Water shortages and pollution will be as big an international issue in the 1980s as energy was in the 1970s, the Council on Environmental Quality predicted yesterday.

Issuing its annual report to Congress and looking back over a decade of pollution-control effort, the presidential agency said water problems include major shortages in the western United States and acid rain in the East.

Toxic chemical pollution threatens the water supply for half the nation, while fish and shellfish catches are spiraling downward on every coast, and especially in Chesapeake Bay.

"We can no longer expect an endless supply of cheap, clean water at the twist of a faucet," said CEQ Chairman Gus Speth.

Still, he added, the past decade has seen "a revolution in environmental protection . . . comparable to the progress we made in the '60s in civil rights and in the '30s in social welfare."

Although pollution controls cost every American $120 in 1978, or $26.9 billion, health benefits and recreational gains that are less easy to count have offset much of that, said CEQ member Robert Harris. A 20 percent reduction in pollutants floating in the air was achieved between 1970 and 1978, and was worth $21 billion alone, he said.

The council's 816-page overview of the global environment showed a world in which the water used for years to clean everything else has finally become hazardous. More and better measurement techniques have discovered more and tougher problems, while old hazards seem to grow the more we learn about them.

Coloring everything is the energy crisis, which involves air and water pollution questions as well as land use options. Speth said, "The single most difficult problem is the conflict between environmental protection and the need to replace oil imports," he told a news conference. "But we believe this is not insoluble."

The report found that ground water, which is used for drinking by half the U.S. population, is increasingly contaminated from a decade in which chemicals, sewage, mine tailings and garbage have been buried. "Once contaminated, ground water may remain unusable for hundreds of years," the study said.

Two-thirds of the nation's lakes, and 80 percent of its urban lakes and ponds, are seriously polluted, even though many rivers have been cleaned up, the CEQ reported. Fish are often inedible when they return to cleaned-up waters, because of contamination by toxic chemicals like PCBs, the study showed.

In Chesapeake Bay 400 million gallons of sewage per day and 800 oil spills per year have cut shellfish catches to one-fifth of what they were 100 years ago.At the same time, 400 miles of bay shoreline are seriously eroded, as residential and recreational use increases.

"Neither Maryland nor Virginia is doing enough to protect this critical resource," Speth said. "It is a high priority, and deserves much more attention." The report noted that despite four years of federal help, Virginia has not come up with legislation to regulate and protect its coastal zone.

Water shortages punctuated by floods will continue to plague the western United States, said council member Jane Yarn. "In some parts of the country, soil erosion is worse now than it was during the Dust Bowl era," she said.

Growing cities eat up 3 million acres of farmland every year, and 1 million of those acres are prime land, she said. Another 4 billion tons of topsoil washes or blows away, much of it becoming either air pollution or silt in the estuaries, smothering shellfish.

The CEQ highlighted a number of other problem areas:

Occupational hazards are now thought to cause between 20 and 38 percent of known cancers, a figure much higher than expected.

Ninety percent of all hazardous wastes are being disposed of in an unsatisfactory manner. There may be 1,200 or more waste sites that are dangerous, but setting up new, safe sites is hard because of local opposition.

Washington area air ranked 11th worst in the country, with an average of 110 "unhealthful" days every year. The worst cities were New York, Los Angeles and Cleveland, with more that 225 unhealthy days each. The best was Honolulu.

Americans produce 1,400 pounds of trash and junk per person every year. Burning all of it could solve our energy problem, but only 1 percent is being burned and only 7 percent recycled, even though "technological barriers are probably the least serious obstacle."

One in every 10 Americans suffers noise pollution that could damage hearing. New evidence links noise and heart trouble, while noise may hurt reading skill development in children more than poverty does.

An area roughly the size of Virginia, or 27 million acres, is deforested in the world's tropics every year. The result is massive erosion, floods and eventual changes in the weather.