Tonle Sap, Cambodia – During Cambodia’s monsoon season, rice farmer Sam Vongsay’s backyard becomes full of water and the plastic rubbish of his neighbors who live in the houseboat while Lake Tonle Sap grows with floodwaters from the Mekong River.
But during the dry half of the year, which runs from December to May, Vongsay barely has access to a drop of lake water from his home in Chong Khneas, located about 220 km (137 miles) northwest of the capital Phnom Penh.
The 40-year-old farmer does not have a viable well or the equipment to pump the lake’s water the 2 km (1.2 miles) distance to his property, and blames farmers upstream for diverting much of the flow around their to irrigate crops.
“The water is not enough to get downstream because the other farmers upstream are also blocking the water,” Vongsay told Al Jazeera.
In the past, Vongsay and his family could grow rice for two seasons, but sparse rainfall in recent years and inadequate water infrastructure have made it difficult to manage a single crop. Vongsay said he tried to grow chilli last year to diversify his crop, but the plants withered and died.
“We do not have enough water infrastructure,” he said. “If we had it, we would not only grow rice, we would grow rice and other vegetables three or four times a year.”
Farmers along Southeast Asia’s largest freshwater lake face a growing threat to their livelihoods as the growing demand for land, droughts attributed to climate change and hydropower development weakens precious water supplies.
Since 2018, the volume of Tonle Juice has fallen below its historical average, according to a Mekong River Commission (MRC) report which examined water levels between November 2020 and May last year.
The lake experienced a severe drought in 2019, as well as the Mekong River system on which it relies, which left a lasting impact on water levels. In January 2020, the lake’s volume was about 6,000 million cubic meters, a little over one-third of its average dry season volume, according to the MRC.
Siem Reap rice farmer Van Ra, 44, told Al Jazeera that the weather had not improved since the 2019 drought, with off-season winds and rain last year digging up seeds placed in the ground during the dry season.
To cover the cost of renting his farmland and spraying fertilizer – which he has to do more frequently due to irregular weather – Ra tried to plant rice twice last year.
“It was useless because I had almost nothing to harvest,” he said. “Doing it twice is impossible because there is not enough water.”
Population growth and rising land prices caused a rush to clear forests in the area for homes and agricultural land, which created more demand for water from the lake and its tributaries.
The lake, whose seasonal floods are linked to melting snow from China’s Tibetan Autonomous Region and Yunnan Province, is also susceptible to the expansion of hydropower dam development, which has linked scientists to unpredictable water levels on the Mekong.
While farmers have experienced increasing pressure on their livelihoods, Tonle Sap’s fishing industry, which produces an estimated 500,000 tonnes of fish annually, is also to report smaller catches, which leads some fishermen to turn to fish farms or agriculture.
Brian Eyler, author of The Last Days of the Mighty Mekong, told Al Jazeera that in addition to hydropower dams on the Mekong, smaller reservoirs created to meet farmers’ needs – often without official approval – put pressure on the lake.
“These reservoirs effectively steal water from surrounding communities and block critical fish migration routes in the world’s largest inland fishery,” Eyler said.
Vongsay, the farmer near Tonle Sap, said the expansion of a canal next to his property in 2019 that was supposed to help him and other farmers get more water from upstream caused him to stop farming altogether.
“We first agreed that it would be good to dig the canal deeper, but we did not expect it to be that deep,” Vongsay said, explaining that he could not drive his rented tractor across the extended canal to to cultivate his rice field. .
Vongsay said he and his family survived a byproduct that made decorations for Buddhist holidays.
Chea Seila, a researcher at the US Agency for International Development’s Wonders of the Mekong project, told Al Jazeera that the combined effects of climate change, deforestation and infrastructure development on Tonle Sap have shown authorities a better understanding of the delicate nature. of the water supply and solutions developed that took these factors into account.
“It is interconnected. “When people use more water without saving and no restoration, there will be insufficient ground and surface water,” she said. “Even [if] we have sufficient irrigation infrastructure, we do not have water from the [groundwater] spring as well as from rainfall. It is still difficult to get enough water for the whole year and [will be] in the future.”