Moscow — One of the most breathtaking and gigantic plans ever conceived to change the face of wide areas of the earth's surface may have come one step closer to reality here.
But the plan is still opposed by powerful Soviet conservationist and environmental officials who fear incalculable changes in Northern Hemisphere weather patterns, and in Soviet wildlife, fishing, and economic conditions.
The plan sounds simple enough: to reverse part of the huge northward flow of water in Siberian rivers, water now rushing through virtually empty land into the Arctic Sea, and send it coursing 1,500 miles south to irrigate deserts in Soviet Central Asia.
First thought of in the 1920s, the plan has been pushed back into public attention here by Abel Agan Begyan, an internationally respected member of the Soviet Academy of Sciences.
Dr. Agan Begyan has just told the Soviet news agency Tass that another enormous development project -- the second Siberian railroad from Lake Baikal to the Far East -- will "serve as a model for other global-purpose-oriented programs in the USSR, among them . . . irrigating Central Asia and Kazakhstan by transferring part of the Siberian rivers' discharge."
According to a Tass report, Dr. Agan Begyan stressed the scope and scale of the new railroad, now roughly two-thirds completed by Soviet accounts. He also emphasized that about 1 1/2 square million kilometers of land around the line were being developed and that such "territorial scientific developments" had never before been carried out on such a scale.
This suggested to Western analysts here that, when the Siberian line is eventually finished in the mid-1980s, the Kremlin might well designate the Siberian river diversion project as the next najor Soviet plan. A decree signed by Soviet leader Leonid Brezhnev and Premier Alexei Kosygin Dec. 21, 1978, ordered full-scale scientific research work to begin.
More than 100 research institutes were involved. Among issues being studied: to what degree the ocean current system of the Arctic would be affected by reducing the flow of the Ob River, one of the five largest in the world? If waters of the Yenisei are also partially diverted, what effect would that have? How would diversions affect the spring breakup of ice?The autumn formation of sea-ice and its spread along the Siberian coastline?
Such plans, including the virgin lands scheme of the 1950s, are highly publicized here, not only for their economic potential, but also as frontier rallying cries for Soviet youth, and as spearheads for Soviet prestige as a superpower.
Indeed, as the analysts point out, a smaller version of the river diversion scheme has been completed, or almost so.
This takes north-flowing waters from the Pechora River in Siberia and sends them through a new canal southward into the Kama River and then on into the legendary Volga River.
The European zone of the USSR contains 80 percent of the country's population but only 20 percent of its river waters. Concentrations of people and industry in the Volga Basin have siphoned off and polluted much water from the Volga River. The level of the Caspian Sea, into which the Volga flows, has been dropping steadily for decades, alarming scientists and now, apparently, the Communist Party.
A canal has been dug from the Pechora to the Kama River, Western sources say.
Far wider in scope would be the plan Dr. Agan Begyan talked of -- to take part of the northern flow of the Ob River, one of the biggest rivers in the world, and of the Irtysh farther east, and pump the water down to the Aral Sea and across into Central Asia.
An American source once likened the project to taking an upper branch of the Columbia River in the US and pumping the water down across the Continental Divide into the North Platte and the the Mississippi.
The Soviet scheme would cost billions of rubles and require the movement of about 100 times more earth than was dug out for the Panama Canal.
Project director Gurgan Sarukhanov refused an interview with this newspaper two years ago. Earlier he had told another US correspondent that the first stage of the work would take 15 years.
Since then a battle between engineers and conservationists has been fought in the pages of the Soviet press, with Dr. Agan Begyan's statement apparently the latest shot.
Confident engineers, backed by impatient party officials worried about a lagging economy, believe diverting the Ob is the kind of grandiose scheme worthy of their skills and prestige.
Conservationists and scientists, especially in Siberia itself, raise the unsolved issues. Among them: What effect would even a 10 percent reduction of the flow of fresh water from the Ob into the Arctic Sea have on weather patterns?
On the one hand, the Arctic could form ice more slowly, since it would be more salty. On the other, with less of the river's warmer water, the Arctic would be colder and ice formation could speed up.
The two phenomena could cancel each other out -- or cause an imbalance that could affect the weather across the top of the world.
In 1977, a senior west Siberian researcher wrote in the newspaper Trud ("Work") that a plan to divert large amounts of the Ob's flow south via pumping stations to the Arab Sea was opposed by oil and gas workers, fishermen, boat crews, farmers, ecologists, and others in west Siberia.
Pumps would work in large reservoirs -- and the reservoirs would drain surrounding rivers, ruin fishing, and perhaps make navigation impossible, workers feared.
Expert after expert has called for more study.
Some Westerners see environmentalists growing stronger in the USSR these days and believe their pressure might confine the Ob diversion to the drawing boards.
Others, less sanguine, think the Kremlin is anxious to provide jobs and income for the fast-growing population of Central Asia and might well be tempted to give the green light in the 1980s.