State of West Virginia Hazard Mitigation

Abstract

This paper proposes a process for natural hazard mitigation planning in Virginia. The process begins with community education and partnership building to build community understanding and support for the various mitigation strategies applicable to local karst terrain hazard areas. Effective natural hazard assessment allows for the relatively precise targeting of regulatory and non-regulatory mitigation strategies to minimize the impact of land use restrictions on the general community, while maximizing the hazard mitigation efficacy of the chosen strategies.

Table of Content

Introduction4

Discussion5

Natural Hazard Mitigation Planning5

Geography6

Climate7

What is a natural hazard?8

Federal Guidelines for Natural Hazard Mitigation Planning10

Conclusion11

References13

Virginia Hazard Mitigation

Introduction

Carbonate bedrock underlies portions of twenty-six counties in western Virginia. The dissolution, or chemical erosion, of carbonate bedrock expresses itself in the formation of landscapes known as karst terrain. Depressions, sinkholes, caves, sinking streams, springs, and underground drainage characterize karst terrain (Kastning & Kastning, 1999). Land development in karst terrain can temporally accelerate and spatially concentrate natural geo-hydrologic processes increasing the risk for several natural hazards including sinkhole subsidence, sinkhole flooding, and ground water contamination. Although rarely fatal to humans, these natural hazards damage private property and community infrastructure and threaten human health.

Urbanization increases the natural hazard risks posed by karst terrains. Kemmerly (1993) asserts that “future [karst natural hazard] losses will increase substantially unless planners recognize risks posed by [karst terrains] and incorporate geologically and hydrologically sensitive guidelines into approval procedures for residential, commercial, and industrial development” (p. 221). A recent survey of local governments, conducted for the Cave Conservancy of the Virginias by the Urban Affairs and Planning Department at Virginia Tech (Cave Conservancy of the Virginias, 2003), indicates that few communities in western Virginia have adopted land use planning and management tools to minimize karst terrain hazard risks. Populous counties that face rapid urbanization, including Loudoun and Clarke counties, have developed the most comprehensive approaches. Both of these counties address karst terrain in their comprehensive plans, zoning ordinances, and subdivision ordinances. Loudoun and Clarke counties also enhance state and local regulations and policies for septic systems, water supply protection, and stormwater and erosion and sediment control management to better address karst concerns. Although few rural counties use the comprehensive approaches characterized by Loudoun and Clarke counties, concern and demand for better planning and management of development on karst terrains is increasing (Giles County, 2002; Highland County, 2002-2003).

This paper describes why and how local hazard mitigation planning effectively addresses potential natural hazards resulting from development on karst terrain. The paper describes new federal requirements for state and local hazard mitigation planning. The author introduces the three most common natural hazards associated with karst terrain including sinkhole subsidence, sinkhole flooding, and groundwater contamination. A summary of the recently completed Karst Protection Survey demonstrates the current extent of karst hazard planning in Virginia and describes several land use planning and management techniques used by local governments to mitigate potential karst hazards concerns. The final chapter proposes a karst terrain natural hazard planning process and describes a karst feature buffer and ...