Water is the most precious resource on the planet; our society is water-hungry to fulfil our basic human needs, and to sustain the environment and socio-economic development. According to the most recent statistics, the world population is expected to be 8 billion by 2025. The urban population in 2014 accounted for 54% of the total world population which is expected to grow on average by 1.63% annually between 2015 and 2030. Two centuries ago, the world population consisted mostly of rural inhabitants, and only 3% lived in the cities. Historically, all cities started small but industrialisation in the nineteenth century caused the rapid expansion of our cities. Today, water security is a major concern for urban cities. The expansion of cities has changed the land use and required a more formal planning process to provide essential services, such as sanitation, water supply, transportation, security, solid waste management and flood risk reduction.
In recent years, many urban cities around the globe have been affected by surface water flooding due to the change in land use, topography and vegetation, and the intensity and duration of storms. In 2007, the UK had an exceptional rainfall event, where surface water was identified as one of the primary causes of flooding that incurred an estimated cost of £3.2 billion. This has led the UK to produce guidance to assist responsible authorities in preparation of surface water management plans, to help with the management of surface water flooding.
Despite the water stress in Saudi Arabia and the Middle East region, there were several disastrous flood events in the last decade that led the Saudi government to invest in a surface water management strategy and flood protection project. In 2013, the capital Riyadh experienced the highest intense rainfall in more than 25 years.
A presentation by Eng. Khalaf Al Dalbahy, Directorate General for Study and Design, Riyadh Municipality during the Drainage and Sewerage Middle East conference in Qatar, February 2015 examined a surface water management case study for the city of Riyadh, and revealed the benefits of using integrated urban drainage modelling within an integrated catchment approach. Within the presentation it was clear that the preference of a sustainable urban drainage system (SUDS) is encouraged by Riyadh Municipality, which recognises the multi-value benefits of managing water in urban areas in a more natural way. They restored elements of the natural drainage system and created a network of blue and green open spaces to serve as an integral element of the flood management infrastructure. The main challenge was the density and layout of the existing urban areas, but the municipality has managed to provide a higher level of flood protection to the community, while creating a range of new opportunities. They have created flood storage with green and recreational areas, and the community is being engaged on both structural and non-structural measures that have significantly reduced the impact of surface water flooding.
This proves that it is internationally recognised that our urban environment and quality of life can be improved by the way we manage our urban water, providing safe, secure and attractive places through integrated urban drainage modelling, design and planning innovation. The municipality of Riyadh deserves praise for the excellent example presented by Eng. Khalaf Al Dalbahy of community engagement on water management in urban cities.