Friday, 1 September 2017

Flooding and urban sprawl

What are the impacts of flooding on new developments - and what can we do to minimise them?
Futures Forum: New developments and flood regulations in East Devon
Futures Forum: Long-term planning for flooding in the West Country

We have one or two planned developments for the Sid Valley where flooding is an issue:
Futures Forum: Knowle relocation project: and flooding
Futures Forum: Plans for Port Royal: anticipating a Regeneration Board >> Scoping Study consultation >> "a stitch-up"
Futures Forum: Beach Management Plan: Town Council chooses breakwaters to protect and regenerate beach
Futures Forum: Sidford business park... and flooding: "Right now there are more questions than answers about how the new climate change guidance is going to be implemented. But be aware: this guidance is already a material consideration for all new planning applications and therefore, a valid reason for planning objections."

Meanwhile, things are not going to get any better:
Futures Forum: Climate change: a significant impact on flooding
Futures Forum: "Exeter rainfall to increase by 73 per cent - and your paved garden will make the city flood"
Futures Forum: Climate change and flooding: last winter’s floods “were a powerful reminder that we need to work with nature to reduce flood risk – and ministers wholeheartedly agreed”.

But there are things we can do:
Futures Forum: Greening grey Britain > tackling pollution and flooding
Futures Forum: Trees and flooding
Futures Forum: The decline of the British front garden: "There's an environmental cost. Paving increases the risk of flash flooding - instead of grass and soil soaking up moisture, it runs straight off paving and overwhelms drainage systems."
Futures Forum: Reducing flooding through sustainable drainage systems >>> Water Sensitive Urban Design in the South-West
Futures Forum: Using natural flood management to protect communities against the effects of storms

One thing is clear: local communities have to be involved:
Futures Forum: Flooding and East Devon... ... and riding roughshod over the concerns of locals
Futures Forum: Flood management: how to hold back the waters >>> >>> "It will require flood schemes to be developed with communities and not just for them."

And surely it is clear by now that we should not be building on flood plains:
Futures Forum: Flooding and building houses
Futures Forum: Urban runoff and flooding in Sidmouth... Relying on 'Victorian plumbing' or building on soakaways...

Which is what has happened in the likes of Houston:

The real villains in Harvey flood: urban sprawl and the politicians who allowed it

There’s never been a more important time to understand the political machinations that led to Harvey’s destructiveness – and dismantle them

hurricane harvey
 ‘The swamps and wetlands that once characterized Houston’s hinterland have been replaced with strip malls and suburban tract homes.’ Photograph: Gerald Herbert/AP

Houston’s catastrophic flood will be framed by leaders in Texas as an unforeseeable act of God. It isn’t. Houston’s unfettered sprawl into the marshland of southeast Texas was a conscious choice by policymakers. So was building a global city on a slowly submerging swamp. Both were decisions that led to disaster.
Houston has quietly become our fourth largest and fastest-growing city, due in large part to cheap housing. But the latter has come at an exorbitant cost to its safety. The swamps and wetlands that once characterized Houston’s hinterland have been replaced with strip malls and suburban tract homes.
Those landscapes once served as a natural flood protection system for the city. Research shows that, if they hadn’t been filled and developed, Harvey’s impact would have been lessened. Sam Brody and his colleagues at Texas A&M University in Galveston have been predicting an event like this for nearly a decade. That their work went unheeded by Texas policymakers should not be forgotten.

There will be an impulse to elide past the political choices that led us to this point. We shouldn’t allow our politicians to use the use Harvey’s victims as human shields by pronouncing that now is not the time for criticism or blame. There’s never been a more important time to understand the political machinations that led to Harvey’s destructiveness, and to do everything in our power to dismantle them.Worse, a generation of civic leaders have completely deregulated Houston’s land development market. In that process, they helped build a far-flung network of poor neighborhoods on top of a swamp. In Houston, there is a simple truth: the poorer you are, the closer you live to a petrochemical plant and the likelier your home is to flood.
Much has been made about Ted Cruz’s vote against Sandy relief funding in 2013. His hypocrisy is fair game for political journalists. But the greater failure of Cruz and John Cornyn is in not seeking funding for a solution to the world’s most predictable disaster before Harvey made landfall.
Much more should be made of Texas Land Commissioner, George P Bush’s failings. As head of the General Land Office, Bush holds a unique and singular power to plan, engineer, and manage the Texas coastline.

But nearly a decade after Hurricane Ike – which hit the city eight years ago – and nearly three years since his election, there’s scant evidence that Bush has done anything to secure Texas’s coastal cities against the threat posed by climate change.
In fact, he’s yet to fully spend the more than $3bn allocated to the General Land Office after Ike. Given that Bush is likely to lead the Harvey recovery, it’s fair for us to question whether or not he’s up to the task.
The question that he and every Houstonian must ponder now is how their recovery can be better than those that followed Ike and Katrina.

Built in 2014 and already suffering a potentially catastrophic pump failure, the New Orleans surge barrier is emblematic of the greater infrastructural challenge facing coastal cities in the US.Erecting a massive barrier system akin to the $14.5bn behemoth rimming New Orleans won’t be enough. But it will be the impulse of every politician eager to project an image of strength and resilience in Harvey’s aftermath – and to expand their political brand by becoming known as Houston’s savior.
Coastal infrastructure is incredibly expensive to build and nearly impossible to maintain, especially when you realize that the maintenance is borne entirely by local governments – none of which have the financial or technical capacity to do so effectively.
Some have already begun to point to Holland, where the world’s most complex flood control system operates, and to proclaim that if the Dutch do it, so can the United States. This simply isn’t true.
The Netherlands has a much higher tax rate, giving it more resources per person to invest in its infrastructure. Dutch storms are also less intense and bring lower surge heights and less rainfall than their American counterparts.
For a lasting recovery, Houston will need to supplement whatever barrier system it builds with a broader, regional network of wetlands, retention ponds, and green infrastructure to restore the once-robust, natural flood protection lost to a half-century of urban sprawl.
Designers have been calling for such an approach since Ike made landfall. Houston should look to New York’s landscape architect-led recovery process as a model worthy of consideration.
A half-century of bad design choices and impotent planning led Houston to this crisis. Now, it’s up to a new generation of Houstonians to do what their predecessors could not – prepare the Magnolia City to rise up and meet its wetter future head on.
Houston deserves the full, fair recovery that never came after Ike. They may not get another chance.
  • Billy Fleming is research director for the Ian L McHarg Center at University of Pennsylvania School of Design, where he earned a PhD in City Planning. He is a co-author The Indivisible Guide and a co-creator of Data Refuge

The real villains in Harvey flood: urban sprawl and the politicians who allowed it | Billy Fleming | Opinion | The Guardian
“The real villains in Harvey flood: urban sprawl and the politicians who allowed it” | East Devon Watch

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