Nanhua Reservoir handled relevant planning in the 71th year of the Republic Era . It was approved by the Executive Yuan in the 75th year of the Republic Era. It is one of the 14 major projects for economic construction. The Taiwan goverment completed the official supply of water for the people in Tainan and Kaohsiung in July of the 83th year of the Republic Era. This reservoir is the largest of the reservoirs with a single target for public water supply. The building Nanhua Dam Project project was approved 9.9 billion 57 million NTD, due to land costs, direct project costs, management fees, engineering fees migration road, water and soil conservation project costs of various items increased fees, the goverment approved the revised plan to finance 12.8 billion 77million NTD.

Nanhua Reservoir is located in Hòukū streams of Tsengwen river zone, which in addition to water catchment itself, by a separate branch Kaoping river provided Jiasian weir to the abundance of water in the fields. The tunnel introduces the excess water volume of Qishan River during the flood season to the Nanhua Reservoir to improve the water supply of the Nanhua Reservoir (the water diversion location is shown in Fig. 1. The main structure photo is shown in Fig. 2.).

The calendar of promotion events of Nanhua Reservoir

The calendar of promotion events of Nanhua Reservoir is shown in Fig. 3.

Planning and results

Planning process plan

The dam site scheme
At the beginning of the planning, the provincial water company suggested that the appropriate dam site should be superior selected in the reaches of Qishan River and the Hòukū dam site. If the Qishan river dam site is better than the Houxi dam site, it may be considered to replace it with the Qishanxi dam site. Qishan River selected four dam sites, namely Jiaxian, Xiaolin, No.11 Bridge and Mínzú dam site. The results of the preliminary exploration were the best for the Mínzú dam site. However, the results of the reconnaissance of the Mínzú dam site have its shortcomings, including (1) from the strong earthquake occurred in the past epicenter of the more closely place, (2) no dam building material, and (3) the use of severe inundation area, mainly in the first and second of the village. So consider reducing the dam height to 70 m, research building concrete dam, and may not be submerged the first and second of the village, but the limited capacity of the reservoir, only 2400ha-m, silt and low water rate problem is serious, and reduce its development value.
Therefore, the first dam site of the Hòukū river ( now the dam site of Nanhua Reservoir), the second dam site (mute lake mouth) of the Hòukū river, and the Qishan river Mínzú and Xiaolin dam site, as a comparison is made (detailed in Fig. 4) . In terms of geology, flooded areas, water supply capacity of various conditions, still the conditions of the first dam site of the Hòukū river are relatively excellent , so the first dam site of the Hòukū river was selected for detail planning object.
Cross-country water diversion scheme
1. Mínzú weir the diversion program: Weir Site in nearby SanMin Township (now Kaohsiung Namasia District) Mínzú village, the diversion tunnel outlet in the pit of the Píng kēng on the tributaries and streams.
2. Mínquán weir the diversion program: Weir Site in nearby SanMin Township (now Kaohsiung Namasia District) Mínquán village, the diversion tunnel outlet in the pit of the xīnměi village of Dàbù Township on the tributaries and streams.
3. Due to the Mínquán weir limite the increasing supply potential, the target year is not enough for demand, and the introduction of water Tseng Wen Reservoir of use, it is not effective introduction to Hòukū reservoir, so the construction plans only consider the Mínzú weir diversion program.