Water stress has specifically magnified for metropolitan cities like Bengaluru, Chennai, Delhi, Kolkata, Pune, etc. with depleting groundwater levels, widening of water demand and supply gap and rising pollution of water bodies to name a few. To combat these rising urban water issues, there is a need to enhance the sustainable water flow and management in cities.

The Mahindra-TERI Centre of Excellence (CoE), a joint research initiative of Mahindra Lifespaces® and The Energy and Resources Institute (TERI), has launched a report recently highlighting the potential water challenges in Chennai Metropolitan Area (CMA). Based on analysis of existing literature, the Chennai Water Sustainability Assessment report assesses the situation in the Chennai Metropolitan Area. It identifies potential risks associated with water sources, governance, infrastructure, and demand and supply, and includes recommendations to mitigate the same.

The study has analysed various parameters i.e. city growth, land use, demographics and social & economic character, water policies and institutional setup at central, state and city level, water sources and its related infrastructure, that are essential to find the avenues for water sustainability, quantify anthropogenic and natural flows into and out of the town, and develop a framework to analyse flows of water within it and selection of dominant indicators that impact urban hydrology.

A number of official reports and documents, Acts etc. by the state government (Tamil Nadu), urban local bodies, municipalities and other concerned institutions including research by private organisations have been studied.

Key report findings:

• Considering the current urban growth trend in Chennai, the city's built-up area is estimated to increase to 708.3 sqkm in 2025, or thrice the area in 1997. At the same time, the city's water bodies are expected to shrink to 38.4 sqkm by 2025, or one-third of their coverage in 1997.
• Chennai's water requirement is expected to reach 2,236.5 MLD (million litres/day) by 2025, from 2,074 MLD in 2019. The report recommends capacity enhancement of Chennai's water treatment plants to 2348.3 MLD by 2025, among other measures.
• Chennai faces a significant risk of pollution of its natural waterways. The quantity of wastewater generated in Chennai is estimated to increase to 1,789.2 MLD by 2025.
• The STP capacity required is estimated to rise from 727 MLD in 2019 to 1878.6 MLD in 2025.

The study of these parameters has led to the identification of potential risks associated with the urban hydrology and management of the Chennai Metropolitan Area. To overcome these threats, a list of recommendations has been listed. The report also goes a step further to identify the reasons for the weak implementation of the proposed recommendations and suggest measures for strengthening it.

The report follows a unique, integrated, 'One Water' methodology that incorporates multiple aspects of water systems - such as stormwater, wastewater, and water supply networks - to recommend best practices for holistic urban water management.

Speaking at the launch of the report, Mr. Viral Oza, Chief Marketing Officer, Mahindra Lifespaces, said, " More than 1 million litres of water are saved annually across our residential projects through rainwater harvesting, sewage treatment plants, water-efficient plumbing fixtures, and regular recycle and reuse. We hope this assessment report will enhance awareness of the present and future water challenges facing stakeholder communities across Chennai; and spur action to secure water sustainability in the city."

The region is expected to experience an unpredictable pattern of rainfall over the coming years due to changing climate, extreme El Nino conditions, and continuous warming of the Bay of Bengal off the Tamil Nadu coast, thus making it difficult to predict the rainfall intensity and period. This could also lead to fluctuations in the water storage capacity in the reservoirs throughout the year.

Mr. Sanjay Seth, Senior Director, The Energy and Resources Institute (TERI), said, "Current climate change and population growth trends indicate that by the year 2025, the inhabitants of Chennai would be faced with multiple water crises. Compounded by extreme weather events and developmental activities, it is projected to result in widespread flooding, pollution, and a shortage of potable water."

Key recommendations for sustainable water management in Chennai Metropolitan Area

• Propagation and adoption of water conservation practices such as rainwater harvesting, wastewater recycling and reuse, to meet the rising water demand due to rapid demographic changes
• Developing policies and designing measures towards protecting the region's ecosystems to strengthen both natural and urban water flow systems
• Identifying and filling up data gaps related to groundwater availability, extraction and use by conducting detailed surveys
• Strengthening of the water governance structure and administration; establishing a transparent and participatory mechanism through capacity building and training programmes

Effective implementation of recommendations

Issue: Governance and institutional challenges

The water resources management and formulations of projects and plans are fragmented, uncoordinated and follows a top-down approach which results in weak implementation. This is primarily due to two main reasons.

• First, the presence of a multiplicity of institutions sharing the responsibility leads to non-accountability in performance.
• Second, in the top-down approach, the decision-makers are not well versed with the local setting and micro-level ground realities which often results in poor decision making

Required intervention: Development of an Integrated Water Resource Management (IWRM) along with bottom-up approach

IWRM is a process that promotes the coordinated development and management of water, land and other related resources in order to maximise economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems and the environment. It is a cross-sectoral policy approach, designed to replace the traditional, fragmented sectoral approach to water resources and management that has led to poor services and unsustainable resource use.

As the local nature and needs of water-related services, resources and management vary, it is ideal that the task of managing them is handed over to institutions in a decentralized manner. A bottom-up approach for an institutional framework with the active involvement of local stakeholders is essential for the effective planning and execution of any programme aimed at water management in a region.

Issue: Lack of high-level political commitment

Most attempts at building political commitment are targeted at national governments because the budgets, laws, policies and regulations that can sustain a water management programme in the long term often flow from governments. However, even when it appears that the political commitment established in a national government is sufficient to sustain a programme, the commitment may still evaporate with elections and a new leadership or simply because of shifting priorities and policy concerns.

Required intervention: Decentralization of water governance structure

Firstly, there should be a sustained political will and strong commitment for the implementation of the designed water-related plans and policies which can translate into prioritization through different layers of government and effective course correction.

But due to the probability of shifting leadership due to elections the commitment changes. Therefore, it becomes important to decentralise the decision making powers to local levels of governance which largely then will remain unaffected by the election results.

Political devolution is also required because it is unlikely that political commitment can be effectively built or sustained by focusing on any single type of stakeholder. Rather, there is a need to understand all of the actors involved in the policy space, e.g. urban local bodies, urban planners, utility providers, industries, citizens, nongovernmental organizations etc., who need to support the programme and its transition.

Issue: Inefficiency in creating water-related databases

Databases of the quantity and quality of water and the consumption patterns of the various sectoral users are necessary to make effective decisions. One of the biggest challenges facing the water management sector in the country today is the lack of adequate scientific data needed for water budgeting, allocation planning and water management decision-making.

Required intervention: Strengthening of databases

There are possibly two processes by which the databases can be strengthened.

Firstly, there is a constant need to update and convert the capacity building into an ongoing process for the water administering bodies. It is time to reimagine capacity building by creating a municipal capacity building management system for all stakeholders, including municipal employees, councillors and citizens. This system could be involved in conducting a training-need analysis, creating quality training materials and arranging for field training. The system could assess the need for lateral hiring of professionals, engaging private institutions, research agencies and corporates for capacity enhancement. Also, training an urban local body needs funds. The system could create blocks that will look at tying up with national and international funding agencies and tapping into CSR to get this going.

The other alternative can be to engage external stakeholders like NGOs, research institutes, private entities etc. who have their expertise in water-related subjects and can play an important role in populating data and its management, research and analysis and the infusion of new ideas.

Science, technology and innovation strategies are integral parts of sustainable development strategies. Many innovations in sustainable water management are high risk and with uncertain returns. Government financing and policies for innovation, supported by public‐private partnerships, can be purposely designed and implemented to reduce risks and promote research and development and diffusion and transfer of technologies.