Revitalizing Intertidal Marsh Habitat

In Texas, between Corpus Christi and Portland, the Nueces Bay intertidal salt marsh ecosystem supports several wetland flora and fauna species. Once spanning approximately 600 acres, the habitat began to deteriorate in the mid-20th century as construction of railways and the Portland causeway bisected the marsh — dredging some areas, filling in other areas, and disrupting natural water exchange throughout the system.

These changes led to the direct loss of 180 acres of marsh complex. Over time, erosion and relative sea level rise compounded the impact, resulting in an additional 160 acres of loss. Recognizing the area's ecological importance, the Coastal Bend Bays & Estuaries Program sought a restoration strategy.

HDR documented existing conditions, conducted an alternatives analysis and led conceptual master planning for 148 acres of new intertidal marsh habitat. To accommodate varying funding levels, design alternatives included construction of terraces, marsh mounds and large planform areas with tidal channels and ponds.

We also served as the lead for permitting, design, agency coordination, surveying and habitat assessments. This included developing each level of design and contract documents, specifications and drawings, followed by bidding assistance and construction administration.

Ultimately, the restoration was executed in three phases. Phase one constructed 56 terraces of varying shapes, curves and interconnection, restoring 70 acres of marsh complex. Phase two introduced containment berms filled with dredged material. Phase three armored the outer berm to enhance shoreline protection and oyster habitat.

After multiple series of plantings and natural recruitment, the marsh is thriving along the terrace features. Higher portions of the terraces have either been colonized by high marsh vegetation or serve as bird nesting and roosting areas. A new observation deck, boat launch and educational signage invite nearby residents, too, to engage with the revitalized marsh.