Saudi’s Riyad Turns Wasteland into Park


Riyad, the capital of Saudi Arabia and is an urban for 7 millions has a valley, Wadi Hanifa that runs through it. While the wadi has traditionally been dry except for during times of flooding, the construction of Riyadh’s first large sewage treatment facility in 1982 has channeled 400,000-650,000 cubic meters of runoff downstream daily, creating a constantly expanding area of small lakes south of Riyadh. Over the past decade, this area has been transformed into a new green corridor nearly 100 kilometers long has been formed. The Saudi government and the Ar-Riyad Development Authority appointed Buro Happold and Moriyama & Teshima architects to plan the preservation of the wetlands of the Wadi Hanifa, as they had become a popular destination for recreational activities such as fishing and picnicking and have also become a stop for migratory birds. The government has invested over $100 million (US) into an environmental rehabilitation project. This includes the construction of dams to regulate water flow, new limits on land use such as the banning of such commercial activities as quarrying and the planting of reeds to further purify the treated and untreated sewage. The completed project won the 2010 Aga Khan Award for Architecture.


The Aga Khan Award for Architecture was established by His Highness the Aga Khan in 1977 to identify and encourage excellence in architecture and other forms of intervention in the built environment of societies where Muslims have a significant presence. The Award is given every three years and recognises all types of building projects that affect today’s built environment, from modest, small-scale projects to sizable complexes. All form of planning practices on the urban and regional scales are encouraged, such as infrastructure and transportation undertakings; development in rural landscapes; housing initiatives; industrial facilities and workplaces; educational and health campuses; new towns, urban conservation and the re-use of brown field sites.








This massive reclamation project involved various stages. First it was necessary to clean up the river waste, which involved removing 1.5 million cubic meters of debris ranging from construction waste to dead animals. The riverbed hand to be cleared and a nearby tannery that was releasing toxic chemicals into the river was shut down. Meanwhile, 35,000 indigenous shade trees were cultivated in greenhouses along with native grasses. Clusters were placed along a 70km stretch of the river, which is now accessible by a new 53km road that provides links to 6 new parks! Additionally, using a constructed wetland system, the team introduced four powerful air pumps that blast dissolved oxygen into the treatment plant, which destroys existing bacteria. Then they added a layered textile mat, where algae and other micro-organisms proliferate, digesting any particulates. Then a series of tilapia feed on the algae so that the water is almost 100% clean and clear when it comes out. This treated wastewater is so clean and free of odor that it has been allowed to continue along the river and forms the basis of an additional 28km of green parks.

via GreenProphet and Wikepedia