Creating disaster-resilient communities: Evaluating the promise and performance of new urbanism

Abstract

Conventional low-density development patterns have been cited as a partial explanation for increasing per capita losses from natural hazards in the United States. There is an emerging appeal for New Urbanist design as an alternative to conventional low-density development, and particular features of New Urbanist design make it theoretically amenable to reducing natural hazard losses. However, because New Urbanist developments are built at relatively high densities, they can exacerbate hazard risk when they locate in areas subject to natural hazards and do not incorporate sufficient hazard mitigation techniques such that hazard risk is adequately reduced. We present a comparative evaluation of 33 matched pairs of New Urbanist and conventional developments located in floodplains to evaluate whether New Urbanist developments are incorporating hazard mitigation techniques at a greater rate than are conventional developments. We find that New Urbanist design does not appear to make a difference in the use of hazard mitigation techniques. While New Urbanist developments use more hazard mitigation techniques on average than do conventional developments, this difference appears to stem not from the difference in design type but rather from increased local government technical assistance in the review of New Urbanist relative to conventional developments. We recommend that New Urbanist designers and local governments engage in more proactive land use planning and take more responsibility to make sure that hazard mitigation techniques are integrated into New Urbanist project site designs.

Introduction

Natural hazards cause average annual economic losses between $25 and $30 billion in the United States, and losses have been rising relative to increases in population and gross national product (Cutter, 2001). While hazardous events such as floods and earthquakes are naturally occurring phenomena, the amount of damage they cause has been exacerbated by the conventional land use pattern of decentralized sprawl, which has fostered a massive buildup of development in areas subject to natural hazards (Burby, 2006).

New Urbanist design has been promoted as an alternative to possibly counter certain adverse societal outcomes of conventional sprawling development (Duany et al., 2000, Calthorpe and Fulton, 2001, Talen, 2005). Based on a set of design principles that are intended to foster more intentional delineation of open space, a better mixture of land uses built at relatively high densities, and pedestrian-oriented transportation networks, New Urbanist design has also drawn increasing attention for its potential to reduce natural hazard vulnerability (Thompson, 2005, Miller, 2007).

Despite this potential, however, when a New Urbanist development locates in a hazardous area, its relatively high development densities can mean that more people and property are placed at risk than would have been the case with a low-density development on the same parcel of land (Berke and Campanella, 2006, Berke et al., 2009). Song et al. (2009) show that more than one-third of all New Urbanist developments in the United States that were completed or under construction as of December 2003 are located in areas subject to flood hazards, and because of relatively high development densities, these New Urbanist developments can pose a greater risk than conventional low-density developments if flood hazards are not anticipated and flood hazard mitigation is not promoted in project design.

Recent research has compared New Urbanist developments with conventional low-density developments to determine whether local communities put forth more effort in reviewing proposals for New Urbanist developments, and whether that effort appears to translate into design that is more resilient to natural hazards. Berke et al. (2009) found that, on average, in comparison with conventional developments, New Urbanist developments (1) were subject to stronger local government development management regulations, (2) involved greater levels of public participation and local government planning staff technical assistance during the development review process, and (3) incorporated more natural hazard mitigation techniques.

In this paper, we expand upon previous research by utilizing analytical techniques that allow us to control for potential confounding factors that might explain some (or all) of the apparent differences between New Urbanist and conventional developments with respect to the incorporation of hazard mitigation techniques that are highlighted in previous research. In particular, we use multiple regression analysis to examine whether New Urbanist developments incorporate more hazard mitigation techniques than conventional developments, while controlling for other potentially relevant factors. Answering this question can help assess whether the potential of New Urbanist design is being translated into neighborhoods and communities that are resilient to natural hazards.

To help answer this question, we first identify and describe particular features of New Urbanist design that we hypothesize will foster the incorporation of hazard mitigation techniques, as well as additional factors that have been found by previous researchers to influence the use of hazard mitigation techniques in development projects. After describing our research design, variables, and methods, we then present a comparative evaluation of 33 matched pairs of New Urbanist developments and a control group of conventional low-density developments located in flood-prone areas throughout the United States, including the results of regression modeling intended to evaluate the importance of New Urbanist design for the incorporation of hazard mitigation techniques. We conclude with a discussion of our findings and their implications for planning practice and natural hazard mitigation.