Padre Island National Seashore Beach Nourishment

Project Description

Padre Island National Seashore (PINS) supports the largest nesting population of endangered Kemp’s ridley sea turtles in the U.S. This critical nesting habitat is being lost at an average rate of 12.5 feet per year (1950’s – 2019). Sea turtle nests created on narrow beaches are at risk of destruction from high water levels, increased wave action during the hurricane season, and vehicles. This project aims to restore critical nesting habitat along PINS, through beneficial use of dredge material from the dredging of the Mansfield Channel. The material dredged from the channel has been routinely placed in nearby Ocean Dredged Material Disposal Site 1 (ODMDS 1) located a mile offshore or in beach placement area (PA) 2 which is adjacent to the northern Port Mansfield jetty. Unfortunately, the concentrated placement of sediment in PA2 has worsened conditions for turtle nesting. Dramatically widening the shoreline, increasing the travel distance for turtles to the dune line, and resulting in severe vertical scarping (bluffs) near the waterline, which hinders sea turtle access to the dry beach, and has resulted in fewer logged nesting events in this section of the beach. This project would distribute dredge material over a longer section of beach with a gradual slope to the waterline to reduce the potential for scarping. The design template will be developed based on guidelines and best practices for sea turtle nesting friendly beaches and will be approved by sea turtle experts at the National Park Service. In addition, work would be conducted within PA2 to improve shoreline conditions. The incremental costs associated with the beneficial use are expected to include costs for data collection and design of the beach nourishment project, costs for pumping sediment to the new placement area (increased distance from channel), and costs for beach placement including dredge pipeline management, dredge material grading with heavy equipment, additional construction surveying, and environmental protection measures. These costs are minor when compared to the costs to mobilize and perform a dredging operation, while providing significant restorative measures for sea turtles, and for placing sediment back into the littoral system for natural northern longshore transport.