Despite an interim accord three months ago that papered over a two-decade dispute over sharing of the waters of the Ganges River, India and Bangladesh remain far apart on a long-term solution to a problem that both sides regard as a matter of life and death.

Bangladeshi officials, while encouraged that the agreement reached in New Delhi in October between Indian Prime Minister Indira Gandhi and Bangladeshi chief martial law administrator Lt. Gen. Hussein Mohammed Ershad had staved off a complete breakdown on the waters issue, stressed the urgency of finding a long-range solution before more flow from the Ganges without reaching this desperately poor and catastrophe-prone country.

"Being on the receiving end of this great river, we cannot afford to put off the solution every two years. For us, finding a permanent solution becomes more important as time goes by," Bangladeshi Agriculture Minister Abu Zafar Mohammed Obaidullah Khan said in an interview.

"At least, for the first time, both sides are seriously looking at each other's proposals before discarding them. How far it will go, I do not know. Unless we can come to some understanding, it will be very difficult for us, because water is our lifeblood," the minister said.

The Ganges dispute, which has periodically soured relations between India and Bangladesh since the first euphoric flush of friendship after India helped Bangladesh win independence in 1971, was smoothed over temporarily on Oct. 6 when an existing sharing formula agreed upon in 1977 was extended for another 18 months, by which time the two countries must agree on a plan to augment the river's flow during the dry season.

The Ganges problem bears directly on the daily needs of 90 million of the world's poorest people during the parched months from January to the end of May.

Ever since Bangladesh split away from Pakistan 11 years ago, both sides have claimed they are entitled to a fair share of the Ganges water, which begins its flow in the Himalayan Mountains of Nepal and courses through northern India and eastward through Bangladesh to the Bay of Bengal.

The Ganges is regarded by Indian Hindus as the holiest of rivers and historically has been a focal point on the cultural development of the subcontinent.

Both sides have consistently agreed on the need to augment the Ganges flow during the dry season, but they have differed sharply on how to achieve the objective. The five-year agreement that expired on Nov. 4, which was renewed with some modifications, gave Bangladesh approximately 60 percent of the flow during the dry season.

According to the new agreement, the rate of the river's discharge will be altered every 10 days, as against every 30 days under the 1977 agreement.

The discharges agreed upon for the first 10 days of January, for example, are 40,000 cusecs (cubic meters per second) for India and 58,500 cusecs for Bangladesh, with the amounts to be scaled down progressively as the dry season sets in and the river begins to narrow. During the last 10 days of April, which is the driest period of the season, India will draw 20,500 cusecs while Bangladesh receives 34,500 cusecs.

Before India completed construction of a dam at Farakka, 11 miles upstream from the border, in 1975, a much larger portion of the Ganges flowed into Bangladesh. India built the dam to divert water to the Hooghly River and to flush silt from the approaches to its Calcutta port, claiming that silt buildups had made it impossible for deep-draft ships to reach either Calcutta or Haldia, a container port 55 miles downstream, for four months of the year.

The Indians justified the diversion on the basis that 90 percent of the 1,200-mile main channel of the Ganges flows through India.

Bangladesh officials, however, counter that a third of their country's population depends on the Ganges for drinking, agriculture, fishery and transport, and that diversion has devastating consequences in the dry season.

Paradoxically, Bangladesh, with vast undeveloped areas and a density ratio of roughly 1,000 people to the square mile, is inundated by water during the monsoon season and the density ratio to dry land can abruptly shift to 2,000 people to the square mile.

On the question of how to augment the dry-season flow of the Ganges, Bangladesh wants to store surplus waters in reservoirs in the upper reaches of the river in Nepal and northern India, a plan endorsed by the United Nations Commission on Environment and Planning.

However, India has been unwilling to bring a third party into the picture, saying that the solution should be to transfer the flood waters of the Brahmaputra River, which runs through the far eastern reaches of Bangladesh, through a 200-mile canal, a third of which would pass through Bangladesh on its way to the Ganges.

Bangladeshi officials say that the proposed canal would displace thousands of peasants and destroy a large area now under cultivation.

Compounding the Indo-Bangladeshi dispute is the prospect of increasing pollution of the Ganges as it winds its way through heavily developed areas of India on its way to Bangladesh.

While Obaidullah Khan said that Ganges pollution was not an immediate problem to Bangladesh, it could become a severe problem if the flow is insufficient.

Water experts say that diminishing headwaters of the more than 100 large and small rivers and canals that cover 3,200 square miles of this country have already contributed mightily to siltation, erosion and salinity, shrinking some rivers to the size of canals. Deforestation in the Himalayas has contributed to the problem.

To address some of the problems of the Ganges, water experts from India and Bangladesh have begun a series of technical meetings here on feasibility studies for augmenting the river's flow at Farakka. The Indian-Bangladesh Joint Rivers Commission is scheduled to submit its recommendations at its next meeting on Feb. 1.