$40M emergency stormwater capture system to be installed in Lahaina

The Hawaiʻi Department of Transportation, County of Maui, and the Federal Highway Administration is installing an emergency stormwater capture system in Lahaina to reduce the environmental impact from silt, ash and other disaster debris potentially entering storm drainage systems.

The $40 million project, which includes design, construction management and continued management of the system through 2024, is funded through the FHWA Emergency Relief program.

The area to be covered by the stormwater capture system includes the entire length of Front Street, Honoapiʻilani Highway between its southern connection with Front Street and Wahikuli Wayside Park, and stormwater inlets in Leialiʻi Hawaiian Home Lands, Kapunakea, Māla, the Puʻunoa Beach area, Lahaina Town, Lunaville, and Waineʻe.

Work to prepare the area for installation has begun. People may notice the Best Management Practices (BMPs) in the form of green “socks” or fences to filter sediment and pollutants being installed in the project area.

Additional measures may include:

• Debris removal through street sweeping, vacuum trucks and road crews.
• Source control through the application of hydromulch in open grubbed areas that are historically prone to erosion during storm events. Only nontoxic and biodegradable materials that have previously been used on Maui will be used for the hydromulch.
• Inlet protection using sediment fabrics on inlets and catch basins to provide additional filtering of stormwater as it enters drainage structures.
• Capture and treatment by temporarily capturing and diverting stormwater for pollutant removal before discharging it back into the storm drainage system.

For more information on Maui stormwater management visit https://www.stormwatermaui.com/ and https://www.mauicounty.gov/2129/Stormwater-Management-Program.