You say you've got mildew in the closet and triple-canopy jungle in the backyard? And your basement walls are weeping or maybe sprouting mushrooms? And your carpet smells like the cat in the mat has come back?

Listen, a little rain never hurt anybody. Stop whining and do your income tax.

Anyway, it's not that wet. True, we've had 2.20 inches more rainfall than normal already this month and the 13.20 inches we've received so far this year is about 30 percent above normal.

It's also true that Fairfax and Montgomery County have had to close their waterlogged playing fields, suspending spring soccer practice for hordes of preadolescent Peles.

And that waterproofing contractors are smiling and sump pump sales are up.

But you forget: we had a drought two years ago and we're still recovering. Ground water levels are only now getting back to normal.

Marvin Lys, a U.S. Geological Survey hydrologist who knows about these things, says the Fairland well is a case in point. The private well in western Montgomery County, one of four the USGS has monitored since 1955 in the western Potomac River basin, showed below-normal water levels for 29 straight months until last month. Its February level was its lowest on record for that month.

After nearly five inches of rain fell in March, however, the well's water level jumped three feet and is now just about back to normal.

"We needed all this," said Leo Harrison, a hydrologist with the U.S. Weather Service. "We got so little rain and snow this winter that the water situation was starting to look a little precarious in January. But people don't want to hear that. It rains a little and people forget it was ever dry."

Harrison believes the Washington area is now "in a wet cycle" after dry years from 1977 to 1981. The wetter-than-normal years should continue until about 1986, he says, "since the full wet-dry cycle appears to encompass about nine years."

Farmers are now "seeing a lot of ponding in the fields which could begin to be something of a nuisance," according to Dave Conrad, commercial agriculture specialist in the office of the Prince George's County extension service.

But Conrad said "farmers are happy to see the rain getting into the water table," even though the wet fields will place many behind schedule in their preplanting fertilizing and plowing.

"Usually you want to get your corn in between April 15 and June 1," he said, with soybeans planted about a month later and tobacco going in in late June. "Most everyone will still have plenty of time if it doesn't keep on too long," he said.

Lys and Harrison say the slow, soaking character of the March and April rains has been particularly beneficial, minimizing runoff.

The Potomac's flow peaked April 10 and 11 at about 65 billion gallons a day, Lys said, and has dropped about 20 BGD since then.

The Chesapeake Bay, he said, was flowing about 17 percent below its 33-year March average of 100 BGD at the end of last month, in part because of drier weather in the Susquehanna Basin. In an average year, the Susquehanna provides from 42 to 48 percent of the bay's water flow. The Potomac provides about 25 percent, and the James about 17 percent, with the bay's hundreds of smaller creeks and rivers making up the remaining 16 percent.

As the fresh-water flow into the bay increases, it will lower the salinity level, making things less hospitable for stinging nettles and oyster parasites but also less hospitable for crabs.

Theoretically, the increased water flow ought to dilute pollution, but even as it does it carries more in the form of silt and nutrient runoff from fertilized farm fields. That, in turn, clouds the water, restricting the transmission of sunlight necessary for the growth of the aquatic grasses--the nurses and restaurants of the bay's marine life. All this, of course, happens every year. The bay survives anyway, and so shall we.