According to a report by the Department of Management and Construction of Irrigation Works (Ministry of Agriculture and Environment), the Northern and Southern regions have rain, moderate rain and scattered thunderstorms, with locally heavy to very heavy rain. Rainfall from 7:00 AM to 3:00 PM on May 21 recorded some points exceeding 70mm, including Son Dong (Bac Giang) reaching 220.8mm; Quang Ha (Quang Ninh) 210.4mm; Cong Bang (Thai Nguyen) 84.4mm; Hiep Thanh (Ca Mau) 96.2mm; Soc Trang (Can Tho City) 78.2mm...
Forecast for the evening and night of May 21, the Northern region will continue to have scattered showers and thunderstorms, common rainfall of 10-30mm, locally over 60mm. The Central Highlands and Southeast regions will also have scattered showers and thunderstorms, locally heavy rain over 50mm.
The Northern region currently has 2,543 irrigation reservoirs. Of which, 31 reservoirs have spillways, and the rest are free-flow reservoirs.
The water storage capacity in irrigation reservoirs in the Northern region averages about 42-77% of the designed capacity. Some localities have high water storage rates such as Quang Ninh reaching 77%, Ninh Binh 73%, Lao Cai 65%, Bac Ninh 64%. Other localities such as Dien Bien reaching 42%, Tuyen Quang 52%, Son La, Cao Bang, Thai Nguyen, Phu Tho, Hanoi are also at about 60%.
In Quang Ninh, some reservoirs are operating overflow discharge such as: Trang Vinh Lake discharging 253m3/s; Chuc Bai Son Lake discharging 18m3/s; Dam Ha Dong discharging 86m3/s; Cao Van Lake discharging 12m3/s; Quat Dong Lake discharging 30m3/s.
Some large lakes in the North are still lower than the normal water level. Yen Lap Lake reached 81% of the designed capacity; Trang Vinh Lake reached 70%; Chuc Bai Son Lake reached 96%; Nui Coc Lake reached 64%; Cam Son Lake reached 65%.
In the North Central region, the whole area has 2,323 reservoirs, including 3 particularly important reservoirs, 171 large reservoirs, 460 medium reservoirs and 1,689 small reservoirs. The average capacity of the reservoirs reaches 57-72% of the designed capacity.
Some reservoirs managed by the Ministry of Agriculture and Environment still have flood prevention capacity. Cua Dat Lake has a current water level of 95.04m, reaching 62% of the designed capacity, discharging 167m3/s through power generation and still 790.32 million m3 for flood storage. Ngan Truoi Lake reaches 44% of the designed capacity, still 430.57 million m3 for flood storage. Ta Trach Lake reaches 73% of the designed capacity, discharging 17m3/s through power generation and still 342.61 million m3 for flood storage.
Also according to the report, as of 5 pm on May 21, no incidents of irrigation works have been recorded.
Faced with heavy rain, the Department of Management and Construction of Irrigation Works requests localities to closely monitor water levels and the current status of works, especially paying attention to key reservoirs, reservoirs with valve gates, and downstream areas with large populations when it rains in the reservoir basin.
Reservoirs must operate according to the approved procedures. For reservoirs with flood discharge valve gates, water level adjustment must ensure the safety of the works, not discharging unusual floods causing unsafety in the downstream area. At the same time, it is necessary to issue early warnings to people in the downstream area before the reservoir discharges floods and when there is a risk of incidents.
For projects under construction, specialized agencies require to have appropriate construction plans, not to let incidents occur; absolutely not to deploy items that do not meet the construction progress exceeding floods.
Localities are required to organize 24/24 hour duty duties during rain and floods; arrange on-duty personnel at works at risk of incidents, reservoirs full of water to promptly handle unusual situations according to the "four on-site" motto.
