LAST WEEKEND a couple asked architect Hugh Newell Jacobsen what to do about their flooded basement. "Underwater lights, tropical fish," he suggested.

For years admitting you had water in your basement, as Jacobsen put it, was like saying you had an incurable unmentionable disease.

But in Washington after Hurricane Agnes and Snow Storm George, water in the basement has become epidemic.

While other people were worrying how to dig them-selves out of the smowbanks, others of us prayed the freeze would hold fast, because apres nous le deluge .

When the rains came, it was worse.We knew then there was no escape. Still, we kept hoping, pretending it wasn't going to happen, lest the gods know we were afraid. We didn't take the upholstered chairs up to the higher level. We didn't bring the frozen hose in frim the snowbank or find the submersible pump. We didn't even make a path between the watercourse and the bathroom toliet (always used by us to drain). We looked at the rain, got in the car and went to Baltimore.

Saturday nignt, we got up courage to take a tenative peek. All was dry! We congratulated ourselves and went to bed early. Sunday morning, we had a leisurely breakfast, averting eyes from the rain. Finally, my husband said, "Well, I think I left my magazine in the sitting room."

I heard him go down the steps. When he didn't come back after 15 minutes, I thought I'd better check. He was tossing furniture up to dry land, shoving things aside, and furiously threatening to sell the house, the furniture and leave for a mountain top.

Already there were four inches of water and rising. He rolled up his trousers, took off his shoes and waded in. I did the same. We rescued my favorited possession, the Saarinen wombchair and footstool. Fortunately it has steel legs. We're not that dumb. We don't have rugs there either.

There was no hope of moving the sofa or the 1840s grand piano. We wished we had bought galoshes for the piano. Only the day besore, I'd said "Now that it looks as though we finally have the basement problem solved, we ought to get some decent furniture for it. What about that leather sofa and chair?" Wisely, he'd proposed a moritorium till the ground dried out.

The hose, excavated out of a snow drift, was frozen. We expected the inside to be one long popsicle. Surprise! The ice pellet was short and blew out with the first pumpful. That first day was not too bad. High tide was six inches. All he had to do was to go down periodically and turn off the pump to let it cool.

He set the clock for 4 a.m. Monday, but turned over when he heard the rain had quit. At 6 a.m., he went down, turned it on. But at the pump's one inch per hour rate, we knew it would never hit bottom by worktime. I went to work, giving thanks that somewhere along the way he'd decided that pumping out the basement was man's work, like filling the gas tank on the car.

At 2 p.m., he began bailing. One it's down to an inch, the pump isn't any good. But as usual, he had invented a gadget to do it with -- an empty can of paint thinner to which he'd afixed a handle. He scorned my device -- the wet/dry vacuum cleaner as "not efficent." Besides, when I'd used the vacuum cleaner, he'd been the one who had to pick it up, all 60 gallons, and empty it. Instead he scooped water and poured it into mop buckets.

He made it through to half an inch, with encouragement from mother and housekeeper Luzenia Eccles, and numerous cups of tea. At that, he lit a fire in the fireplace (it took a great deal of wood scrap) to finish the job. He collapsed in the rescued Saarinen chair with a Scotch. He figured he and the pump had removed 3,500 gallons of water, half the volume of the swimming pool. One friend suggested he'd earned an equal amount of Laphraig Scotch. I agreed.

What to do the keep from ever happening again?

"In architecture school," said Jacobsen, "there was a sign up in the drafting room reading, 'If you can't hide it, make it sensitive. If you can't make it sensitive, paint it red. Maybe that's the answer. Put in the lights, the fish and invite everybody down to see your newest thing."

Ludwig II, the Bavarian king at the turn of the century, had a similar idea. At his castle at Linderhof, he made an underground grotto, complete with nude nymphs, swan boats and a place for the orchestra to play operas by Richard Wagner.

My husband figured a canoe, a ukulele and even the Wagnerian orchestra might be cheaper than a sump pump.

Architect John Wiebenson has another proposal. "Pretend the basement isn't there. Move the washing machine and furnace upstairs. Close the basement door. No one should build a basement anyway. Hardly anyone does in the West. They all leak -- even the Metro, with all of its heavy waterproofing."

Wiebenson remembers clients who had to have a basement. But they lived in San Francisco, famous for its banana slugs -- slimy garden slugs as big as bananas. "We couldn't keep the dampness and the slugs out. So finally we added a second floor with a water memberane in between and let the slugs have the lower level.

"A sump pump is about all that's practical to do here in an existing house," Wiebenson went on to say. "Though on my own house, the fellow who had the house before us put a regular gutter at the bottom of the wall, draining away from the house. It works fine.

"Roof overhangs help too. Several feet of overhang, properly guttered, will keep the water from the main roof from collecting at the bottom of the wall and seeping down into the basement. Overhangs are good too for protecting windows and the walls of the house. We should use them more often."

Jacobsen remembers one Georgetown house he worked on where the basement leaked every time the people next door watered their garden. And the waterers weren't about to have their garden dug up to have a drain put in to help Jacobsen's client. "So we dug a hole and put in a sump pump, and put a wall in front of it. It worked."

Jacobsen says that if any of his houses leak, the clients have been too kind to call him. He recalls the story of the S.C. Johnson house by Frank Lloyd Wright. "Johnson called him to say the roof was leaking on his bed. Wright said, 'Move the bed.'"

Kevin Callahan, senior design engineer of the National Concrete Masonry Association, and Dave Johnson, assistant director of the National Association of Home Builders, say the conventional wisdom is to dig down on the outside all the way to the floor level, parge (cover with a mixture of coment and sand, topped with an asphalt coating) the basement walls, lay perforated drain tile in a gravel-filled ditch all the way around the house, then re-cover with dirt, stamped hard.

"That's terribly expensive and a lot of work," says Johnson. "You have to decide whether it's worth it to you. If it doesn't happen too often, it might be better to just bail it out.

"It depends upon where the water's coming from. When we have the tail of the hurricanes come through, or flooding from a storm such as last week, there isn't a lot you can do. The water table rose because the ground is so saturated from snow runoff and rain. The hydraulic pressure forced it in. This clay soil can do funny things. The water doesn't always move the way you expect it to."

A study by the NAHB also questions the effectiveness of this major procedure. "Basement Water Leakage... causes, prevention and correction," is a study for members only prt out by the National Association of Home Builders, prepared by the NAHB Research Foundation.

The study says the traditional parging really may not work well. It concludes that plastic film, adhered to the foundation with asphalt coatings, is more successful.

Instead of drain tiles it suggests a surface slope away from the house of at least 1/2 inch per foot for a distance of 8 to 10 feet. "If downspouts are used, water should be directed well away from the basement wall." The study also recommends a system of weepholes to allow water to flow through the wall beneath the basement slab, but that's obviously something that has to be done before the basement is built.

This study reports that 85 percent of builders answering a questionnaire reported basement leakage problems.

"Heavy leakage tended to be associated with ground water while light leakage was associated with control of surface water. The survey results showed masonry block and poured concrete almost equally susceptible to leakage... Over 85 percent of the reported leaks appeared onlu after rain storms or melting snow."

After suggesting, like Wiebenson, not to build basements in areas with high water tables, the study goes on to say that it you must, you should "provide a sump and pumping system with sufficient capacity to keep the ground water table lower than the floor of the basement. "It warns that it just isn't possible to build a water-tight "barge" basement. "Even if it were possible, under some conditions the house would float out of the ground."

Both Johnson and Callahan emphasize the importance of grading the soil around your house so that water is directed away.

"I once lived in a house for 13 years without ever having water come in," says Callahan. "When I sold it, the VA made me connect the house to the county sewer, though the septic tank had worked well. We did. Not long after the buyer called me and complained that the basement had leakage. I went out and looked at it and realized that when they'd dug around the house for the sewer, they had left the soil soft and airy. He tapped it down and planted it with grass and had no more trouble."

Callahan thinks that happens to a great many people when they put in shrubbery close to the house. "Often rain coming off the roof may make channels around the house, collecting water. You need to fill those with dirt." Callahan agrees that roof overhangs could be a help. "They'd serve the same purpose as grading, taking the water away from the foundation and helping with wind driven rain."

In general, nobedy thinks much of measures such as waterproof coatings inside. And everybody warns against those who promise to pump strange alleged sealants around the perimeter of the house without digging down. But Callahan thinks that if you only get water in around the joint between wall and floor, and then only during major storms, it might be some help to seal the joint with an asphalt-type compound.

Johnson notes: "Agnes and Eloise were once-in-a-hundred-year storms. Such a snow as this only happens once in 57 years. It's almost too expensive to keep out water on these scales. You have to draw the line somewhere, on how much you're willing to spend to dam the floods, otherwise it's not cost effective."

Or you could, as one fellow put it, "move to the ninth floor of a Foggy Bottom apartment. If the Potomac rises that much, it's too late to worry anyway."