Aug 22, 2019

Hawaii Plans Watershed Flood Control Project

Hawaii flooding damages have totaled an estimated $700,000 annually each five years

Hawaii flooding damages have totaled an estimated $700,000 annually each five years

In Lahaina, Hawaii, flooding has occurred every five years resulting in annual damages. According to Lahaina News, district stewards want to change that with the completion of the Lahaina Watershed Flood Control Project.

"The Lahaina Watershed Flood Control Project included five phases: 1, 2B, 3A, 3B, and 4/5. Phase 1, a Diversion Channel, was installed in 2011. Phase 2B, also a Diversion Channel, was installed in 2013. Phase 3A, Hokiokio Place, was installed in 2014. The design of Phase 3B, a Debris Basin, was completed in 2014. Phase 4/5 was not completed," said Susan Kubo, Natural Resources Conservation Services spokesperson, according to Lahaina News.

The flood control project has struggled getting off the ground since it was first proposed to the USDA Natural Resources Conservation Service by the West Maui Soil and Water Conservation District (WMSWCD) in 1981, according to Lahaina News

Now, multiple WMSWCD volunteers are making sure the two-mile flood diversion system is completed. According to Lahaina News, the project will help “channel floodwaters southwesterly from Lahainaluna Road to Waianukole, through about 10,000 ft of grass-lined channel, four sediment basins, one debris basin on Kaua'ula Stream and one outlet basin near Lahainaluna Road.”

The Kahoma Watershed experienced the heaviest flooding in 1960, with 21.7 in. of rain flooding 30 businesses and homes. According to Lahaina News, the financial hit was $5 million to $10 million.

According to Lahaina News, the next 100-year storm could leave lasting damage. It is projected to impact 197 residences, 35 condominiums, 157 businesses, two parks, two schools and the main roads. According to The Maui News, the Lahaina facility has operated in compliance with state and federal Safe Drinking Water Act permits for decades.

Flooding damages have totaled an estimated $700,000, according to The Maui News. Since 1879, there have been 26 major floods.

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