SAN JUAN, Puerto Rico – On an island that is flirting with default, fending off comparisons to Greece and losing its people to the mainland, the biggest problem most people face is something more elemental – one of the worst droughts in Puerto Rico’s history.

There has been so little rain here that two months ago the government was forced to start rationing water on the populous eastern side of the island, including in many San Juan neighborhoods. Carraizo, the major reservoir serving parts of the city, has dropped nearly 18 feet in recent months, shrinking so noticeably that people can now fish off its sandy shores.

The last time water rationing was ordered on the island was two decades ago.

For 160,000 residents and businesses on the island, water is turned off for 48 hours and then back on for 24 hours, sending people into a frenzy of water collection. Another 185,000 are going without water in 24-hour cycles, and 10,000 are on a 12-hour rationing plan.

"This is the strictest rationing we’ve ever had," said Alberto M. Lazaro, the executive president of the Puerto Rico Aqueduct and Sewer Authority. "It’s been raining, though the showers that should drop water in the east coast are dropping the water in the west coast."

The drought here has not received as much attention as the one in California and other Western states. But the dry weather, which meteorologists say is caused by the Pacific warming pattern known as El Niqo, has spread across much of the Caribbean, affecting countries like Cuba and the Dominican Republican as well as crops and livestock. In Puerto Rico, some reservoirs have come within 30 days of running out of water.

The drought here has cost the water authority as much as $15 million a month as payments have fallen and operating costs have risen, a big hit for an agency already $5 billion in debt. So far, 340,000 households and businesses – about 28 percent of the island’s total – in 13 municipalities are at times going without water. And the problem is growing worse. The U.S. Drought Monitor reported last week that 73 out of 78 municipalities on the island were experiencing drought, some on the extreme side.

The desertlike weather is making it difficult for ranchers to feed their cattle, and farmers on the south coast have postponed planting vegetables so far. Even fish are feeling the pain. At the La Plata reservoir in Toa Alta, thousands of sardines have died from lack of oxygen.

On the other hand, tourists are mostly unaffected, because most of the island’s resort hotels are served by a "supertubo," the North Coast Superaqueduct that pulls water from a separate system in the center of the island.

Ask any of the worst-hit residents about the water scarcity and they will rattle off the rationing timetable by rote, keeping careful track of when water is turned off and on. Pots, pans, buckets, gallon jugs, liter bottles and garbage cans are scattered about houses like flourishes of conceptual art. So many people have bought cisterns for their roof, some hardware stores have run out.

When the aqueduct releases water, the rush begins – dishes are washed, bodies are scrubbed and, most important, containers are filled in preparation for the next 48 hours.

And while the restrictions have brought out the cranky side of some islanders, particularly those used to tempering Puerto Rico’s swelter by showering once or twice a day, they have also spurred bursts of inventiveness and camaraderie as residents try to capture every drop of water and then recycle those drops in every way imaginable.

"Necessity is the mother of invention," said Carli Davila, 39, who lives in the Hyde Park section of San Juan, near the University of Puerto Rico. "It’s like Cuba. When you are missing stuff, when you have shortages, you definitely move toward the creative side."

Davila, an online video content producer who calls himself compulsive about cleanliness, said he had experienced an epiphany about the global scarcity of water (even though his dirty car and windows are driving him crazy).

"You realize how much water you waste and how much you can do without," Davila said, adding that not everyone was being as conscientious. Friends, he said, are showering at work or taking luxurious 30-minute showers on days the water is flowing. "It’s part of the selfish selfie generation."

After weeks of dealing with rations, Davila has pieced together a survival system. He cleans his hands in his toilet tank (not the bowl); he washes dishes with water saved in pots and pans next to his kitchen sink; he keeps the dishwasher full, on a countdown toward water; and his fridge is stocked with pitchers of water.

He also equipped his shower with a small "pocket" water holder that when uncapped lets loose a flow of water. It is cold but functional. Next to the shower sits a large plastic garbage can full of water.

Others are equally inventive. One man placed a reverse pump in his pool and uses pool water for his toilet, shower and sinks. Another has punctured the caps of two-liter bottles, to make the water stream out more slowly. Children are going old-school and bathing in buckets. Shower water is put in the toilet tank for flushing.

Analdin Saldaqa, 83, walked around his old, small wood-framed house, describing his system of buckets, as his wife, who has health problems, watched from the couch. There are the drinking bottles, the paint buckets for the shower, the plastic barrels that fill the paint buckets and the jugs that fill the drinking bottles. He has placed a giant blue drum next to the sink to wash dishes. When the water is on, he fills them all with the garden hose.

"We survive," he said, adding that he was envious of neighbors with cisterns.

Meanwhile, radio stations and newspapers run public service announcements about the schedules. Advice – including a suggestion that men should shower with their wives, offered up by one former mayor – is traded like gossip. The aqueduct authority provides 95 "oasis" water tanks where people can fill their bottles. And more restaurants and homes have resorted to disposable tableware.

Some activities are simply forbidden, and people risk fines if they are caught. For example, use only recycled water to hose down driveways, fill swimming pools, wash cars or water lawns (and that only during the day).

Cisterns pose a problem. Because they end up holding nearly as much water as some people use in 48 hours, they can undermine the rationing.

Lazaro, of the aqueduct board, said he was hopeful that an end to the drought was in sight.

"We are optimistic this will pass sooner rather than later," he said. "We are getting into the season where we get tropical waves every two, three or four days."

But Puerto Rico is already looking for ways to handle the next drought. It recently finished dredging a part of the Carraizo reservoir to remove decades of sediment and sand; maintenance of the reservoirs has suffered during the economic crisis.

Without more money, options are limited. Dredging would help, Lazaro said, but so would bringing in more water from the west side of the island and restarting old wells in the north.

But what is needed now – a lot of rain, not just stray showers – is beyond Puerto Rico’s control. Asked when he thought the natural order would resume and it would pour in Puerto Rico, Saldaqa pointed skyward: "Ask him," he said.