16-07-2025
Rain reimagined: could monsoons be the answer to Pakistan's water problems?
In Pakistan, where flooding devastates some regions while drought cripples others, rainwater harvesting is an uptapped lifeline that could turn the monsoon season from a nuisance to a resource.
Rainwater harvesting is the collection and storage of rain for reuse before it drains away. From rooftop catchment tanks in homes to large underground reservoirs in communities and farms, this system allows water to be stored for irrigation, washing, livestock, and even safe drinking with basic filtration.
In cities like Karachi, Lahore, and Islamabad, flash floods during monsoon seasons cause chaos, yet the same water could be stored to recharge groundwater or provide months of clean utility water.
In rural Pakistan, especially in arid zones like Tharparkar, Cholistan, and Balochistan, where rainfall is rare but intense, harvesting systems could mean the difference between survival and starvation. These areas desperately need community based water tanks, dug wells, and natural catchment restoration all of which can be done with low cost, local materials.
According to the Pakistan Council of Research in Water Resources (PCRWR), more than 29 million acre-feet (MAF) of rainwater goes unused annually. That's enough to meet the drinking and household needs of every Pakistani for a year yet it simply washes away. Dams dry up, groundwater drops, and climate change tightens its grip.
What's more, cities draw groundwater at unsustainable rates, causing the water table to fall dangerously low. In parts of Punjab and Sindh, groundwater depletion has already reached crisis levels, threatening both drinking water and food production.
As Pakistan faces yet another year of unpredictable rains, parched fields, and shrinking water supplies, a centuries old solution is knocking from the sky.
Rainwater harvesting - once a common practice in rural communities that has faded into obscurity amid urban expansion and mismanaged water systems - needs to be revived.
'It's not rocket science'
'Pakistan is now ranked among the top 10 countries most vulnerable to water stress. With an alarming per capita water availability of less than 900 cubic meters, we've plunged below the scarcity threshold. And yet, every year, billions of liters of precious rainwater are wasted flowing off rooftops, flooding streets, or evaporating unused,' associate professor at Sindh Agricultural University Dr Aasia Akbar Panhwar said.
She said rainwater harvesting 'isn't rocket science'. Countries like India and Australia have already made it part of their national water management.
Dr Panhwar called for mandatory rainwater harvesting in all new buildings and housing schemes; community tanks and recharge pits in water stressed areas; training and awareness programmes for farmers, builders, and local governments; integration of rainwater harvesting in school and college curricula; and government subsidies and technical support to promote adoption.
'As climate change worsens and rainfall becomes more erratic, we must act now or face an even drier, more divided future.'
'Rainwater harvesting offers a rare win-win situation as it reduces flood risk, replenishes aquifers, supports agriculture, and strengthens water independence. Let's stop watching the rain as a passing storm and start seeing it as a precious gift.' she said.
Assistant Professor Dr Tanveer Ahmed Gadhi - who works at the US Pakistan Center for Advanced Studies in Water at Mehran University of Engineering & Technology, Jamshoro - said Pakistan receives an average of 137 billion cubic meters of rainfall annually, equivalent to 111 MAF.
Yet, due to inadequate infrastructure, poor urban planning, and a lack of strategic catchment systems, over 60–70% of this goes unutilized, either running off into drains or evaporating.
'If even 30% of annual rainfall were effectively harvested and stored through rooftop systems, urban recharge schemes, and small check dams, Pakistan could potentially capture around 33–35 MAF/year, or over 90 billion liters per day - that is nearly four times the nation's drinking water requirement, and about 15% of total agricultural water use, a meaningful cushion for drought-prone periods,' he said.
He said for urban areas, rooftop rainwater harvesting alone holds significant promise. In cities like Karachi, Lahore, Islamabad, and Quetta, annual rainfall ranges from 150 mm to 500 mm. A single 1,000 sq. ft. rooftop can collect up to 50,000 liters/year, which, when scaled across urban housing units, could offset municipal water stress significantly.
Similarly, rain-fed (barani) areas of Punjab and Balochistan could enhance agricultural resilience by using localized harvesting and storage systems for supplemental irrigation.
On top of that, groundwater recharge, now critically low in urban centers, can be dramatically improved by channeling rainwater through percolation pits and aquifer injection wells. In parts of Islamabad and Lahore, pilot recharge systems have already shown promising results in restoring shallow aquifers after monsoons.
'From scarcity to sustainability'
Despite the potential, rainwater harvesting in Pakistan remains underutilized due to weak policy support, lack of public awareness, and fragmented institutional ownership. While countries like India have legally mandated rooftop harvesting in many states, Pakistan's uptake is still mostly limited to pilot projects and donor-funded initiatives.
'Harnessing even a fraction of the annual rainfall through systematic harvesting could transform Pakistan's water outlook from scarcity to sustainability. It is not a question of availability, but a question of will, planning, and action,' Dr Gadhi said.
According to the World Bank and FAO studies and reports, Pakistan requires an estimated 922 billion liters of water per day, equivalent to 236 MAF annually, to meet its national needs across drinking, domestic use, livestock, and agriculture. However, the breakdown of this demand reveals a striking imbalance in how the country allocates its water.
Despite a population exceeding 241 million, the combined requirement for safe drinking water and basic household needs accounts for only 36 billion liters per day, less than 4% of total usage. This includes around 12 billion liters for drinking and hygiene (at 50 liters per person/day) and 24 billion liters for broader household use.
In stark contrast, agriculture alone consumes nearly 880 billion liters daily, making up over 93% of Pakistan's total water use.
This is largely due to inefficient irrigation methods and cultivation of water-intensive crops like rice and sugarcane. With nearly 200 million animals, the livestock sector adds another 6 billion liters daily to the national demand.
These numbers underscore a systemic misalignment, while safe drinking water needs are modest, they remain unmet in many regions, often due to poor infrastructure and contamination. The data suggests that Pakistan's water crisis is not purely about scarcity; it's fundamentally about governance, efficiency, and misplaced priorities.
Without urgent policy shifts towards equitable distribution, sustainable irrigation, and investment in treatment systems, the country risks deepening its water insecurity even with more than enough water on paper.
