Urban Geology: Quantifying Geological Descriptions into Guidelines and Ordinances

Peter M. Allen
Baylor University, Waco, TX

The Dallas Fort Worth metroplex is growing at an annual rate of approximately 140,000 people which translates into 40,000 houses and 10,000 apartments. As cities spread out from their center and travel times increase to the workplace, less buildable land, once bypassed, is now being built upon; suburban growth rates exceed 20-50%. Construction is accompanied by impacts such as soil erosion, increased runoff and flooding, filling in floodplains and wetlands, cut and fill leading to slope stability problems, stream channel erosion and lower water quality, and, at the same time increased demands on infrastructure and resources as water supply, raw materials (gravel and cement) as well as highways, and sewer and water distribution systems. Ordinances, guidelines, and land use plans have been developed in the Dallas-Fort Worth area to reduce such impacts. They are based on detailed measurements and testing of geological materials and quantifying geomorphic processes in liason with the engineering and planning community. Hillslope, stream restoration and floodplain ordinances and reservoir sedimentation history of the metroplex and greater Blackland Prairie will be discussed.