The HOUSE is about to vote, perhaps today, on funding for 17 of the 18 water projects that President Carter has asked Congress to stop. The vote has developed into an important battle between prodevelopment interests and enviromental groups. It will also be a test of presidential influence in a field in which Congress and individual legislators have traditionally held away.

One thing this vote is not is a final referendum on the projects themselves. Even as the House girds for a confrontation, key senators are trying to tie down a compromise that might quell White House thoughts of vetoing the appropriations bill. Thus some tacticians regard the House vote mainly as a gauge of whether a veto could be sustained if it comes to that.

There is, however, an issue of considerable substance facing the House. In recommending funds for the 17 projects, the House Appropriations Committee declared that the question is not whether water resources should be developed, but "how rapidly." We would put it another way: The question is not how rapidly, but how. Should the nation continue to rely so heavily on dams and dredging to furnish water for agriculture and communities, reduce flood damage, augment power supplies and stimulate economic development? Or is it time to take a sharper look at how well this approach works, to recognize that most of the best projects have been built, and to modify or halt those that are environmentally damaging and economically unsound?

One can, of course, endorse a thorough-going review and still maintain that these particular 17 projects are sound and should not be stopped arbitrarily in midstream. One can argue, too, that Mr. Carter has tackled the subject in a hurry, with a heavy hand and perhaps more attention to the projects' budgetary impact than to their economic import for the areas concerned. Yet even if one concedes a lot along these lines, two points remain that, in our view, justify House support for Mr. Carter's stand.

The first is that, while some of the political thrashing-about may have been unnecessary, it's impossible to mess around with water policy without, shall we say, making waves. Large projects have such a long lead-time that any review with practical effect is bound to upset something that is under way and that agencies, communities and legislators have been counting on.

The second and more substantial point is that the administration's review has fetched up, in general, at the right place. The projects at the center of this year's fights have been perennially controversial - and in many cases marginal - on economic and environmental grounds. Indeed the pulling and hauling over the "hit lists" has already produced important truncations of the Central Aizona Porject and the Garrison Diversion Project, the two largest endeavors of all. Mr. Carter's initiative also spurred at least one congressman, Butler Derrick (D.S.C.), to reassess a congressman, Bulter Dirrick (D.S.C.), to reassess a project in is own district (the Rusell project) and conclude that it can no longer be justified.

Such rethinking needs to be continued. Water, after all, is not an inexhaustible resource; expecially in the West, painful choices among competing uses and beneficiaries have to be made. Conservation of water, of environmental assets and of public funds is as desirable as conservation of energy. Unfortunately, there is not perfect way or time to launch the policy changes that this view entails. The forthcoming House vote will indicate how many legislators are willing to start somewhere - and to start now.