By Alex Kirby
BBC News website environment correspondent, in Tashkent
A senior Uzbek government official has said the states of central Asia must find a compromise over water resources.
Tuskan's fishermen are doing well
Mr Sergei Samoilov, who is the deputy chairman of the state committee for nature protection, said negotiations to resolve the dispute were continuing.
He said the region's two main rivers, the Syr Darya and the Amu Darya, could meet the needs of everyone in the area.
But it was unfortunate there was still no agreement on the prices which states charged each other for water and fuel.
The Uzbek leader, President Islam Karimov, and President Saparmyrat Niyazov of Turkmenistan agreed in November to share their water resources.
There had been warnings of a water crisis in southern Uzbekistan if a crumbling Soviet-built water pumping station on the Amu Darya river in Turkmen territory should collapse.
Mr Samoilov, effectively the Uzbek deputy environment minister, was speaking to journalists here about the disagreement involving Uzbekistan, Kazakhstan and Kyrgyzstan over the use of the Syr Darya's waters.
Kyrgyzstan uses the river for hydropower, while its two downstream neighbours rely on it for irrigation.
They want a good summer flow, but prefer Kyrgyzstan to impound the river during the winter to prevent floods on their territory. They have for years sold coal and gas to Kyrgyzstan for winter use.
Asked by the BBC whether Kyrgyzstan was accusing Uzbekistan of charging too much for its gas and paying too little for its water, Mr Samoilov said: "This issue should be resolved.
"We've raised it specifically at the Inter-State Water Resources Committee, which consists of the heads of state of our three countries plus Tajikistan and Turkmenistan, and which deals with the use of transboundary water.
"The question of the regulation of prices remains unfortunately still unresolved. But we have to solve it - we have to find a compromise."
A few hours' drive from Tashkent is a stark example of the changes caused by past disagreements over the rivers' use.
Volodya says the Aral Sea should get the spare water
Beyond the town of Djizak a rough track winds over the arid grey-green steppe to end suddenly on the shores of a vast inland sea.
Lake Tuskan is the first in a string of lakes stretching to the horizon and beyond, 42 cubic km of water.
There were some small lakes here before, but the whole area was inundated in 1969, when 21 cu km of water was released by Kazakhstan from the Chardarya reservoir just across the nearby frontier.
It was a year of high rainfall, and the Kazakhs opened the sluice gates to prevent a disastrous flood on their territory.
The creation of this massive Uzbek lake system drowned a huge collective farm, though no lives were lost.
Volodya, a pensioner, ekes out a living as guard of a makeshift fishermen's camp by the water's edge.
"The lake rose by eight metres (26ft) in seven years, affecting many villages," he says. "Even now, it rises three metres (10ft) every spring.
Mels and his family have a precarious hold on the land
"People do suffer, but the lake is full of nutrients, so the number of fish is increasing.
"The water here should be going into the Aral Sea, but that would need a canal, and nobody can be bothered to do anything about it."
Nearby at Kizilkum ("Red Sands") farm, Timur raises 200 cattle. No crops will grow in this stony semi-desert.
It is just enough to support his wife, daughter and three sons. The youngest is called Mels, from the initials of Marx, Engels, Lenin and Stalin.
Timur says: "The water is rising gradually, the pastureland is shrinking, and every year more people have to leave."
Central Asia's waters form a single river basin. With five governments now in charge, politics cannot afford to ignore this natural reality.