Southern Regional Office
GIS Services

The Gulf Intracoastal Waterway (GIWW) has both federal and state economic importance as it provides an effective and safe transportation system. However, balancing economic values with environmental concerns borne from its effects on adjacent coastal marsh systems along the Texas coast is challenging. From its initial construction to the current day, the GIWW poses negative impacts to adjacent coastal marshes, which have both ecologic and economic importance. Continued shoreline erosion and alteration or loss of marsh through saltwater intrusion impact the ability of these wetland systems to support wintering waterfowl populations, as well as other coastal fish and wildlife. Rock breakwaters are robust, dependable structures employed to dissipate wave energy, stabilize shorelines and support reestablishment of emergent marsh along the GIWW shoreline through retention of sediments. They also protect against degradation of interior marshes. However, implementation can be costly.

Through the use of GIS and aerial imagery, Ducks Unlimited has developed a decision support tool for landowners, agencies, private industry and conservation organizations to use for identifying immediate threats to coastal marshes and for prioritizing implementation of breakwaters as funding becomes available. More than 50 miles of high priority and another 100 miles of medium priority shorelines have been identified through this exercise. DU offers this information to its partners and interested parties as a method to evaluate, prioritize, and strategically deliver breakwater protection where it is most urgently needed and compatible with navigation and land management.

Reports
Breakwater Model Report

Web applications
Marsh Specific Model

KMZ links (Google Earth)
Ducks Unlimited shoreline priorities (Marsh Specific Model)
Ducks Unlimited shoreline priorities (General Marsh Model)
Proposed Army Corps of Engineers South setback plans
Proposed Army Corps of Engineers North setback plans