Puerto Rico imposed strict water rationing Wednesday that will make daily showers a challenge for tens of thousands of people and force businesses such as restaurants and car washes to brace for a summer expected to be drier than usual.

More than 160,000 people living in and near the capital of San Juan will have access to water only every other day, with officials warning that service could be cut for up to 36 hours if water levels at the island's main reservoirs keep dropping. The measures could remain in place for months.

"This is not the time to be filling up pools, washing cars or using hoses to clean," said Alberto Lazaro, executive president of Puerto Rico's water and sewer company.

He said rationing could be extended to an additional 70,000 people if rain doesn't fall soon.

Gov. Alejandro Garcia Padilla recently declared a state of emergency given the increasingly dry conditions.

May usually is one of Puerto Rico's wettest months, but only a tenth of an inch has fallen so far in San Juan. That compares to the average 2.31 inches (6 centimeters) that usually fall in the first two weeks, said Odalys Martinez with the National Weather Service.

"Puerto Rico has been dragging this shortfall since last year," she said by phone, noting that rainfall overall has been below average because of the El Nino phenomenon, which leads to drier conditions and high temperatures.

Thermostats recently reached the mid-90s, breaking records for the month of April and causing dry conditions blamed for several fires around the island.

Residents of the U.S. territory have emptied store shelves of gallon-sized jugs of water as they prepare for sponge baths, and restaurants and other businesses are preparing for possible economic hurt amid an eight-year recession.

Omar Carrion, vice president of the Autocare car-washing company, said he worries business will drop even though it recycles all of its water.

"People might not know we do this," he said. "They might think, 'Well, if we go to the car wash, we'll be wasting water.'"

Carrion said he has not prepared his home for a possible cut in service, noting he can always go to one of the car wash locations and draw water from their own wells.

The dry spell also has affected the Dominican Republic on the neighboring island of Hispaniola, where more than 800 neighborhoods have been affected by interruptions in water service. Dominican authorities say the dry spell there has withered crops and helped spread fires that were intentionally set and have consumed nearly 1,260 hectares (3,113 acres) of forest.

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