The effectiveness of reservoir and dam systems in irrigating spring and summer-autumn rice crops.

(Baonghean) - In recent years, Nghe An province has received concentrated resources from the State to invest in the construction of many large reservoirs serving rice irrigation and people's needs, such as Vuc Mau, Xuan Duong, Ve Vung, and Song Sao reservoirs... These large reservoirs and dams have all been effective in ensuring irrigation water throughout the year. However, there are still some reservoirs and dams managed by the local authorities that have not yet reached their full capacity...

These days, walking along the Xuan Duong reservoir project (Dien Phu - Dien Chau), you see a vast expanse of green rice fields in their prime. Ms. Nguyen Thi Sam, from Dien Phu commune, said: "In previous years, this field could only be cultivated for one rice crop, leaving the summer-autumn crop fallow due to water shortages. The lives of the people have truly changed since the Xuan Duong reservoir system was upgraded. Now, people have water to cultivate two rice crops, and the water also serves for daily life and livestock development."

It is known that the Xuan Duong reservoir, built in the 1930s, has severely deteriorated over time, leaking and causing water loss, threatening safety during the rainy season and floods. In 2007, the Xuan Duong reservoir received an investment of over 60 billion VND for upgrades, along with a comprehensive canal system.

Mr. Nguyen Huy Dung, head of the Xuan Duong reservoir irrigation cluster (Dien Chau Irrigation Enterprise), said: The reservoir has been rebuilt to a modern standard, reaching a capacity of 10 million cubic meters. Both sides of the dam are paved with stone, and the spillway is made of permanent concrete. The main canal system has been reinforced for 6.4 km, canal N2 for 1.8 km, and canal N3 for 2 km, ensuring irrigation for over 500 hectares in the communes of Dien Phu, Dien Tho, Dien Loi, Dien An, etc.

In addition, the reservoir also has over 2 km of paved service roads and an administration building. The Xuan Duong reservoir irrigation cluster has 6 staff members who are assigned to work in shifts day and night to manage the water supply efficiently for rice irrigation in the communes. According to Mr. Dung, during the winter-spring crop season, an irrigation cycle is organized every 7-8 days, providing 5,200 m3/ha of water, following the principle of "irrigating the farthest and highest areas first, then the nearest and lower areas." Therefore, even the areas at the end of the canals have enough water for irrigation. There is absolutely no competition for water among the communes like in previous years.

The Vuc Mau reservoir (Hoang Mai-Quynh Luu district) is the largest and most modern in the province, with a capacity of over 75 million cubic meters of water. Mr. Bui Van Hao, Director of the Quynh Luu Irrigation Enterprise, added: After receiving the reservoir, the Enterprise assigned staff to protect and operate the facility effectively. The reservoir ensures irrigation for 2,500 hectares of rice fields in Hoang Mai town and neighboring communes such as Quynh Hoa, Quynh Trang, Quynh Tan, Quynh Van, Quynh Thach, etc.

Notably, the reservoir also supplies domestic water to over 100,000 people and provides sufficient water for the Hoang Mai Industrial Zone, reaching 6.8 million cubic meters per year. Furthermore, the reservoir helps reduce flooding downstream and provides water for aquaculture covering approximately 400 hectares. The Vuc Mau reservoir has 6 operating staff, and during the winter-spring season, it operates an irrigation cycle every 13 days, delivering 7,000 cubic meters of water per hectare.

Mr. Ho Ngoc Mai, Director of Bac Thuong Irrigation Company Limited, shared: "The company manages 17 reservoirs and dams, and in recent years, the State has invested in upgrading 11 of them. All of them are operating effectively, ensuring irrigation for two rice crops per year."

However, six other reservoirs are still severely degraded, causing water loss. A typical example is the Nha Tro reservoir in Tan Thanh commune, Yen Thanh district. The earthen dam is very weak and leaks are occurring. The company has spent money repairing the culvert, but there is still a shortage of irrigation water. Regarding the irrigation system for the winter-spring crop, water conservation measures are being implemented to save water for the summer-autumn crop...

Mr. Nguyen Truong Thanh, Head of the Planning Department of the Nghe An Irrigation Sub-Department, added: The entire province of Nghe An currently has 750 reservoirs and dams irrigating over 20,000 hectares of rice fields, including over 50 large and small reservoirs and dams managed by the State. In 2011, the abundant rainfall meant that most reservoirs still had considerable water reserves, so the water supply for the winter-spring crop was not a concern. In addition, many reservoirs have been upgraded by the State, so they store water and operate quite well, ensuring sufficient water for rice irrigation.

However, right from the start of the season, the province directed irrigation management units to treat reservoirs as water storage facilities, thereby operating them rationally and conserving water resources. In particular, most of the canals in the reservoir system have been dredged and cleared, making it easier to irrigate rice fields.

However, the current challenge is that the system of small and medium-sized reservoirs managed by local authorities mostly has small capacities, many are degraded or damaged, while the local reservoir management team is weak. This leads to inefficient water management, easily causing water loss and shortages for rice cultivation and domestic use.

In response to this situation, the Nghe An Irrigation Sub-Department will soon coordinate with relevant agencies to organize training courses for local irrigation staff to improve their professional skills. In addition, the Department of Agriculture and the Provincial Irrigation Sub-Department are collaborating on a project titled "Management of Irrigation at the Grassroots Level," aiming to effectively operate the local reservoir and dam system.

Van Truong