Agenda - Planning Commission - 03/03/2011

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much more affordable. Masonry construction is inherently much more floodproofthan con- ventional stick -built homes. Proximity of Refuge Mixed use is a hallmark of smart growth. Mod- ern conventional diffuse growth dictates the separation of uses, with miles and miles of suburban residential developments unbroken by business districts. Smart growth practitio- ners design communities where residential and commercial areas are in close proximity, if not intermixed. Commercial buildings can be built to much more rigorous standards than residential single-family buildings, no matter what the type of construction. The nearby presence of substantial commercial buildings could provide very real refuge when storms approach with little time for evacua- tion. But to be bona fide refuges, they must be nearby —not miles away as they were in most of the Lower Ninth Ward and elsewhere in New Orleans. This idea of refuge on a community scale is the "safe room" writ large. Galveston provides a good example of how such a refuge could work. During the 190o hurricane the highest rate of survivor- ship was of people who took refuge in the Strand. The only way to have substantial buildings within walking distance of residen- tial areas is to build an area compact enough that pedestrian traffic could be a significant part of the retail business. Most municipali- ties along the Gulf Coast have codes that proscribe this kind of mixed use, and most places prescribe such large lots for single- family homes (greater than 7,00o square feet) that walkability is out of the question. Greater Social Cohesion An urban pattern that facilitates and pro- motes more walking perforce promotes and facilitates more social interaction. More social interaction should lead to a greater amount of social capital or social cohesion. Networks of mutual assistance on a neigh- borhood scale can only occur where there is interaction. Interaction is likely to be less in car -dependent neighborhoods than walk- able neighborhoods. Where people can walk to the corner store or coffee shop, they are much more likely to frequently encounter their neighbors and know more about the details of their lives (e.g., who might need as- sistance making it to a shelter or evacuating). Transit and Evacuation Denser cities will have far fewer cars per capita than diffuse cities. Mass transit enables the transport of many morepeople over equiva- lent distances than cars can. Whether or not a mass transit system could move more people out of harm's way than the equivalent popula- tion in private automobiles is an open ques- tion. The debacle of the Rita -inspired Houston evacuation, with its clogged freeways, is still fresh. The state of Texas and Houston, how- ever, have taken extensive measures to ensure that contra flow is put in place early, such that the next evacuation could be much smoother. How well a mass -transit -aided evacuation would work depends on a number of factors, including the number of buses and trains available, the lead times involved, and how far the transit system extend beyond the areas of immediate danger. It is conceivable that hurricane -safe refuges or sanctuaries could be built at the inland termini of major coastal metropolitan transit systems. O Building vibrant urban character into coastal communities may also lead to greater urban resilience in the face of coastal hazards. PLANNING AND CODING FOR COMPACT, MIXED USE PLACES Just building compact, mixed use, and vibrant places will not cure all that ails coastal development. To a certain extent, smart growth in a "stupid" place should not be considered smart. But as previously discussed, just about anywhere on the coast could be considered hazardous, so we are at a disadvantage from the beginning. Coastal communities must address three funda- mental questions about development along the coast: Where do we build? What do we build? And how do we build? WHERE DO WE BUILD? Advocating for compact, mixed use, and vi- brant places on the coast does not eliminate the need to examine the lay of the land for the best possible location. During a storm event, a difference of a foot or two in eleva- tion on a flat coastal plain can mean the difference between a community suffering severe flooding damage and escaping rela- tively unscathed. Ultimately, this question of where to build is a planning question. Building behind coastal dunes is obvi- ously better than in the dunes or in front of them. Likewise, building outside of the floodplain or surge zone or behind an engi- neered levee is clearly better than building in one of these zones or in an area outside some community -scaled protection. Even in a hazardous coastal environment, there are still choices to be made. These choices will usually be of the "Bienville Dilemma" type discussed above, but some effort can be taken to decrease vulnerability. This idea of allowing the natural, or in some cases manmade, features of the land to tell us how to plan and code for development is nothing new. This type of approach was advocated by landscape architect lan McHarg in his influential book, Design with Nature (1969) and more recently refined by architect Douglas Farr in his book Sustainable Urban- ism: Urban Design with Nature (zoo8). There are multiple approaches to plan- ning that are rooted in McHargian theory and smart growth principles. Your community's approach may vary, but objectively mapping the natural and built environment to identify the following areas of your community can help answer the question of where to build: • Low resiliency (undeveloped): areas that are too environmentally sensitive, too vul- nerable to hazards to develop • Low resiliency (developed): areas that have been repeatedly destroyed by storms or flooding and are infeasible to protect through engineered defensive strategies • High resiliency (infill): developed areas with proven resiliency that can become more compact • High resiliency (undeveloped): undeveloped areas that are elevated or protected by multiple layers of defense and could be targeted for future compact, mixed use development High and low resiliency are relative terms. For example, an unprotected mound three feet above sea level might be an area of high resiliency in the porous Delta Plains of Terrebonne Parish, Louisiana, but may be considered low resiliency in Gulfport, Missis- sippi, where the engineered seawall gener- ates safer places. In Terrebonne Parish this mound might be the safest place for a small hamlet -style rural settlement, while in Gulf- ZONINGPRACTICE 1.11 AMERICAN PLANNING ASSOCIATION ipage 5