Karachi, Pakistan’s largest city, is drowning in its own waste. The city’s sewerage system has collapsed – and the Karachi Water and Sewerage Board (KW&SB) bears much of the blame.
A thematic audit by the auditor general of Pakistan (AGP) lays bare the extent of this institutional breakdown. The findings, part of the AGP’s report on Sindh for 2023–24, reveal a city struggling under decades of neglect, weak management and a complete disregard for environmental laws.
The KWSB was created under the Karachi Water & Sewerage Board Act, 1996, to build, maintain and operate water and sewerage systems. Its mandate includes collecting, pumping, treating and disposing of domestic and industrial waste. However, the audit reveals how far reality has deviated from the law. Karachi’s sewerage infrastructure is in a state of decay. Trunk mains are inadequate, pumping stations malfunction and treatment capacity is almost nonexistent.
The AGP found that over six million people in Karachi have no access to public sewerage service. Network coverage is barely 60 per cent. Maintenance is rare. The system, the report notes, has received “very little maintenance since 1960”.
Karachi’s three sewage treatment plants – STP-I (Site), STP-II (Mehmoodabad) and STP-III (Mauripur) – were designed to handle 150 million gallons of wastewater per day. None of them works. The audit observed that all three have been non-functional for years.
Meanwhile, Karachi produces roughly 455 million gallons of sewage each day, most of it flowing untreated into the sea. Even if all three plants were fully operational, the treatment gap would still exceed 300 million gallons per day. Because the plants remain shut, an estimated 455 million gallons of raw sewage is dumped directly into the Arabian Sea.
To picture that volume, imagine filling about 689 Olympic-sized swimming pools with toxic sludge and emptying them into the Arabian Sea every single day.
Marine scientists have been warning about this collapse for years. The Arabian Sea near Karachi now receives one of the largest volumes of untreated municipal waste of any megacity in South Asia.
The ecological damage is visible. Algal blooms thrive on nitrogen and phosphorus from sewage. When these blooms die, they deplete oxygen and create ‘dead zones’ where marine life cannot survive.
Industrial waste from the Sindh Industrial Trading Estate (SITE) and from factories in Korangi’s Industrial Area add another layer of danger. Heavy metals like mercury, cadmium, and lead sink into seabed sediments and accumulate in fish. Studies have shown that these toxins already exist in seafood sold in Karachi markets. The health risks are real for both marine species and humans.
Karachi’s mangrove forests, once natural shields against storms and saltwater intrusion, are dying under sewage. Mangroves also serve as nurseries for fish and habitats for migratory birds. Their loss deepens environmental and economic damage. Without mangroves, saltwater creeps inland, contaminating soil and groundwater. Farmland has turned barren, and migratory bird populations along the Indus delta have sharply declined.
The audit’s findings match what coastal communities have experienced for years. Fishing villages like Ibrahim Hyderi, Rehri Goth and Keamari depend on nearshore catches. Those catches are shrinking. Fishermen now travel farther and spend more to bring home less. Some report their daily hauls have fallen by half in the past decade.
Fish caught near polluted waters often smell foul and fetch lower prices in markets. Contaminated fish also threaten public health. Alongside sewage, plastic waste adds to the problem. Microplastics enter the food chain through marine life and end up on dinner tables.
Fisherfolk working in polluted waters suffer from skin infections, respiratory problems and stomach diseases. Their livelihoods and health are both under attack. It’s a bitter irony: those least responsible for the city’s waste are suffering its worst effects, echoing the claims made by Pakistan’s government at international fora about the terrible impact of climate change on those least responsible for creating the problem.
The danger extends inland. Untreated sewage breeds cholera, hepatitis and gastroenteritis. Beachgoers at Clifton or Hawke’s Bay expose themselves to infected waters. Children fall ill. Even the air carries the foul stench of decay.
The economic toll is also steep. Pakistan earns about $500 million a year from seafood exports, with Karachi handling about 70 per cent of the trade. International buyers are growing increasingly wary of Pakistan’s seafood.
Tourism, another potential money spinner for Sindh, is equally affected. Karachi’s beaches – Clifton, Hawke's Bay, Sandspit – could rival global coastal attractions. Instead, they’ve turned into dumping grounds for crud.
The AGP’s report also exposes a threat rarely discussed: the damage to Pakistan’s maritime assets. Polluted seawater accelerates metal corrosion. Ships, submarines and port equipment such as hydrographic equipment, anchors and other installations deteriorate faster in Karachi’s harbor than in cleaner waters. Estimates suggest this pollution reduces vessel lifespan by nearly a third.
The cost of repairs to naval and commercial fleets runs into billions. Floating debris, especially plastics, clogs the cooling systems of boats and fast-response vessels. Engines overheat or fail. The total cost over service careers for repairs to ships, submarines and equipment for the Pakistan Navy alone is projected to be in the billions of dollars.
Even desalination plants that are critical for Karachi’s freshwater supply are threatened. Polluted seawater with high chemical loads can shut them down or make operations too costly. The lack of proper sewage management directly impacts the safety of Karachi’s water supply.
The audit noted that Reverse Osmosis (RO) Water Desalination Plants, such as those in Muwach Goth and Musharraf Colony, were not producing water as per WHO Standards. For instance, the plant at Muwach Goth produced water with 2,200 parts per million (ppm) of Total Dissolved Solids (TDS) which is four times the safe standard of 500 ppm.
What makes this catastrophe particularly maddening is its preventability. The audit reveals that the sewerage system has received "very little maintenance since 1960”. Between 1998 and 2017, Karachi's population surged by 63 per cent, generating 137 per cent more sewage. The KWSB conducted no studies, made no plans and took no meaningful action to accommodate this growth.
Take the vital S-III Project, designed to cater to the city's overall sewerage needs, which was approved in 2007. Nothing happened till 2018 when a revised plan set a 36-month completion deadline – meaning the project should have been finally completed by 2021. Four years later, it remains incomplete. When auditors asked for documentation, management refused to provide key records, displaying a contempt for accountability. This is a governance failure at the most fundamental level.
The audit's recommendations aren't technically complex: operationalise the three existing treatment plants; complete the S-III Project; establish uniform management standards; clear illegal encroachments from sewer lines; align sanitation goals with Pakistan's Sustainable Development Goals commitments; commission demographic studies to guide infrastructure investment; and provide documentation to auditors.
None of this requires breakthrough technology or foreign consultants. What it demands is something that has been conspicuously absent: political will and administrative discipline.
Karachi's sewage crisis is a story about institutional inertia and decay, but it's also about whose suffering matters. The fisherfolk with skin infections. The families in informal settlements who have never had sewerage access. Their voices don't echo in the corridors where decisions are made or, more accurately, where decisions go to die.
In a functioning democracy with accountability, such a massive failure of governance would spark outrage, force resignations and drive reform. The question for Karachi, and for Pakistan, is whether the political system can respond to the crises that result in a daily 689 Olympic-sized swimming pools’ worth of sewage pouring into the Arabian Sea.
The writer is a group director at the Jang Group. He can be reached at: iqbal.hussainjanggroup.com.pk