2012-08-30

Co.Exist

Turning Flood Waters Into Liquid Assets

As Isaac continues to pour down rain on the Gulf Coast and test New Orleans’s new flood-prevention system, there are lessons we can learn from other cities about how to design a city to make the most of too much water.

You would think we humans would have an innate alliance with water. After all, the ocean covers 71% of the Earth’s surface. Our own body mass is more than 50% water. And each of us needs some 50 liters of water a day (for drinking, sanitation, hygiene) to maintain our water balance, although Americans use notably more than that. Water is life and death; it’s our primal paradox.

And yet, that colorless, transparent liquid that demands our attention when it falls furiously from the sky (or conspicuously doesn’t) continues to bewilder us, threatening individuals, society, and the environment, more so than ever before--a change in status that was noted by the World Economic Forum this past year. It moved “water supply crises” in all its myriad forms to its list of Top 5 Global Risks. Climate uncertainty, predicted rise in sea level, and rapid urbanization are likely conspiring to create the perfect ugly storm, which we’re seeing with ubiquity lately. This year alone, floods have devastated China, India, Bangladesh, the Philippines, the U.K., Florida, Minnesota, Haiti. The list goes on and now includes the aftermath of a hurricane called Isaac, all while America’s heartland languishes in drought.

Gensler

With sudden deluges, our immediate response is to get rid of the offending water fast. Storm water is the enemy. It can cause damage and kill in its ferocity.

But what if people and governments took another view of storm waters that might cause floods and adopted a broader vision of water as life? What if we forged an alliance with storm water, slowed it down, and turned it into a temporary amenity and even a long-term economic benefit and lifeblood for our cities and communities?

Soccer fields might turn into temporary ponds without even flipping a switch, giving the surging water a place to go. Streets would be designed to become canals (with appropriate warning signage when they do), putting the homes along them above most storm water levels. Heck, gulley washers (as I refer to furious rains) might even be construed as something good for the rose bushes or, more generally, the landscape, which in turn, keeps our cities cool and sequesters the carbon dioxide that’s likely causing the problem in the first place.

We’re doing some of this and more in Houston, where we face a never-ending Gulf stream of bad storms with nice kids’ names along with the consequences of our historic lack of urban planning (which we are now trying to correct)--not to mention a clay soil that doesn’t drink water very efficiently.

Gensler

Although Houston has a different story than Manila, Beijing, or Bogota, many of the lessons learned down here in the Texas Gulf for managing storm water could be tweaked and implemented in other cities. In fact, I did some “exporting” earlier this summer. As an architect whose passion is making the built environment more flexible and resilient to disaster, I was invited to speak in Bogota, Colombia, at a symposium titled “Infrastructure for Climate Change.” It was sponsored by the CAF Development Bank of Latin America, and the bankers, policy makers, and engineers in attendance came looking for ideas on how to make South American cities more resilient to their own water supply crises.

The bottom line, whether we’re talking Houston or Bogota or Manila: Figuring out how to tame the surge is first order. But the ultimate goal is to transcend the crisis and turn those flood waters into an asset. Lemonade out of lemons. That kind of thinking--part of larger disaster planning--saves lives and economies and that’s big stuff.

Floods now affect an estimated 520 million people annually, causing global economic losses between $50 and $60 billion, according to data from the 5th International Conference on Flood Management held in Tokyo last year (and organized by the International Centre for Water Hazard Risk Management under the auspices of UNESCO and the Public Works Research Institute). The flooding in Beijing alone this summer forced 70,000 people to temporarily relocate and caused $1.6 billion in economic losses, according to The Wall Street Journal. More than 75 people died.

What we created here in Houston over the course of many decades and lots of trial-and-error and what is fodder for other cities and communities is our approach to infrastructure. We like to turn this hardened “element” into something mutable. We’ve made key roads, parks, and parking lots able to transform into giant water containers that leap into action when a gulley washer strikes.

Some of this goes way back. In the late '30s and '40s (following massive flooding), the U.S. Army Corps of Engineers created several earthen dam reservoirs (a.k.a. flood control lakes) in an area just outside Houston that was not prime real estate. Only when storm waters surge do these dry reservoirs (which were excavated just a few feet lower than the surrounding land) turn into “natural” lakes.

Gensler

Over the years, several parks (with fully flood-able, naturally draining soccer fields, softball fields, tennis courts, walking trails) were scattered throughout those large earthen reservoirs. So essentially, and to this day, our giant storm water basin to the west looks and acts like a large-scale recreation area--an amenity for the city--most days of the years. Lemonade out of lemons.

Tropical Storm Allison in 2001, which was not particularly fierce but one of those hangers-on, taught us lessons (also applicable to other cities) about thinking “small” too.

With most of Rice University, the Texas Medical Center, and downtown Houston under water, we learned the importance of micro water collection elements(PDF)—a series of parks, water gardens and other low-impact catchment strategies as well as roads-as-canals scattered throughout the city to manage an extended deluge.

High-flood-risk streets were identified throughout the city and rebuilt. They now dip down several feet so water moves from the property level. These designated streets become canals in a big storm, while maintaining others high and dry for emergency access. Houses escape the surge. We likewise “sunk” soccer and rugby fields throughout the Rice campus. Fields become temporary water features that generally drain very quickly. Parking lots in Houston have alter egos, too. We dug many of them up and inserted sub-surface water tanks and then repaved the surface with permeable materials.

Gensler

While we “dug deep,” we also “raised up” vital electrical facilities on dikes/berms and gave them and other critical facilities such as hospitals protection by hydrostatic or submarine-like doors at ground level and below. These doors are pseudo flood gates that establish a controlled flow of water into a building to prevent structural damage from water pressure.

Costly? You bet. But it’s cheaper than flood damage--and you can’t put a price tag on human life.

The soccer field/pond idea is one that works for many South American cities (given the strong soccer culture and, hence, presence of fields) and one I highlighted in Bogota. I took the concept a step further, though, and proposed that the water collected in those game fields somehow be channeled to the rose farms in the plateau surrounding the city where water is needed for irrigation. Flowers are one of Colombia’s main exports. In figuring out how to move it, flood water would then become an economic advantage for the city. Again, lemonade out of lemons.

Water is boon and bust. It’s floods and drought and power outages too, as we learned this summer from the massive one in India and the lack of a sufficient water supply in the power plants there. We need to wrap our minds--and our infrastructure--around this important resource in new, creative ways.

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