First published in Water e-Journal Vol 4 No 2 2019.
Bangalore Water Supply and Sewerage Board (BWSSB) is the water utility for Bengaluru – India’s information technology (IT) capital and a megacity with a population of more than 10.5 million – and is responsible for managing the city’s water services. As Bengaluru’s population continues to grow, BWSSB is facing multiple challenges in the form of increasing water demand and the lack of a diverse water portfolio, with severe over dependence on a distant, depleting, monsoon-fed and sole surface water source: the River Cauvery. In addition, overexploited groundwater, a polluted urban waterscape caused by ingress of untreated used water into the city’s drains and lakes from unconnected areas, ageing water assets, a retiring workforce, and increasing costs are leading to non-sustainable water service delivery. Climate change projections for Cauvery River basin predict spatial and temporal variability in rainfall leading to an erratic runoff pattern, and an increase of up to four times in drought frequency. Lack of sufficient storage dams in Cauvery Basin will further exacerbate the impact of climate change.
In order for BWSSB to continue providing resilient, sustainable and affordable water services into the future, Jacobs developed a Strategic Water, Used Water and Asset Management Master Plan, and Vision – 2050 Document. Strategies were developed to ensure long-term water security and water quality, proper used water and biosolids management, optimised operation and maintenance, continual public engagement, capitalise on digital innovation and big data prowess, and implement fiscal ingenuity to achieve long-term financial sustainability for BWSSB. This Master Plan is a first step for BWSSB to prepare itself for transformation as a Water Utility of The Future (UoTF).
Bengaluru is the state capital of Karnataka, the third most populous city in India and a globally-significant IT and biotechnology centre. Between 2019 and 2035 it is predicted that Bengaluru will have the third fastest economic growth of any city in the world (Oxford Economics 2018).
Bengaluru’s water supply and used water management infrastructure has been developed progressively, in line with demand growth. The city’s first formal water supply system dates back to 1896, when a scheme sourcing water from the proximal Arkavathi River (at a location 18 km north of the town) was constructed. A second dam on the Arkavathi was constructed (TG Halli) in 1933, with a water treatment plant (WTP) at its foot.
In the period shortly prior to and post Indian independence in 1947, the population of Bengaluru started to grow, mainly because of the opportunities the city had to offer. To support the water needs of this growing population, an alternative water source was required, and in 1964 the scheme to harness water from Cauvery River (approximately 90 km to the southwest of the city, and around 350 m below the city’s elevation) was sanctioned by the Government of Karnataka (GoK). BWSSB was established in 1964 as one of the first water boards in India, to deliver this project and provide water management services to the city of Bengaluru. When India opened its market for global investment in the early 1990s, Bengaluru picked the race by attracting IT-based industry. The pleasant climate, friendly people and good infrastructure provided additional impetus for people to migrate to Bengaluru (Figure 1).
Today, BWSSB is one of the largest water utilities in India, serving an area of approximately 800 km2 and more than 9.5 million customers. BWSSB now employs about 4000 staff to manage, operate and maintain a diverse range of assets that are valued at more than US$1 billion. Figure 2 provides an overview of BWSSB’s assets.
As one of the fastest growing cities in the world, Bengaluru faces several challenges for effective and efficient water and wastewater management (Figure 3). These challenges were comprehensively evaluated and addressed in the master plan, ensuring BWSSB is better prepared for the future. The challenges include:
In order to have a secure and sustained water future for Bengaluru, it is imperative that the potential impacts of climate change are considered in water resources planning and management. This means creating system-wide resiliency for extreme events such as droughts and flooding.
Cauvery basin covers an area of approximately 64,679 square kilometres2. Figure 4 shows the entire basin of Cauvery River; the three sub basins highlighted reflect the part of Cauvery Watershed that contributes to KRS Reservoir3, Kabini Reservoir4 and to the point of water extraction from Cauvery to Bengaluru. Collectively, this watershed represents the northwest quadrant of Cauvery watershed, and is approximately one quarter of the total Cauvery watershed area.
A detailed climate change analysis was carried out including climate modelling to predict future meteorological parameters. The first step was to understand how rainfall, temperature and drought frequency in the Cauvery River basin (and other potential water sources) may change in future. The Intergovernmental Panel on Climate Change (IPCC) recommends that the most recent 30-year climate 'normal' period should be adopted as the climatological baseline period when conducting climate change impact and adaptation assessments. This master plan adopted 1995 as the baseline year, in accordance with IPCC guidelines, and evaluated potential future climate changes in terms of temperature, precipitation and drought frequency based on:
Annual baseline precipitation for the Cauvery basin was noted for its seasonality and also its spatial variability. Large areas of the basin receive less than 600 mm annually, with only the far northwest highlands receiving substantial falls, but even these are highly seasonal. These high rainfall areas do, however, fall largely within the sub-basins that feed the Cauvery weir, and hence the Bengaluru water supply. Figure 5 shows the spatial variation in precipitation in Cauvery Watershed for a baseline scenario.
The year 2050 spatial variation in estimated annual precipitation changes for the three basins is shown in
Figure 6.
Measures such as: creating enough water storage in Cauvery Basin to cater during droughts; identifying a diverse water portfolio that includes local water resources such as recycled water and harnessed rainwater; creating a network of sensors at strategic points in Cauvery Watershed for early preparedness in the event of a flood; identifying a suite of used water treatment technologies that would be more feasible to operate and produce the desired effluent at relatively higher temperatures, etc., are detailed in the subsequent section of this paper.
Our approach (Figure 7) focused on identifying existing and potential future challenges for BWSSB (Figure 3), and establishing Key Performance Indicators (as indicated in light blue boxes in Figure 7) that were aligned to project initiatives (Figure 8). These will enable BWSSB to achieve the attributes of high performing water utilities up to 2050.
There were three key drivers for the master plan: population growth, water demand and climate change. The subsequent development of planning criteria for water and used water management through the master planning horizon involved identifying and selecting water resources for a diverse portfolio; expanding the water transmission and distribution network as well as used water collection and conveyance system to cater for future demand; upgrading, expanding and creating new water and used water treatment plants; creation of recycled water infrastructure; application of digital innovation and big data prowess for creation of knowledge through data collection, storage, retrieval and analysis; creating financial sustainability; optimising operation and maintenance, asset management and stakeholder engagement.
The key tasks included performing and recording utility-wide physical and operational condition assessment of water and used water assets including treatment process performance (via staff consultation and physical inspection) and creation of asset condition grading as well as asset hierarchy; migrating water and used water network data in various formats onto the GIS platform; developing Multiple Objective Decision Analysis Criteria for evaluating alternate water resources, water supply strategies and treatment technology evaluation; water and used water network modelling to develop strategies for network rehab, upgrade or new construction to cater for future flows, as well as identifying interconnections in the water network to enhance resiliency; phase wise upgrade, expansion and creation of new water and used water treatment infrastructure; and subsequently developing a capital infrastructure implementation plan with timelines and financial outlay up to 2050.
Given the interdependence of water and used water management measures, the project initiatives were further refined into strategic initiatives (Figure 9) to coherently structure the projects that are specific to water, used water, asset management and common across all three, and yield a series of overarching outcomes (Figure 10) which support BWSSB’s vision.
This strategic initiative outlines the policies and measures that BWSSB are adopting to encourage the wise use of water, ensuring that everyone recognises the value of this precious resource. Two components were identified under this strategic initiative:
Organisation and governance
Water demand management
This strategic initiative aims to ensure long-term water security for Bengaluru by identifying a reliable and resilient water portfolio, comprised of existing and future water (re)sources, including a timeframe for their development and deployment. This strategic initiative forms the core of BWSSB’s approach to develop a sustainable and climate change resilient water portfolio. At present, Bengaluru receives its water supply through the Cauvery Water Supply Scheme (CWSS), which was developed in four stages (namely Stage I, II, III and IV of respective design capacities of 135 MLD, 135 MLD, 300 MLD, 300 MLD and 540 MLD). At present, Cauvery Stage V Water Supply Scheme is under execution, which will provide an additional 750 MLD of water to the unconnected peripheral areas of Bengaluru. The scheme is likely to be commissioned in 2023.
Development of a long-term and sustainable water portfolio for Bengaluru was guided by the following factors:
In 2050, the projected water demand for Bengaluru is estimated at 3860 MLD. To select the portfolio of water supply options (out of all identified water sources for Bengaluru) that best support the sustainable growth of this city, the relative performance of each water source option was assessed against a series of criteria, grouped into economic, technical, social, environmental and implementation categories (MODA - Multi-Objective Decision Analysis). Each short-listed option was assigned a score from 1 (very bad) to 5 (very good) against each of the criteria (Figure 11).
The water sources (Figure 12) considered included:
Figure 13 presents the preferred water portfolio, which indicates the potential estimated yield along with implementation timeframes for respective water resources.
Short term to 2020
In the period to 2020, the focus will be on the following water source initiatives:
In addition, demand management measures should be implemented through a progressive programme that extends across the lifetime of the master plan. A strategy for reducing physical NRW was defined and front loaded to achieve feasible quick wins.
Medium term: 2021 to 2035
Long term: 2036 to 2050
In the scenario that the extent of the benefits achieved through NRW and demand management measures are not as expected, and the flows of used water and harnessed rainwater that ultimately supply the proposed reuse scheme does not fill the demand supply gap, the backup water source initiative, i.e. Linganamakki Scheme, will be implemented (1000 MLD capacity) to meet 2050 demand.
This strategic initiative focuses on the cyclical use of water in Bengaluru’s urban waterscape. It envisages implementation of advanced treatment technologies to reliably treat and to produce high-quality recycled water that exceeds drinking water standards.
Under this initiative, BWSSB will implement a comprehensive stakeholder and public outreach program, and continually engage to build support and confidence for recycled water utilisation. In continuation, BWSSB will create opportunities to utilise recycled water for indirect potable and industrial purposes, through construction and operation of advanced recycled water treatment plants.
Short to midterm to 2035
In the short to medium term, the activities of this strategic initiative include:
Long term: 2036 to 2050
This strategic initiative aims to ensure that the BWSSB’s used water infrastructure is resilient to potential future climate change and that it continues to deliver a high standard of service.
The primary components of the used water system that can be impacted by climate change induced weather events are the used water pipe networks and water reclamation plants (WRPs). Potential interaction of flow between the used water pipe system and stormwater drains during floods is also of potential concern. Under this initiative, an assessment of potential climate change impacts on the existing treatment technologies in BWSSB’s UWTPs/WRPs and conveyance infrastructure – pipe material has been made.
Under this initiative, BWSSB will identify suitable adaptation action plans and integrate these commitments into their existing capital investment and maintenance programs. Adaptation options can be 'soft', including management, operational and policy changes, or 'hard', such as physical modifications to existing infrastructure or new assets.
A time-phased implementation plan for the recommended climate change adaptation initiatives has been developed.
Short term: now to 2020
Medium term: 2020 to 2035
Long term: 2035 to 2050
This strategic initiative aims to ensure that all stakeholders with an interest in sustainable water resource management for Bengaluru, endorse and work together to achieve the vision of this Water, Used Water and Asset Management Master Plan, and that such engagement is continuous throughout the Master Plan horizon. Key activities under this initiative include (Figure 14):
One of the critical aspects of the study was to establish a set of processes and indicators that will measure the performance of strategic initiatives. The first step was to identify the Target Service Level Benchmarks (SLB) as shown in Table 1 below.
Further, to accomplish the identified Service Level Benchmarks (SLB) by the respective horizon years, the following activities were put into action:
Figure 15 presents the implementation timeline for the master plan.
The authors would like to thank the staff of Bangalore Water Supply and Sewerage Board (BWSSB) for their constant support throughout this project.
Gaurav Bhatt | Gaurav Bhatt is a civil engineer with more than 14 years of working experience in India, Singapore and the United States. Currently, he is working as a project manager in the water sector, delivering large interdisciplinary feasibility, planning, and design studies.
Vinod Singh | Vinod is a civil engineer with more than 25 years of working experience in India, Singapore, ASEAN, Middle East and ANZ. He has worked in desalination, water and wastewater infrastructure, water sector reform, and project management. Currently, he is Director – Asia and India for Buildings and Infrastructure leading projects in the water sector.
Dr Vivekanand Honnungar | Vivekanand is an environmental engineer by training with more than 10 years of working experience. He has worked in academia, research, not-for-profit and consulting sectors in the United States and in India. Currently, he is working in the water sector in areas such urban water, climate change, feasibility studies and water resources.
Dr P. N. Ravindra | Dr. Ravindra served one of the largest water utilities in India, BWSSB, for more than 30 years. He recently retired as Chief Engineer at BWSSB. He has led and been associated with many key projects for BWSSB. Currently, he is heading the Water Cell at the Industries and Commerce Department of the Government of Karnataka.
Oxford Economics (2018), ‘Which Cities Will Lead the Global Economy by 2035?’ Available at: http://resources.oxfordeconomics.com/global-cities-2035 [Accessed: 20 Jan 2019].