Nourishment of San Luis Beach, Galveston Island, TX: An Assessment of the Impact. ASCE Conference on Coastal Sediments.
The Galveston Island shoreline has been retreating for a number of years. The cause of the shoreline retreat is a result of both geometric process and human intersaction with the environment. Following the construction of the Seawall along the Gulf side of Galveston Island, the ebach in front of the Seawall began to disappear. In an effort to maintain the beach and to protect the toe of the Seawall, thirteen groins were constructed along the eastern portion of the wall. and revetments consisting of large granite blocks were placed at the Seawall's base. Although these actions protect the toe of the Seawall, to some extent, the beach remained narrow and this limited its recreational use. One proposal to combat shoreline retreat and protect the foot of the Galveston seawall is to buil a wide beach by nourishing the entire beach in front of the seawall. A small-scale nourishment project was initiateed in the spring of 1985 along a 485 m section of the Seawall. the project has been monitored through November of 1986. The beach was nourished with 11,460 m^3 of material that ranged from 0.08- 0.15mm. The native beach grain size ranged from 0.10- 0.42mm. During the 17 months of monitoring, the shoreline retreated approximately m and lost approx. 16% of the material comprising the beach after the nourishment was completed. Beach material was found to have exited the system via the following pathways: 1)suspension and subsequent movement offshore, 2) end loss, 3) profile adjustment, and 4) aeolin transport.