Ensuring dam safety during the rainy and stormy season

(Baonghean) -The rainy and stormy season is coming, the issue of ensuring the safety of the dam system in the province is becoming a real concern as most of them are in a state of degradation and damage, some of which are at high risk of bursting when floods come. Meanwhile, the source of capital for upgrading and repairing in recent years has been extremely difficult; management and operation work in localities is still very limited.

With a system of 625 dams, with a total capacity of over 387 million m3, our province is one of the localities with the largest number of dams in the country. Of these, about 100 dams are managed by irrigation companies, the rest are assigned to localities for management. These dams, in addition to providing water for 39,000 hectares of production land and serving people's lives, also play a role in regulating floods and protecting downstream areas. However, due to being built a long time ago, combined with a lack of funds for upgrading and repairing, many dams are damaged and seriously degraded.

In Nghia Dan district, there are currently more than 100 large and small dams, most of which are managed by the local authorities. These dams were built in the 70s and 80s and are now seriously degraded and damaged.

Mr. Le Cong Tam, Head of the District Agriculture Department, said: The dam system managed by the locality mostly has a small capacity, under 2 million m3, ensuring safety for the people. The characteristic of these dams is that they are built manually, so the quality of the works is not guaranteed. Due to a long period of time without repair, they are seriously degraded.



Cay Da Dam (Nghia Trung commune, Nghia Dan district) is seriously degraded.

The most seriously degraded dam in Nghia Dan district is Cay Da dam (Nghia Trung). With a capacity of about 1 million m3, Cay Da dam is responsible for irrigating about 300 hectares of land for people in Nghia Trung commune and regulating water from upstream when the rainy season comes. But now, the dam body is degrading, the embankment system at the foot of the dam has been eroded.

Mr. Nguyen Van Binh - Vice Chairman of the Commune People's Committee said: "The dam was built in 1972, so up to now the lake bed has been silted up, the upstream slope has been eroded a lot. Besides, the dam body has many termite nests, every time the water level rises, it is clearly visible, a lot of water flows through these termite nests. The dam body used to be about 7 meters wide, 2 cars could go together, but now it is only about 3 meters wide. Therefore, the safety of the dam during the flood season is not high and if the dam breaks, more than 400 households of 5 hamlets living in the downstream area will be greatly affected."

In Yen Thanh district, there are currently over 200 dams, mainly managed by the locality. Because they were built a long time ago, the general state of the dam system in the district is degraded, with serious upstream landslides.

At Nha Tro dam (Tan Thanh), the dam foot paving stones have been peeled off and are no longer connected. The dam surface is designed to be 4 meters wide but is now only 1 meter wide. The dam body has many termite nests and leaks, and when floodwaters come, the risk of the dam breaking is very high. In fact, in the district, many dams have broken in recent years. In the recent flood of 2012 alone, Yen Thanh had over 12 dams eroded, collapsed, and the dam body broken. In particular, the Vu Giang dike broke on the night of September 6, 2012, isolating many hamlets in Khanh Thanh and Long Thanh communes, causing damage to hundreds of hectares of rice, crops, and many people's properties.

The deterioration of dams is also a concern for the authorities and people in many other localities. According to the Department of Irrigation, there are currently about 500 dams in the province that need to be upgraded and repaired immediately. Most of them are managed by local authorities and have a capacity of less than 2 million m3.

Over the years, with various funding sources, a number of dams in the province have been upgraded and repaired in many important areas. Since 2005, more than 140 dams have been funded for repair and upgrading. Dams with low safety and high risk of failure are prioritized for repair.

Therefore, large reservoirs with a capacity of over 5 million m3 are now basically safe. However, small reservoirs with a capacity of less than 2 million m3 are in a highly unsafe state. Mr. Pham Huu Van - Deputy Head of the Irrigation Department said: The need to upgrade and repair the dam system in our province is very large.

However, due to limited capital, the focus has been on weak projects. Recently, the province issued Decision No. 2291 dated June 7, 2013 on allocating VND 8.4 billion to districts to repair 29 items of weak projects, to ensure safety during the rainy season. Currently, contractors are focusing on construction, ensuring completion before August 30, 2013.

The rainy season is coming, ensuring the safety of the dam system in the province is of concern to the sectors and localities. Currently, irrigation companies and localities have developed a flood prevention and control plan, ensuring the safety of the dam system during the rainy season. For dams managed by irrigation companies, staff are regularly assigned to monitor 24/7 to have a solution when problems arise. As for dams managed by localities, localities have developed a "4 on-site" plan, in which the relocation of households living downstream is of special concern.

However, the management and operation of dams still has limitations, especially for local management. Currently, the staff assigned to monitor dams do not have much experience in responding to floods. Therefore, when incidents occur, localities are still confused in the rescue work. The preparation of means and materials for flood and storm prevention is not yet complete and timely, so the efficiency is not high. Therefore, improving the knowledge and skills of staff managing and operating reservoirs in localities needs to be paid more attention. In addition, localities need to trim trees, identify termite nests and leaks for timely handling. Water storage and discharge plans need to be built in a specific, scientific and correct manner to ensure the highest level of safety for dams during the rainy season.

Pham Bang