Engineering Agency,Taipei Water Department

Overview

Ⅰ. Background

　　The Phase II Construction was a short-term program. Even with improvements to various water sources, the maximum output capacity reached only 682,000 cubic meters per day (CMD), which was insufficient to meet projected demand beyond 1973. As the water demand within the supply region increased with population growth, it was estimated that the peak demand in 1973 would exceed 700,000 CMD. Given this shortfall, the Taipei Government Water Supply and Sewerage Construction Commission initiated the Phase III Construction Program, conducting a comprehensive feasibility study and financial planning.

Ⅱ. Objectives and Benefits

　　To address the sharp rise in water demand, the target year for this program was set for 1979. The program aimed to increase daily water output by 480,000 CMD to meet the needs of the region. The main objectives of this expansion were:

(1) Construct water storage facilities to ensure sufficient raw water intake.

(2) Upgrade water purification facilities to enhance treatment efficiency.

(3) Build new raw water conveyance routes, distribution reservoirs, booster pumping stations, and improve the distribution network.

Ⅲ. Service Population and Water Demand

　　Upon completion, the system’s total output would reach 1,057,000 CMD, achieving a water supply coverage rate of 86% and serving a population of 2,680,000.

Ⅳ. Scope

　　This phase of the construction program included the construction of one Zhitan Dam with a storage capacity of 4,200,000 metric tons, and one Qingtan Weir, responsible for regulating the tailwater discharge from the Xiaochukeng Hydroelectric Power Plant during peak operations. The program also involved the construction of one intake facility with a capacity of 1,085,000 CMD and a raw water conveyance pipeline measuring 11,119 meters in length. In addition, the slow sand filtration system on the Xindian River (located at the current site of the Gongguan Water Purification Plant) was dismantled and replaced in situ with a rapid filtration system with a maximum design capacity of 520,000 CMD. Other key components included a distribution reservoir with a capacity of 62,000 metric tons, a booster pumping station with a capacity of 551,000 CMD, and associated distribution pipelines.

Major Program Components

(1)Water Source Infrastructure

1.Zhitan Dam: A concrete gravity dam measuring 117 meters at the crest, equipped with seven radial gates. The water level reaches 44.7 meters, with a total storage capacity of 4,200,000 metric tons. Construction began in October 1973 and was completed in January 1978.

2.Qingtan Weir: A concrete weir with a length of 69.6 meters and a crest elevation ranging from 17 to 19 meters. It features a stilling basin 23 square meters in area and is designed to regulate up to 800,000 cubic meters of tailwater from hydroelectric power generation. Construction started in November 1972 and was completed in September 1975.

3.Raw Water Conveyance Pipeline: Measuring 11,119 meters in total length, this pipeline comprises 5,851 meters of tunnel and 5,268 meters of culvert. It supports a raw water intake volume of 1,085,000 CMD. Construction began in December 1972 and concluded in December 1976.

(2)Water Purification Facilities

　　Xindian River Water Purification Plant: Featuring a treatment capacity of 520,000 CMD and an output capacity of 420,000 CMD, this facility includes 41 types of water basins and 12 water pumps. Construction began in 1973 and was completed in September 1977.

(3)Distribution Reservoirs and Booster Stations

1.Datong No. 1 Distribution Reservoir and Booster Station: Located at the planned site of Park No. 4, at the intersection of Minzu East Road and Xinsheng North Road. Constructed from reinforced concrete, it offers an effective capacity of 28,000 metric tons and a pressurized water delivery capacity of 185,000 metric tons. Construction started in September 1976 and was completed in October 1977.

2.Zhongshan Booster Station: Situated north of Minzu Road and east of Songjiang Road, near the highway interchange. Constructed from reinforced concrete, it includes an inlet pipe with a diameter of 1,000 mm and an outlet pipe with a diameter of 800 mm. Construction commenced in September 1976 and was completed in October 1977.

(4)Pipeline Engineering

　　The pipeline network for this expansion phase covered the entire service area, radiating outward from the Xindian River Water Purification Plant as the central hub. The total length installed was 42,131 meters, with pipe diameters ranging from 500 to 1,200 mm. Construction began in July 1972 and was completed in February 1977.