THE IDEA of creating a Depatment of Natural resources is so old that its history is already blurred. Harold Ickes supported it, or something like it, in the 1930s. The Hoover Commissions on government reorganization recommended it in the 1930s and again in the 1950s. President Nixon specifically proposed such a new department in 1971. All those efforts, and others going back at least half a century, failed for reasons that had little to do with the merits of the idea.So it is not surprising that President Carter's plan to create a new department encountered immediate criticism despite its overwhelming logic.

The president's plan is to add two agencies -- the Forest Service and the National Oceanic and Atmospheric Administration -- to the existing Interior Department and give the combination a new name. The rationale is simple. The Park Service and the Bureau of Land Management, which are housed in Interior, do essentially the same job -- manage federally owned land -- done by the Forest Service, which is part of the Department of Agriculture. It makes little sense, for example, to have the nation's wilderness areas managed by two different government departments, as they are now. Similarly, NOAA, which is located in the Commerce Department, has missions that overlap with three agencies now housed in Interior. The White House claims the merger would save around $100 million a year and elminate about 2,000 jobs.

Under the present system, no one below the president is responsible for the government's policy toward natural resources, and the buck can be passed readily from one agency to another. The objections to the president's plan to remedy this -- beyond the disruptions in the bureaucracy it would cause -- are almost all political. The merger would change the existing channels through which industry groups and members of Congress try to influence policy. It would also reduce the importance of some congressional committees, which stand to lose jurisdiction. Not that it would take long for those who have particular interests to learn their way around the new bureaucracies. But these are comfortable for them now. And the same is true of the congressional jurisdictions and baronies -- at least for those in charge.

The genuine weakness in President Carter's proposal is not that it would upset these arrangements. It is that it falls short of achieving the goal he staked out during the campaign, namely including the critical natural resource -- water. The Corps of Engineers and the Soil Conservation Service belong in the new department just as much -- and for precisely the same reasons -- as NOAA and the Forest Service. They are not included because President Carter was convinced that Congress would kill the plan if they were.

His judgment on that count is understandable and, perhaps, wise. Every previous effort to create a department of this kind floundered because too many members of Congress chose to protect the status quo, and their own pleasant arrangements, rather than approve a ligical and needed administrative overhaul. But, in an age of fiscal restraint and energy shortage, when the nation is confronted with a desperate need for a comprehensive natural-resources policy and the means to make it effective, a short step in the right direction is better than none at all. The president is trying to take that step, and Congress should help him.