Sylvan Beach is located on the west shore of Galveston Bay in the City of La Porte, Harris County Texas. This beach was a popular recreational destination in the early 20th century and was bordered by a historic park with many amenities that was referred to as the “Grove.” It is generally recognized that after the opening of the Houston Ship Channel in 1928, wave action initiating from navigation along with waves due to prevailing onshore wind began to erode the small native bayside beach. These forces combined with regional subsidence, and tropical storms resulted in the complete erosion of Sylvan Beach.
A beach restoration project which included the construction of two beach cells was completed in November 2009 with a subsequent localized renourishment conducted during the spring of 2013. Initial construction was conducted from April to November 2009, facilitated by CEPRA (CEPRA 1404) funding. Each beach cell includes two arcuate terminal groins and beach fill material consisting of coarser than native, beach-quality sand that was borrowed from an upland source (Trinity River). The length of each beach is approximately 500 ft. The length of the beach shoreline itself is truncated by about 50 ft due to the curvature of the groins. According to the BMMP, on the order of 17,000 cu yd of sand was originally placed to create each beach for a project total of 34,000 cu yd (reported as 46,000 Tons). The landward boundary of the beach, previously consisting of a deteriorating bulkhead and concrete rip rap, was replaced with an articulated pavement and sidewalk bordering a partially exposed rock revetment. The landward edge of each beach was designed to meet the hardened border with minimal difference in elevation. The design width was specified at 75 ft with a mean elevation of 3 ft.
During May 2013 the two beaches at Sylvan were re-nourished with a focus on the south-end of each beach which has experienced focused erosion since construction. It is important to note that the volume of sand that Harris County placed on the beach during 2013 was on the order of half that recommended by URS in their 2013 maintenance report. The purpose of the nourishment was not to restore the beach to the original state but to alleviate the accelerated erosion on the south end of each beach cell and restore greater recreational access. The decrease in the applied volume may have been based on two factors; 1) funding limitations, as this project was not supported by a grant or 2) sand availability, rather than original design guidance. According to Harris County officials, approximately 1,500 cu yd (reported as 2,000 tons) of sand was placed on the north beach and 2,300 cu yd (reported as 3,000 tons) of sand was placed on the south beach. The nourishment was initiated and conducted by Harris County and was not funded by CEPRA or other TGLO resources. The beaches were surveyed by CBI within 2 weeks of completion on 06 June 2013. Harris County staff reported that another small-scale nourishment targeting the south end of each beach was planned for June 2016. To date no information of the volume of that placement had been provided.
Sylvan beach has been surveyed by CBI during June 2012, June 2013 (immediately post-nourishment), July 2014 (1-year post-nourishment) and September 2015 (2-years post-nourishment. The survey grid consists of 17 transects at 100-ft spacing and includes the submerged region between the beach cells. Each transect extends to a depth of -10 ft, beyond the depth of closure of -7.5 ft which has been determined based on the comparison of data from 2012-2015.
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