Engineering Agency,Taipei Water Department

 Overview

Ⅰ. Background

　　Phase V of the Taipei Metropolitan Water Supply Infrastructure Construction Project was initiated by the Taipei Water Department to meet the staged water supply demands of the Greater Taipei region through the year 2030, while ensuring supply stability and improving water quality. The project was first planned in 1988 and officially approved by the Executive Yuan in 1991. The project is being implemented in two phases, covering the construction, expansion, and renewal of various water infrastructure components, including raw water systems, purification facilities, transmission pipelines, distribution reservoirs and booster stations, distribution networks, and sludge treatment systems. Phase I was carried out from 1991 to 2006, with a total project cost of USD 7.256 billion. Major completed components include: the channel section of the second raw water transmission system, the fourth and fifth purification units at the Zhitan Water Purification Plant, the second treated water transmission pipeline, the Minsheng Booster Station and Distribution Reservoir, and the Neihu Line treated water transmission pipeline.

　　In recent years, the number of incidents affecting the stability of household water supply has increased significantly. These include earthquakes, droughts, heavy rainfall, high turbidity in raw water, and infrastructure failures. As a result, the Taipei Water Department launched Phase V Construction Project - Stage 2 in 2006, undertaking a renewed assessment of supply and demand conditions. The goal is to meet projected water needs through 2030, while establishing reserve capacity and system redundancy to strengthen the overall reliability and security of the water supply system.

Ⅱ. Objectives and Benefits

1. Ensure that the water supply system meets projected water demand through the year 2030.

2. Establish backup and redundancy capacity within the system to reduce supply risk.

3. Strengthen the district-based distribution network to improve the overall stability and safety of the water supply system.

Ⅲ. Service Population and Water Demand

　　The projected water demand for this project includes 2.39 million CMD for direct supply and supported distribution areas, along with an additional 185,000 CMD for the Danhai New Town Development Plan and 1.01 million CMD for the Banxin Area Water Supply Improvement Plan, bringing the total daily water demand to 3.585 million CMD. The project is designed to serve a supply area population of 4.3 million people by the target year 2030.

Ⅳ. Scope

　　The scope of this project is divided into four major components: the raw water system, the water purification and clean water system, distribution reservoirs and booster stations, and distribution main and network infrastructure. The project will be reviewed every five years to adapt to changing environmental conditions and adjustments in related plans. A summary of each component is provided below:

(1) Raw Water System

1.The Zhitan Dam equipment renewal project involves upgrades to the intake facility for the primary raw water route at Zhitan Water Purification Plant. Planned work includes slope reinforcement on the right bank downstream of the water intake, sediment removal, replacement of gate seals, and renewal of electromechanical equipment.

2.The rehabilitation project for the secondary Zhitan raw water route (Chukengtou section) includes converting open channels to box culverts, tunnel widening, relocation of drainage channels, and improvements to the upstream Taipower Chukengtou water route.

3.The rehabilitation of the primary Zhitan raw water transmission route will be carried out after the completion of the secondary route, which will assume the original capacity, allowing restoration work on the first route to proceed.

4.The Qingtan Weir improvement project includes extending the length and width of the existing stilling basin on the right side and raising the elevation of the downstream weir crest to ensure the safety of the weir foundation.

5.The installation of a raw water quality early warning and sampling system is intended to address the issue of high turbidity in raw water by monitoring turbidity variations and promptly activating high-turbidity response protocols within the water treatment plant.

(2) Water Purification and Clean Water Systems

1.The Changxing Water Purification Plant equipment renewal project aims to improve treatment capacity to meet growing water demand. The project involves updating the treatment units on the east and west sides of the facility.

2.The Zhitan Water Purification Plant will carry out improvements to the first set of rapid sand filters and construct additional treatment facilities. To meet the increased demand for supplying the Banxin area, the plant’s treatment capacity will also be enhanced.

3.To address issues related to high raw water turbidity, the Zhitan Water Purification Plant will install clamp-on flow meters, construct a wastewater pumping station, replace sludge pumps, and add mechanical sludge scrapers, flash mixers, flocculators, and new sludge dewatering units to strengthen overall purification performance.

4.The 2nd Clean Water Mains – Xinyi Branch Project aims to improve water transfer flexibility by linking the 1st and 2nd Clean Water Mains. Construction will be coordinated with the common utility ductwork of the Xinyi MRT line.

5.The No. 1 Water Trunk (Chenggong Road in Zhonghe and Yonghe PCCP) Backup Pipeline Turnkey Project will strengthen water supply safety and dispatch capabilities in response to increased demand in the Banxin area.

6.The Gongguan Sludge Treatment Facility Expansion Project addresses urban operational impacts by installing an additional sludge dewatering unit to shorten operating time and reduce disturbances to surrounding residents.

(3) Distribution Reservoirs and Booster Stations

1.To support water supply for Tamsui, Sanzhi, and the Beitou-Shilin Technology Park, and to provide dual-system supply for Shilin and Beitou, the project will construct the third Datong Booster Station and a distribution reservoir for the Dadu Booster Station.

2.To enhance backup and redundancy capacity across districts and enable mutual support between adjacent areas, the plan includes construction of the Sanchong No.2 Distribution Reservoir and Booster Station, Nangang Distribution Reservoir and Booster Station, Mingsheng–Nangang Line pump installation, upgrades to Datong Urban Line pumps, and the addition of intermediate booster facilities for the Neihu, Muzha, and Tianmu Distribution Reservoirs, as well as construction of the Datun Distribution Reservoir.

3.To resolve summer water shortages in the Yangmingshan area, the project proposes lifting flatland water up to higher elevations, creating a dual-system supply. This includes the construction of the Xin’an Distribution Reservoir and Booster Station.

4.To address climate change and reduce seismic risk, seismic assessment and reinforcement will be carried out for existing distribution reservoirs, including those in Zhonghe, Muzha, Neihu, and the Tianmu flatland area, to improve overall supply stability.

(4) Distribution Main and Pipeline Network Infrastructure

1.For dual-system water supply in the Shilin–Beitou area, where a single pipeline currently poses high supply risk, new pipelines will be constructed along the Datong–Guandu Line and the Dadu–Danhai Line to form a dual-system network.

2.To enhance backup and redundancy capacity across districts, the project includes construction of the Anhua–Xindian Line, Anhua–Xindian Extension Line, and Ankang Line, along with inlet and outlet pipelines for the Sanchong No.2 Booster Station.

3.Dual-system water supply is planned for high-elevation areas. To establish a dual-system water supply network for the Yangmingshan area, the project includes the construction of the Zhishan, Huaxing, and Yongling pipelines, as well as pipelines for the Xiazhulin Booster Station and the Xin’an Booster Station.

4.To enhance the distribution network across supply zones, the project includes the construction of new pipelines such as a ∮ 700mm pipeline along Nanjing East Road, an ∮ 800mm pipeline along Huanhe South Road, a ∮1000mm transmission main in Donghu, and a ∮ 1500mm transmission main across Zhongxiao Bridge.

5.In response to climate change and to reduce seismic risk, the project includes seismic assessment and reinforcement of water pipeline bridges. This encompasses the Yongfu Pipeline Bridge, the No.2 Water Mains Transmission Bridge across the Xindian River, the Yuanshan Pipeline Bridge A, and the Jiantan Pipeline Bridge B, aiming to improve overall supply stability.