by Chloe Soltis
The natural landscape of Saudi Arabia is quite dry and has few natural freshwater resources. Currently, the main freshwater source is desalinated seawater, a product that is expensive because it uses electricity generated from fossil fuels. In addition, a large portion of Saudi Arabia’s population has moved from rural to urban areas, which has changed the landscape’s inherent hydrology, causing large urban floods to plague the city once a year. Guizani (2016) believed that rain water harvesting could be a green solution to both of these issues.
Guizani analyzed eight cities – Hail, Median, Buraidah, Jeddah, Taif, Jizan, Riyadh, and Holy Makkah – using data on average rainfall, water consumption, and pavement area, available from government agencies, and developed three equations to estimate rainwater harvesting potential, collection reservoir sizing, and environmental impact. He also compared the current costs of water desalination against the costs of storm water harvesting in order to predict whether it would make economic sense for cities to invest in this new infrastructure.
Guizani found that harvesting rain in the cities of Riyadh, Hail, Taif, and Jeddah was less expensive than desalination using green energy sources such as solar panels, but more expensive than desalination using fossil fuels at current oil prices. Gaizani predicts that the price of oil and gas will increase in the coming years, and when it does, water management officials will be more open to using rainwater harvesting. Gaizani concludes that the most important benefits of rainwater harvesting in Saudi Arabia would be the decrease of greenhouse gas pollution and less severe flooding events.
MokGuizani, M., 2016. Storm Water Harvesting in Saudi Arabia: a Multipurpose Water Management Alternative. Water Resources Management 30: 1-15. http://link.springer.com/article/10.1007/s11269-016-1255-4.