By Ray You, Han Huang, Chin-Ling Huang, Taipei Water Department
Taipei Water District (TWD) serves 3.7 million people with a 99.7% service coverage, directly supplying water to its primary service area, with an extended infrastructure supporting an additional 1.73 million cubic metres per day (CMD) and 0.71 million CMD, reaching more than 6 million residents in 2023. As a water utility owned by the Taipei City government, TWD focuses exclusively on water supply services, extracting 97.5% of its raw water from Xing Dian Creek. The utility relies on a single major water catchment, leaving it without alternative water resources. Challenged by the impacts of climate change, the utility experiences droughts, resulting in inevitable water shortage. In 2002, TWD experienced a severe drought that led to water rationing for two months in Taipei.
Typhoons and heavy rains cause significant spikes in raw water turbidity, which can exceed treatment capacities and compromise water treatment plant operations. These extreme weather events frequently lead to temporary shutdowns of water supply, disrupting the utility’s ability to provide consistent water services.
For example, in 2015, the residents had to endure the unendurable – turbid tap water supply and/or water outage during the strike of a typhoon Soudelor. During such challenges, organisational assets can be controlled and maintained, whereas environmental impacts are uncontrollable and unpredictable. However, two decades ago, TWD’s pipeline networks suffered severe leakages due to their old and obsolete nature. In 2006, the leakage rate rose to 27%, reporting about 13 leaks. High leakage rates significantly increase the risk of water shortage by compromising the utility’s water resource management and reducing the effective available water supply.
Historically, TWD has demonstrated poor energy efficiency, with water pumping consuming approximately 90% of its power and generating significant greenhouse gas emissions, recording 91,600 tCO2e for Scope 1 & 2 in 2005 alone. While these challenges are substantial, they are addressable through a comprehensive approach that integrates adaptation, mitigation strategies, and strong leadership.
Adapting to climate change
In efforts to enhance the resilience of the water supply to adapt to the changing climate, TWD has diversified its water portfolio comprising three water sources, which are 97.5% of the water from XingDian creek, 1.1% from ShuanXi creek and 1.4% from YangMing mountain’s watersheds.
TWD also initiated the ‘Water Supply Network Improvement and Management Project’ from 2006 to 2025 with the aim of reducing the leakage rate to 10% by 2025. Continuously, a new Network Improvement project will be implemented from 2025 to 2034, targeting a leakage rate of 7% by 2034.
To ensure water supply safety, TWD has rolled out a rehabilitation programme from 2020 to 2034 by systematically reviewing and improving to achieve a stable water supply, optimised management and disaster prevention. Activities under this programme include transmission pipe maintenance such as cleaning, inspection, renewal or replacement of high-risk pipelines of 75 kilometres. Such improvements enable an agile response to face the impacts of climate change and enhance the resilience of essential infrastructure for disaster recovery.
Also, as a response to the high turbidity risk of raw water during the typhoon season, TWD invested in a raw water tunnel from the Feitsui Reservoir Project in 2015. This tunnel is capable of water intake of low turbidity from the reservoir directly. TWD has established vital facilities for urban disaster prevention, and by 2026, 29 additional wells are expected to be installed. These facilities are meant to help during the water interruption period, including setting up temporary water stations & groundwater well drilling.
Lastly, TWD believes in investments to increase resilience. From 2006 to 2025, a total investment of over $1.86 billion USD has been allocated to enhance water infrastructure and resilience. This includes $500 million (2006–2024) for system backup through water trunk and WTP redundancy, $560 million (2020–2034) for facility rehabilitation, focusing on trunk line overhauling and WTP upgrades, and $730 million (2006–2025) for network improvements such as pipeline replacement, pressure management, and leakage control. Additionally, $78 million (2015–2024) has been dedicated to constructing a new raw water trunk for direct intake from the reservoir, while emergency water rationing measures are being implemented through temporary water stations and groundwater well drilling to mitigate supply interruptions. Due to these investments, TWD has been able to increase the redundancy rate of its water treatment capacity from 13% in 2006 to 67% in 2023, increasing water treatment capacity up to 4.53 million cubic metres per day compared to the maximum daily water supply of 2.72 million cubic metres.
Mitigation actions
With short-term carbon reduction targets of 25% by 2025, 40% by 2030, 65% by 2040, and net-zero emissions by 2050, TWD is making ongoing decarbonisation efforts to meet these targets. Compared to the 2005 baseline of ISO14064-1 Scope 1 & Scope 2 GHG emissions of 91,600 tCO2e, the utility’s GHG emissions in 2023 have been reduced to 48,200 tCO2e, a 47.4% reduction.
Energy savings are considered the primary source of decarbonisation for the utility. Through the adoption of Variable Frequency Drives (VFD), feedback control in pump stations, and use water heads from gravity for by-pass supply without pumping during off-peak hours, TWD’s electricity consumption for water supply has decreased from 0.176 kWh/m3 to 0.107 kWh/m3 with an annual consumption fall from 161 GWh to 96 GWh. This has resulted in a huge reduction of 65 GWh, equivalent to a daily savings of about 178 MWh, indicating significant energy savings. Another area of energy savings is the development of renewable energy. The utility has tendered out the construction of the commercial solar panels and small hydropower plants with a capacity of 2.13 MW on their premises. In 2023, they generated renewable electricity of 2,283 MWh, equivalent to carbon reduction of 1,162 tCO2e.
To quantify energy-saving and green energy solutions, TWD has carried out an organisational level GHG inventory & verification for OPEX carbons, also establishing a methodology by ISO14067 for CAPEX carbons estimation. This will help identify significant indirect emission sources and continuously improve carbon reduction actions.
Smart management is also employed by TWD to accelerate leakage reduction and improvement. Through integrating smart meters, IoTs into DMA, the behaviours of the pipeline network are monitored with a hydraulic digital twin or an AI algorithm for smart leakage control. As of 2023, 458 DMAs were completed with a leakage rate under 10%. Approximately 280 million cubic metres of water loss is saved annually, showing a significant achievement in leakage reduction and mitigation of GHG emissions.
Communication with citizens
In 2023, TWD transitioned its Corporate Social Responsibility (CSR) Committee into the Sustainable Development Committee to align with ESG priorities. The committee’s key responsibilities included formulating sustainability policies and action plans that address economic, environmental, and social dimensions, while promoting human rights and aligning with the UN Sustainable Development Goals, to achieve net-zero emissions by 2050. It also emphasises fostering employee capabilities by cultivating a strong learning culture to continuously update knowledge and skills, benefiting not only TWD’s workforce but also customers, suppliers, and contractors. Additionally, the committee prioritises global knowledge exchange, sharing best practices with utilities at both national and international levels, such as the 9th IWA-ASPIRE conference in 2023, where TWD presented 50 oral and poster presentations. Furthermore, TWD collaborates with stakeholders to promote water conservation, delivering 38,490 household services and 55 water conservation sessions between 2016 and 2023, resulting in 1.4 million cubic metres of water savings.
Lessons learned
Establishing the resilience of water supply against climate change nowadays is not just a single task from the engineering department, but rather, a collaborative effort across the entire organisation, involving scientific research, best practices, and workforce management.
The key to success is strong leadership within the team, however, engagement with stakeholders & ability of employees are essential too.
Building resilience is a long-term, complex process that demands sustained, multifaceted efforts spanning decades, requiring numerous interconnected initiatives and strategic approaches implemented progressively over time. During the long-term implementation periods, the organisation must be flexible enough to make some alterations or adjustments, while remaining on the same goal irrespective of the changing & evolving environment, technologies, and even people themselves. TWD has already practised this during the implementation of their leakage control initiatives and believes this can be realised again, given the issue of resilience & net zero as well.
