Long Islanders use more water than people in much of the rest of the country, putting most of it toward maintaining their lush lawns.
Residents of Nassau and Suffolk counties use an average of about 130 gallons per person per day, but that jumps to as much as 500 gallons during the summer, said Dennis Kelleher, president of Melville-based H2M water resource engineers and a consultant to 30 water suppliers on Long Island.
On a hot summer day, about 90 percent of the water used on Long Island goes for lawns, Kelleher said.
As a regional comparison, the average per-person per-day use in the Rochester area, served by the Monroe County Water Authority, is 82 gallons a day. Residents of the Latham Water District near Albany use an average of 120 gallons per day, Kelleher said.
Nationally, the average per-person daily water use is about 100 gallons, said Sarah Meyland, director of the Center for Water Resources Management at the New York Institute of Technology in Old Westbury. And between 50 and 70 percent of that national average is used for watering lawns and gardens, according to the U.S. Environmental Protection Agency.
Careless water use
"Long Island uses its water carelessly," said Richard Amper, executive director of the Long Island Pine Barrens Society. "We don't think about it in terms of quality or quantity."
Environmental advocates and researchers said signs of Long Island's overuse include salt water intrusion into the aquifers in some areas of Nassau's north and south shores, and around Montauk in Suffolk. Salt water can seep into Long Island's sole source of drinking water when the amount of fresh water being removed exceeds the amount being recharged by precipitation.
Meyland cited the imbalance in Nassau where, in the summer of 2010, more than 404 million gallons were taken out and 341 million gallons were put back in.
"We're depleting the aquifer," she said. "We're certainly depleting the best water that is in the system."
James Gaughran, chairman of the Suffolk County Water Authority, said there was no imbalance in his county.
"We are blessed in that we do not have an issue in Suffolk County," he said. "We have plenty. . . . The aquifer is always recharging."
Runoff a problem too
Excess irrigation of residential lawns, parks, business centers, golf courses and other green spaces also affects surface water quality. Runoff from watering lawns or irrigating farm fields washes fertilizers, pesticides and waste into streams, lakes and bays, contributing to nitrogen loading that can ultimately kill off fish and other aquatic life.
Long Islanders use so much water partly because it's plentiful. Aquifers under the Island act like sponges, absorbing the precipitation that filters through the surface into the groundwater.
The Island's water also is cheap -- typically less than the $2-per-1,000 gallons national average. The costs can rise to as much as $10 per gallon in more arid parts of the country such as Las Vegas.
Peak watering hours on Long Island often start at 2 a.m., when automatic sprinkler systems kick into action.
The spread of automatic in-ground systems -- confined to a handful of affluent communities a few decades ago -- accounts for the dramatic increase in use, Kelleher said. A homeowner with a half-acre property can outfit it with an irrigation system for about $1,500.
But much of the water used in sprinkler systems doesn't fulfill the intended purpose of reaching the grass roots, Meyland said. A lot of it evaporates as mist when the water comes out of the sprinkler head or it evaporates after hitting the grass, she said. Little finds its way into the ground to recharge the aquifers.
"It's a total loss of water from the system," she said. "There's a tremendous amount of waste."
EPA's WaterSense program estimates that outdoor water use can make up as much as 60 percent of a household's total use and that about half of it is wasted.
Also troubling is that many sprinkler systems automatically start even when it is raining, Meyland said. And owners often set theirs to turn on every day even though every other day is sufficient, Kelleher said.
"After sprinklers, Long Islanders' highest household water use is in the bathroom, mostly from flushing toilets and taking showers. Other high-water residential uses include washing dishes and clothes. Swimming pools also account for significant usage in summer.
Drinking water amounts to less than 2 percent of total water use, Kelleher said.
Residential systems make up the majority of water use, but commercial businesses also represent a sizable amount, especially golf courses, Gaughran said.
Jeff Seeman, superintendent of Calverton Links, said the 18-hole golf course has over the past four years cut its water use from as much as 28 million gallons a year to about 18 million.
The course achieved that reduction by planting native grasses that don't require water beyond natural rainfall, watering dry areas with hand-held hoses instead of turning on the entire irrigation system, using a "light spray" rather than dumping huge amounts of water on the grass and other changes, Seeman said.
"We are feeling that environmental need to be responsible," he said, adding that he thinks the national move toward more judicious water use on golf courses will eventually trickle down to landscaping businesses and homeowners.