After years of legal wrangling, federal and Alexandria city officials may be close to agreement on how to curtail commercial development of the city's historic waterfront.

Alexandria City Manager Douglas Harman called waterfront plans, released yesterday by the Interior Department, "extremely helpful" and said the government proposals "show we are really not too far apart."

The proposal follows closely a plan put forward by city officials last year. Both sides have proposed limiting commercial use of the river edge, which stretches 16 blocks from the Pepco power plant on the north to Jones Point, near the Woodrow Wilson Bridge.

Specifically, the Interior plan would create a series of parks and recreational areas near the river. It also calls for a pedestrian and bike path 50 feet wide, set among grassy acres and specially-planted trees.

The area in question is now a hodge-podge of unused land, abandoned meat factories, processing plants and $200,000 townhouses.

Virtually all development of the riverfront stopped in 1973 when the federal government, at the urging of environmentalists and others, filed suit against the city, claiming title to the land based on an obscure 1791 survey.

Bob Harman and an Interior spokesman said yesterday it was "premature" to speculate on an end to the suit, which has languished in federal court for the last six years.

Harman said city officials will meet with federal planners "sometime in September" to study specifics of the proposals.

A dramatic rise in real estate values in the early 1970s, culminating in developers' plans for a series of massive high-rises along the Potomac shore, led to the federal suit. The city later changed its zoning ordinances to prohibit high-rises at the river's edge, but the government has never before produced its own plans for the area.

The area includes about 50 acres of choice real estate.

Interior yesterday presented the city with two alternatives. One calls for park and recreational uses of 42 of the 50 acres, with mixed residential and commercial use on three acres. The other would permit park use on 32 acres, with houses and stores on 13 acres.

Both plans permit the continued use of five waterfront acres by the Robinson Terminal Warehouse, but permit no other industrial use in the area. Robinson owns the other land not on the waterfront.

"The challenge is to renew the area in a manner both compatible with its historic environment and responsive to contemporary human needs," states one section of the 46-page Interior document.

Estimated costs of the project range from $37.1 million to $44.6 million, mainly for acquisition of property. The figures could be considerably less if Interior wins its suit, and then transfers the land either to local government or another federal agency, according to the report.

The federal report calls for an end to all new development within 50 feet of the water's edge, and recommends that any new building near the water be no higher than 30 feet. Other structures further back from the water should be limited to 50 feet, the report contends.

The land should have "convenient access for public use," outdoor parking lots and temporary structures. "Incompatible industrial uses," should be discouraged, the report says.

The Interior report goes considerably further than the city in urging archeological excavations along the waterfront, but Harman said yesterday that this was not "incompatible" with the city's ideas.

The Robinson Terminal warehouses, which occupy a total of 6.8 acres, would be permitted to remain under the federal plan "as long as economically feasible," but should be removed for improved public access if they become "obsolete." The warehouses are owned by The Washington Post Co.

If Interior's lawsuit is lifted, the Alexandria city council is expected to come under considerable pressure from developers to adopt the federal plan calling for 13 acres of mixed use development, rather than only three acres.

As many as 40 residential townhouses per acre are now permitted by the city code. Those homes currently sell near the river for at least $125,000 each.