Project Undertaking: S20-6300/38.5, SC14-200/6.3
It is reported that Longtang Dam was first built in 1969 and became effective in 1971. It is a comprehensive hub project that integrates urban water supply, agricultural irrigation, flood control, drainage, and power generation operation.
The Nandu River Longtang Dam Hub Renovation Project in Haikou City is located on the Nandu River in Longtang Town, Qiongshan District. The proposed hub dam is located 70 meters downstream of the original hub dam site (Longtang Dam), mainly for water supply, while also considering irrigation, ecological water replenishment, power generation, tourism, etc., and creating conditions for improving upstream flood control and drainage. After the conflict between water source protection and navigation is resolved, shipping can be taken into account. The normal water level of the proposed hub is 8.35 meters, with a corresponding storage capacity of 16.4 million cubic meters and a verified flood level of 14.25 meters. The total storage capacity of the reservoir is 140 million cubic meters, and the engineering grade is Class II large (2) type. The main building grade is Class 2. The proposed hub mainly consists of river gates, diversion gates, power stations, fishways, irrigation channels, etc.
After the implementation of the Nandu Jianglongtang Dam Hub Renovation Project in Haikou City, it can comprehensively enhance the water supply safety guarantee capacity of Haikou City and Jiangdong New Area, reduce the flood control and drainage pressure in the upstream area of Longtangba, and create a landmark water conservancy building and tourist node in Haikou City, serving the construction of Hainan Free Trade Port.