San Marcos Flooding Analysis

Due to a unique set of geomorphologic and hydrological aspects, the residents of San Marcos, Texas are always under the possible threat of flooding. In October of 1998, the town received almost thirty inches of rainfall in a two-day period. This caused the San Marcos and Blanco rivers to reach near their 100-year flood levels in some areas. The flooding caused thirty-two deaths around the Central Texas region; nearly all of these deaths were caused by high-level fast moving water at low-water crossings. Motorists tried to cross the river at these dangerous areas because they were not evacuated in time and or they knew no other route. The flooded crossings also made it difficult for emergency crews to access certain neighborhoods.

The objectives of this project are to alleviate damages and facilitate evacuation during a major flood event.
Factors will include:
  • 100 year and 500 year flood plain identification
  • low-water crossings and potentially dangerous road segments
  • fire station and evacuation shelter locations
  • the City of San Marcos road network
  • October 1998 flood damage
  • population distribution
The final product will produce a report identifying low water crossings and other restricting road segments, fire and rescue station service areas, evacuation shelter service areas, and correlations between population distribution and flooding. The results will be spatially displayed in map form.