The local Arriyadh Development Authority (ADA) is currently conducting technical studies on parcels of polluted land that could become Riyadh’s second environmental rehabilitation project at Wadi Hanifa.

ADA completed its first $275m Wadi Hanifa project in April this year, and a source at the ADA says several sites are being seriously considered for a second rehabilitation project, although no site has been officially chosen.

Wadi Hanifa is a 120-kilometre valley that cuts through the centre of Riyadh which, due to decades of unregulated waste dumping and mining, had become polluted to the point of being a health hazard.  

The first Wadi Hanifa project was finished in April. UK-based civil engineering firm Buro Happold was appointed in 2001 as the consultant on the scheme which involved building:

• A 120-km water canal
• Dams to regulate 500,000 cubic-metres of water flowing out of Riyadh per day 
• 24-hour watchtower facilities to monitor land use
• Removal of more than 2 million cubic metres of construction and non-inert waste from the wadi bed
• Fences around public parks and protected areas
• Models for potential development
• A network of roads and sidewalks

The engineer was also the lead consultant on the Wadi Hanifa water purification plant, which is the largest non-chemical water treatment facility in Saudi Arabia.

Canadian-Japanese landscape architects Raymond Moriyama and Ted Teshima designed Wadi Hanifa with Buro Happold in 2001.  

At present, Riyadh consumes around 1.3 million cubic-metres of water per day, a number which is expected to increase to 3 million by 2021. The ADA aims to use the Wadi Hanifa facility to recycle up to a million cubic metres of water per day by that time.   

Local media in Saudi Arabia have suggested that the government is revitalising the wadi to capitalise on its potential for residential and commercial development. One such project that uses rehabilitated land is Ajmakan, Riyadh’s estimated $6.2bn luxury gated community (MEED 18:5:10).