Analysis Construction Sponge City Initiative could fix Mena’s growing flood threat By Andy Sambidge October 4, 2022, 8:21 AM Supplied Instead of relying on pipes, dams and channels, sponge cities allow urban areas to absorb water in times of high rainfall and release it in times of drought Rainfall may become more frequent or heavier with climate change China hopes concept will turn 80% of urban areas into sponges Flood mitigation solutions save lives and limit repair costs A Dubai-based company is in talks with authorities across the Middle East about bringing a revolutionary “sponge city” concept to the region following the UAE’s recent record levels of rainfall which led to loss of life and flood damage. Dake Rechsand, which specialises in sustainability solutions for water conservation, rainwater harvesting and stormwater management, exhibited the Sponge City Initiative (SCI) at WETEX Dubai last month. Instead of relying on levees, pipes, dams and channels, sponge cities allow urban areas to absorb water in times of high rainfall and release it in times of drought. UAE invests in future flood control after record rainfall Rising inflation leaves UAE businesses underinsured Make it rain: UAE pins its hopes on cloud seeding After successful trials, cities in China are now obligated to build sponge city elements, with authorities hoping to turn 80 percent of urban areas into sponges by 2030. The concept has yet to take off in the Middle East and North Africa (MENA), despite many arid cities such as Cairo, Kuwait, Riyadh, Casablanca, Muscat and areas of the UAE having experienced flash floods. “The concept has yet to be adopted in the Middle East but in recent years meteorological data has pointed toward the visible impact of climate change,” Chandra Dake, CEO of Dake Rechsand, said. “We have been increasingly witnessing changes in precipitation patterns in the UAE. “Various studies from reputable organisations have suggested that rainfall could become more frequent or heavier with longer dry spells in between. “Owing to the region’s longstanding water scarcity, the solution should be multi-pronged. “The flooding-scarcity dichotomy finds a fit-for-purpose solution in the SCI which characterises both sustainable stormwater management and efficient rainwater harvesting in a single, decentralised system.” Chandra Dake, CEO of Dake Rechsand, says the Sponge City Initiative is a “monumental concept” The UAE’s National Centre of Meteorology said this July was the wettest in the UAE for over 40 years with 234.9mm of rain falling from July 25-28 alone. The UAE usually averages 100mm for an entire year. Seven people died in the floods, 870 people were rescued by emergency teams and 3,897 people were placed in temporary shelter in nearby hotels in Sharjah and Fujairah. The MENA region is home to 6.3 percent of the world’s population but has access to only 1.4 percent of the global renewable fresh water, which constitutes acute water scarcity. Research in the US suggests that for every dollar invested in flood mitigation solutions, it returns six dollars in long-term savings from damage repair costs. “The savings vary between locations, but the bottom line is that stormwater drainage solutions pay incrementally generous dividends,” Dake said. “The absorbed rainwater – the purest form of natural water – brings economic value while the averted damage saves repair costs. “Likewise, the concept can be applied at scale in different locations, unlocking colossal economic value incrementally every time it rains, all for one-time investment and implementation and little to no maintenance.” Torrential downpours led to deadly floods in the UAE this summer. Image: WAM There could also be a knock-on impact on home insurance costs. Homes in SCI projects are less prone to flooding and could entail comparatively lower premium payments. Dr Yuming Su, vice director of State Key Laboratory of Silica Sand Utilisation and an advisory committee member on a couple of successful SCIs in China, said that increased flooding incidents could become commonplace in the MENA region if efficient stormwater management is not undertaken. “Arid regions like MENA where rains weren’t a typical phenomenon, could face more challenges, as evident from several instances in recent years,” he said. “However, the large-scale impact is contingent on public interest, awareness, cost-benefits reconciliation, friendly government policies, and land-ownership clarity. “I’m confident that stakeholders in MENA will embrace it wholeheartedly.”
