Pakistan, Aug. 1 -- Pakistan's major cities experience the same cycle of disruption every monsoon. A few hours of heavy rainfall are enough to inundate roads, submerge underpasses, paralyse traffic, disrupt businesses and overwhelm urban infrastructure. The immediate response usually focuses on pumping water out of the city as quickly as possible. While this remains necessary, it addresses only the symptom rather than the underlying problem.

Urban flooding is no longer simply a drainage issue; it is a consequence of decades of unplanned urbanisation. As cities continue to expand, natural soil has been replaced by concrete roads, parking areas, commercial buildings and housing developments. Rainwater that once seeped into the ground now r...