The urban Lei river consists of a catchment area of about 211 km 2 . About 55% lies in Islamabad (population about 3 million) and the rest in Rawalpindi (population about 3 million). The city of Islamabad is growing without considering its hydrogeological set-up, which is creating further flood problems in Rawalpindi. Even after the drought of 1994, groundwater is being privately exploited without any central legal control. Measures for increasing the amount of available groundwater would improve drinking water both qualitatively and quantitatively, reduce loss through uncontrolled runoff, reduce aquifer depletion and lead also to improved monitoring. The chessboard regional city planning of Islamabad, as laid down in the Master Plan (1960), has to be replanned inter-disciplinary according to topographical, geological, meteorological, hydrological and hydrogeological investigations. Sustainable ecological solutions ought not be sacrificed to political short-sighted expedience.