Early development of flood discharge scenario for Vuc Mau lake (Hoang Mai town)

(Baonghean) - Vuc Mau Lake is a lake with a large water reserve in Nghe An. In addition to providing water for 3,600 hectares of production land and domestic water for 100,000 people in 12 communes and towns in Hoang Mai Town, it also has the function of flood prevention. Unfortunately, in 2013, the flood discharge of Vuc Mau Lake caused unfortunate consequences. This year, people in the affected area hope that the authorities will soon develop a flood discharge scenario and make this scenario public, but there is still none. The evacuation plan is very general.

Flood discharge system of Vuc Mau lake. Photo: V.D

Obviously, the flood discharge in 2013 showed confusion and passivity, leading to passivity in the downstream area and extremely heavy damage. Therefore, after this incident, those responsible must review all stages, from legal documents to flood and storm prevention plans, from operating procedures to flood discharge scenario development, from the responsibilities of individuals and groups involved, to public service awareness and ethics.

It is known that the flood and storm prevention plans of Hoang Mai Irrigation Enterprise have been built and deployed. The 2014 flood and storm prevention plan was also sent to Hoang Mai Town early. Hoang Mai Town has also built a flood prevention plan in the area, and has added the subcommittee commanding Vuc Mau Lake to be the Chairman of Hoang Mai Town People's Committee. However, the document of the province on the operation process of Vuc Mau Lake has not been revised, or rather, it is being submitted and not signed. Deputy Director of Hoang Mai Irrigation Enterprise Nguyen Huy Phuc said: "The flood discharge scenario is not yet available. Basically, it must be capital, otherwise we cannot build it no matter what the flooded area is. The operation process of Vuc Mau Lake is being revised, being submitted, and not yet available."

Returning to Vu Mau Lake on a day in mid-July, looking out into the distance, Vu Mau Lake was clear and rippling. The lake was surrounded by green trees and hills, the landslides caused by the lake's discharge last year were only traces left. Chairman of Quynh Di Commune People's Committee Nguyen Quang Dai told us: "Last year's flood in Quynh Di is at the end of the source but the damage was huge. This year we see that Hoang Mai Irrigation Enterprise has made progress in notifying people about flood discharge, they called us to inform us about the flood discharge 2-5 hours in advance, and then how many gates to release. But we hope that Bac Irrigation Company will soon develop a flood discharge scenario, announce that flood discharge scenario to people and publicize both sides of National Highway 1A, how high the water will be when releasing 2 gates, what to do when releasing 5 gates, do not let people live in anxiety and passivity. Hoang Mai Irrigation Enterprise needs to proactively release flood so that the lake is always safe during the rainy season while people's lives and property are still guaranteed". Mr. Dai also added that his house is close to the bank of Hoang Mai River, so for decades he has been familiar with the tides and water levels. The tide rises once a day, the tide rises with the moon, the moon rises the water rises, when the tide is high the Hoang Mai river rises 2-3 meters, if the flood is released along with the rising tide, it will flood into people's houses. Those who release flood need to understand this, do not release flood right at high tide.

Quynh Trang residents living along the riverbank believe that there should be flood warning signs for them and these signs should be publicly displayed along the river and along National Highway 1A. When releasing many flood gates, there should be sirens, just calling the commune leaders is not enough. "We request that the above tasks be done early before the flood season, and not wait another year" - Mr. Cong, Hamlet 5 said.

This year, regarding the organization plan: Hoang Mai Irrigation Enterprise will mobilize 200 militiamen from Quynh Trang commune as the core force along with the lake management group to handle technical incidents of the project, with Mr. Nguyen Huy Phuc - Deputy Director of Hoang Mai Irrigation Enterprise as the technical commander. The rescue force is the People's Committees of Quynh Trang, Quynh Thang, Tan Thang, Quynh Tan, Mai Hung, Quynh Di communes, Hoang Mai town, requiring each commune to have 200 militiamen participate in the rescue when there is an incident at Vuc Mau lake. Regarding the evacuation plan: “When the lake water level reaches the peak of +21 and is rising, Vuc Mau Lake will discharge flood water according to the operating procedure. When the lake water level is at the emergency warning level (+21.92), it is necessary to evacuate people and property in the downstream area of ​​Vuc Mau Lake. When the lake water level is at +22.72 and is rising, according to the procedure, Vuc Mau Lake will operate at maximum flood discharge. If combined with high tides and additional rainfall in the downstream area, it will cause severe flooding. To ensure the safety of people and property, it is necessary to evacuate people to safe areas”. The regulations are like that, but both Hoang Mai and the Bac Irrigation Company do not have a specific plan for how many hamlets and communes to evacuate because there is no flood discharge scenario. Therefore, the evacuation plan is very general. For example: “Quynh Loc commune, the evacuation area is Quynh Loc, the evacuation sites are school headquarters, high-rise buildings, and hills; Quynh Di commune, the evacuation area is Quynh Di, the evacuation sites are the ward People's Committee headquarters, high-rise schools, and mountainous areas…”.

Talking with Mr. De - Deputy Director of the Department of Agriculture and Rural Development, it is known that the Department of Agriculture and Rural Development is currently amending some contents in the flood discharge operation process of Vuc Mau Lake (this process was issued in 1999). The reason for the late submission is because of the need to meet and collect opinions, but only some legal issues have been presented, but the technical aspect has not been done yet. The technical factors here need to be studied to calculate the natural disaster conditions, weather, water storage level, and water level flowing into the lake because the time since the issuance of this operation process has been too long, and many conditions have changed. Also according to Mr. De, the current conflict is the need to properly resolve the relationship between upstream and downstream. Upstream, many households have encroached to build houses in flooded areas, so when the water is high, about 200 households (Tan Thang area) will be flooded. If the reservoir does not discharge floodwaters, these households will be flooded, but if all of them are discharged downstream, the downstream will be flooded. Therefore, Quynh Luu district needs to relocate households in the flooded area of ​​Vuc Mau lake.

Regarding the necessary conditions to soon have a flood discharge scenario, there are also funds and human resources. Assessing how many gates to open and how much flood is not yet possible, scientists need to get involved. Even in Vuc Mau Lake, there is a monitoring system, but only monitoring upstream, not downstream.

Thus, the expectations of the people in the flood season this year in the downstream of Vuc Mau Lake have not been achieved. They still have to live in fear and if the work of flood prevention and control still has loopholes and subjectivity, the consequences can still occur.

Chau Lan