This has caused massive drought onhundreds of thousands of hectares of farmland, blocked waterwaytransport and seriously polluted the rivers, a conference heard onFebruary 11.
At the conference on management of the Hong-ThaiBinh river system, PhD Rodolfo Soncini-Sessa of the Technical Universityof Milan said that the flow of the Hong River must reach about 1,200cubic metres per second to supply enough water for the Red River delta.
However, in the past several years, the flow fell to 900 cubic metres per second.
"Itis vital to keep the water level of 2.3 metres high in Hanoi's LongBien district to ensure the supply of water for the city," he said.
TheRiver covers Hanoi and 25 other provinces in the north with apopulation of 26 million people and total agricultural area of nearly1.1 million hectares.
In terms of waterway transport, he said theminimum of the water level in the area around Long Bien Bridge must be1.1 metres, but many vehicles were banned to operate as it was down tounder 0.4 metres sometimes.
According to the Italian expert, thedecrease of water level at pumping stations in lower section of theriver and the construction of hydro-power plants have affected the flow.
Since1960, Vietnam have spent more than 500 million USD to curb the changesof flow in the Red River, but the effectiveness remains limited.
A2.2 million USD project, which has been implemented in Vietnam since2012, will help improve study on the flow allocation of the two rivers,maintain essential ecological services and improve the economic benefitsof hydro-power production and agriculture, he said.
The projecthas managed to specify 24 indexes on exploiting the river water in fivesectors and the shortage of electrical energy of hydro-power plants indry seasons.
It is being funded by the Italian Ministry ofForeign Affairs, the Technical University of Milan and the Institute ofWater Resources Planning under the Ministry of Agriculture and RuralDevelopment.
Bui Quang Tuan, representative of the Institute ofWater Resources Planning, said the irrigation system has downgraded asmany pumping machines were built more than 50 years ago and reachedabout 70 percent of their performance.
Moreover, the encroachmentof the river and the discharge of waste water from industrial zones andresidential areas have made it seriously polluted, he said.
DeputyMinister of Agriculture and Rural Development Hoang Van Thang said theministry has carried out a programme on improving the irrigation systemwith the estimated investment capital of 20 trillion VND (940 millionUSD) until 2020.
The programme will supply more water fromreservoirs in Hoa Binh, Thac Ba, Tuyen Quang and Son La. A series ofirrigation works, such as Trung Ha, Bach Hac, Dai Dinh, Thanh Diem, DanHoai, Xuan Quan and Long Tuu, and a system of dykes will be built andupgraded.
As many as 129 pumping stations and 14 culverts will bebuilt, and more than 230 pumping stations and 14 culverts upgradedunder this programme, he said.-VNA