The influence of land use planning and exposure to flooding on urban growth in San José, Costa Rica

We estimate areas of potential flooding exposure within the San José Metropolitan Region with morphometric methods. Based on this potential hazard zoning, we use a spatial-statistical model to explore the difference introduced by land use regulations (municipal and regional) on urban growth, controlling for potential exposure to hazards and other sources of spatial heterogeneity. The potential flood zoning derived coincided with upstream rivers and flat areas between them (likely susceptible to urban drainage capacity problems). We estimated regional land use regulations significantly constrain urban development (with urban growth reductions of about 6 %), but the constraint does not increase in areas exposed to potential flooding; municipal environmental protection zoning was estimated to decrease urban development by 8 %, with an additional but very small 0.1–0.9 % reduction in potential flooding areas. Regional instruments fundamentally applied to the steeper (and hence less exposed to flooding) periphery whereas municipal land use instruments did constrain land from development (especially along rivers) within urban areas.