Rhode Island’s water supply is overused during the hot summer months, sometimes dangerously drawing down reserves and threatening reliable access and watersheds that serve as wildlife habitats, according a report released yesterday by a special House commission to study water issues.

The commission, led by House environmental policy adviser Sandra Whitehouse, highlighted several aspects of Rhode Island water usage and distribution, as well as a conservation effort in one Massachusetts town that significantly reduced water usage by limiting lawn watering to once a week.

The group, created by Majority Leader Gordon Fox, D-Providence, presented its findings to a handful of state representatives but did not make any specific recommendations.

The purpose of the report is to examine ways that the state can provide clean, reliable water to residents, allow for economic growth and protect natural resources.

The study focused on reducing demand for water and the costs associated with different ways to increase supply, such as digging new wells, desalinization plants or creating a reservoir in the Big River Watershed, a plan rejected by the U.S. Environmental Protection Agency in 1989.

Since the 1970s, winter demand has stabilized, but summer demand has continued to increase and often exceeds the “safe yield” of 83 million gallons a day, according to data from the Providence Water Supply Board, which provides water to more than 60 percent of the state’s population and draws from the Scituate Reservoir.

This demand is driven by outdoor uses, such as lawn watering.

Lawmakers in both the Senate and the House are considering bills that may limit this practice and add other measures to ensure consistent water supplies statewide.

“We really need to conserve to ensure our water supply,” said Rep. Frank Ferri, D-Warwick, the sponsor of the House water bill. “We have to get people to think differently about their lawns.”

After the presentation by Whitehouse, Rep. Carol Mumford, R-Scituate, asked if farmers would also be asked to curtail water use.

Mumford, whose husband is a Christmas tree farmer, said she worries about farmers losing the right to use water that flows through their property.

One concern about unlimited use of these waters is habitat and species loss if streams are drawn down too far. During the summer of 2005, parts of the Hunt River, near the Potowomut dam, dried out, along with areas of wetlands, the report said.

Currently there are no stream-flow standards that define when water is low enough to restrict or prohibit use.

Mumford said that farmers conscientiously self-monitor because they will not deplete a resource that secures their livelihood.

“We would never overuse streams on our property because then they would not be there,” she said.

Whitehouse said her report did not examine limits for farmers, but said that since farming uses 4 to 5 percent of the state’s water supply, it is not the sector to target for conservation efforts.

The report suggested a statewide per capita usage goal of 65 gallons per day.

Currently, statewide water use for domestic, industrial and irrigation purposes is 136 million gallons a day, which is more than twice as much as the goal proposed by the commission.

The House bill, H 7787, is under consideration in the Environment and Natural Resources committee, and the Senate bill, S 2798, is being held for further study in the Environment and Agriculture committee.

ngarcia@projo.com