IT MAY COMFORT Americans to know that the civil defense crowd has been dutifully drawing up elaborate plans to evacuate 400 "high-risk" communities in case of nuclear attack. It may discomfort them to learn, however, that not much about the plans makes sense.

For example, the "crisis relocation" plan for the nation's capital, naturally one of the riskiest areas, calls for some 80,000 Washington residents to travel 188 miles and descend on the resort spa of Hot Springs, in Bath County, Va. Nice place to sit out a nuclear holocaust.

The problem is that you first have to find someone who knows that a nuclear attack is coming, say three days in advance, and who will take responsibility for telling us all to scram. The plan, you see, assumes that the White House will receive a conveniently early notice of missile madness, that some "period of international tension" is sure to be recognized as the right one.

How do we know an attack will follow such a tense period, defined in one federal civil defense document as an event that "would probably make the Cuban missile crisis look like business-as-usual"? "We don't," says John Colbert, assistant director for planning in the District of Columbia Office of Emergency Preparedness, Wonderful.

Nonetheless, Colbert's office, like others around the nation, has prepared an extensive evacuation booklet, ready to be published and distributed instantly if the Soviets are considerate enough to let us surmise their plans. But how will Colbert's office know when to start printing it? "We've just got to watch the headlines," he says.

And who will drive the buses needed to carry 275,000 carless Washingtonians to "safe" areas? "We hope that people will volunteer," says Ken McNaughton, the city's nuclear civil protection officer. "If people don't volunteer, we'll have to pay them or get government workers licensed to drive." v

And won't there be traffic snarls? "We hope and pray that this plan will never have to be put into effect in a snow storm. You know what happens when there's an inch of snow here," McNaughton says. Great.

Still, Colbert and McNaughton insist that the capital could be evacuated in three days, God and the bus drivers willing, and Colbert keeps handy a camera-ready copy of the pamphlet, which he says could be on the street in several hours.

It instructs fleeing Washingtonians to pack their cars with clothes, bedding, soap, sanitary napkins, a first aid kit, shaving articles, toilet paper, a portable toilet, medicine, baby care items, all the food you can carry, water, eating utensils, a shovel, a hammer, a saw, a screwdriver, nails, screws, your Social Security card, deeds, insurance policies, stocks and bonds, your will, savings account books, credit cards, checks and money. Items to leave behind: guns, booze and drugs.

There are maps of the Disrict's eight political wards, with detailed routes for heading for the hills. For example, Ward 1 residents are to take the beltway to I-95, turn south to state road 3, then west to state road 20 and west again to Orange, Va. They are to report to Orange County High School, their "reception center," when they arrive.

The D.C. officials estimate auto evacuation would take a day and a half. Then carless residents would be assembled at local schools, assigned by wards in the pamphlet, where Metro buses would pick them up and carry them to the countryside. It would take an estimated four trips to evacuate these people, if enough volunteer bus drivers could be found.

What happens after Washingtonians meet their hosts and turn in forms listing name, Social Security number, sex, age, address, occupation or skills? The booklet says the Virginia and West Virgian welcomers may "direct you to a hosting facility where you will sleep, eat, etc." But that may merely be some more wishful thinking, as McNaughton found out when he drove Ward 2's evacuation route to Hot Springs, Va.

"When I got down there," he says, "I found a fabulous hotel, the Homestead. They have their own water system, their own sewer system." Pause. "And that's it. They do have a beautiful golf course," but "there's no facilities, so to speak, to house people. It's a lot of open area down there."

"Open area" is not very good to be in a nuclear attack, since communities that are not enemy targets still stand a good chance of having radioactive fallout blown in from elsewhere.

Dan Reichartz, vice president of the Homestead, says that while his hotel has 694 rooms, Hot Springs "is a small village by any standard." Bath County has no other large hotels, and there is no abundnce of the "non-residential" buildings the government says would be used to house 80,000 evacuees.

Similarly, if you ask Colbert what kind of shelter, food, sanitation, water and other supplies will be waiting in Bath County and other "host" areas, he will tell you "little or nothing." Indeed, Colbert says, "I have never bought the concept of evaculation for metropolitan areas because there's nowhere to go."

But the federal govermnent certainly has bought it. The Federal Emergency Management Agency has given out about $17 million in contracts since it began paying local governments to come up with their "crisis relocation" blueprints. Some of that money has been used to identify fallout shelters in the risk areas themselves, but mainly it went for the evacuation plans, which have become the mainstay of our civil defense program.

FEMA estimates that it will be about 10 years before evaculation and host-area plans are done for all 400 high-risk areas. Civil defense officials contend that if this scheme works, about 80 percent of us would survive a heavy Soviet nuclear attack of U.S. military and industrial targets, while without it only about a third of us would live. Lots of luck.