Maui County Council members are looking at funding a study to find if there are more sources of fresh water near Lahaina and take a look at potential changes in the aquifer.

The council’s Water and Infrastructure Committee recommended Bill 19 authorizing the mayor to enter into a joint funding agreement with the U.S. Geological Survey to determine the sustainable yield of the Launiupoko aquifer by selecting a site for a monitoring well.

The availability of water remains a major issue as Lahaina residents look at ways of having a ready supply to fight future wildfires and increase the nearby affordable housing inventory.

Maui County Council chair Alice Lee said it is “essential” the county develops new water sources in Lahaina.

The bill was requested by Maui County Mayor Richard Bissen.

Lee said the county administration should take a leadership role in bringing all relevant parties together such as the state Commission on Water Resource Management, state Department of Hawaiian Homes and private purveyors to produce a fair, viable and workable plan that can be implemented immediately.

The USGS said it has limited information from wells inland above sea level at Launiupoko where a study indicated groundwater levels are hundreds of feet above sea level. The agency said a deep monitor well in the Launiupoko area will help to provide more information and track changes in the freshwater lens.

According to the state Commission on Water Resource Management, the sustainable yield of the aquifer is 7 million gallons a day.

The USGS said withdrawal from all groundwater sources at Launiupoko peaked at 16.4 million gallons a day in 1995 before sugarcane cultivation by the Pioneer Mill shut down operations in 1999.

A recent study identifies Launiupoko as having the greatest decrease in aquifer system recharge on Maui.

According to the USGS, groundwater recharge in the Launiupoko aquifer system area is generally greatest in wet mountainous areas and least in deer coast areas, although irrigation has greatly enhanced recharge in dry areas.

Estimates of ground water recharge at the Launiupoko aquifer have varied widely in the past from 16.83 million gallons a day to 42.68 million gallons a day, depending on the condition of the land.

The cost of the first phase of a one-year study is $150,000 and does not cover the cost of equipment and supplies, according to the USGS.

In a summary, the USGS said the resident population of Maui has increased from 38,691 in 1970 to 154,100 in 2020, increasing the groundwater demand for public water supply and increasing groundwater withdrawals.

The proposed work at Launiupoko involves looking for a place to build a monitoring well and eventually drill additional wells to collect more information and refine the existing model for groundwater, the USGS said.