FARMINGDALE, N.Y. (CBSNewYork) — There’s a warning on Long Island about the water supply.

The Suffolk County Water Authority says residents should stop watering their lawns during the early morning hours.

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Many areas are now reporting record or near record usage levels, CBS2’s Jennifer McLogan reported Tuesday.

The authority says it hit an all-time high in water pumping Monday at 5:35 a.m.

A sufficient water supply is critical to maintain pressure to fight fires to keep the flow to hospitals.

The new all-time water usage record high in Suffolk County — and tied for the record in Nassau County — came during the first heat wave of the season.

“Our message is very simple we need the help of our customers,” said Jeffrey Szabo, CEO of the Suffolk County Water Authority.

Szabo says homeowners are now refilling evaporating swimming pools, watering their lawns and gardens like crazy. Eighty percent of irrigation timers are set between 3 a.m. and 7 a.m.

“Our system is under tremendous stress during those hours,” Szabo said.

That means there’s a potential water pressure risk to fight fires.

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“There is no better sight to see when your house is on fire then seeing a fire truck pull up. That is your hope,” said Farmingdale homeowner Laura Keena.

The Keenas were victims of of an early morning house fire and the risks first hand.

“To find out there wouldn’t be enough pressure for them to do their job would be devastating,” Laura Keena said.

Firefighters stress Long Island is also experiencing an unusually dry summer: Almost three fewer inches of rain than average.

“This is really a special case here on Long Island. We are a sole source aquifer,” said Adrienne Esposito of the Citizens Campaign for the Environment.

Esposito says it’s time to conserve water no more than every other evening or night. The Long Island Water Conference recommends residents shorten watering times by five minutes and install small controllers that shut off when rain is in the forecast.

“We can have a green lawn and we can also protect the quantity of our drinking water,” Esposito said.

Many wells are not operating, undergoing upgrades to treat 1.4 dioxane and other contaminants.

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Water experts say they are on a dangerous threshold due to peak usage.