Drought not over yet, Nghe An farmers worry about saltwater intrusion
(Baonghean.vn) - If the lack of water for production and electricity has made it impossible for many localities in the province to cultivate, now there is a situation of water being contaminated with high concentrations of salt, there is water but it cannot be pumped for irrigation because it will kill the crops.
Present at Rum River, a branch of Lam River flowing through Chau Nhan Commune, Hung Nguyen District on the morning of June 23, the reporter recorded that the water level in the river was very low, estimated at about 1 meter, the riverbed was dry, people could wade across this river easily.
Rum River is responsible for irrigation water for many communes in Hung Nguyen district such as Chau Nhan, Hung Loi, Hung Phuc, Hung Nghia... The highest water level in this river can reach up to 7 meters (when the water touches the bridge wall), however, from May until now, when the tide is at its highest, the water level has only reached 2-3 meters, not enough water to irrigate crops, many pumping stations in the area have also significantly reduced pumping time due to lack of water.
However, currently, people in Chau Nhan commune as well as neighboring localities are facing a new concern, which is the situation of saltwater intrusion. The salinity concentration of the water has exceeded the allowable level, causing people to fall into a "dilemma" when there is water but they do not dare to pump it into the water because if they pump it into the rice, it will dry out immediately.
Hung Chau Pumping Station of Hung Nguyen Irrigation Enterprise is the largest pumping station in the district with 6 horizontal shaft units (capacity of 1,000m3/hour/machine) and 8 vertical shaft units (capacity 8,000m3/hour/machine). This pumping station has three main functions: drought prevention, flood prevention and water source creation, responsible for irrigating nearly 1,000 hectares of rice in the communes along the dike of Hung Nguyen district. However, since the water source was affected by saltwater intrusion, irrigation pumping has not been able to take place as smoothly as before.
Mr. Le Van Hung - Deputy Head of Hung Chau Pumping Station shared: “From mid-June until now, the daily salinity concentration measured at Rum River fluctuates from 2 - 3 parts per thousand. While the concentration allowed for irrigation of crops is less than 1 part per thousand. Only when the tide rises, the salinity concentration decreases slightly, when the tide falls, the water source becomes salty again. Therefore, it is impossible to pump water for crops because the plants will die faster than in the drought.
“Since May, the water level has been low, and the rotating power outage schedule has interrupted irrigation pumping. The pumps are powered entirely by grid electricity, so diesel pumps or field generators cannot improve the situation. Now the water is salty, and there is no other way to supply water to save the summer-autumn rice crop at this time,” Mr. Hung emphasized.
Not only in Hung Nguyen, saline intrusion also occurs in Nghi Loc district. Especially in the Cam River system, from the downstream of the Cam River bridge (road N5) down to Nghi Quang, the salinity is over 1 part per thousand, making it impossible to pump water for crops.
On June 22, Nghi Loc district issued Official Dispatch No. 1805/UBND-NN on the implementation of measures to combat drought and saltwater intrusion into the fields. Accordingly, the Provincial People's Committee has allowed Nam Irrigation Company Limited to build a temporary dam to block the Cam River at the N5 bridge point (Nghi Thuan commune) and to pump alternately between localities: From 7:00 p.m. on June 21, 2023 to 7:00 p.m. on June 26, 2023, pumping stations along Thap canal (Nam Dan, Hung Nguyen) will stop pumping to divert water to Gai canal to improve the water source for Nghi Loc district and push back saltwater from encroaching further into the system.
Therefore, Nghi Loc district has directed localities along the Cam River with pumping stations from bridge N5 down to Nghi Quang sluice to absolutely not pump water for production because the salinity concentration has exceeded 1 part per thousand.
Localities along the Cam River, Gai Canal from Road N5 upwards, and Khe Cai Canal mobilize maximum human resources, machinery, and means to operate pumping stations managed by the commune and coordinate well with the Irrigation Enterprise to operate the Enterprise's pumping stations to pump water for rice irrigation, making the most of the improved water source when building a temporary dam on the Cam River and during the time Nam Dan and Hung Nguyen districts stop pumping. Before and during pumping, the salinity of the water source must be regularly checked; absolutely do not pump when the salinity exceeds the allowable level.
It is known that this summer-autumn crop, Nghi Loc district has restructured nearly 6,000 hectares, however, the risk of drought and saltwater intrusion is a big concern, especially in localities such as Nghi Thuan, Nghi Hung, Nghi Yen, Nghi Tien, Nghi Thiet, Nghi Quang...
According to some irrigation officials, the salinity intrusion is very difficult to handle, there are only two ways to minimize this situation. One is to wait for rain to reduce the salinity in the water. Two is when water flows from upstream, it will also contribute to reducing salinity for downstream localities, however, this is a very low possibility because currently, the water in rivers and hydroelectric reservoirs in the upstream is also very low. Therefore, the most feasible way to reduce salinity is to wait for heavy rains.
This summer-autumn crop season, Nghe An will plant 81,000 hectares of rice. According to assessments, this is a crop facing many difficulties and challenges. Temperatures are generally higher while total rainfall is lower than the average of many years. Water in dams, rivers, streams and key projects is at low levels, and saltwater intrusion is increasing. It is estimated that the whole province has over 6,500 hectares at risk of drought and water shortage.
