Saving our desert cities

December 9, 2014

The 20th United Nations Conference of Parties (COP) is taking place in Lima this week, with Ecocity Builders in attendance. Lima is an obvious choice to host this gathering focused on solutions to climate change. Lima is the 2nd largest desert city, right behind Cairo, and Peru is estimated to be the third-worst affected country by climate change, after Honduras and Bangladesh, according to the  Tyndall Centre for Climate Change Research.

Lima lies in the great rain shadow of Peru, sandwiched between the Andes and the sea. The area receives less than a third of an inch of rainfall per year. The bulk of Lima’s municipal water comes from rivers fed by Andean glacier melt. But over the past decade the glaciers have all but disappeared and mountain rainfall has declined as well. Lima is poised on a precipice of a frightening future. Over the edge is imminent water shortage. City officials are looking for alternatives with increasing urgency.

We’re no stranger to drought here in California. Despite the plentiful early winter rain, cities, agriculture and industry in the lower half of the state are still threatened with running dry. While bad luck and climate change can be blamed for the shortages, there’s another human villain behind the misfortune: bad planning. Problems arise when cities don’t take into account the resource flows of the ecosystems they exist in. Problems arise when humans put their plans and values above the basic facts of the environment that needs to support them.

City bridge over an almost-dry Río Rímac. Photo by AgainErick, Wikimedia Commons.

Lima city bridge over an almost-dry Río Rímac. Photo by AgainErick, Wikimedia Commons.

Peru, with its mountains and rainforest, is rich in hydrological resources. But 98% of the Andes’ liquid bounty, including the source of the Amazon river, flows east into the Amazon basin. Why, then, does two-thirds of Peru’s 30 million inhabitants live on the arid Pacific coast?

“This mismatch began 500 years ago with the arrival of the Spaniards,” said José Salazar, president of urban water regulator, Sunass, in The Independent (2011). The massive empires of Incas and other pre-Columbian civilizations built their major cities near water sources in the Andes. But because they wanted to be closer to Spain the conquistadors founded their capital on the coast: “Today, we are picking up the bill for this colonial legacy,” Salazar concluded.

Unfortunately we are left with the legacy of decisions–both deliberate and unintentional–made be previous generations. Lima, a city of 9 million, shouldn’t have been built in the 2nd driest desert in the world. But we have to work with what we’ve got.

Many cities are flocking to “smart” solutions to resource management and the scope of innovation in this area is truly exciting. However, smart solutions aren’t always the best. They can be expensive, resource depleting (rare metals used in computing are a source of devastating pollution), and not culturally appropriate. “If the many failed development projects of the past 60 years have taught us anything,” wrote Toilets for People founder Jason Kasshe, in the New York Times, “it’s that complicated, imported solutions do not work.”
The best solutions are often the simplest. In that spirit, here are a few basic principles and tools that can help water-strapped cities survive the next decades.

1. Reduce. It comes before reuse and recycle for a reason! Reducing our need is the cheapest and easiest option. In fact, it requires you to do LESS, in some cases. Other investments such as removing thirsty vegetation, fixing leaks, and replacing old fixtures are cost saving in the long run. Responsibility isn’t all on the average citizen: big water users like industry and agriculture need to pitch in updating their processes to reduce water consumption, too.

The poorest population of the city can teach the rest of us valuable lessons. Residents of the slums, shanty towns, and other informal peripheries of cities like Lima use dramatically less resources than the more affluent areas. Materials are more efficiently used and better recycled, and water is treated as the precious resource it is.

One of Lima’s informal settlements on the outskirts of town. Photo by Håkan Svensson, Wikimedia Commons.

Unfortunately, the poorest of Lima (and elsewhere) don’t have a choice to conserve. One million of Lima’s 9 million residents don’t have access to treated water, instead paying for water delivered from privately owned trucks at enormous mark-up (watch this video to learn why the poor pay more for everything). The great challenge we face is elevating and equalizing the quality of life for all, while avoiding the adoption of upper-class waste and consumerism that often occurs with the process.

2. Decentralizing/diversifying water sources may have a great impact on conservation. Rain catchment and grey water systems at the parcel or neighborhood level reduce strain on city infrastructure and can take advantage of natural water (primarily rain and other atmospheric moisture).

David Sedlak, a professor of civil and environmental engineering at U.C. Berkeley and author of “Water 4.0,” traces the expectation of controlled, centralized water distribution to the Roman era. The Roman’s aqueducts supplied their cities with abundant water carried from miles away. But the Roman model doesn’t make sense for large water-limited cities today (if it ever did, ecologically speaking). The millions of residents of today’s cities overburden single-source water systems, especially in times of drought.

Unlike Lima, Los Angeles (another desert city) does get a fair amount of rain in the winter. Elmer Avenue, in a working-class neighborhood of East Los Angeles called Sun Valley, is a prototype for noded smart water management. Rain catchment systems, drought tolerant landscaping, and permeable surfaces collect and redistribute precious water at a hyper-local level, preventing floods and providing water between rains.

3. Learn from the past. Indigenous architecture has often evolved over generations to respond precisely to local conditions. The flat roofed adobe of the Americas regulates ambient temperature (both inside and out) and can be adapted to collect rainwater. The pitched roofs of European-inspired houses don’t make sense here as they are designed for northern climates to shrug off snow. Rethinking native materials and processes often conserves materials and energy over a building’s lifetime.

4. Innovate “dumb”. Low-tech water solutions abound. Warka Water and other projects that use mesh to capture atmospheric moisture and could potentially generate 25 gallons of drinking water per day. Moisture farms are well suited to Lima which, while short on rainfall, is very humid. Improved techniques for passive desalinization greenhouses could reduce water need for this thirsty sector.

These ideas will likely be implemented in the places that need them most, like water-strapped Lima or California. But every settlement should take advantage of conserving technologies and approaches. It is too easy to compartmentalize climate change, to see it happening as “elsewhere”. That is, until your city feels the impact. The truth is we are all living in ecosystems of resource limitations. We’re all stuck on this resilient, yet delicate, closed system of Mother Earth.

Rio Aladago – The Flooded City

December 12, 2013

How well does your city move people? Chances are complaints about the inefficiencies of public transit pop up daily. After all, you interact with cars, roads, buses, and light rail constantly. At the same time, other systems of movement that go more unnoticed are essential to the functioning of the city organism. How well does your city move waste and energy? How well does it move water?

Here in Rio de Janeiro water is a constant of life. Whether flocking to the ocean, complaining of the clouds (or lack of cloud cover), or wondering when it will rain, Cariocas (residents of Rio) are surrounded by water. It doesn’t rain here as often as you might imagine, as in, say, the daily downpours of Singapore, but it is tropical. Unfortunately when the rain comes the saturated ground turns anything more than few hour’s drizzle into a potential disaster.

Tuesday night it rained as much in one night as it normally does in a month. Rio is a huge city filled with micro-climates due to the dramatic mountains that corral it. In Barra da Tijuca, a new area in the south, it seemed like a sprinkle. For the residents of the North, it was a downpour. Those living in this predominantly poor area awoke to find several feet of muddy water in their streets and homes. The extend of the flooding is astonishing. Entire neighborhoods are underwater.

Read the rest of this entry »

Floating cities becoming a reality

April 16, 2013

Building on water eliminates flood risk and enables expansion

For thousands of years, human settlements have clustered around flood planes, from the banks of the Amazon River to lake Tonle Sap in Cambodia, to the marshes of the Netherlands. These settlements are designed to account for the seasonal ebb and flow of sea and fresh water, often by constructing buildings on raised platforms and/or building dykes, dams and canals. Yet as global climate change leads to increasing sea levels, almost every coastal city will face the challenge of encroaching waters.

Presenters at the Global Town Hall for infrastructure solutions held last week in Germany introduced innovative solutions for cities on the brink. “13 out of the world’s 21 megacities are harbor cities, of which Shanghai is most vulnerable to flood and related hazards,” said Professor Markus Quante at the town hall.

Instead of holding back the flood, several presenters suggested ways to completely re-imagine a city on the water. Rutger de Graaf from DeltaSync, a design firm that specializes in sustainable flood-proof urban development in delta areas, says cities can float on water and yet stay dry and resilient. Floating structures on water eliminate the threat of flood damage and can be a viable option for city expansion. In addition, city waste such as carbon dioxide and biowaste can be used to farm algae and in turn raise fish in urban areas.

“Urbanization in delta areas has caused increasingly severe flood. It has also added pressure on space, food, energy and other resources,” said de Graaf, adding that by 2025 the world will run short of at least 22 million km2 of land – an area equivalent to the North American continent.

Rijnhaven Pavijlioner. Images from DeltaSync

The city of Rotterdam is already experimenting with floating urbanization, building its first floating pavilion at the Rijnhaven harbor. Designed by DeltaSync, the three domed structures cover the area of four tennis courts and are not only self-sufficient, relocatable structures that purify their own waste water, but also rise automatically according to rising water levels. The city plans to add many more floating buildings, including a park, as part of the Rijnhaven harbor redevelopment master plan.

Another 1,200 floating structures are planned to open in 2040 in Stadhavens – an area designated for sustainable housing development, floating communities, recreation, and research on energy generation such as tidal energy and cooling and heating from river water.

The city of Semarang, the capital of Central Java, and other coastal cities are working with the Dutch to implement their water management expertise in their own districts. Semarang has already lost 98.2 hectares of land between 1991 and 2009 due to land erosion accelerated by climate change.

Find out more about DeltaSync’s project at their website.

Topsoil: The World’s Urban Sponge

October 27, 2009

All those urbanites growing organic food in the city has a certain appeal for the media, but to the average person, it may feel like a temporary marginal fad at best.  So why are city governments around the world taking it so seriously?  As it turns out, this trend has the potential to solve some of the worst problems that cities face – namely, climate change and water shortages – with a simple element: Topsoil.

Over the last several decades, many of the rainforests that act as our “carbon sinks” have been slashed and burned to make way for agricultural production.  Likewise, grasslands and savannas in Africa and America are routinely burned to make space for agriculture.  The farms that consequently inhabit those places feed the world’s cities – from Buenos Aires to Anchorage, Tokyo to Sydney, and everywhere in between.  Moreover, as cities expand to make room for sprawling communities, former farmlands are converted to suburbs because land-holders typically sell to the highest bidder – developers.  Consequently, more farmland must be created and more wild places (habitat) destroyed to make room for more farms.

The global market for agricultural products has obvious implications for climate change, as carbon-sequestering forests are cleared and products are shipped long distances using vast amounts of fossil fuels.  However, what may be less obvious is the solution to feeding the world’s cities without encroaching on our wild lands and carbon sinks.

Most people know by now that forests pull carbon dioxide out of the atmosphere, helping to fight climate change.  What might be less apparent is that soil sequesters carbon with far less risk than forests.  As temperatures rise due to climate change, bark beetles have begun to infest many of North America’s forests, killing off thousands of acres of forest and priming these vast swaths of land for massive forest fires.  Once the trees are dead, one lighting strike or one match will be all it takes to send all that sequestered carbon back up into the atmosphere.  If sequestering carbon in forests is our plan, this is quite a gamble.

Healthy topsoil, on the other hand, can soak up carbon with a remarkable rate of absorption and no risk of loss to the atmosphere during forest fires.  Collectively, tillage management and cropping systems in the U.S. are estimated to have the potential to sequester 30–105 million metric tons of carbon per year, says R. F. Follett in an abstract on ScienceDirect.  Unfortunately, we are losing topsoil around the world at an alarming rate. According to Allan Savory and Christopher Peck of Natural Investment Services, LLC, it is estimated today that our crop and range lands lose 4 tons of soil every year for every person alive. That’s 21 gigatons of soil lost to the sea, lost to productive use on land and releasing vast amounts of carbon (New Scientist, December 2006).  Thus, the problem with our current practices lies not only in deforestation, but also in our astronomical loss of topsoil to the world’s ocean because of overgrazing, poor farming practices, resulting erosion, and urban runoff.

Topsoil is not the only thing we are giving away to the world’s oceans.  Fresh water is systematically being diverted from our aquifers in an attempt to avoid flooding.  The unintended consequence of our diversion strategy is that we are depleting our aquifers and causing severe water shortages for ourselves and for species that rely on fresh water.  The water wars that happen every year in communities around the U.S. have as much to do with our ecological illiteracy as with a drought in any given year.  Our cities’ lack of permeable surfaces and topsoil to store the water mean that it’s not sinking into the ground and reaching our aquifers, nor is it being caught and stored for use in the dry season.  Instead, this fresh, drinkable rainwater is often contaminated by chemical lawn fertilizers, motor oil, and other products before hitting the asphalt and concrete gutters that will carry it to storm drains and ultimately, to the ocean.

Although the system may seem too set in asphalt and concrete to change, cities are catching on and, along with community-based organizations, pioneering a new pathway to solve many of their woes at once.   They are addressing climate change and water shortages (and epidemic obesity) simultaneously by building sustainable local agricultural systems that feed their residents on-site while acting as a giant sponge for both water (to recharge the aquifers) and carbon.

One example of such a city is Petaluma, CA.  On October 24th of this year, the City of Petaluma, along with nonprofits Daily Acts, Rebuilding Together Petaluma, and Petaluma Bounty, came together with over 200 citizens to sheet mulch 25,000 square feet of unused lawn at City Hall and install edible landscaping, community gardens, and a rooftop water catchment system.  Leaders at the event spoke about carbon sequestration in the soil, replenishing the aquifer, and providing a source of local organic food for city residents.  Large-scale private-public partnerships include the City of Detroit and Hantz Farm, which together may soon create the world’s largest urban farm, although it’s unclear what their plans are as far as sustainable farming practices go.

According to a U.N. climate change paper on agriculture last year, by 2030 an estimated 5.5 gigatonnes of CO2 equivalent a year could be avoided by agriculture with about 89% achieved by soil carbon sequestration.  Cities have an opportunity to build carbon sequestering capacity, thus potentially qualifying for carbon credits while also reaping the benefits of tax revenues from the sale of agricultural products within their borders.  By creating permeable surfaces and building topsoil, cities will also begin to recharge their aquifers, avoiding the water wars with farmers that are so common in today’s system.  Perhaps those urban farmers are really onto something.

To learn more about urban agriculture around the world, consider attending the Eighth Annual International EcoCity World Summit.   A highly influential community of architects, planners, designers, policy makers, green businesses, political and nonprofit leaders, with the added participation of international experts and delegates will be convening for the conference to present papers and ideas on the EcoCity and its role in the escape from dangerous climate change.  Participants from Australia, the U.S., the U.K., Israel, France, Senegal, Egypt, Singapore, India, Nepal and more will join together in the discussion in Istanbul this December.  In addition, more than 100 papers will be presented in concurrent sessions from more than 40 countries representing young emerging and pioneering talent from around the world.

For more information, go to:

Stacey Meinzen

Water, Power, Planning and Carbon

October 5, 2009

Recent disputes over water use in deserts that are well suited for solar thermal power plants have illustrated the need for a holistic approach to urban needs. Solar thermal plants use cheaper technology than photovoltaics (solar panels), but require substantial water because mirrors heat a liquid to create steam that drives an electricity-generating turbine. Similar to a fossil fuel power plant, the steam must be condensed back to water and cooled for reuse.  Typically this happens in a cooling tower and requires constant replenishment of water as the excess heat and water evaporates.  Alternatively, dry cooling can be used, but requires fans and heat exchangers and is much more expensive.

The American Southwest is currently the site of plans for dozens of multibillion-dollar solar power plants on thousands of acres of desert.  In California, solar developers have already been forced to switch to less water-intensive technologies when local officials have refused to give up water. Furthermore, some large solar projects are currently tangled in conflicts with state regulators over water consumption.

Considering the effects of power generation on the ability to provide water for a community will be crucial as water becomes even scarcer and renewable power projects burgeon to replace fossil fuel production.

Using low-carbon technologies that are not water-intensive combined with smart city planning and sound water use policies will help cities to avoid water disputes among stakeholders.  Cities around the world have already implemented rainwater harvesting policies to help address water shortages by simply catching and using the rainwater that is currently diverted into storm drains – and ultimately, into the ocean.  Moreover, California implemented a new policy at the beginning of 2009 to allow the installation or alteration of a clothes washer greywater system to be exempt from a construction permit that was previously required.  Greywater systems allow a household to irrigate a landscape with recycled water.

Employing green rooftops and community gardens in dense cities and maintaining substantial surrounding open space is a strategy for water conservation as well because the less paved or impermeable surfaces exist, the less urban runoff occurs and the more ground water can be recharged. Furthermore, water use intensity is greatly affected by population density.  According to the Sierra Club’s Challenge to Sprawl, three households per residential acre (typical suburban sprawl) on average equates to 1,032 gallons of water used per household per day.  Conversely, 100 households per residential acre on average equates to 192 gallons of water used per household per day

Such policies will relieve pressure when citizens take advantage of them to conserve and they mean greater efficiency in the use of resources. Policies that force vital human services (such as power production and delivery of water) to compete for the same resources are unlikely to succeed.  Moreover, the monetary and environmental cost of water projects like desalinization is substantially higher than simply allowing citizens to catch rainwater or irrigate with recycled water.  Thus, tax payer dollars are better spent when policies support sound urban design and resource conservation.

Several city planning and policy experts will be addressing the issue of water use in cities at the upcoming EcoCity World Summit in Istanbul this December. Presenters will include Richard Register of EcoCity Builders, Walter Hood (urbanist, landscape architect), Ken Yeang (bioclimatic design), David Hall (New Vista Ecocity), the World Bank Eco2Cities program, Global Footprint Network, Janet Larsen of Earth Policy Institute (representing Lester Brown’s Plan B), and Brent Toderian, head of City Planning for City of Vancouver, Canada and author of the EcoDensity Initiative.

Stacey Meinzen