Consideration of Water Levels in Coastal Roadway Design

Stillwater level represent the water surface absent wave height and wave runup. Fluctuations in stillwater levels along the Texas coast are influenced by astronomical tides, storm surges, and long-term sea level changes. Tides and storm surge reflect dynamic processes that move water in a fairly short time period, but their effects are still incorporated into the overall term “Stillwater level.” The stillwater level should be considered for all roadway projects located in coastal areas to determine the landward extent and elevation of inundation and wave forces.
Identification of a stillwater level is a critical element in the design of a roadway infrastructure located in coastal areas.
This section seeks to:
  1. Synthesize – at a high level – the various factors that contribute to water level fluctuations along the Texas coastline; and
  2. Provide guidance on the estimation of appropriate stillwater levels for design of coastal transportation infrastructure.