VietNamNet Bridge – The decrease of surface water on rivers, lakes and streams and the depletion of underground water, which has been caused by the massive construction of hydropower plants, has worsened the dry season in the Central Highlands, senior officials said.

The main dam at the An Khe hydropower plant in Gia Lai Province. Construction of hydropower plants has worsened the dry season in Central Highlands provinces. — Photo: VNA/VNS

Pham Dinh Thu, chairman of the Gia Lai Province's People's Council, said that the construction of An Khe-Ka Nak has changed the direction of the water stream of Ba River to Kon River in the central Binh Dinh Province.

Figures from the council showed that more than 300 billion cubic metres of water from Ba River have flowed annually to Kon River to service the hydropower plant.

This has caused drought to tens of thousands of hectares of cultivated land in six districts of the province. To make matters worse, about 400,000 residents living along Ba River have suffered from pollution in their water source, officials said.

The river flow of Se-re-pok, which ran through Dac Nong and Dac Lac provinces, has been redirected for the construction of the Buon Tuar Srah hydropower plant. It has caused serious impacts to the water source for agricultural production in eight communes in the two provinces.

The construction of Se-re-pok 4A in Dac Lac Province has caused serious drought to low-land areas and affected the ecological system of the Yook Don National Park.

The Pongour Waterfall in Lam Dong Province used to be a well-known tourism site. However, since the Dai Ninh hydropower plant was built, the water flow of Da Nhim to the waterfall was limited, making it an abandoned area free of tourists.

Truong Thi Dang, manager of the Pongour Waterfall Ecological Tourism Site, said that although representatives of the plant committed to fix the problem, nothing has been done and the situation has not yet been improved.

In Kon Tum Province, the Thuong Kon Tum hydropower plant, which is under construction, has threatened the low-lying area since it altered the direction of water flow of Dak Snghe to Tra Khuc River in central Quang Ngai Province.

While the region faces a serious water supply shortage, drought prevention depends on the irrigation system, which has been downgraded.

Currently, there are about 1,150 reservoirs, 950 dams, 5,000 kilometres of channels and hundreds of pumping stations.

Mai Trong Dung, deputy director of the Dac Lac Province's Department of Agriculture and Rural Development, said that the management of irrigation works was assigned to local authorities. Most were downgraded or encroached on due to loose and weak management, Dung said.

As a result, farmers must find their own water supply sources for cultivation by digging wells. This has resulted in the decrease of 10 and 15 metres of the underground water level.

There were about 600,000ha of coffee and 60,000ha of pepper plants. Only 30 per cent of the total area gets its water supply from the irrigation system.

According to experts, it is necessary to invest in the construction of channels and upgrade the irrigation works to supply more water to agricultural production.

A plan to exploit underground water effectively should be set up to avoid the depletion of water, they added.

VNS