It's springtime at Fletcher's boathouse, Washington's outdoor window on the fast and muddy Potomac. Last weekend could have marked the start of the annual white perch spawning run, but high water was keeping the fish downstream and the anglers home.

The river started falling on St. Patrick's Day after cresting at seven feet above normal - flood stage. That meant two feet of water covered the road into Fletcher's.

A barricade blocked the entrance off Canal Road. "Closed," it said, but down at the concrete and tin shacks where warms, shad darts, bicycles and paddles deck the halls and walls, the river rats were holding court.

There was Ray Fletcher and his big brother Joe. They make their living off the river in a family tradition that dates back generations. Others came and went as the spirit moved them - Dicky Tehaan, who parks cars at Sibley Hospital for a living so he can dash down at lunchtime and fish; Mark Binsted, the architect-to-be who is nuts about shad fishing; John Splaun, Carl King, John Murto and others.

They drift down to Fletcher's these prespring days to watch the river sweep by, to swap stories about fish, ducks, beavers, people, hawks, turkeys and deer.

It's a peaceful place, but it won't be for long. The onslaught of white perch will start a sequence of fish arrivals that won't slow until the rockfish thin out and summer begins in earnest.

The Potomac is "probably the biggest spawning river on the East Coast," said Michael Haire, aquatic biologist with Martin-Marietta Corp. His firm has been studying the river with Maryland state officials working on power plant projects.

Haire said the yearly harvest in the Potomac has ranged in recent years from 500,000 to a million pounds of fish. "It's our most important spawning river," he said, "and the Chesapeake is our most important spawning system."

The end of the line for Potomac sponsors is Little Falls, just above Fletcher's, which means great spring fishing between Key and Chain bridges.

Here's the expected sequence, as gleaned by Joe Fletcher from a lifetime of river-watching.

WHITE PERCH - Due anytime, as soon as the water clears and the floods abate. The run lasts four to five weeks and the fish range from three inches to about a foot in length.

Fish with worms on the bottom, which is 30 to 50 feet down off Fletcher's Joe has a slick technique of attaching his sinker with a rubber band so when he gets caught in the rocks, which is inevitable, he can yank off the sinker but not lose his two-hook bottom fishing rig.

White perch are superb table fare either cleaned, breaded and fried, fileted and fried or used in soups or stews.

HERRING (not herrings, please - Should arrive by the thousands sometime after April 7 and disappear around mid-May. Herring are almost always substantially smaller than a pound and are caught by snaggling with treble hooks or dipping with nets. They rarely bite bait or lures when spawning.

The herring run draws working people from as far away as Pennsylvania and western Maryland. They set up camp around Key Bridge and burn campfires at night as they spend two or three days loading up oil drums with the fish. Herring are extremely bony. Most folks pickle them in brine, which softens the bones so they can be eaten whole.But if you're willing to put up with the hassle, fried fresh herring are said to be delicious. The roe is tasty, too.

SHAD - Arrive a week or so after the first herring. These are white shad, highly sought after for the flesh and for the roe of the spawning females.

For four years the shad run has been depressingly poor, though Fletcher said it picked up just slightly last year.

The shad weigh from two to four pounds and bite shad darts and sahd-dar-type flies fished near the surface. They are wonderful fighters, the sportiest fish the Potomac has to offer. The run, if it occurs this year, will last six weeks or slightly more, according to Fletcher.

ROCKFISH - Most people here-abouts don't know that there are rock (striped bass) to be taken in Washington waters, but the Fletcher's crowd does well with bait and lures. Binsted caught 17 small rock one day last year on shad darts, and Fletcher caught four ranging up to 10 pounds one morning using cut herring heads. Some of the regular anglers at Fletcher's claim yearly totals of 50 or more rockfish.

The spawning run begins about May 15 and fish can be caught into July. Best fishing is early morning just upstream from the boathouse.

Rock are so highly regarded as table fare that some folks will even try to trick their old friends to better the odds.

Fletcher remembers the time his clan of rivermen was trying to outsmart each other.

"We're all sitting around one evening when the fishing was good. Everybody's asking each other, 'You goin' out tomorrow' and everybody's saying, 'Not me, I've got stuff to do.'

"Well, next morning at 5 o'clock I'm rowing upstream to the rockfish hole. I come around the bend and there's 12 boats out there, full of these guys. They had oars hid all over the place so they could sneak down early, borrow one of my boats and catch all my fish."