A Canadian planning and architecture firm has won an Aga Khan Award for Architecture for the sweeping transformation of a once-polluted Saudi waterway into a system of parks in the heart of the desert, using a system of bio-remediation.
The 120-kilometre-long Wadi Hanifah, an oasis that cuts through the Saudi Arabian capital of Riyadh and the surrounding desert, was an odorous receptacle for the city's refuse, clogged with algae, dead animals and weeds "twice the height of a man," said George Stockton, president of Moriyama & Teshima planners. In 2001, his firm began planning its transformation into a parkland.
First, crews hauled garbage out of the Wadi and fitted the waterway with strategically placed rocks to encourage the growth of organisms that would devour nutrients and clean the water. Next, they regraded the banks to stop flash-flooding. Finally, they planted bushes and trees, including 4,500 date palms, and built trails, parks and lakes.
The Wadi has been around for thousands of years and was once the site of an adobe city that served as the original seat of the House of Saud, Mr. Stockton said. Mindful of local norms that value privacy, Moriyama & Teshima filled the parks with semi-enclosed family spaces, in which low walls encircle a fire pit.
The valley now returns 400,000 cubic metres of water per day to the city for use in irrigation and cleaning - a precious resource in a region that gets only 100 millimetres of rain in a year. The Wadi has become a magnet for waders, hikers and anglers, visited by thousands of people every weekend. "Seeing people and families enjoying it is the greatest reward," said Drew Wensley, M & T's executive vice-president.
Moriyama & Teshima received one of five Aga Khan Awards for Architecture, which are handed out every three years to environmentally, socially and economically sustainable projects that improve the quality of life in the community in which they are built.