Maui project aims to restore landscape, mitigate axis deer damage and reduce erosion above Kīhei

A collaborative project to protect against erosion, reduce flood risk, mitigate axis deer damage, and improve water quality is being implemented in an 11-acre area mauka of Kīhei. 

The Hapapa Watershed Axis Deer Damage Mitigation project is a joint effort managed by the Central Maui Soil and Water Conservation District (CMSWCD) in partnership with Haleakalā Ranch, Maui Environmental Consulting and the Hawaiʻi Department of Health. The endeavor will revegetate and stabilize an area on the leeward flank of Haleakalā that has been overgrazed and denuded by axis deer and other feral ungulates.

Lacking vegetative groundcover, exposed landscapes are highly susceptible to soil erosion. During rain events, sediment can be swept away in stormwaters and deposited on streets, homes, and in critical habitats such as wetlands and coral reefs. 

“When there’s been heavy rainfall on the slopes above Kīhei, South Maui has been hit by brown water events that are very costly both environmentally and economically,” said Mae Nakahata, CMSWCD chair. “Roadways, bridges and homes get flooded; sensitive ecosystems are smothered by sediment; and coastal water quality is compromised. We’re very excited to move forward with this project, to help reduce those risks by restoring those upslope acres to a healthier state.”

The Hapapa Watershed Axis Deer Damage Mitigation project also aims to improve water quality by re-establishing vegetation in the project area using R-1 recycled water from the Kīhei Wastewater Treatment Facility for irrigation.

Currently, millions of gallons of R-1 water from the Kīhei Wastewater Treatment Facility are injected into underground wells each day. The nutrient rich water percolates through the ground and drains into the ocean, negatively impacting nearshore water quality and degrading important marine habitats. Incorporating R-1 water into the project removes that water from underground injection wells, supports revegetation of the landscape, and contributes toward aquifer recharge and improved water quality. The newly grown groundcover will be managed by cattle grazing.

Funding for the project totals $156,700, which includes $119,900 from the US Environmental Protection Agency and $36,800 in matching contributions from Maui Environmental Consulting and Haleakalā Ranch.

The Central Maui Soil and Water Conservation District works to protect and conserve soil and water resources via watershed planning, improving water quality, flood prevention, restoration, runoff control, wildlife habitat restoration and environmental education. For more information, visit www.mauicountysoilandwater.org. 

This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement C9-96978722-0 to the Hawaiʻi State Department of Health, Clean Water Branch. The contents of this document do not necessarily reflect the views and policies of the EPA, nor does the EPA endorse trade names or recommend the use of commercial projects mentioned in this document.