Twin Cities Submerged: How Institutional Failures, Upstream Runoff, and Governance Gaps Cause the Annual Urban Flooding Crisis
By: Asghar Ali Mubarak
Urban flooding in Islamabad and Rawalpindi is a man-made disaster driven by failed municipal planning, choked natural drainage systems, and structural negligence. Despite repeated early warnings from the National Disaster Management Authority (NDMA) and the Pakistan Meteorological Department (PMD), torrential monsoon downpours routinely turn the Islamabad Expressway and Rawalpindi’s low-lying residential sectors into dangerous waterways, stranding thousands of citizens and destroying infrastructure.
Current Ground Situation
The most recent spell of unrelenting torrential rain started at 3:20 PM and stopped at 8:00 AM, leaving a trail of severe urban devastation across the twin cities:
Record-Breaking Downpour: Deputy Commissioner Rawalpindi, Captain (retd) Nadeem Nasir, confirmed that a staggering 200 mm of rain was recorded in Rawalpindi, marking the highest rainfall recorded in the last 3 years.
Neighborhoods Submerged: Roads and low-lying sectors rapidly transformed into deep ponds, with water accumulating up to knee-level in many places and actively flooding residential houses.
Nullah Lai Gauges Breach Dangerous Levels: The immense volume caused adjacent drains to backflow. The water level at the Kattarian Bridge gauge peaked at a dangerous 29 feet high, while the Gwalmandi Bridge gauge reached 24 feet high, crossing the critical emergency mark.
Mass Evacuations & Closures: In view of public safety, the district administration ordered the immediate evacuation of all settlements surrounding Nullah Lai and announced a holiday in educational institutions across the affected areas.
Emergency Relief Deployment: To counter the crisis, the Pakistan Army was deployed to secure high-risk zones around Gwalmandi alongside Rescue 1122 and WASA teams, who conducted large-scale drainage operations to clear submerged sectors.

Root Causes
Encroachment on Natural Streams: Housing developments and commercial spaces have legally and illegally built directly over natural storm channels, choking critical waterways like the Korang River and Nullah Lai.
The “Concrete Runway” Effect: Rapid urbanization has replaced porous green fields with concrete roads and plazas. Rainwater can no longer sink into the ground, transforming into immediate, fast-flowing surface runoff.
Solid Waste Choking Drains: Millions of tons of plastic garbage, domestic trash, and construction debris are dumped directly into the city’s drainage channels, forming massive bottlenecks that cause the water to back up onto roads.
Outdated Infrastructure Capacity: The sewage and storm-drain networks built decades ago lack the cross-sectional capacity to handle modern climate-induced cloudbursts and high-intensity rainfall.
Upstream Catalyst
Catchment Monopoly: The Nullah Lai basin spans roughly 235 square kilometers. Islamabad occupies a staggering 69% of this upper catchment area, encompassing the Margalla Hills where the primary feeding tributaries originate.
Gravity and Topography: Sitting at a much higher elevation, Islamabad acts as a steep funnel. The Capital Development Authority’s (CDA) failure to create rainwater-retention lakes or maintain its mountain streams means millions of gallons of concrete-driven runoff are accelerated downhill into Rawalpindi within minutes of a storm hitting.
Spillway Dilemma
Preventing Dam Breach: As water surges toward the maximum storage threshold of 1,752 feet, engineers must initiate a controlled discharge to prevent catastrophic failure of the dam structure.
Downstream Aggravation: While this saves the dam, releasing thousands of cusecs of water directly into Korang Nullah and Nullah Lai instantly overloads channels that are already completely full, prompting emergency sirens and forced evacuations across low-lying sectors.
Provincial Inaction
Failure to Clean Nullah Lai Bottlenecks: Despite receiving detailed weather alerts weeks in advance, provincial administrative bodies—including WASA Rawalpindi and the Rawalpindi Municipal Corporation—fail to conduct deep desilting or remove major structural obstacles from the main path of Nullah Lai.
Shelving Long-Term Engineering Solutions: The Punjab government has repeatedly delayed or politicized permanent structural overhauls, such as the long-proposed Nullah Lai Expressway and Channelization Project. Instead of widening and concreting the banks to increase water flow velocity, successive administrations rely on cheap, temporary pre-monsoon dredging that washes away during the first heavy rain.
Unchecked Real Estate Connivance: The Punjab government has turned a blind eye to illegal housing societies cropping up on the natural riverbeds and floodplains of Rawalpindi’s borders. Commercial encroachments are allowed to expand with impunity, completely disregarding the environmental warning data provided by federal climate bodies.
Future Suggestions
Construct Upstream Sponge Infrastructure: The Capital Development Authority (CDA) must build deep detention basins, artificial wetlands, and rainwater-harvesting lakes in Islamabad’s higher sectors to absorb and delay the rapid downhill rush of water before it reaches Rawalpindi.
Execute the Nullah Lai Channelization Project: The Punjab Government must prioritize the long-delayed widening, deepening, and concrete-lining of Nullah Lai, replacing temporary seasonal dredging with permanent, high-velocity concrete flood channels.
Establish a Unified Twin-Cities Flood Taskforce: Establish a single, legally empowered regulatory authority bridging the CDA, WASA, and Rawalpindi municipal bodies to eliminate bureaucratic finger-pointing and enforce uniform drainage master plans across provincial borders.
Launch a Zero-Tolerance Encroachment Crackdown: Conduct aggressive, non-partisan demolition campaigns to clear commercial plazas, residential housing societies, and informal settlements built over natural floodplains and choked drainage tributaries.
Deploy Modern Automated Sluice and Trash Gates: Install heavy-duty mechanical trash-skimmers and automated sluice gates along major inlets to intercept plastic waste at the source, preventing massive underwater blockages during intense downpours.
Enforce Green Building Codes: Mandate that all new commercial and residential developments incorporate permeable pavements, open green zones, and localized water-soakage pits to restore natural ground absorption.