Ho Tri An Lake Faces Water Shortage, Impacting Water Quality and Livelihoods

Ho Tri An Lake in Dong Nai Province, southern Vietnam, is experiencing a significant water shortage due to the dry season, causing the lake's water level to recede considerably. This has led to widespread algae blooms, impacting water supply operations, fisheries, and the daily lives of local residents. In late July, the water level of Ho Tri An Lake dropped sharply, with dense algae appearing in the raw water intake area. This forced Gia Tan Water Supply Joint Stock Company to extend two pipelines and move its intake point nearly 2 km from the pumping station to the middle of the lake. The algae formed a thick layer, at times compelling the plant to halt operations for cleaning storage tanks to ensure water quality met Ministry of Health standards. The company is also excavating a channel to draw water further from the shore to increase raw water exploitation capacity. In response to the situation, the People's Committee of Dong Nai City proposed that the Tri An Hydropower Plant temporarily regulate and maintain the lake's water level at approximately 52 meters during periods of high demand. This aims to ensure the stable operation of the raw water intake system, limit algae intrusion, and maintain a capacity of 33,000-35,000 cubic meters per day and night. Currently, the plant meets about 90% of the demand from residents and businesses, but around 2,000 households still face water shortages. About 5 km from the water supply plant, in the Ben Nom area of Thong Nhat commune, the water's edge of Ho Tri An Lake has receded by more than 2 km. Fishermen have to anchor their boats far offshore and use motorbikes or tractors to cross the muddy terrain to transport their catch to markets. According to fishermen, during the end of the dry season, intermittent rain and sunshine cause algae and seaweed to appear and drift ashore with the wind. "The smell of algae is very unpleasant, but it will disappear in a few weeks when the water rises," said Mr. Tai, a fisherman from Thong Nhat commune. During the dry season, some hills and grassy areas in the middle of Ho Tri An Lake emerge from the water. "Every time the water recedes, these hilltops appear, becoming resting spots for fishermen while they are out catching fish," said Mr. Tan, a resident of Ben Nom hamlet. The Ben Nom area in Thong Nhat commune has also attracted many young people who come to camp on the grassy areas exposed in the middle of the lake. "Camping services have developed on weekends, creating a new tourism model and a source of income for local residents," said Ms. Hang, a resident of Ben Nom hamlet. The receding water has exposed the lakebed, revealing a network of branching paths that resemble tree branches when viewed from above. In the Thong Nhat and La Nga communes, the receding water has revealed the vestiges of square-shaped fields and small streams that existed before Ho Tri An Lake was filled. Local residents are utilizing these exposed lands for grazing their cattle. Ho Tri An Lake covers an area of approximately 323 square kilometers. Besides power generation, it supplies water for domestic use, irrigation, and prevents saltwater intrusion during the dry season, causing its water level to typically drop. In communes like Thanh Son, La Nga, and Thong Nhat, the water sometimes recedes far from the shore. From August, as the rainy season enters its peak, the lake's water level is expected to begin rising again. Source: VnExpress