Maha Sarakham, The Director-General of the Royal Irrigation Department urgently ordered the closure of the earthen dam next to the spillway building of Huai Chiang Kham Reservoir, Maha Sarakham Province, due to heavy rains, resulting in a large amount of water eroding the earthen dam, causing water to overflow to the area downstream of the reservoir. Mr. Chuchai Rakjit, Director-General of the Royal Irrigation Department, said that he urgently ordered the deployment of machinery and tools to remove obstacles in the waterways in order to expedite the drainage of water that overflowed from the Huai Chiang Kham Reservoir into the Siao Yai River and the Mun River respectively to reduce the impact of water flowing into the area downstream of the reservoir. It is expected that the flood-affected areas will be able to drain water within 5 days. The cause of the erosion of the soil was due to heavy rain, causing the amount of water flowing into the reservoir to exceed its capacity. On July 15, there was approximate ly 2.72 million cubic meters of water in the reservoir, or only 54% of its capacity. Over the past 1-2 days, there has been heavy rain in the area, with the highest rainfall in 24 hours being 145.50 millimeters (mm). Huai Chiang Kham Reservoir, Non Rasi Subdistrict, Borabue District, Maha Sarakham Province, was completed and used since 1956. It has been in use for over 68 years. It has a storage capacity of approximately 5.07 million cubic meters (million cubic meters). The average volume of water flowing into the reservoir is 24.20 million cubic meters/year. When comparing the volume of water flowing to the storage capacity, it was found that the volume of water flowing in was 4.77 times higher than the storage capacity, causing the dam to be at risk of overflowing the dam from the rain that fell in an amount greater than normal. While the spillway can discharge water at a maximum of 24.2 cubic meters/second, causing water to overflow the temporary earthen dam and flow into the spillway channel, causing ero sion of the building and the earthen dam, damaging it for a length of approximately 50 meters, flowing down to the affected area of ??approximately 3,000 rai. The 6th Irrigation Office by the Mahasarakham Irrigation Project mobilized machinery, tools, and large rocks to block the water on both sides of the earthen dam to prevent further damage. Today, two Deputy Directors-General of the Royal Irrigation Department were assigned to travel to direct the repair of the dam and expedite the drainage of water to help the people as soon as possible. The current situation is that the water level is below the erosion level, which is the level at which the broken earthen dam can be closed by building a semi-permanent water barrier, leaving a gap for water to flow through. When the rainy season is nearing the end, the dam will be permanently closed to store water for use in the next dry season. Since the construction of the dam has been in use for a long time, it has increased the stability of the dam. In the fiscal year 2024, the Royal Irrigation Department has improved the spillway building to be able to drain more water from the original 24.20 cubic meters/second (2.09 million cubic meters/day) to 54 cubic meters/second (4.06 million cubic meters/day). However, the unusually heavy rain caused the incident during construction. The Royal Irrigation Department will monitor and control the situation 24 hours a day until the situation returns to normal. Source: Thai News Agency
Monday, September 16, 2024