Thursday, July 13, 2006

Fair Weather

Here's an article i just wrote with Jennifer Cox (Regional Plan Association, Hunter College):

Each year for the last three years, this region has suffered from increasingly severe floods. Last week the most recent floods struck New York, New Jersey and Pennsylvania. Newspaper articles and television reports, both local and national, reported the worst of the damage and highlighted the most dramatic scenes of wreckage. Residents were advised on flood safety and evacuation plans; there was even some discussion of the connection to longer-term climate patterns.

All in all, though, the flooding was treated as an unavoidable act of nature. Indicative of this trend was the New York Times editorial of June 30, which lamented the death toll but ended by simply praying for less rain in July. Missing was the true story – that this flooding has a direct cause and can be avoided. Not all rainstorms need to lead to floods, and we can, in part, blame the pavement. The region’s rapid pace of sprawling development has replaced absorbent soil with impervious surfaces, leaving the rain with no place to go but into our streets and homes.

From 1965 to 1995, the amount of urbanized land in this region doubled. Urbanized land as a share of total land increased from 20% to 40% during those 30 years. Since then, the pace of development has almost certainly increased. This pattern has generated the necessary conditions for extreme floods. The more we make the land impervious to water with brick, concrete, and asphalt, the more heavy rains can turn in to flood hazards. Impervious surfaces prevent the rain from soaking into the ground effectively, slowly entering our streams and rivers over time. Instead the rain water quickly becomes runoff, funneled into our water ways via storm drains far too fast, causing extreme flood events. Last week, this was painfully evident in Pennsylvania, New York, and New Jersey.

While the general patterns of climate change may increase the frequency and strength of storms all over the world, the severity of the impact of those storms will be greatest in places, like this region, that have built over too much of the land. The solution is not necessarily to curb development altogether, but rather to find more sustainable development patterns. This is not a new concept. Ian McHarg’s classic text, ‘Design with Nature’ (1969) gives many examples that have successfully led to regions managing natural hazards in a sustainable way. On a large scale, this means investing in more mass transit and fewer highways, denser, centered development and open space preservation. On a site-specific scale, this can mean residential and commercial developments using green roofs, semi-permeable pavements, rainwater harvesting, and on-site irrigation to create a sustainable built environment in healthy riparian zones.

As we saw with Hurricane Katrina, a region’s vulnerability to storms is borne most heavily by the poor, the elderly, those without access to transportation, and those living within the flood plain. While our exposure to storm and flooding risk is critical, it is our socio-economic vulnerability that is the true measure of our ability to cope with a disaster. Since socio-economic divisions are also reflected in our settlement patterns, there is a complex dynamic between land use development patterns that promote flooding and those that leave vulnerable populations most exposed. In flood-prone areas, the poor are less likely to have flood insurance, have less access to transportation and are more vulnerable to economic disruption. In short, the more our sprawling land uses are perpetuated, the more severe flood events we can expect, and the more these populations are likely to be at risk. This changes the meaning of ‘Fair Weather,’ does it not?

2 comments:

JimmyQ said...

I LOVED this post! I studied water use in college, and remember having to calculate water runoff quantities based on imperviousness of land, watershed size, etc. This is such a good argument against sprall, too.

crosswordkaji said...

OMG, your brilliance never fails to impress (though not surprise) me. You are awesome.