«John S. Jacob, Ph.D. Ricardo Lopez, M.S. Heather Biggs, M.S. Texas Coastal Watershed Program Texas Sea Grant/ Texas Cooperative Extension The Texas ...»
Anticipated Local Response to Sea Level Rise Along
the Texas Coast:
A First Approximation
John S. Jacob, Ph.D.
Ricardo Lopez, M.S.
Heather Biggs, M.S.
Texas Coastal Watershed Program
Texas Sea Grant/ Texas Cooperative Extension
The Texas A&M University System
December 20, 2007
Table of Contents
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
CONTROLLING LEGAL ISSUES FOR SEA LEVEL RISE RESPONSE IN TEXAS............. 8 COUNTY DESCRIPTIONS
SAN PATRICIO COUNTY
APPENDIX A: GEO-SPATIAL PROCESSING
APPENDIX B: METADATA
1. SLRR EXISTING DEVELOPMENT FOR TEXAS COASTAL STATES................. 56
2. SLRR NEW DEVELOPMENT FOR TEXAS COASTAL STATES 2007-2040....... 63
3. SLRR STUDY AREA
List of Tables
1. Public and private landowner classifications
2. Summary of GIS data applied in study
3. Population Growth in Texas Coastal Counties, 2005-2040
4. Informants List of Figures
1. Map of Project Study Area
2. Schematic of Legal Controls on Development on Gulf and Bayside Shorelines
3. Map of Projected Population Increase from 2005 to 2040
4. Sea Level Rise Response in Orange County
5. Sea Level Rise Response in Jefferson County
6. Sea Level Rise Response in Chambers County
7. Sea Level Rise Response in Harris County
8. Sea Level Rise Response in Galveston County
9. Sea Level Rise Response in Brazoria County
10. Sea Level Rise Response in Matagorda County
11. Sea Level Rise Response in Jackson County
12. Sea Level Rise Response in Calhoun County
13. Sea Level Rise Response in Refugio County
14. Sea Level Rise Response in Aransas County
15. Sea Level Rise Response in San Patricio County
16. Sea Level Rise Response in Nueces County
17. Sea Level Rise Response in Kleberg County
18. Sea Level Rise Response in Kenedy County
19. Sea Level Rise Response in Willacy County
20. Sea Level Rise Response in Cameron County
This report was prepared under contract to Industrial Economics, Inc., in consultation with Jim Titus of the EPA. The purpose of this project was to prepare a set of maps
showing anticipated local response to sea level rise in 17 Texas Coastal Counties:
Jefferson, Orange, Chambers, Galveston, Harris, Brazoria, Matagorda, Jackson, Calhoun, Refugio, Aransas, San Patricio, Nueces, Kleberg, Kenedy, Willacy, and Cameron. This report is part of a national effort on the part of the Environmental Protection Agency to begin a national assessment of the impacts of sea level rise and to begin to encourage long-term thinking and planning for sea level rise by local officials.
The maps presented here are based on extensive conversations with local experts as well as our own local knowledge (particularly in Galveston Bay region counties).
The principal assumption of this report is that people will protect developed areas along threatened shorelines. We make no assumptions as to the degree of effort that people might make, nor as to the effectiveness of their efforts. Our maps show where these efforts can be expected to take place in the next 20-30 years. There can be little doubt that greater or lesser efforts will be made as sea level rises, and difficult choices have to be made. The maps in this report basically assume that if resources were sufficient, all of the indicated areas where protection is certain or likely would have a substantial protection effort.
In order to represent the areas that would mostly likely be affected by sea level rise, a
mask for the study area was created. Two main components for the study area include:
1. Elevation: Less or equal to 20 feet (6.096 m)
2. Shoreline Buffer: Less or equal to 1000 feet. The buffer was used to complement the first criterion (elevation) in shoreline areas with high elevation values where otherwise only a very small strip would be shown.
The following categories, laid out by Industrial Economics and the EPA, were used for
1. Shore Protection Almost Certain: Any currently developed areas, including areas of somewhat spotty development, where we assume that the whole area would be subject to protection. We used no strict rule or protocol to make this determination.
Certainly if an area had 50% or more development, we would categorize the entire area as Almost Certain. But many areas of significantly less than 50% development were also categorized as almost certain protection. If substantial infrastructure (especially roads) were already in place, then it seemed obvious to us that protection would occur in the entire area.
Within this category we also included areas not yet developed, but that are already slated for development, or where there is good agreement that development is ―imminent‖. The printed maps delivered with this project show a single ―Almost Certain‖ category, but information on existing and yet-to-be-developed areas is preserved within the GIS shapefiles associated with this project.
2. Shore Protection Likely: Areas forecast to be developed within the next 30 or so years, and not within currently developed or very soon-to-be-developed areas. The current map is based on personal and expert knowledge of areas undergoing development and corridors that will likely see development in the future.
We did not include areas that were excluded from insurance under the Coastal Barrier Resources Act (CBRA) in this category. Many of these areas are already protected as state parks (e.g., Matagorda Island and Mustang Island State Parks).
The non-state park CBRA areas theoretically could be developed by self-insured developers with deep pockets, but our informants did not think this was likely within the time frame of this report.
3. Shore Protection Unlikely: All croplands, rangelands, and woodlands that are not wetlands or areas otherwise shielded from development. No development is foreseen for these areas.
4. Wetlands. Wetlands from the NWI maps (1993). These include both palustrine, estuarine, and lacustrine wetlands. We excluded diked, excavated, and farmed wetlands. The printed maps do not differentiate between palustrine and estuarine wetlands, but the information is preserved in the digital GIS associated with this project.
5. Conservation Lands. Known conservation areas with permanent or long term (+100 yrs) easements. Most of these areas probably would not be subject to protection against sea level rise.
Table 1. Public and Private landowner classifications
Figure 1: Project Study Area
CONTROLLING LEGAL ISSUES FOR SEA LEVEL RISE RESPONSE IN TEXASAfter market forces, the next largest controlling factor of where development will go is the law, i.e., where can one legally build? The focus of this section is on laws and regulations that control or limit development near the shoreline.
The major state controlling laws for development in Texas coastal areas are the Open Beach Law (Title 12, Section 61), the Coastal Public Lands Management Act (Title 12, Section 33), and the Dune Protection Act (Title 2, Subtitle E, Chapter 63). The major federal controlling law is Section 10 of the Rivers and Harbors Act, and to a lesser extent Section 404 of Clean Water Act. Figure 1 graphically displays the spatial controls of these laws. There are no state wetland laws of any significance.
The State of Texas has exclusive control over state lands. The most important category of state lands in the coastal zone is ―submerged lands‖, defined as lands within tidewater limits (§33.004). Within these lands, the State, through the Texas General Land Office, can control any construction or significant land modification. The state rarely cedes complete control of its lands; the applicant or potential user of the land must obtain a lease or an easement from the state.
Submerged coastal lands in Texas are also governed by Section 10 of the federal Rivers and Harbors Act. The submerged lands are owned by the State of Texas, but are also considered ―waters of the U.S.‖ Because most of the submerged lands are owned by the State of Texas, relatively few development projects are likely to occur directly on these lands. But permits can be obtained for piers, jetties, bulkheads, etc, that impinge on these waters, and it is unusual that one or another of these structures is not present where development occurs adjacent to these waters or submerged lands. For these kinds of developments, an easement or lease from the General Land Office must be obtained as well as Section 10 permit from the U.S. Army Corps of Engineers.
Through the Open Beaches Act, additional state control above the mean high tide is extended to the vegetation line on beaches fronting the Gulf of Mexico, even though these lands are for the most part privately owned. In addition, critical dune areas behind the vegetation line on the Gulf of Mexico are subject to additional protection through the Dune Protection Act. All dunes on Gulf-of-Mexico-fronting shorelines are considered to be ―critical‖.
Although the Gulf of Mexico beaches are theoretically well protected against development through the Open Beaches Act, the private lands adjacent to these beaches are subject to intense development pressure. The prohibition against development on private lands between the mean high tide and the line of vegetation (LV) is well established in state law. Landward of the LV, the state Dune Protection Act (Natural Resources Code, Chapter 63) requires that local governments establish a dune protection plan, and most of these require a minimum setback landward of the LV. The dunes landward of the LV usually have some kind of protection, but development on them can and does occur under permit conditions of ―no net loss‖.
The use of the Line of Vegetation, as the landward line of public access and state control, means that the state essentially has a ―rolling easement‖ on these lands, given that the line is subject to change from storms and sea level rise. Sellers are in fact required to notify potential buyers of property fronting the Gulf of Mexico of the potentially changing line.
Gulf of Mexico beach-front development cannot legally be protected from erosion by armoring, except under a few exemptions. The rolling easement and prohibition against armoring does not mean that landowners cannot undertake protective measures. Beach nourishment is allowed and in fact encouraged along most of the coast, as long as it follows the stipulations of the state Coastal Erosion Protection and Recovery Act.
Structural methods such as sand-filled geotubes are also allowed under current interpretation of state law. Where these geotubes are in place, they have become the effective LV (Ray Newby, TXGLO, personal communication). It remains to be seen how interpretations will change if a major storm effectively moves the LV landward of existing geotubes. If geotubes are used, then the landowners are also required to maintain the existing beach width through nourishment.
The bottom line for this area of Texas is that development is likely to occur near the Gulf shoreline for the foreseeable future as long as federal flood and state wind and hail insurance can be obtained. The only areas where this insurance is not available are in areas governed by the federal Coastal Barriers Resource Act (CBRA).
On bayside shorelines, there is no guaranteed public access or state control above the mean high tide line. Marina developments will continue to occur on bayside properties, and easements will be granted to dig canals through submerged lands to open bay waters, but relatively little development is likely to occur in Section 10 estuarine wetlands/ submerged lands of Texas because both a Section 10 permit is required as well as a lease or easement from the state. Development adjacent to these lands can occur with little or no restrictions. Bulkheads can be built just adjacent to submerged lands without a permit as long as they are just inside the upland line.
Section 404 of the Clean Water Act theoretically prohibits development in wetlands other than those covered by Section 10 of the Rivers and Harbors Act, but permits are generally easier to obtain for inland wetlands than for estuarine wetlands.
Figure 2. Schematic of Legal Controls on Development on Gulf and Bayside Shorelines
COUNTY DESCRIPTIONSThe majority of the Texas coastal counties are increasing in population. Over 6 million more people are expected to move to the Texas Coast over the next 30 years. This is over twice the current amount. Kenedy county, where the majority of the land is primary owned by the Kenedy and King Ranches, is the only county that is expected to decrease in population. A brief description of the growth patterns as well as the current land uses for each of the coastal counties is explained in the county summaries below.
Table 3 and Figure 3 depict the percent of change as well as the increase of population within each county between 2005 and 2040. The maps corresponding to each county description demonstrate the categories outlined by Industrial Economics and the EPA mentioned earlier in this report.
Table 3. Projected Population Growth in Texas Coastal Counties
Figure 3: Map of the Projected Population Increase from 2005 to 2040 (Harris County increase not to scale) Source: Derived from Texas State Data Center and Office of the State Demographer, Data from the Texas State Demographer’s Office. Accessed October 2007.