Rainwater harvesting for Pakistan

Catch the rain. Refill the ground.

Filters, storage and recharge wells designed for Pakistani roofs, monsoon storms and falling water tables. For homes, schools, mosques and farms.

Estimate my roof Meet the founders
بارش
BAARISH / RAIN
1 mm × 1 m² = 1 LEvery millimetre of rain on a square metre of roof
1 marla ≈ 25.3 m²The roof area most Pakistani homes think in
Jul – SepThe monsoon window most of the country plans around

Why Pakistan

The rain comes in a rush, then the taps run dry.

Most of the year's rain falls in a few weeks. Roofs and roads send it to the drain, and the city pumps groundwater the rest of the year.

Three months of rain

Across most of the country the monsoon from July to September brings the bulk of annual rainfall. Storage turns that burst into water you can use in May.

Falling water tables

Cities such as Lahore and Quetta lean heavily on groundwater, and levels have been dropping for years. Recharge wells put clean runoff back into the aquifer.

Flooded streets

Paved neighbourhoods send monsoon runoff into drains that cannot keep up. Catching water at the roof and in the plot reduces what reaches the street.

Pakistan has done this before. The tobas of Cholistan have held rainwater for generations. Eco Harvesting brings the same idea to concrete roofs and city plots.

What we build

Three ways to keep a monsoon storm.

Roof to tank

Rooftop filters

A leaf and silt screen with a first-flush diverter that throws away the dirty first minutes of a storm. Sized for the flat RCC slab roofs common in Pakistani cities, with an overflow that leads to your tank or recharge pit.

Street to aquifer

Groundwater recharge

A silt trap, filter bed and recharge well that send clean runoff down to the aquifer instead of the sewer. Suited to house plots, school grounds, parks and farm edges.

Whole building

Systems for institutions

Complete designs for houses, mosques, schools, universities and farms: gutters, downpipes, storage, pump and overflow, planned around the building's roof area and daily water use.

Demonstration: the prototype opened up and put back together, then shown on a rooftop downpipe (concept illustration).

Our filter

A filter you can open, inspect and clean.

The Eco Harvesting filter sits between the downpipe and your tank or recharge well. It comes apart in seconds, so you can see what the monsoon left behind.

Removable lid
Lifts off so you can look inside and clear debris.
Mesh screen
A fine mesh insert catches leaves and grit before they reach storage.
Two-piece body
The lower section separates from the upper one for cleaning.
Side ports
Connect to the pipework on the way to the tank or recharge well.

What it measures

  • Live
    Intake

    Estimates how much water enters the filter from your roof area and the rain intensity. Try it in the calculator below.

  • Planned
    Water quality

    Measuring the quality of the harvested rainwater, such as pH, turbidity and total dissolved solids (TDS), so you know what is in the tank.

How it works

From roof to tank in five steps.

  1. Roof catchment

    Rain lands on the slab, tiles or sheet metal and runs to the low corner.

  2. Gutter and downpipe

    A mesh-covered gutter carries the flow down the wall without leaves.

  3. First-flush diverter

    The first dusty litres are set aside so they never reach storage.

  4. Filter

    Silt and fine debris are screened out before the water goes on.

  5. Tank or recharge well

    Clean water is stored for use, or sent underground to refill the aquifer.

Roof calculator

How much rain can your roof catch?

Enter your roof size in marla, kanal, square feet or square metres, then pick your city and the rain intensity. The numbers update as you type, including how fast water enters the filter.

Rounded long-term annual rainfall for planning.
Used to work out the intake rate of the filter.
Rain you could catch in a year
0litres
0days of household water
0tanks of 1,000 litres
0litres from one 50 mm storm
0litres per minute entering the filter

Copy the summary and share it with the founders when you ask about a system.

Annual rainfall by city

Your city is highlighted. Dry cities still catch useful water from a roof.

Approximate long-term averages, rounded. Actual rainfall varies a lot from year to year.

Founders

Two NUST students building for Pakistan's water.

Hassan Aun Ali

Founder

Student at NUST

Hussain Aun Ali

Founder

Student at NUST

Eco Harvesting is a student-led project from NUST working on rainwater harvesting for Pakistani homes, schools and institutions.

Questions

Before you install.

Can I drink harvested rainwater?

Treat it first. Filtered rainwater suits washing, gardens, toilets and cleaning. For drinking, boil it or disinfect it and use a certified purifier.

Does it work in dry cities like Karachi or Multan?

Yes, with smaller yields. Karachi averages about 200 mm a year, so a 100 m² roof still catches roughly 16,000 litres.

What kind of roof do I need?

RCC slab, metal sheet and clay tile roofs all work. A flat slab with a parapet is the easiest to drain to a single downpipe.

When should I install?

Before the monsoon, ideally by June, so the system is ready for the first storm of the season.

Can it tell me if the water is clean?

Not yet. Measuring water quality is planned. Until then, treat harvested rainwater as untreated and filter or disinfect it before drinking.

Will stored water breed mosquitoes?

Not in a closed tank. Mesh over every inlet and overflow keeps mosquitoes out.