Will Urban Green Infrastructure Help Mitigate Megadrought?

Nanyang Technical University, Singapore

NASA’s new report on the likelihood of megadrought in the Central and Western United States is a harsh yet timely wake-up call for cities and the need for green infrastructure. It’s ironic but those taking the earliest green infrastructure leadership–such as Philadelphia, Portland and Copenhagen–have historically had adequate rainfall and water supplies. Meanwhile, Los Angeles and other global cities in extreme drought such as São Paulo and Beijing that at least partially depend on aquifers for drinking water, are now exploring how green infrastructure can be part of a climate-change resilient city’s main arsenal in water retention or conservation.

The joint NASA-Cornell and Columbia universities report forecasts that if we continue on our current path, climate change will fuel multi-decade droughts for the Central and Southwest US on an order of magnitude not seen for 500+ years and worse, with intensity far beyond what has already been experienced during the past several extreme drought years in California, Colorado and Texas.

On a recent 70+ degree January day–historically warm even by Los Angeles standards but becoming the norm during the state’s multi-year extreme drought–the sustainable city group from Autodesk and I met with Los Angeles Mayor Eric Garcetti’s office along with top water officials at the Los Angeles Department of Water and Power (LADWP), the nation’s largest municipal utility. We explored how green infrastructure analytical and capital planning technologies developed by Autodesk (a client of my consultancy) and partner company, Impact Infrastructure, can model economic, environmental and social benefits. These would include recharging aquifers and preventing localized flooding in LA’s San Fernando Valley and other city districts. Autodesk is also preparing to work with Washington, DC and Atlanta on district and metro area green infrastructure modeling and prioritization approaches.

Impact Infrastructure, meanwhile, helped develop Autodesk’s new AutoCASE automated triple-bottom line project analysis software, which has been successfully used to model the costs and benefits of green infrastructure in arid cities such as Fort Worth, Texas and Tucson, Arizona. AutoCASE calculates economic, social and environmental benefits of green stormwater infrastructure, including flood prevention, reduced urban heat island impact, reduced greenhouse gases, increased public recreational values and improved air quality.

According to John Parker, Chief Economist of Impact Infrastructure, “Tucson is teaching the world that water is a scarce and precious, but undervalued, resource that is going to get scarcer and more valuable: because of its many benefits, nature’s green infrastructure is often the best way to deal with problems of water scarcity, quality, flooding, and urban heat islands.”

Megadrought and Megacities

Globally, the need for integrated development and water planning is just as urgent. In Beijing overuse of underground aquifers has caused ground subsidence–sinking–inducing cracking pavement, roads and buildings. Fresh water is rapidly being withdrawn from metro-area aquifers that have been the primary source of drinking water for the city of 20 million (full-time) to 30 million (including part-time) inhabitants. Major climate change-exacerbated drought and industry-induced water shortages have forced the city to import water long-distance (like Los Angeles does) from a national South-North water diversion project.  Indeed, Beijing is currently perhaps the most water-starved megacity in the world, but there are other cities poised to achieve that dubious status.

In 2013, Common Current advised the Beijing metro government on methods by which to systematically capture and reuse its stormwater, which often falls as rain during July and August in torrents that overflow the streets and wash off pavement into stormwater outflow systems. As the climate has been warming, much of the rest of the year is now almost devoid of major precipitation. Besides banishing the lawn for use in landscaping, (especially when used as pure decor in office parks, on freeway embankments, and around retail developments), Beijing needs to use urban planning, standards and new technologies to make low-impact development the guiding and enforceable rule so it can recharge its vanishing aquifers with fresh water, while also controlling its sometimes-deadly seasonal flooding.

Superstar Soil

Green infrastructure uses Low-Impact Development (LID) such as permeable pavement, bioswales, filter strips, rain gardens, green roofs, catchment basins and planters designed as part of the built environment to naturally filter precipitation and run-off through soil, gravel, sand, compost and other absorptive media, instead of letting pavement or rooftop run-off wash straight into storm drains.

Pollutants are naturally filtered by green infrastructure through its main component, healthy soil. Native trees or plants can be major ingredients of green infrastructure, but healthy soil is the main component of most redevelopment projects or engineered systems. Healthy non-compacted soil, in even in cities with poor soils, can be improved through the use of low-cost practices including composting,amendments and mulching. Of course trees–where they are appropriate–and native perennial plants tremendously boost soil’s water retention and carbon sequestration, while adding shade, wildlife habitat and more pleasant overall environs.

São Paulo, another megacity on the precipice of global climate-change water crisis, is facing a growing water supply shortage where taps are running dry and some of its 23 million citizens might be soon forced to abandon the city. I moderated a panel last week in the Silicon Valley with Marcelo Ignatios, Superintendent of São Paulo’s sustainable infrastructure programs, who outlined the programs the city has developed to incentivize green infrastructure with tax credits, air development rights and other innovative programs. The city has produced a sophisticated map of its soils and types of water retention qualities (see slide 13) in order to limit runoff and restore aquifers and creeks feeding reservoirs.

A biological inventory of São Paulo state concluded that 48 percent of its surface was covered by impermeable surfaces or completely devoid of vegetation. At the time of the survey, forests still covered 21 percent of the state, but they are rapidly vanishing to development. The city now is realizing that its fate is tied up with its forests and vegetation as much as are the fates of endangered local inhabitants such as the howler monkey or the red-breasted toucan: forests, vegetation and healthy soil retain water, cool cities and recharge aquifers. Indeed, recent research has posited that the ecosystem services of forests, vegetation and green infrastructure may help stabilize regional water cycles.

Singapore  “Global Hydro-Hub” Model

Nowhere else is urban green infrastructure planning and design combined with other water reuse and conservation approaches more successfully and artfully than Singapore. Originally lacking a sustainable fresh water supply as Singapore’s population grew, it was forced to import water from Malaysia, an agreement that terminates in 2060. Building upon the foundation of a visionary 1972 water master plan, Singapore launched a bold campaign about in the early 2000′s to become the world’s foremost knowledge and practicing city center for green infrastructure, smart city water management technologies and wastewater reuse. Singapore’s Utilities Board markets a bottled “New Water” product that comes from triple-membrane filtrated sewage treatment plants.

The crowning glory of Singapore’s water savvy is the engineered surface of its city, much of it designed or retrofitted in green infrastructure. Two thirds of the city–rooftops, parks, medians, sidewalks, roadways–capture rainwater and convey it via microprocessor controlled channels or tunnels to 18 reservoirs. LID in Singapore contributes 35 percent of the city’s water supply, with much of it integrated into innovative architecture as well as landscaping for pedestrian or recreational amenities. Eventually, the city has plans to turn ninety percent of its surface area into rainfall catchment.

Singapore not only demonstrates for the world the design and engineering potential of urban water reclamation through green infrastructure, but it shows how doing so can create an international center of excellence that can result in substantial economic returns in water-sensitized forms of urban planning, architecture, engineering, information technology and green infrastructure innovation (Singapore’s 2014 International Water Week event alone resulted in $11.2 billion USD in announced deals or contracts).

The rest of the water-challenged world–that includes or will include most of our cities–should take careful notes, and get very busy.

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Urban Sustainability Focus of Shanghai Expo

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Danish Pavilion, Shanghai Expo

Sure, the Shanghai World Expo might be the largest World Fair in history, with more than 70 million expected, the majority of visitors coming from China. With the theme of “Better City, Better Life,” the Expo will also be thick with urban sustainability related proceedings and exhibits during its May to October gestation.

Shanghai is officially China’s largest city, a metro area of more than 18 million that competes with the capital for national prominence (Beijing has an official metro population of 13 million). From Opium Wars and cunning “Green Gangs” (not those Greens!), Shanghai’s economy has emerged as the international polestar for service and information industries

Like other cities approaching 20 million, planning for global climate change and adaptation is of concern. Shanghai is examining how information and communications technologies (ICT) enable low-carbon management; Seoul, Amsterdam and San Francisco similarly have piloted “Connected Urban Development” projects designed by Cisco and MIT over the past few years, mostly in transportation demand management (broadband enabled work centers, handheld transit alerts).  

The Expo marks the first time that buzzing Shanghai, and thus China, has publicly focused so much attention on the issue of urban sustainability, in one venue. China’s urban population is expected to go from more than 600 million in 2009 to more than 1 billion by 2030.

Shanghai Expo Bureau events are orchestrated by China’s national leaders. The Bureau addresses climate change and low-carbon development through the exploration of applied information and communication technologies in the service of sustainability management. The event, referred to as the “Economic Olympics,” is a happening staged with great investment: $55 billion

During a soft launch period in April, officials examined how to make nearby Chongming Island into a low-carbon development. An Expo “ICT and Urban Development” forum earlier in May covered “social responsibilities” as they apply to smart + digital (IT-driven) urban areas.

IBM and Metropolis will be exploring ICT enabled urban management solutions as part of a “Smarter Cities” forum in Shanghai (loosely affiliated with the Expo) on June 2-3. Topics of consideration will include: energy and utilities, water, transportation, healthcare and public safety.  

The Climate Group, Metropolis and Cisco–in conjunction with the Shanghai Expo Bureau– jointly host Partnership for Urban Innovation (PDF) on June 17-18. The two day invite-only confab will cover “Urban Design and Networked Development,” “Sustainable Cities: Challenges and Solutions,” and “Smart and Connected Urban Mobility.”

San Francisco will highlight its urban best practices in sustainability on June 17-25 at the Expo. As a sister city of Shanghai, it is the only US city that Shanghai provided a week for a dedicated display (though Vancouver also boasts an Expo pavilion, also green themed). A delegation from the Bay Area including US Senator Dianne Feinstein and Fog City Mayor Gavin Newsom will be part of a Green Energy Seminar in June that will be broadcast throughout China on China Business Network TV. 

Forums on transportation, energy, waste management, water, health services and housing will occur throughout the Expo, leading to a green exit. A thematic week ending October 31, 2010, is devoted to sustainability management in megacities. The Expo finale will also consider the role of an ICT-enabled green economy as it simultaneously emerges in global markets, developing nation cities, and of course, Shanghai.

Warren Karlenzig is president
of Common Current, an
internationally active urban sustainability strategy consultancy. He is
author
of
How Green
is Your
City? The SustainLane US City Rankings
and a Fellow at the Post
Carbon
Institute
.

 

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The Next Decade’s Top Sustainability Trends


The top ten sustainability stories of the past
decade
was my last post.
What trends are likely the next ten years? One thing for sure, 2010 through
2019 will be one day be looked at as 1.) the turning point for addressing climate change
by using effective urban management strategies, or it will be remembered as 2.)
the time when we collectively fumbled the Big Blue Ball.

 

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