The outlet area of Hoang Khai lake was seriously eroded.

Ngoi La 2 irrigation work, Trung Mon commune, Yen Son district was built from 1973 to 1975 completed and put into use, with a capacity of 3.2 million cubic meters of water, serving the needs of more irrigation. 700 hectares of rice and crops per year. In 2017, the project was invested in reinforcing and repairing major dams, water intake culverts, flood spillway, operation management road and downstream canal after spillway. However, the main canal system of more than 3 km long, built in 1999 with thin-walled concrete, has deteriorated over the years. The canal walls are subsidence, broken, leaking water, the canal goes through a crowded residential area but has no lid, so waste is regularly thrown into the canal, causing flow congestion. Currently being overcome temporarily such as: Clearing, dredging flow; temporary reinforcement with bamboo and wood in the places that have subsidence.

Mr. Nguyen Van Ngoc, technical officer of Ngoi La 2 Irrigation Management Team, said that there are still seven households living in the safety corridor of the project because there are no plans during construction compensation, land acquisition. These households have lived here for many years before the project was built, so to clear the site, it needs a huge budget. In 2017, there were households who violated the safety corridor to protect the work, the construction management team coordinated with the authorities to ask the family to return to the original state, not to violate the corridor safety protection for lakes and dams.

Being at risk of unsafety, needing to be repaired and upgraded, Hoang Khai irrigation project located in Hoang Khai commune, Yen Son district has more than 31 ha of water surface area, providing irrigation water for nearly 270 ha of rice / crop / year and 38 ha vegetables, aquaculture. The project was built in 1966, although it was upgraded and repaired in 2002, but after many years of use, the lake bed is being deposited, reducing the water storage capacity, the drainage area of the lake is being eroded; the existing sub-dam with earth, the dam upstream roof was eroded and eroded. The dam surface combined with the road was previously paved, however, due to the large amount of traffic, the road surface has deteriorated, many potholes appear, making traveling difficult. Currently, the irrigation project management board has to ban vehicles with large tonnage to ensure safety for the project. Or as Thia lake in Tan Trao commune, Son Duong district is also damaged. The main dam is an earth dam, the downstream roof has not been reinforced, heavy rain causes severe landslides causing strong permeability in the dam body and intake culverts, overflowing with damaged masonry in many locations, ...

According to the Tuyen Quang Irrigation Department, there are 1,436 dams and reservoirs in the province of Tuyen Quang that supply water for production. Of which, the number of works is classified according to Clause 1, Article 1 and Article 3, Decree No. 114/2018 / ND-CP including 403 works (374 reservoirs and 29 dams) have been decentralized to 143 boards. Irrigation management (including a provincial department, 142 grassroots departments) organizes the management, exploitation and protection of which two reservoirs do not store water due to damage and risk of failure high safety; 30 damaged reservoirs must contain limited water; 31 reservoirs damaged dams, spillway, water intake culverts causing unsafety. In recent years, many irrigation works have been invested and built, but due to lack of funding, the works have not been invested synchronously from the focal point to the field water system, the number of works temporarily occupied. More than 47% of the total projects of the whole province are often damaged after each flood, the local budget can not meet, especially for the damaged works with large scale and investment. . The earth canal system also accounts for a large proportion (nearly 30% of the total length of the canal in the whole province), is often affected by natural conditions and floods, so it is landslides, burying, causing water loss to reduce efficiency irrigation fruits of the project.

In addition, through inspection, review also found many cases of violating the regulations on the management, exploitation and protection of irrigation works in the province, especially canals passing through residential areas such as: encroaching on the safety corridor of works to plant trees, grazing cattle; prevent flow on the canal to arbitrarily take water, discharge domestic and livestock wastewater into the irrigation system ... In 2019, there were 34 cases of violation of the protection scope of irrigation works in the province. In which, in the form of making minutes, mobilizing dismantling and moving out of the safety corridor of works for 30 cases. The reason for this violation is that it has not been able to place landmarks on the safety corridor of the work (because there is no funding to do it, so the scope of the work is assigned by assigned organizations. management responsibilities are not clear, specific, causing difficulties for the management, exploitation and protection of irrigation works, lack of legal basis to handle violations according to current regulations). In some places, local authorities have not focused on propaganda and law enforcement on irrigation, have not really paid attention to, coordinated with management and exploitation units in preventing and resolving resolutely and resolutely to the violations. Some projects have been built for a long time, records are lost or there is no land acquisition decision, so most of the land in the protection corridors above works is used stably and under management. People's management, in which some households have been granted a long-term land use right certificate, so it is difficult to manage and protect the works. There is no funding to support, compensation and site clearance to support and move people's houses out of the safety corridor to protect works ... In addition, some parts of the people have not strictly complied the regulations on handling violations after being reminded by the local authorities, making a written request for dismantlement, restoration, and restoration of the original state to the work.

Director of Irrigation Sub-Department of Tuyen Quang Bui Chi Thanh said that, due to the number of dams and reservoirs in the area, most of them were built long ago (more than 20 years), public related documents. Most of the projects are lost, so it is very difficult and time-consuming to review the technical parameters to classify and register safety of dams and reservoirs for each dam and reservoir project. irrigation. The capacity and qualifications of a number of management and exploitation units are limited, so they have not actively implemented the legal regulations on safety management of dams and irrigation reservoirs. Dam and reservoir projects in the province have not been invested in the installation of hydro-meteorological monitoring equipment; operation monitoring system, safety warning information equipment for the dam and downstream areas due to the lack of funding for implementation. In addition, the demarcation of dams and reservoirs has not been performed due to lack of funds, leading to inadequate management and protection of the safety corridor of the works.