A BIOENGINEERING SYSTEM FOR
COASTAL SHORELINE STABILIZATION
By George Farek and John Lloyd-Reilley
For many years, the Shoreline Erosion Committee of the Texas State Association of Soil and Water
Conservation Districts has implemented shoreline erosion control projects with smooth cordgrass
(Spartina alterniflora). However, many of these projects, where bluffs were encountered, failed to
completely solve the shoreline erosion problem. Either the planting would not become established,
or in some cases the bluff just continued to erode. With the development of geotextiles, there is the
potential to implement low-cost shoreline projects that address these highly eroding bluff sites.
Geosynthetic turf reinforcement mats (TRM) provide a low-cost alternative to hard armor on
eroding critical areas. The mats along with the root reinforcement of seeded or planted vegetation
resist damage from wave energy and high velocity surface flows. On high-energy wave sites, cellular
concrete blocks are an alternative to concrete and rip-rap. Both of these erosion control materials
provide for the opportunity to install native salt tolerant plant species. These plants are not only
aesthetically appealing but their roots and stems are a critical component of an effective long-term
erosion control system.
In partnership with the San Patricio Soil and Water Conservation District we implemented a
shoreline project in October, 1997, under a grant from the Texas Coastal Management Program.
We evaluated turf reinforcement matting and cellular blocks while testing several plants such as
marshhay cordgrass (Spartina patens) gulf cordgrass (Spartina spartinae) and marsh elder (Iva
frutescens) for adaptation and added environmental and engineering enhancement.
The location of the project is near the city of Portland, Texas along the Nueces Bay. The shoreline
had a bluff that ranged in vertical height from 0 to 8 feet. The soil of the site was a Monteola clay.
The slope of the tidal area was ap