The next president should set up a "water council" in his executive office to coordinate federal water policy, which is now fragmented among several agencies, a Harvard University study recommends.

Such a council should include representatives of the states and should be headed by a chairman free of ties to existing departments, said a paper from the Harvard Water Policy Project, part of the energy and environment program at the university's John F. Kennedy School of Government.The new council "would derive its principal influence from its direct relationship with the president," the paper said.

"The absence of such an entity at present has led to the intolerable situation of no agency within the executive branch currently responsible for taking a comprehensive view of federal water programs."

The report was written by Peter P. Rogers, professor of environmental engineering and city planning, and Charles H.W. Foster, adjunct research fellow and environment secretary in the administration of Massachusetts Republican Gov. Frank Sargent in 1971-1975.

The project was supported by grants from Resources for the Future, a Washington think tank which released the report last week.

Several previous attempts to coordinate federal water policy have failed. Most recently, a statutory interagency Water Resources Council of Cabinet secretaries was formed in 1965 to oversee planning, but was killed by agreement of the Reagan administration and Congress in 1981.

Reagan's Cabinet Council on Natural Resources, which tried to do some of the same work, "proved ineffectual and became essentially non-functional after its principal enthusiast, Interior Secretary James Watt, left office."

In an interview from Cambridge, Mass., Rogers said the Water Resources Council "moved in on agency programs, and the agencies quite properly went to Congress."

The new council, he said, should "stay out of agency turf," and try to "pull the policy debates out of the agencies, where people are debating themselves, and put them in a forum where they debate other agencies."