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.


UN’s Shanghai Manual Launches to Guide Urban Futures

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A powerful triumvirate,
the United Nations, Bureau International Des
and the mayor of Shanghai, released this week the Shanghai Manual:A Guide for Sustainable Urban Development in the 21st Century.This timely (and free!) manual is
aimed at helping leaders of the world’s cities use integrated urban
planning, management, financing and technology to green their
economies and build climate and economic resilience.

“The Shanghai Manual details
the experience and practices of cities across the world in addressing common
challenges and achieving harmonious development…and is therefore of great
theoretical and practical value,” Shanghai Mayor Han Zheng said at
Monday’s launch, according to the Shanghai Daily.

Aimed at a
target readership of mayors and executive leaders of developing nation cities,
the bilingual (English and Chinese) Shanghai
is the basis for capacity building and training being rolled out in Asia next week by the United Nations. City leaders representing 12 Asian nations will attend the United Nations Center for Regional Development in
Nagoya, Japan, where UN officials and I will lead urban sustainability training
for leaders ranging from Colombo, Sri Lanka, to Karachi, Pakistan,
to Makati (Manila), Philippines. In addition smaller cities including Chiang Mai, Thailand are participating.

Continue reading


Global Green Cities Preview


From Singapore’s high tech congestion management system to New York’s
PlaNYC 2030 to Yokohama’s zero-carbon emissions goal, the future greening of
cities is becoming our global “Plan A” for survival–economic and
species–and will be the topic of the “Global Green Cities” conference in San
Francisco, Feb. 23-25. The invitation-only event will mash up top planners,
designers, strategists, technologists, mayors and financiers on how design,
technology and behavior can facilitate the cross-fertilization of critical
ideas and perspectives.

By now most have heard that cities will be the century’s
Rosetta Stone to mitigating the resource depletion and carbon emissions of
humanity. China alone will add 400-700 million people to its cities by 2050.
Developing nation urban growth is set to double by 2030 the urban footprint
that existed way back in 2000.

If you are old enough to read these words, you will be living in a whole new world than
the one in which you grew up.

The global cities of 2030 will be created with ten
times the speed it took to cobble together the global cities of 2000, which has
acute sustainability implications. That’s why international organizations
ranging from the United Nations to Natural Resources Defense Council are
feverishly creating strategic plans and training for green city innovation
including energy supply and energy efficiency, land use and planning, green
building, water supply and use, food supply and production, green
infrastructure, and enabling information and communications technologies.

The financial sector is well aware that 90 percent of
urban economic growth will come in developing nations, so the leaders of The
World Bank
, the IMF and private banks and investment firms are scrambling to
integrate financing in a dizzying array of new life-cycle costing instruments,
revenue sharing agreements and public-private partnerships.

Consider Guangzhou’s new bus rapid transit system (photo above, Karl Fjelstrom), now the
largest in Asia, or Mexico City’s Metrobus system. Both were supported by
private foundations, while Mexico City’s Metrobus also garnered support from an
international and Mexican non-governmental organization. Green economic innovation
is not just occurring in developing nation cities. San Francisco was able to
achieve a leadership role in solar energy projects through a voter-supported
bond measure, while Berkeley created its groundbreaking residential PV solar
financing program through a mortgage-like approach that cuts costs
and financial risks for homeowners.

Global Green Cities will host breakout sessions on the:

  • design of livable, compact, transit oriented
  • technologies of digital, efficient and
    low-carbon urban systems;
  • behaviors and lifestyles of the urbanite

A “Breakout Synthesis” will focus on how planning,
technology and behavior can provide a specific vision for the future.

In a wrap-up discussion of the Global Green Cities plenary
session, I will address the issue “Enabling the Green City of the Future,”
which will look at best practices and driving change in finance, policy and
business. On Friday Feb. 25, the conference goes off-site to study planning for
sea level rises caused by climate change. It will also analyze California’s
planning for its landmark state climate change bill of 2006, AB 32, and its
companion, SB 375, a historic land use planning law trying to prevent further
exurban sprawl while enabling denser, transit-oriented development in existing

Here’s a preview of who will address the invitation-only
gathering of “Global Green Cities,” which is sponsored by Deutsche Bank, Cisco,
AT&T and the Bay Area Economic Institute and is advised by the London
School of Economics:

Top confirmed speakers include Bruce Katz, of the Brookings
Institute’s Metropolitan Policy Program
(recent Time magazine essay and video); Peter Calthorpe–he created the
term “transit-oriented development”–of Calthorpe Associates; Khoo Teng Chye of
the Singapore Public Utilities Board; Kent Larsen, of MIT’s Smart Cities
Changing Places Research Group; Siegfried Zhiqiang Wu, of Shanghai’sTongji University
College of Architect and Planning; James Sweeney, Director of Stanford
University’s Precourt Energy Efficiency Center; Jeffrey Heller of Heller-Manus
; John Kriken of Skidmore, Owings & Merrill; Incheon, South Korea
Mayor Young-gil Song; San Jose, USA Mayor Check Reed and Dmitri Zenghelis, of
the London School of Economics.

Many others are invited, and I will provide another post reviewing this seminal symposium.

One last sober observation. By all appearances, there
appears to be no “Plan B.”

Warren Karlenzig is president of Common Current. He is a fellow at the
Post-Carbon Institute, strategic adviser to the Institute for Strategic Resilience and co-author of
a forthcoming United Nations manual on global sustainable city planning and management.