Urban Water Supply and Sanitation

In the Indian administrative architecture, the management of urban water supply and sanitation is primarily a state subject. Under the Seventh Schedule of the Constitution of India, ‘Water supply’ and ‘Sanitation’ are listed under the State List (List II). The 74th Constitutional Amendment Act of 1992 further decentralized these functions by empowering Urban Local Bodies (ULBs) through the Twelfth Schedule, which assigns them the responsibility for water supply for domestic, industrial, and commercial purposes, public health, sanitation, conservancy, and solid waste management.

Macro-Demographic and Operational Matrix

The scale of water supply and sanitation coverage across urban India reveals significant infrastructural deficits and varying service delivery standards between metropolitan cities and smaller urban centers.

Core Engineering and Ecological Challenges

The rapid pace of horizontal urban expansion combined with population concentration has triggered severe structural vulnerabilities within urban water and sanitation networks.

The Crisis of Groundwater Depletion and Vulnerable Surface Sources

Many Indian cities rely heavily on groundwater extraction to bridge the gap between demand and municipal supply. This over-exploitation has caused drastic drops in water tables, leading to land subsidence risks and saltwater intrusion in coastal metropolises like Chennai and Kolkata. Surface water sources are also vulnerable; urban rivers such as the Yamuna in Delhi and the Mula-Mutha in Pune face severe pollution from the direct discharge of untreated industrial effluents and domestic sewage.

Infrastructure Backlogs and the Challenge of Infiltration

Urban sanitation networks face a massive backlog in underground sewerage coverage. While metropolitan cores typically feature partial sewerage networks, peripheral peri-urban tracts and informal settlements rely predominantly on on-site sanitation systems like septic tanks. Poor construction often causes these tanks to leak, contaminating local shallow aquifers with nitrates and fecal pathogens. During monsoons, storm-water drains routinely become clogged with plastic waste, causing flash floods that mix raw sewage with drinking water networks.

Unscientific Waste Disposal and Legacy Landfills

Metropolitan centers generate thousands of tonnes of municipal solid waste daily. Due to historical deficits in processing infrastructure, the majority of this waste undergoes unscientific open dumping at massive legacy landfills, such as Ghazipur and Bhalswa in Delhi, Deonar in Mumbai, and Dhapa in Kolkata. These sites cause chronic air pollution from spontaneous methane fires and produce highly toxic leachate runoff that contaminates local groundwater resources.

National Policy Frameworks and Central Flagship Initiatives

The Ministry of Housing and Urban Affairs (MoHUA) implements targeted central schemes to upgrade physical utilities and instill environmental sustainability across statutory towns.

AMRUT 2.0 (Atal Mission for Rejuvenation and Urban Transformation)

• Core Objective: Launched to make all 4,041 statutory towns water-secure through functional piped tap connections to every urban household.
• Infrastructural Focus: Upscales sewage treatment capacities, expands underground sewerage networks, and enforces the “Pey Jal Survekshan” to evaluate water security, water quality, and conservation practices across cities.
• Circular Economy Integration: Mandates that cities formulate a Water Balance Plan focusing on recycling treated municipal wastewater for industrial use and thermal power plants, thereby reducing the consumption of fresh surface water.

Swachh Bharat Mission – Urban 2.0 (SBM-U 2.0)

• Core Objective: Focuses on sustaining Open Defecation Free (ODF) outcomes and transitioning all Indian cities into complete “Garbage-Free” status.
• Mechanisms for Sanitation: Mandates 100% source segregation of municipal waste, mechanical processing of all plastic and organic fractions, and the complete bio-remediation of all legacy dumpsites across the country.
• Certification Protocols: Establishes a rigorous multi-tier grading protocol under the Star Rating for Garbage Free Cities and the Swachh Survekshan to evaluate city cleanliness metrics. Cities are certified as ODF+, ODF++, or Water+ based on their efficiency in septage management, public toilet hygiene, and wastewater treatment.

National Urban Sanitation Policy (NUSP)

This policy layout provides the institutional framework for states to formulate individual State Sanitation Strategies and City Sanitation Plans. It shifts the planning focus from simple asset creation to complete sanitization chains, encompassing safe containment, conveyance, treatment, and final disposal of human excreta.

Tech-Driven Solutions and Global Best Practices

Indian municipalities are increasingly deploying advanced engineering and digital automation systems to optimize utility networks and improve service delivery.

Supervisory Control and Data Acquisition (SCADA) Systems

Cities like Indore and Nagpur deploy SCADA technology across their water distribution grids. This system uses IoT-enabled sensors and automated valves to monitor pipeline pressures, track flow velocities, detect real-time leakages, and isolate unauthorized water tapping instantly from a centralized command center.

Water+ Certification and Wastewater Recycling Models

To achieve Water+ certification under SBM-U 2.0, a city must treat all domestic wastewater to prescribed environmental safety standards before discharging it into natural water bodies. Indore secured India’s first Water+ certification by diverting sewage from open nullahs into localized treatment plants and recycling the treated water for public gardens, industrial cleaning, and construction activities.

Decentralized Wastewater Treatment (DEWATS)

DEWATS represents a sustainable sanitation model for peri-urban areas and informal settlements where laying expansive underground sewer grids is economically or physically unfeasible. It uses modular, gravity-driven biological systems—such as anaerobic baffled reactors and constructed wetlands—to treat sewage locally without heavy electricity demands or chemical additives.

Essential Facts and Trivia for UPSC Prelims

The Concept of “Day Zero”

This geographical term describes a critical situation where a city’s municipal water supplies dry up completely, forcing authorities to shut off public taps and strictly ration water to citizens. In 2018, Shimla faced an acute seasonal “Day Zero” crisis due to the drying up of natural mountain springs, while Chennai experienced a major “Day Zero” event in 2019 when its four primary surface reservoirs dried up simultaneously.

Continuous Water Supply (24×7 Pressurized Delivery)

Traditional Indian urban water networks function intermittently, which causes negative pressure in empty pipelines that pulls surrounding groundwater pollutants into the drinking water supply. To eliminate this hazard, Puri (Odisha) became the first major Indian city to achieve a 100% city-wide “Drink from Tap” mission under the Sujal initiative, delivering safe, continuous 24×7 pressurized drinking water directly to all households without requiring domestic filtration systems.

The “Water-Energy-Food Nexus” in Urban Hydrology

Urban geographers emphasize that urban water management cannot be analyzed in isolation from energy and food systems. Pumping water from distant regional reservoirs to supply high-altitude metropolitan areas consumes immense amounts of electricity, while discharging untreated urban wastewater into peripheral agricultural zones contaminates the peri-urban food supply chain with heavy metals and chemical residues.

Extended Producer Responsibility (EPR) in Municipal Solid Waste

Under the Plastic Waste Management Rules, EPR mandates that brand owners, producers, and importers of plastic packaging take structural responsibility for collecting and recycling an equivalent volume of plastic waste generated by their products in urban markets, helping to reduce the volume of non-biodegradable waste entering municipal landfills.