawai‘i Department of Transportation revealed erosion and scour around the abutment, creating an imminent threat of bridge collapse.

Built in 1929, the deterioration of the structure has concerned county officials for several months. According to the Department of Public Works (DPW), scour and erosion over the past 30 years has gradually resulted in the foundation of the bridge to weaken, requiring repair or rehabilitation.

“Because Ka’ahakini Stream Bridge is a perennial stream, scour and erosion has been slow, but gradual,” DPW officials state.

Old Māmalahoa Highway remains closed between the intersections of Chin Chuck Road and Kaiwiki Homestead Road. A detour route is available traveling mauka on Chin Chuck Road to Kanna Road and Kaiwiki Homestead Road.

The decision to restore Ka‘ahakini Stream Bridge will be at the discretion of the next Administration.

Before the recent inspection, the bridge was looked at in June 2019 as part of a biennial bridge inspection mandated by the Federal Highway Administration (FHWA) and HDOT. Also, DPW has been monitoring the bridge every three to four months, due to its condition.

Approximately 30 to 40 residents live along the portion of Old Māmalahoa Highway where the bridge is located. The County plans to repair the nearby Kolekole Bridge to improve access for Kaiwiki Homestead Road residents. The project is estimated to take about 18 months.

Hawai‘i Island has a total of 129 bridges in the National Bridge Inventory (NBI) that are inspected every two years as part of the Federal Bridge Inspection Program. NBI structures are bridges or culverts that carry vehicular traffic and are more than 20 feet long.

Of those, 51 bridges are classified as structurally deficient according to the FHWA and HDOT rating system. Additionally, many other bridges are classified as functionally obsolete.