Saudi Arabia makes efforts to reuse urban wastewater for irrigation

During the Kingdom’s rapid process of urbanisation, the condition of Saudi Arabia’s natural waterways deteriorated. The wadis that first attracted settlers to Riyadh were neglected and their waters rendered undrinkable. These were replaced by desalinated water produced hundreds of kilometres away on the east coast. In Jeddah, flash floods claimed 123 lives in 2009 and struck the city once again in 2011. In recent years there has also been a resurgence of interest in the restoration of the natural wadis and waterways beneath the Kingdom’s cities and a growing appetite for more efficient treatment and reuse of wastewater.

Flood Prevention

Jeddah responded to the flooding of 2009 and 2011 by investing SR3.5bn ($932.8m) in emergency flood measures and permanent solutions. Four firms were tasked with building seven dams and over 20 km of rainwater culverts, which now cross the city from the high ground in the east to the Red Sea. In July 2013 a further SR1.8bn ($479.7m) in construction contracts were signed for flood defence works in east Jeddah, which were due to be completed in late 2014. In December 2014 a court in Jeddah jailed 45 people for a total of 118 years and handed out SR13.7m ($3.65m) in fines for offences related to the 2009 floods. They were blamed for real estate and land planning that exacerbated the impact of the heavy rainfall. The lessons learned from the city’s experience have been applied in a new development 15 km east of Jeddah. Murooj Jeddah is designed to house 170,000 people in a 130-sq-km“sustainable city”. British engineering firm WYG is working on the 20-year project. “When it rains, the area is prone to flooding and the water just runs straight into the Red Sea, so we worked on flood defences with a specialist dam consultancy as well as carrying out all the transport and infrastructure planning and design,” said WYG’s project director, Colin Shields. “As part of our programme, our ecologists looked at the site and were delighted by the unique flora and fauna that they found. Some of the new planting is now complete, irrigated by river water, and this is providing a natural oasis for the wildlife, as well as a series of parks for visitors from Jeddah.”

Wastewater

The concept of treating wastewater and using it for irrigation has been employed in Dammam on Saudi Arabia’s east coast. In 2014 Modon Lake was inaugurated by Eastern Province Governor Prince Saud bin Naif. The lake is 210,000 sq metres and is set in a 400,000-sq-metre green space, including 760 date palms at the Second Industrial City in Dammam. The Saudi Industrial Property Authority (MODON) commissioned engineering consultancy CH2M Olayan to complete the project in order to deal with wastewater from industrial firms in the district. “The site was only supposed to serve the industrial city itself, but now it has become a park for the whole city, which in turn has created demand for additional facilities such as walkways, cycle paths and a retail outlet,” Amer Khan, CH2M Olayan’s general manager, told OBG. Khan hopes the example of Modon Lake will encourage both private developers and municipal authorities to consider replicating this use of wastewater. Mohammed Al Solaiman Al Fraidi, general director of Riyadh Municipality’s Parks and Landscape Management Department, is responsible for the city’s parks and other green spaces, and said he hopes to see more treated water used in the future. “In some areas we have used treated water, but these only constitute 10% of the total and we would like to see more of this in the next two or three years,” Al Fraidi told OBG. “Well water is more salty and is hazardous to plants, so we prefer to use treated water.”

Sewage Systems

Residents of Jeddah and Riyadh rely heavily on the use of septic tanks, which can leak during floods or rises in groundwater levels. A report by the Arriyadh Development Authority (ADA) in February 2015 said 62,103 cu metres per day is drained from the capital’s septic tanks and that 30,103 cu metres is trucked to the sewage treatment plants in Heat. The ADA report said that, together with Riyadh Municipality, it is seeking to give these issues more attention to resolve them and improve the situation.