Design and implementation of an ecological engineering approach to coastal restoration at Loyola Beach, Kleberg County, Texas

Abstract

Ecological, coastal, and civil engineering techniques were integrated to obtain a structurally sound, ecologically beneficial engineering restoration method for preserving the shoreline at Loyola Beach, Kleberg County, Texas. The erosion management strategy was based on a plan to integrate the natural landscape, riprap rock, and local fill material, along with native vegetation for beach preservation. Geotechnical parameters including soil moisture, shear strength, plasticity, and grain size were measured for pre-construction site characterization and baseline evaluations, and compared to measurements for the restored areas. The shear strength of the beach after project implementation increased along with a decrease in moisture content when compared to the original site. Higher shear stress values will be required to reach the critical value to cause sediment erosion on the restored structure. A model is suggested to estimate erosion potential for these types of structures using Shields parameter for sandy soils. The Shields parameter calculations predicted an increase in erosion resistance above the pre-construction beach soils. The model provides a method to evaluate erosion resistance of certain coastal ecosystems based on geotechnical analysis techniques. The final project implementation provided an economical alternative to conventional coastline restoration, costing one-third of a typical seawall, in addition to preserving the natural beach ecosystem.