Coastal Resiliency: Studying Sand Movement Along the Texas Coast
Freese and Nichols, in partnership with the Texas General Land Office (GLO), is working to unravel the mysteries of longshore sediment transport – the process that moves sand along the shoreline. Longshore sediment transport is the invisible hand that sculpts our beaches. It’s the force that would mysteriously drift you down the shore as you played in the sand as a child.
Our work began with the GLO in 2020, when Freese and Nichols conducted a Sediment Budget Analysis and Modeling study for Regions 1 (Sabine to Galveston) and 4 (South Padre Island) of the Texas coast, a Tier 1 project under the GLO’s Texas Coastal Resiliency Master Plan. The study aimed to understand how much and in which direction, sand travels along the shoreline, and is believed to be the first statewide sediment transport budget developed in the U.S.
“This knowledge is crucial because it determines whether beaches grow or shrink over time,” said Carl Sepulveda, a coastal engineer who leads the firm’s coastal and port projects.
In collaboration with modeling subconsultant HR Wallingford, the team contributed to data collection and processing, model verification and report writing. Initially scoped for GLO Coastal Regions 1 and 4, the first study laid the groundwork, and now the team is delving deeper, analyzing Regions 2 and 3 of the Texas coast.
Imagine the coast as a conveyor belt of sand, constantly in motion. These studies involve the complex assembly of hydrodynamic, wave, and sediment transport models, all working in unison to simulate the movement of sand under normal conditions and during extreme events like hurricanes. The modeling helps identify areas of sand accumulation and erosion, crucial for designing effective coastal protection and restoration projects.
“Freese and Nichols’ efforts have led to a better understanding of the two distinct zones of sediment transport along the shoreline,” Carl said. “One zone is influenced by waves near the shore, and the other, slightly offshore, is influenced more by ocean currents. This insight is vital for engineers and designers planning beach nourishment projects, making sure these efforts are both effective and sustainable.”
The beaches of Texas, like North Padre Island National Seashore and Sargent Beach, are not only recreational hotspots generating millions in tourism dollars but also vital barriers protecting coastal towns. Understanding the complex movement of sand along the shore is critical to safeguarding the state’s economy and the people who live along the coast.
“The data gathered from these collaborative studies with the GLO, support the design of better coastal protection projects, ultimately contributing to the preservation of Texas’s beaches,” Carl said.
Coastal Resilience Initiative
Freese and Nichols Coastal Resilience Initiative aligns with our vision of making a positive impact on the world we inhabit. It’s also linked to our corporate responsibility structure, which aims for a balanced strategy towards community guardianship. This involves consistent evaluation of metrics, feedback from clients and employees, and ongoing examination of environmental and societal needs.
Our coastal clients and communities are dealing with a multitude of challenges such as erosion, rising sea levels, increased storm surges, and more frequent disasters. Our aim is to help them tackle these problems to ensure the safety of their residents and the protection of their assets.
