Overview Located in the coastal belt of Bangladesh, Khulna City is one of the most vulnerable areas to climate change in the country. Rising sea levels associated with climate change exacerbate saltwater intrusion into groundwater aquifers, affecting freshwater supply. This was a major problem for the city, which relied entirely on groundwater for all its water needs. Home to about one million people, Khulna needs a sustainable source of clean water to meet growing demand. In 2010, access to piped water supply was limited and intermittent, and the water and service quality was poor. Only 23% of households had access to piped water; the rest resorted to alternative sources, such as shared public taps and privately built tube wells. A project parallelly co-financed by the Asian Development Bank (ADB) and the Japan International Cooperation Agency (JICA) developed and climate-proofed a new water supply system to reduce saltwater intrusion and introduced surface water as the main source of water to avoid excessive groundwater extraction. It also expanded the distribution network of piped water to improve households’ access to potable water. Climate change impact assessment and adaptation studies were considered during the project design. JICA supported the upstream infrastructure, while ADB supported the downstream infrastructure. The project also strengthened the corporate management of the newly established Khulna Water Supply and Sewerage Authority (KWASA) and automated the water supply monitoring system. This case study is adapted from the project completion report and other project documents. It provides lessons replicable across the region. Project Information 42171-013 : Khulna Water Supply Project in Bangladesh Project Snapshot Dates 14 June 2011 : Project Approval 29 December 2019 : Completion Date Cost $323.7 million : Total Project Cost Institutions / Stakeholders Financing : Asian Development Bank Financing : Japan International Cooperation Agency Executing agency : Khulna Water Supply and Sewerage Authority Challenges Demand for water is increasing in Khulna, the country’s third largest city. However, it faces two major water supply challenges: unsustainable groundwater extraction and high salinity in groundwater and surrounding rivers. Before the project, majority of residents do not have access to piped water and instead used public standpipes, hand pumps, and private tube wells. Households, mostly women, spent an average of 90 minutes fetching water on most days. Total groundwater abstraction was estimated at 113,000 cubic meters (m3) per day. Excessive pumping can lower groundwater tables, putting water resources further at risk. In coastal cities like Khulna, overextraction of groundwater can also result in saltwater intrusion. Changing precipitation patterns and sea-level rise caused by climate change can also increase the salinity of freshwater. Context The vast low-lying areas along the Ganges–Brahmaputra–Meghna deltas of Bangladesh are highly vulnerable to the impacts of climate change. Khulna is located in the Ganges River Delta in the southwest of the country, where the consequences of climate change are expected to be particularly severe. The city suffers recurring and worsening waterlogging problems. Investments in the water supply infrastructure need to take into account climate risks into the project design. Solutions The Khulna Water Supply Project helped Bangladesh develop a new sustainable water supply system in the city. It built a surface water treatment plant with a capacity of 110,000 cubic meters (m3) per day to meet the growing demand without increasing the groundwater abstraction and undermining its sustainability. The project was designed to be climate-proof—the intake facilities were located upriver to avoid salinity and an impounding reservoir was built to store fresh water to ensure water quality even with the expected increase of river salinity. ADB conducted a study to simulate climate change impacts in Khulna and develop an adaptation strategy. The results of the study are reflected in the project design. JICA supported the development of the surface water treatment plant and impounding reservoir and other upstream infrastructure, including a surface water intake facility and a raw water transmission main. ADB supported the downstream infrastructure, including a clear water transmission main, new and rehabilitated piped networks, metered-household connections, and the creation of water user groups for community-managed connections. The project constructed the water intake facility with a capacity of 110 million liters/day at Mollarhat along the Madhumati River in Bagherhat district. It built the intake structure and the pump house on the riverbank adjacent to Mollarhat bridge, which is 58 kilometers (km) northeast of the city center. It installed three pumps with total capacity of 129.6 million liters/day (129,600 m3/day) and 250-kilowatt (kw) capacity each. A 1,500-kilovolt-ampere sub-station was also built as dedicated power supply. The surface water treatment plant with a capacity of 110 million liters/day (110,000 m3/day) was constructed at Samanto Sena, 25 km from the city. Sufficient power supply with a 250-kW solar system as backup ensures its continuous operation. The plant runs with an automatic control system. A water quality testing laboratory with state-of-the-art testing equipment was established at the treatment plant site for continuous monitoring. The laboratory tests the water quality of deep production tube wells to keep the water quality at national and international standards. The impounding reservoir is 331 meters long, 208 m wide, and 12 m deep (maximum). It was designed to keep water abstraction to a sustainable level. It can reserve enough water to provide water supply for 7 days during the dry season (March–May) with a reserve capacity of 775 million liters, equivalent to 775,000 m3. A 33-km, 1,400-millimeter (mm)–diameter raw water transmission pipe was laid from the intake structure to the treatment plant. Seven distribution reservoirs, 10 overhead tanks, and seven pump stations were constructed with two electric generators provided for emergency power supply. The 45.47-km clear water transmission main line was installed across the Rupsha River to deliver water from the surface water treatment plant to the new distribution reservoirs. A total of 662.59 km of distribution pipelines were installed and connected though the 8.5-km transmission main to overhead tanks and a 1.5-km main was connected to deep tube well connections. The project connected 40,000 houses, including KWASA’s existing and new customers. The project strengthened the corporate management system of KWASA through various capacity-building activities. It also introduced an automated supervisory control and data acquisition system with three different type of district metering areas—single inlet, multiple inlet, and flowing. This enabled KWASA to monitor operations in real time and receive updated analysis. Information is collected through a combined system of cables and wireless connection. Results The project created an entirely new water supply system from intake to household connections, delivering treated surface water for the first time. It resulted in additional production capacity, limiting KWASA’s groundwater abstraction in Khulna city to a maximum of 50 million liters/day throughout the implementation period and maintaining the sustainable groundwater level, which is maximum 6 m drawdown throughout the period. It expanded the distribution network and increased access to piped water to 65% of households by 2019 from 23% in 2010, majority of which are headed by women. It reduced physical loss due to leakage from 36% to 20% and formed 255 water user groups, with 45% women’s representation and 45% of leadership positions held by women. By 2019, households with piped connections enjoyed water supply 24 hours/day. The project also helped KWASA to improve its average response time to customer complaints, increase revenue collection to 94% throughout the implementation period, and provide better and equal opportunities for male and female staff. Lessons The project supported the transition of the city’s water resource from groundwater to surface water, which can be costly and technically complex. The overall design of the project considered the city’s vulnerability to climate change, studied ways to mitigate its impacts, and incorporated them into the project design of the intake facility. It innovatively located the intake facility upriver with an impound reservoir and reduced the salinity of raw water. The impound reservoir stores low-chloride freshwater collected during the rainy season. This stored water is used to dilute high-chloride water during the dry season. The project integrated the capacity strengthening of KWASA to operate and maintain the new water supply system. It used information technology to equip KWASA’s district metering areas with real-time monitoring capabilities and improve efficiency of operations. Finally, the project promoted partnerships and leveraged resources through cofinancing arrangements with JICA. Resources Asian Development Bank (ADB). Khulna Water Supply Project in Bangladesh. ADB. Strengthening the Resilience of the Water Sector in Khulna to Climate Change. ADB. 2022. From the Ground Up: How Khulna City Shifted from Groundwater to Surface Water. Video. 9 August. ADB. 2020. Khulna Water Supply Project: Completion Report. Manila. Independent Evaluation Department. 2021. Bangladesh: Khulna Water Supply Project. Manila: ADB. Ask the Experts Mohammed Sayeedul Haque Associate Portfolio Management Officer, South Asia Department, Asian Development Bank Mohammed Sayeedul Haque is based in ADB’s Bangladesh Resident Mission where he is responsible for both project management and portfolio management. He holds a master’s degree in Engineering Structures from University of Melbourne in Australia and a bachelor’s degree in Civil Engineering from Khulna University of Engineering and Technology in Bangladesh. Before joining ADB, he worked in Afghanistan for the United Nations Assistance Mission in Afghanistan (UNAMA) and in Bangladesh for consulting firms as design engineer. Asian Development Bank (ADB) The Asian Development Bank is committed to achieving a prosperous, inclusive, resilient, and sustainable Asia and the Pacific, while sustaining its efforts to eradicate extreme poverty. Established in 1966, it is owned by 69 members—49 from the region. Its main instruments for helping its developing member countries are policy dialogue, loans, equity investments, guarantees, grants, and technical assistance. Follow Asian Development Bank (ADB) on Leave your question or comment in the section below: View the discussion thread.