Lifts, generators and paintwork get a line in every building’s maintenance budget. The water tank usually does not, until tenants start complaining about brown water. For a landlord or property manager in Karachi, the tank is one of the cheapest assets to look after and one of the most expensive to neglect.

This guide is written for anyone acting as a property manager for a water tank in Karachi: owners of rental houses and portions, managers of apartment blocks and commercial plazas, and union office-bearers who have ended up with the job.

In brief

• Whoever controls the tank, usually the landlord, union or manager, should hold the cleaning schedule.
• Shared tanks need cleaning every three months; single houses every four to six.
• Neglect shows up as tenant complaints, damaged plumbing and, in the worst case, liability.
• Write tank cleaning into tenancy agreements and maintenance budgets.
• Never send building staff into an underground tank.

The maintenance item most managers overlook

A tank is out of sight, it has no moving parts, and it gives no warning. Water looks clear while sludge builds on the floor and a bacterial film grows on the walls. By the time tenants notice a smell or colour, the problem is years old. The usual contents of a neglected tank are described in what we find in Karachi’s water tanks.

Why Karachi makes it worse

• Intermittent supply. Water arrives in turns and is stored for days. A World Bank document describes supply ranging from two hours every two days to four hours a day at very low pressure.
• Dirty first flow. Each of the city’s supply crises, such as the Dhabeji failures of 2026, sends silt and rust into underground tanks when the mains are recharged.
• Tankers and boreholes. Sand, salt and scale.
• Heat. Rooftop tanks are warm most of the year. See heat and bacteria in water tanks.
• Sea air. Near the coast, lids, hinges and inspection covers corrode quickly, and a rusted cover is an open tank.

The supply side is explained in our guide to KWSB water supply.

Who is responsible?

There is no single rule in Karachi that names who must clean a tank. In practice responsibility follows control of the tank.

Property	Who normally holds the duty	Common gap
Single house, rented	Whatever the tenancy agreement says; if silent, the landlord for the structure and the tenant for routine upkeep	Agreement says nothing, so nobody does it
Portion in a divided bungalow	The owner, because tanks are shared between portions	Each tenant assumes another will arrange it
Apartment building, handed over	The residents’ union or association, funded from maintenance charges	No budget line; disputed or inactive union
Apartment building, not yet handed over	The builder	Builder has moved on to the next project
Commercial plaza or office building	The building management	Tenants each assume it is in the service charge
Managed portfolio	The property manager, under the management contract	Not listed in the scope of services

For flats in particular, see who is responsible for an apartment building’s water tank. If your situation is disputed, the documents that decide it are the tenancy or sub-lease agreement and the union’s rules, and a lawyer is the right person to read them.

What neglect costs

Tenant complaints and turnover

Water quality is one of the things tenants cannot fix for themselves, which makes it a reliable source of friction. A smell in the bathroom or a brown bucket is a reason to withhold rent, to move out, or to warn the next applicant.

Damage to the building

• Sediment drawn into pipes, where it is far harder to remove than from a tank
• Scale and grit in geysers, float valves, pumps and tenants’ appliances
• Corroded reinforcement where cracks in an RCC tank go unnoticed
• Seepage from a leaking underground tank into foundations or a neighbour’s wall

A cleaning is also the only time anyone looks at the inside of the tank. Cracks, exposed steel and failed joints found early are small repairs.

Liability

If tenants fall ill and the tank turns out not to have been cleaned in years, the question of who was responsible becomes pointed. And if a caretaker or labourer is sent into an underground tank and is overcome by gas, the person who sent him will have to answer for it. In June 2025, five men died in a household water tank in Karachi. Do not let building staff enter a tank.

The property manager’s water tank in Karachi: a maintenance calendar

When	Task
Every month	Check lids, mesh and hatch; look inside each tank with a torch; note any smell or colour
Every 3 months	Professional cleaning of shared tanks in apartment and commercial buildings
Every 4 to 6 months	Professional cleaning for single houses and portions
May or June	Pre-monsoon cleaning; repair lids; raise the underground hatch above floor level
After the rains	Inspect; clean again if floodwater reached the hatch
At every change of tenant	Clean before the new tenant moves in and hand over the report
After a main line failure or long outage	Inspect the underground tank for silt; bring cleaning forward if needed

The reasoning for the intervals is in how often to clean a water tank in Karachi, and the rainy season in our monsoon guide.

Budgeting for it

Tank cleaning is a predictable cost, so treat it like one. For an apartment building, add a line to the annual maintenance budget for four cleanings and divide it across the flats. Spread over twelve months and many households, the amount per flat is small, and it is far easier to collect as part of the regular charge than as a special levy after a complaint. For a portfolio, agree a schedule and a fixed basis of pricing with one contractor so that every property is on the calendar.

What to put in a tenancy agreement

A few sentences prevent most disputes. Have your lawyer adapt them to the property.

• Who arranges cleaning, and how often. For example: the landlord will have both tanks professionally cleaned every six months.
• Who pays. Landlord, tenant, or shared.
• Condition at handover. Tanks cleaned within the previous month, with the service report attached.
• Access. The tenant will allow access on reasonable notice for cleaning and inspection.
• Day-to-day care. The tenant keeps lids closed and reports damage, leaks or changes in the water.
• Safety. Nobody is to enter the underground tank except a professional crew.

A handover checklist for each change of tenant

1. Have both tanks cleaned after the outgoing tenant leaves and before the new one arrives.
2. Walk the new tenant to the tanks. Show them the lids and the motor switch.
3. Hand over a copy of the service report and note the next cleaning date in the agreement.
4. Record the condition of lids, float valves and the hatch in the inventory.
5. Explain the supply days for the area and whether the property uses tankers or a borehole.
6. Make it clear who to call about water, and that nobody is to enter the underground tank.

Ten minutes at handover prevents the most common argument at the end of a tenancy: whose fault the dirty tank is.

Choosing a contractor for a managed property

1. A report for every job, dated, with photographs. This is your evidence to owners and tenants.
2. A proper tax invoice. Managers who pay cash to individuals cannot account for it. See why SRB and FBR registration matters.
3. Safe entry to underground tanks: ventilation, gas check, harness, attendant.
4. Capacity to cover the portfolio across the city, and to work around supply days.
5. A fixed, written price.

The full list is in what to ask before hiring a tank cleaning company.

How we work with property managers

Buildings are surveyed first, free of charge. Cleaning follows our eight-step procedure and is timed for just before the supply turn, when the underground tank is low. Where there are two rooftop tanks they can be cleaned in turn so residents always have one in service. Each tank gets its own dated report with photographs and a recommended next-service date, plus a numbered SRB/FBR tax invoice, which is what owners and unions need for their accounts.

Real estate clients on our clients page include Rufi Builders and Shamir Residency. Properties in the south are handled by our DHA and Clifton branch and those in the east, centre and north by our Gulshan and Jauhar branch. Single houses can get a fixed price online.

The reputational side

Good tenants stay where the basics work. A building that can show a prospective tenant a cleaning report from last month is making a statement about how it is run. It costs very little to be that building.

Frequently asked questions

Who pays for tank cleaning in a rented house in Karachi?

Whoever the tenancy agreement says. Where it is silent, many landlords pay for periodic professional cleaning and tenants handle day-to-day care. Put it in writing at the next renewal.

How often should a rental property’s tank be cleaned?

Every four to six months for a house, every three months for shared building tanks, and at every change of tenant.

Can cleaning be done without cutting water to the whole building?

With planning, yes. Work is timed around the supply turn and rooftop tanks can be cleaned one at a time.

What records should a property manager keep?

For each tank: dates of cleaning, service reports and photographs, invoices, and notes of any defects reported and when they were repaired.

Should the caretaker clean the tank to save money?

No. A small rooftop tank can be rinsed from outside between professional cleanings, but nobody should enter an underground tank without ventilation, a gas check and an attendant.

Can the cost of tank cleaning be recovered from tenants?

If the tenancy agreement or the building’s maintenance rules provide for it, yes. Agree it in advance; trying to recover it after the event causes disputes.

Does a clean tank affect rental value?

It will not raise the rent by itself, but water complaints are a common reason for tenants to leave, and vacancy is the most expensive cost a landlord faces.

Sources

Figures in this article were checked in October 2026 against the following:

• World Bank, 2019: Karachi Water and Sewerage Services Improvement Project, project information document
• Dawn, 1 May 2026: Most Karachi areas suffer as water crisis enters second week
• Dawn, 11 June 2025: Five dead after inhaling toxic gases in water tank in Karachi
• Geo News, 13 September 2025: Naegleria claims another life in Karachi, toll hits five in Sindh

About Khan Tank Cleaning

Khan Tank Cleaning is a Karachi company that does one thing: clean and disinfect water storage tanks. It was started in 2005 by Mateen Khan and now runs branches in DHA Phase 2 and Gulshan-e-Iqbal. Read our background or reach the nearest branch on 0333 0293174 (DHA) or 0340 2717530 (Gulshan), day or night.