Southeast Texas’ coastal region has been plagued with severe storms and flooding in recent years. And sadly, the stormwater infrastructure is inadequately equipped to manage the frequency and magnitude of these storms. Fine muddy sediment deposited in the coastal shallow-grade storm drain system has caused significant flooding problems for many years, and the problems have become more severe under extreme weather conditions. A comprehensive study assessing the exposure to flooding risk using up-to-date hydrological analysis would help the community to determine the most cost-effective measures to address both the stormwater runoff and sedimentation deposition in the drain system.
Researchers Qin Qian, Milad Ketabdar, Mien Jao, and Xianchang Li took on the challenge and evaluated the sediment load from surface runoff under different hydrological and roadway conditions, to better understand the sediment transport mechanics in storm drain systems. The authors collected nine runoff samples to determine the sediment characteristics and concentration to assess the required flow velocity to clean the sediment from the drain system. Their findings published in the Journal of Irrigation and Drainage Engineering, “Modeling Sediment Load in Storm Drain System of Southeast Texas Coastal Region”, will help communities address nuisance flooding. Their paper is available in the ASCE Library at https://doi.org/10.1061/(ASCE)IR.1943-4774.0001672. The abstract is below.
Sedimentation in a drain system has been recognized as one of the major causes of nuisance flooding produced by localized storms in southeast Texas. The objective of the study is to assess the sediment load from runoff under different hydrological and road conditions to implement design guidance for a proper self-cleaning drain system. A diffusion wave model is developed to simulate runoff hydrodynamics on the roadway with curb inlets. An empirical sediment load equation is developed as a function of rainfall intensities, road conditions, and field sediment characteristics. The required flow velocity to erode the cohesive deposited sediment, and transport the deposited sediment incorporating the sediment from runoff in the drainpipe has been investigated to implement design guidance for a self-cleaning drain system. Regional hydrological conditions and field sediment characteristics are critical to design an effective drainage system for improving coastal resilience under severe weather conditions.
Read the paper in the ASCE Library: https://doi.org/10.1061/(ASCE)IR.1943-4774.0001672