The first big fight President Carter picked with Congress four years ago was over water projects, and for a long time it looked as if Carter would lose.

Now it looks instead that he has battled Congess to a draw.

The President has not won approval of the new systems he proposed for evaluating and financing water projects, to save both water and money.

But neither has Congress been able to crank out new rivers and harbors projects with anything like the ease it once did.

For the fourth straight year, in 1980, it now seems likely that Congress will be unable to produce a water-resources bill.

A $4.4 billion House-passed measure, authorizing dozens of new flood-control and navigation projects, seems to be a victim of too many demands for too many projects at too much cost.

Faced with a likely presidential veto and a congressional calendar suddenly short of working time, the legislation is languishing in a Senate Public Works subcommittee that is getting reorganized under a new chairman.

"The bill isn't going anywhre," said a subcommittee aide, "and there's really no way for us to make a fresh start. The White House already has identified 151 unacceptable items in our bill, plus 50 more in the House bill that aren't in the Senate version yet."

Beyond that, and maybe more significantly, small rumblings of a pocket rebellion against the traditional pork-barrel water program are being heard around Capitol Hill.

The first of these came from Rep. Robert W. Edgar (D-Pa), who stirred House emotions last winter with a series of attacks on dubious projects in the pending authorization bill.

Edgar failed to stop those projects, but embarrassed his Public Works Committee colleagues by exposing how the committeehad ignored the usual cost-benefit rules and loaded up the bill.

Now, the chairmanship of the Senate Water Resources subcommittee -- where the House bill is hung up -- has been taken by Daniel Patrick Moynihan (D-N.Y.), one of the Senate's most vocal critics of the present authorizing system.

Moynihan and his predecessor, Mike Gravel (D-Alaska), who took over the environment subcommittee, often tangled over water policy issues.

"What you're seeing from this stalemate in Congress over water projects is the possibility tht the old palsy-walsy front on public works could crack," said Brent Blackwelder of the Environmental Policy Center.

"The last water bill was in 1976, which means there has been a freshman and a sophomore class with no pork.The leadership has no sword to hand over those heads, and those members are seeing they can get by without the pork. That means opportunities for reform."

Blackwelder, the EPC's chief lobbyist for water reform, said Moynihan is seen as a force for "insisting on greater equity on projects, which will make it difficult for heavy pork to emerge."

The first mark of Moynihan's water attitudes showed up as part of a bill, adopted surprsingly by the Environment and Public works Committee two weeks ago, that would shake up the present system of authorizing water projects.

Sen. Pete V. Domenici (R-N.M.), another critic of the system, and Moynihan have come up with a proposal for a five-year demonstration that would alllow the states -- rather than Congress -- to decide which water projects they need and want built.

The plan would authorize up to $1 billion over each of the next five years, with money going to the states through a formula based on area and population.

Such an approach is almost certain to appeal to the north-central and northeastern states that historically have had fewer projects than the southern states, whose legislators, through seniority, have controlled the authorizing and appropriating committes.

The Carter administration has taken no position on the Domenici-Moynihan plan, but the water-conservation lobby gives it qualified support.

The current problems over water policy date back to the earliest days of the Carter administration, when the president proposed sweeping changes that would have subjected projects to closer economic analysis and required more state cost-sharing.

Carter's plans to scrap a number of projects already authorized by Congress touched off a storm of protest and energized legislators who saw the changes as intrusion into a traditional province of Congress -- deciding how the pork barrel is divided up.

Presidential proposals to have more cost sharing and independent economic and environmental review of projects have languished on Capitol Hill, and not until last month did the administration publish new rules for coordinating federal agency review of projects.

Carter drew more wrath with his veto of a public works appropriations bill that contained money for projects he opposed. And since 1977, time factors and now the veto threat have thwarted congressional efforts to pass a new authorizing bill.

For example, led by Chairman Jamie Whitten (D-Miss.) and Water subcommittee Chairman Tom Bevill (D-Ala.), the House Appropriations Committee quintupled the administration's water resources funding request in the 1980 supplemental appropriation this month.

The bulk of a $210 million appropriation -- some $58 million -- would go to the Tennessee-Tombigee Waterway, the costliest Corps project in history, which cuts through Mississippi and Alabama. The original fiscal 1980 appropriation was $165 million.

Moynihan, now in a position to wield some influence of his own on matters such as this, has derisively called the waterway a wasteful "cloning" of the Mississippi River caused by an outdated congressional authorizing process.

That's not the way they used to talk about such projects; the politics of water have changed a little.