Ecologically-oriented coastal engineering at Schicke Point: A phased approach for construction of a living shoreline, Matagorda Bay, Texas

摘要

Schicke Point is located on the mid-coast of Texas in Matagorda Bay, roughly 12 miles north of the Matagorda Ship Channel entrance. It is the southeast point of Carancahua Bay at the confluence of Matagorda and Carancahua Bays. This "living shoreline" creates a multi-layered system that approaches engineering design considering ecological design criteria. The project was constructed through a Construction Manager At-Risk (CMAR) alternative delivery method that provided a framework for collaborative engineering design with the construction contractor, minimizing adversarial relationships during construction and maximizing cost-savings, and ultimately providing operational optimization for a comprehensive living shoreline project. The project implemented design and construction efforts for protection of back bay shorelines to help sustain intertidal marsh habitat through a phased implementation of an adaptively managed "living shoreline" system. The primary design components provide for a low, broad-crested breakwater, situated on an alignment consistent with historical shorelines at the project site, an upland and nearshore beach renourishment, and marsh revegetation. The environmental permitting for the project was initiated with an all-hands meeting for state and federal regulatory agencies and stakeholders: Natural Resource Conservation Service (NRCS), Texas Parks and Wildlife Department (TPWD), U.S. Army Corps of Engineers-Galveston (USACE), National Marine Fisheries Service (NMFS), Texas General Land Office (GLO), U.S. Fish and Wildlife Service (USFWS), and Texas Sea Grant. This living shoreline design will encourage oysters to attach and tie together to strengthen the rock breakwater, helping it grow with rising sea level. This ecology-based engineering project created over 3,281 feet (1,000 linear meters) of low, broad-crested breakwater under USACE Nationwide Permit 27 and protected over 70 acres of intertidal marsh in 14 months from start to finish. Young oysters were colonizing the living shoreline within three weeks after construction began.