Hawaii will receive $22 million in new federal funding to help offset the estimated $90 million in design and construction costs to realign 4.5 miles of Honoa­piilani Highway vulnerable to sea-level rise and coastal erosion.

The state Department of Transportation submitted a grant proposal in July for the maximum $25 million award under the U.S. Department of Transportation’s Rebuilding American Infrastructure with Sustainability and Equity, or RAISE, program.

U.S. Sen. Brian Schatz, chairman of the Senate Appropriations Subcommittee on Transportation and Housing, announced the grant award today. Schatz said in a news release the project also will receive additional federal funding as part of at least $2.8 billion earmarked for the state in the new bipartisan infrastructure law “to strengthen roads and bridges and make them more resilient to climate change.”

Honoapiilani Highway is the main link between West Maui and the rest of the island. The stretch of roadway from Ukumehame to Launiupoko proposed for realignment is mere steps from the shoreline in some spots, and it’s not unusual for waves to wash over the two-lane highway during periods of high surf.

Olowalu, at roughly midpoint, is ranked as the No. 2 priority site in DOT’s 2019 Statewide Coastal Highway Program Report, and Ukumehame is 12th.

The proposed Ukumehame-to-Launiupoko realignment would connect to the 2.7-mile Lahaina Bypass Phase 1B-2, which opened in April 2018 and runs mauka of Lahaina town. That segment cost $38.6 million.

The remaining costs of the proposed realignment would be covered by 80% federal highways funding and 20% from the state, according to the state DOT. Should the project be fully funded, construction is anticipated to begin in late 2024.

The state agency has said it will work closely on the project with Maui County and the state Department of Land and Natural Resources, which own most of the land needed for the realignment.