State of the Beach/State Reports/TX/Beach Erosion
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Texas does a very good job of collecting coastal erosion rate data. Maps indicating the average erosion rates can be found online at the GLO’s coastal erosion Web page, through links on that page to the website of the University of Texas Bureau of Economic Geology.
The University of Texas at Austin’s Bureau of Economic Geology (BEG) Coastal Studies Group runs the Texas Shoreline Change Project. This online resource contains maps depicting historical Gulf and selected bay shoreline change rates along segments of the Texas shoreline. This data is published and maintained as part of the ongoing Texas Shoreline Change Project undertaken by the BEG through funding assistance from the GLO as required by the Coastal Erosion Planning and Response Act (CEPRA) statute (Texas Natural Resources Code §33.607(b)-(d)), which requires the Texas Land Commissioner, in consultation with the BEG, to monitor historical erosion rates on an ongoing basis and publish historical erosion rate data for public consumption. These are available online and are easy to understand.
The report Texas Gulf Shoreline Change Rates through 2007 (2011) describes the 2007 update to older long-term change rates that were published in various print formats and online by the Bureau of Economic Geology in GIS-compatible format. Those rates were calculated from selected shoreline vintages that began in most areas with the 1930s aerial photographs and included Gulf-shoreline-wide aerial photographs acquired through the mid-1990s, ground-based GPS surveys conducted in select areas during the mid-1990s, and coast-wide airborne Lidar surveys acquired in 2000. This report uses the wet beach/dry beach shoreline position as interpreted from georeferenced aerial photographs taken in September and October 2007 along with the earlier shorelines used to calculate the pre-2000 rates to update long-term change rates through 2007. Aerial photographs from 2007 were chosen because they were the latest coast-wide imagery that predated Hurricane Ike, a category 2 hurricane that struck the upper Texas coast in September 2008 and had significant impact on beach morphology and shoreline position. Also see this article with one of the report's authors, Jeffrey Paine.
Erosion data is also collected and stored by Texas A&M University's Institute for Sustainable Coastal Communities. Their website houses the Coastal Communities Planning Atlas which is comprised of the Coastal Atlas and a Tri-County Atlas. The Coastal Atlas is a detailed and comprehensive web-based program providing information for anyone wanting to know more about the Texas coast. In 2014, it is the most comprehensive online, interactive database ever compiled about the Texas coast.
In 2003, the Texas General Land Office launched Coastal Texas 2020, a long-term statewide initiative to unite local, state and federal efforts to promote the economic and environmental health of the Texas coast. Five regional advisory committees encompassing the 18 Texas coastal counties comprising the Texas coastal zone developed and vetted a list of key coastal issues affecting specific locations along the Texas coast. Specific projects were proposed to address these issues and a Technical Advisory Committee made up of state natural resource agency representatives and coastal experts reviewed these projects to offer feedback and determine feasibility and cost. Many of the key issues and projects identified involved responses to critical coastal erosion.
An estimate of the amount of critically eroding shoreline in Texas is outlined in Section I of the CEPRA report to the 81st Texas Legislature, published in January 2009.
This report emphasizes that Texas has one of the highest rates of coastal erosion in the country. Approximately 234 miles or 64% of Texas’ 367-mile Gulf coast is critically eroding, while about 7.9% of the coastline is accreting. On average, the state loses 235 acres of Texas Gulf shoreline each year. The highest rate of erosion, 46.2 feet/year was recorded along the 2.5-mile long section of Matagorda Island.
"Critical Erosion" is defined under GLO rule (Texas Administrative Code, Title 31, Chapter 15, Part 1, Sub-Chapter H, Rule §15.2) as locations with greater than two feet per year erosion where infrastructure, habitat, public health, safety or welfare is threatened. In consultation with the BEG and the ongoing efforts of the Texas Shoreline Change Program, the Land Commissioner has determined that 60 miles of developable Texas Gulf coast are subject to erosion. In addition, there are “hot spots” that are monitored on a case-by-case basis over time. Historically, critically eroding areas and response needs have been identified through submission of the (CEPRA) Project Goal Summaries, which constitute the CEPRA funding application mechanism. Collectively, these Project Goal Summaries express the extent of coastal erosion response needs as identified by the various stakeholders along the coast.
Table I-1 on page 5 of the CEPRA Report to the 81st Texas Legislature summarizes the critically eroding areas of the Texas coast. Below is a region-by-region breakdown of erosion rates from that report.
In Jefferson and Orange Counties, the highest rates of Gulf shoreline erosion are occurring between Texas Point National Wildlife Refuge (NWR) and Sea Rim State Park. Critical erosion rates range from 35 to 43 feet annually along this 20-mile section of the coast. The following points describe the shoreline change on the Gulf shoreline in this region:
- Due to local circulation patterns in the area immediately adjacent to Sabine Pass jetties, this short segment of shoreline is accreting at rates of up to 31 feet a year.
- As mentioned above, the highest rates of Gulf shoreline erosion for this region are occurring between Texas Point National Wildlife Refuge (NWR) and Sea Rim State Park. Critical erosion rates range from 35 to 43 feet annually along this 20-mile section of the coast. This erosion can be attributed in part to a lack of sediment coming down the Sabine and Neches Rivers and the interruption of the longshore sediment transport induced by the jetties.
- Gulf-facing beach erosion is affecting the dunes in the vicinity of Texas Point NWR at Texas Bayou
- Portions of the Gulf shoreline are stable for 10 miles from Sea Rim State Park to Clam Lake but the shore is critically eroding along the remaining 17 miles of coastline that stretches to the border with Region II. The McFaddin NWR encompasses most of this shoreline.
- State Highway 87 runs along the Region I Gulf shoreline. This road was severely damaged in 1989 by storms, and segments have been closed because of high erosion rates. Parts of the highway now rest in the Gulf of Mexico.
- Erosion in this area threatens wetlands at McFaddin NWR, Texas Point NWR and Sea Rim State Park. These parks are adjacent to the Gulf shoreline and are threatened by coastal erosion, as well as saltwater intrusion.
For Chambers, Brazoria, Galveston and Harris Counties there are critical erosion rates along 57.1 miles of this 97.8 miles stretch of Gulf shoreline. The critically eroding areas of note include:
- The majority of Bolivar Peninsula (20 miles), particularly around Rollover Pass, is critically eroding at rates that range from 2.8 to 6.4 feet a year. However, areas of the western end of Bolivar Peninsula and the far eastern end of Galveston Island adjacent to the jetties are accreting with sand that gets trapped behind the jetties.
- The shoreline at the Galveston Seawall remains stable because of protection by the seawall, but erosion is occurring on the island west of the seawall. This western 20 miles of the island to San Luis Pass is eroding at an average of 5.6 feet annually. A major roadway (FM 3005) is threatened, as are municipal and county roads, water and sewer systems and other utilities. Numerous homes along the shoreline in this area also are threatened.
- Down the coast to the southwest of San Luis Pass, erosion rates are as high as 9.9 feet a year and extend along Follett’s Island. This area includes the Treasure Island development.
- A few miles of the Follett’s Island Gulf shoreline in front of Drum Bay are stable. However, south of this area, the coastline is critically eroding at a rate of 9.1 feet a year. The Village of Surfside is in this eroding area and sees erosion rates that range up to 8.4 feet annually along the northern edge of the Freeport jetties.
- The Town of Quintana – on the south side of the Freeport jetties – sees erosion rates of up to 9.8 feet a year. There should be accreting areas here but there are not, due to lack of sand and possible leaks in the jetties. These erosion rates occur down the coast to the mouth of the Brazos River.
- Erosion in the Surfside and Quintana areas has significantly narrowed the public beach and threatens homes and other structures.
- On average, the Gulf shoreline from High Island to the mouth of the Brazos River is retreating at two to 10 feet a year. Erosion of the Gulf shoreline at Bolivar Peninsula, Galveston Island and Follets Island threatens numerous structures in several beachfront communities.
- South of the Brazos River, the shoreline is accreting at rates running from 2.2 feet a year to 9.5 feet a year. Approaching the county line between Brazoria and Matagorda counties, the Gulf coast is eroding at rates of 9.3 feet annually.
For Calhoun, Jackson, Matagorda and Victoria Counties, about 58 miles of the region’s 97 miles of Gulf shoreline are critically eroding, most of it along the Matagorda Peninsula and Matagorda Island. As mentioned above, this region is home to the highest rate of erosion recorded along the Texas Gulf Coast – 46.2 feet a year along a 2.5-mile-long section of Matagorda Island just south of the Matagorda Ship Channel.
For Aransas, Kleberg, Nueces, Refugio and San Patricio Counties, 31.6 miles of the region's 57.8 miles of Gulf shoreline are critically eroding. Shoreline change highlights include:
- About 17 miles of San Jose Island is critically eroding at rates that range from 6.4 to 3.2 feet a year, with the exception of an area adjacent to Aransas Pass. A portion of the extreme northern end of the island is also eroding, but at lower rates.
- To the south, the area around the jetties at Port Aransas is stable or accreting, in part because of the sand that becomes trapped behind the jetties. This 20-mile stretch of coast includes part of San Jose Island and most of Mustang Island near Corpus Christi. A few miles of coastline in middle of this section, starting at the south end of Port Aransas near Mustang Beach, is critically eroding.
- The area from Packery Channel to the start of Padre Island National Seashore is also critically eroding at rates from 4.5 to 6.4 feet annually. This erosion threatens public beaches and private property.
- From the north end of the Padre Island National Seashore to the Kenedy County border, the Gulf shoreline is essentially stable or accreting.
For Cameron, Kenedy and Willacy Counties, two-thirds, or 64.7 miles, of the region’s 85.7 miles of Gulf shoreline is critically eroding. The highest rates of erosion are located just north of Mansfield Cut, a few miles south of the Willacy-Cameron County line and at the mouth of the Rio Grande. Highlights of shoreline change in this region are described below:
- The Gulf shoreline of Kenedy County is eroding at rates that range from 1.2 to 7 feet a year. Most of this area is losing more than two feet of shoreline annually and is considered critically eroding.
- A five-mile stretch of shoreline north of Mansfield Cut has erosion rates of 16 feet per year. These high rates of erosion are seen again three miles south of the pass. In this area, erosion rates range from 9.5 to 18.5 feet a year
- The northern portion of the Town of South Padre is eroding up to 5 ft per year and becomes stable toward the south. The relative stability of the coast at the Town of South Padre is a result of the continual nourishment of the beaches. The Land Office has partnered with the town and the USACE to protect this valuable resource as well as the infrastructure along this portion of the Gulf coast.
In some areas of the Texas coast, land subsidence is exacerbated by the withdrawal of groundwater or hydrocarbons (Morton et al., 2004). Natural tidal passes that separate the barrier islands and peninsulas can act as sand “sinks” by capturing littoral sediments in either the ebb- (Gulf side) or flood- (lagoon side) tidal deltas. Inlets that have been jettied for navigation can stop the transport of sand and create accretion on the updrift side while erosion results downdrift due to the deficiency of sediments. Other human influences are the construction of revetments, seawalls, and groins which impede sediment transport, and waves from motorized water craft.
In general, the Gulf shorelines undergoing the greatest rates of erosion (more than -8 ft/year [-2.5 m/yr]) are located between Sabine Pass to Rollover Pass, on Galveston Island west of the seawall, Quintana Beach to Sargent Beach, Mustang Island (north of Packery Channel), Padre Island near Port Mansfield Channel, southern Padre Island (Willacy County and Cameron County sections), and the southern portion of Brazos Island near the Rio Grande (Figure 1). Between the 1930s and 2012, the annual land loss was calculated at 178 acres/year and the total land loss during that time frame was 14,597 acres.
Comparison of the 1930s to 2012 and 1950s to 2012 datasets, show that the percentages of advancing and retreating shorelines are similar; nearly 20% advance and 80% retreat. The Paine and others (2014) report also provides an evaluation of the decadal trend for shoreline change from 2000 to 2012. The 2000 to 2012 decadal trend demonstrates a 33% advance and 67% retreat for the entire Gulf coast shoreline. Possible reasons for the overall percentage differences between advancing and retreating areas could be due to more precise monitoring methods used during the time frame (comparison of lidar surveys), or the percentages may have been influenced by the initiation of CEPRA-funded projects. In general, the locations of eroding shorelines (those losing more than two feet per year) have been fairly consistent through time (Paine et al., 2014).
Pages 60 and 61 of this report have a list of observations and recommendations to address erosion along the Texas Gulf Coast. Following is the report's summary:
Coastal erosion remains a continuing threat to the Texas Gulf and bay shorelines. Whether the erosion is caused by the lack of sediments to balance the long-term losses within the coastal compartments, or the episodic erosion brought on by storms or human activities, planning and implementation of erosion response and sediment management practices is essential to the sustainability of the shoreline and public beaches. This report summarizes the latest shoreline change research results published by the Bureau of Economic Geology at the University of Texas at Austin and maps are provided that show critical erosion areas along the Texas Gulf shoreline. The CEPRA program is still dealing with Hurricane Ike recovery issues as many emergency recovery projects relied on FEMA cost-shared funds and a number of those projects continue to await federal cost-shared funding approval. Managing coastal erosion and maintaining the balance with private property and the public’s right to access and use of the Gulf beaches has become even more difficult since the Texas Supreme Court opinion was issued in 2010 and reaffirmed in 2012. The results from the Supreme Court of Texas opinion regarding public access to the Gulf beaches and the “hands off” management by the City of Galveston have allowed west Galveston Island shorefront landowners and local homeowners associations to face public use and construction activities on their own. Since Galveston does not follow up with construction inspections after permits are issued, it is not known if structures are built within the appropriate rules for protecting dunes or from flood risks. With high erosion rates, beachfront homes on west Galveston Island are more vulnerable to storms and elevated water levels and without proper erosion response projects, will eventually wind up on the public beach and eventually on state-owned lands. Though erosion of the Gulf and bay shorelines are continuing, human intervention is making an impact through the efforts of the CEPRA program in maintaining the shoreline position. It is important to stress the necessity for keeping eroded and dredged sediments in the local littoral system and practicing sediment conservation. The highest benefit-to-cost ratios for CEPRA projects are realized from partnerships with the USACE for the beneficial use of dredged material arising from federal navigation maintenance events for beach nourishment and dune restoration, and the restoration of eroded habitats. With the exception of a few, local governments are doing their best at shoreline management practices through the implementation of their dune protection/beach access and erosion response planning efforts which protect coastal sand dunes and locate new structures as far landward as possible. These efforts should help ensure public access and use of the beaches and reduce the potential for future public expenditures on managing erosion and storm damage losses.
A 1999 mapping project conducted by the Federal Emergency Management Agency concluded that approximately 70% of Texas’ gulf beaches were retreating at a rate between 1 and 35 ft/year, 25% were stable and 5% were accreting.
The CMP GLO coastal erosion website notes that Texas is moving aggressively to fight coastal erosion via the CEPRA program. It states that Texas is committed to working closely with coastal communities to learn more about their erosion concerns, developing innovative program ideas and working towards effective, long-term management practices that will stem erosion and preserve a valuable habitat, protect public infrastructure and enhance the tax base of coastal communities.
CEPRA has been funded by both general revenue and through a designated fund. For Cycle 5, $17.2 million was appropriated by the 80th Texas Legislature by dedicating revenue collected through sales tax imposed on the sale of sporting goods sold in the 18 Texas counties comprising Texas’ Coastal Management Zone. Because sporting goods sales tax revenue is appropriated by way of existing law to the Texas Parks and Wildlife Department, the Legislature required TPWD to transfer the funding to the GLO by way of an inter-agency agreement. Efforts to pursue a dedicated funding source for CEPRA were made during the 81st Texas Legislative session in 2009. The GLO is working to utilize the federal fiscal year 2007-2010 Coastal Impact Assistance Program allocation as a source of match funding for CEPRA erosion response projects.
A report to the 78th Texas legislature from the Texas Coastal Coordination Council titled Recommendations to Address Beachfront Erosion Along the Upper Texas Coast was issued in January 2003. The report's recommendations include changes to funding mechanisms for beach fill projects; preparation of a long-term comprehensive erosion response plan update every two years; a preference for regional approaches to address erosion; an increase in enforcement actions (removal of encroachments on public beaches) for the Texas Open Beaches Act; and establishing a funding assistance program to aid in relocating structures that encroach upon a public beach. This last recommendation was addressed by the 79th Texas Legislature through amendment of the CEPRA statute (Texas Natural Resources Code §33.607 (b)(11)), whereby projects for the relocation and removal of structures from the public beach were added to the list of projects that the Land Commissioner may fund under the CEPRA program.
A summary of CEPRA Program Rules can be found at: http://www.statutes.legis.state.tx.us/?link=NR
The adopted rules outline the process by which the GLO will evaluate and assist in the funding of coastal erosion studies and projects, in cooperation with qualified project partners and make beneficial use of dredged material where practicable..
Maps showing the location of all CEPRA Erosion Response Projects undertaken to-date (Cycles 1-6) and project summaries can be found at: http://www.glo.texas.gov/what-we-do/caring-for-the-coast/grants-funding/cepra/index.html
These projects involve a variety of activities including dune restoration, beach fill, and structural shore protection.
The Coastal and Marine Geology Program of the U.S. Geological Survey has generated a comprehensive database of digital vector shorelines and shoreline change rates for the U.S. Gulf of Mexico. These data were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project.
The USGS report National Assessment Of Shoreline Change: Part 1, Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Gulf Of Mexico (2004) states:
- "In Texas, a combination of erosion and submergence contribute to land loss, which is concentrated along the Gulf shoreline and along bay marshes and bluffs (Morton and Paine, 1990). Wetland losses, which constitute about 75% of the total land losses, have dramatically accelerated both directly in response to human activities or indirectly as a result of modifications to the coastal system. Rates of land loss around bays are highest near the heads of the largest bays where long wave fetch and high bluff elevations produce unstable conditions. Wave erosion at the base of bluffs causes slumping and bluff retreat at rates of -0.6 to -1.2 m/yr (Morton and Paine, 1990) that threatens houses, power lines, and pipelines.
- Erosion of Gulf beaches in Texas is concentrated between Sabine Pass and High Island, downdrift (southwest) of the Galveston Island seawall, near Sargent Beach and Matagorda Peninsula, and along South Padre Island. The most stable or accreting beaches in Texas are on southwestern Bolivar Peninsula, Matagorda Island, San Jose Island, and central Padre Island.
- Long-term erosion at an average rate of -1.8 ± 1.3 m/yr characterizes 64% of the Texas Gulf shoreline. Although only 48% of the shoreline experienced short-term erosion, the average short-term erosion rate of -2.6 m/yr is higher than the long-term rate, indicating accelerated erosion in some areas. Sargent Beach is a good example of accelerated erosion. Since the mid-1800s, Sargent Beach has retreated almost 700 m at an average rate of -4.4 ± 2.2 m/yr. That rate has increased to -6.4 m/yr since the 1970s. Here the beach is steep, narrow, and composed of many clam and oyster shells that normally grow in the bays but not in the open Gulf. The absence of dunes and presence of a low overwash terrace that forms the backbeach are clear indicators of the rapid erosion and frequent storm waves that are responsible for the rapid land loss. Sargent Beach is far from sand sources and engineering projects and yet there is an unmistakable connection between updrift activities and the accelerated erosion. In 1929, the mouth of the Brazos River was relocated so that the entrance to Freeport Harbor would not shoal when the river flooded. After the river diversion, a delta formed at the river mouth and trapped the sand that normally would have flowed toward Sargent Beach."
Also see the USGS site on Coastal Change Hazards: Hurricanes and Extreme Storms which provides links to their growing list of products. Shortly after Hurricane Ike (September 2008) they posted a strip of post-storm oblique photos covering much of the north Texas and west Louisiana coast (via a Google Earth .kml file), along with pre/post storm photo comparisons.
The Website of Richard L. Watson, a consulting geologist, has several reports concerning coastal erosion in Texas. http://texascoastgeology.com/report.htm
The Heinz Center's Evaluation of Erosion Hazards, conducted for the Federal Emergency Management Agency (FEMA), studied the causes of coastal erosion hazards and proposed a variety of national and regional responses. The study, published in April 2000, concentrates on the economic impacts of erosion response policies as well as the cost of erosion itself to homeowners, businesses, and governmental entities.
A NOAA website that has graphs of sea level data for many coastal locations around the country over the last 40 to 50 years and projections into the future is Sea Levels Online.
NOAA Shoreline Website is a comprehensive guide to national shoreline data and terms and is the first site to allow vector shoreline data from NOAA and other federal agencies to be conveniently accessed and compared in one place. Supporting context is also included via frequently asked questions, common uses of shoreline data, shoreline terms, and references. Many NOAA branches and offices have a stake in developing shoreline data, but this is the first-ever NOAA Website to provide access to all NOAA shorelines, plus data from other federal agencies. The site is a culmination of efforts of NOAA and several offices within NOS (including NOAA’s Coastal Services Center, National Geodetic Survey, Office of Coast Survey, Special Projects Office, and Office of Ocean and Coastal Resource Management) and other federal agencies to provide coastal resource managers with accurate and useful shoreline data.
A related site launched in 2008 is NOAA Coastal Services Center's Digital Coast, which can be used to address timely coastal issues, including land use, coastal conservation, hazards, marine spatial planning, and climate change. One of the goals behind the creation of the Digital Coast was to unify groups that might not otherwise work together. This partnership network is building not only a website, but also a strong collaboration of coastal professionals intent on addressing coastal resource management needs. Website content is provided by numerous organizations, but all must meet the site’s quality and applicability standards. More recently, NOAA Coastal Services Center has developed a Sea Level Rise and Coastal Flooding Impacts Viewer as part of its Digital Coast website. Being able to visualize potential impacts from sea level rise is a powerful teaching and planning tool, and the Sea Level Rise Viewer brings this capability to coastal communities. A slider bar is used to show how various levels of sea level rise will impact coastal communities. Completed areas include Mississippi, Alabama, Texas, Florida, and Georgia, with additional coastal counties to be added in the near future. Visuals and the accompanying data and information cover sea level rise inundation, uncertainty, flood frequency, marsh impacts, and socioeconomics.
The Heinz Center report notes that states bordering the Gulf of Mexico have the nation's highest average annual erosion rates (6 feet/year). The rates vary greatly from location to location and year to year. A major storm can erode the coast inland 100 feet or more in a day.
You might also try the Texas Sea Grant Website.
Erosion Contact Info
Planning, Permitting & Technical Services
Texas General Land Office
Phone: (512) 463-8664
Hazard Avoidance Policies/Erosion Response
See the Erosion Response section.
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