Wadi Hanifah runs through the heart of Riyadh and was once the city's main source of water. Over reliance on the Wadi's underground water reserves has, however, caused the water table to fall to the extent that most of the city's desalinated water supply is piped in from the coast, 350km away, at great cost. More recently, rapid urban expansion has turned the Wadi into a permanent flowing river in its lower reaches, due to rising groundwater and sewage effluent discharge from the city causing pollution and degradation.

Buro Happold has been appointed with Canadian architects Moriyama & Teshima to plan the restoration and development of the Wadi as an environmental, recreational and tourism resource. The masterplan's focus is on restoring the Wadi's natural beauty, which has been spoiled by decades of unrestricted dumping and development, but also to harness and rehabilitate its water.

The project is complex, due to the technical challenges facing the many individual engineering disciplines and the co-ordination of these elements into a restoration project. It involves three major components: an appraisal of current conditions, a comprehensive development plan and an implementation programme.