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U.S. Department of the Interior - Office of Policy, Management and Budget
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Chapter 9: Galveston Bay of Texas


Physical Description: The Galveston Bay region encompasses approximately 600 square miles of a highly productive and diverse ecosystem on the upper Texas coast. The major components of the system include the Trinity and San Jacinto Rivers and myriad streams, bayous, and other freshwater runoffs and inflows along with four bays: Galveston, Trinity, East, and West. (See Figure IX-1.)


The Galveston Bay System

Characteristics and Functions: The Galveston Bay region
  • Supports the most productive commercial and sports fisheries on the Texas coast (the fin and shellfish were valued at over $64 million from 1977 through 1983);
  • Serves as the endpoint of congregation for the largest number of waterfowl found anywhere on the Central Flyway;
  • Sustains a number of furbearing species of economic importance including the river otter, muskrat, and nutria;
  • Includes the Menard Creek Corridor of the Big Thicket National Preserve along with the Anahuac and Brazoria National Wildlife Refuges (total acreage, 13,680);
  • Hosts eight federally-listed endangered or threatened species and five State-listed endangered species;
  • Buffers inland areas from storm waves and tidal surges and treats runoff waste from agricultural, urban, and industrial sources;
  • Contains highly valuable marine resources (e.g., food, recreation, waste assimilation, flood control, energy flow, and transport).
NOTE: If this table does not appear as a table, please click on this link to view it as a graphic file.
Table IX-1 (9Kb gif)
Table IX-1: Wetland Acreage in the Galveston Bay Region, 1956 & 1979
Habitat Type 1956 1979 Percent Change

73,017 67,325 -12.6
154,588 130,397 15.6
Marine Beach Bar
3,015 1,413 -53.1
Deeper Water

River Bottom
3,499 3,835 +9.6
Saline Open Water
363,213 388,397 +6.9
Source: U.S. Fish and Wildlife Service, National Wetland Research
Center, Slidell, LA, unpublished data, 1989.

Original Acreage: The number of wetland acres in the Galveston Bay region at the turn of the century is not known.

Current Acreage: About 203,000 acres remained in 1979. However, this figure includes some marshes that have since eroded or subsided to become shallow, unvegetated, water bottoms.

Trends: From the mid-1950s through the 1970s, the Galveston Bay area lost about 1,110 acres per year to open water. The rate of loss appears constant, except when hurricanes and tropical storms blow through. In addition to the quantitative loss, pollutants have exceeded the assimilative capacity of the area, and wetlands are declining in quality. f 

Factors Adversely Affecting Wetlands  

Agriculture based on rice and cattle accounted for the early loss of wetlands. Agricultural conversions have diminished, and the key factors contributing to wetland decline today are (1) industrial development, including oil and gas development and refining; (2) urbanization; (3) navigation channels; (4) flood control and multipurpose water projects; and (5) pollution due to industrial, urban, and agricultural runoff.

An industrial "flight to the south" occurred from 1972 through 1978 largely because of substantial tax breaks to industries by certain southern States (including Texas) and relatively cheap labor. In particular, the size of petrochemical refineries increased dramatically. In addition to the labor cost and tax incentives, the petrochemical expansion was driven by ready access to oil and gas supplies, shipping, and pipelines, the OPEC oil embargo, and a series of severe winters in the north. The Texas Gulf now has the world's largest petrochemical capacity. The area has the nation's most important supply of natural gas, refines 6 percent of the nation's gasoline, and provides the organic chemicals that serve as the feedstock for plastics, synthetic fibers, solvents, surfactants, and pharmaceuticals.

Industrial wastes abound and infiltrate channels which carry them to the bays. Crude oil processing, for example, requires an average of 18 gallons of water per gallon of oil. Ten to twenty percent of this water comes into direct contact with oil and chemicals in the refining process. The processing water is commonly contaminated with oil, grease, phenolic compounds, sulfides, cyanide, ammonia, suspended and dissolved solids, and various other chemicals. Extraction adds brine to the contaminant load. The pollutants from refining and extraction overtax the purifying capacity of wetlands and lead to fish kills.

Sections 402 and 303 of the Clean Water Act are the primary methods of dealing with water quality. The Act works through two sets of standards. The first, effluent standards determined by the Federal Government, are technology based,1 and limit the pollutants that may be discharged from a particular kind of industrial source. These standards are enforced by the National Pollution Discharge Elimination System (NPDES) which makes it unlawful for point sources, such as discharge pipes and conduits, to discharge designated pollutants without a permit. NPDES permits for toxic discharges from point sources must meet both effluent limitations and water quality standards. The second set of standards, water quality standards, includes designated uses of waters, narrative and numeric criteria, narrative biological criteria, and an anti-degradation policy. States classify waters based on uses set forth in the Clean Water Act: public water supplies; protection and propagation of fish, shellfish, and wildlife; recreation; agricultural, industrial, and other purposes including navigation. Thus, allowable pollutant concentrations differ according to the designation of the particular stretch of stream. However, the regulations prohibit designations such as waste transport or waste assimilation, i.e., primarily to receive pollutants.

Several problems have been identified with current water pollution control practices as applied to the Galveston Bay system:

  • Contaminants concentrate in sediments at the disposal sites for brine and other effluents. Organisms living and feeding in the Bay sediments at these disposal sites are affected by the concentrated contaminants. Permittees are not currently required to monitor the concentration of contaminants in the sediment at discharge points.
  • Waters flowing through the Houston Ship Channel, a stream segment designated for high pollutant concentrations, flow downstream into a designated fish spawning area, and eventually flow out into the Galveston Bay, an area of significant importance for commercial and sport fisheries. EPA regulations require that when designating uses, water quality standards shall provide for the attainment and maintenance of the water quality standards for the downstream waters outside of the mixing zone (the zone within which an effluent combines with the receiving water body). For Galveston, this requirement applies to the downstream fish spawning area and Galveston Bay. Texas water quality standards allow for a 200-foot mixing zone, but survey data have demonstrated that over time downstream sediments outside of the mixing zone are accumulating high levels of regulated contaminants.
  • Although EPA guidance requires that stress which lowers reproductive capacity be taken into account in determining water toxicity, in the field, stress tests are infrequently required of permit applicants.
Urbanization is taking its toll on area wetlands. The Houston-Galveston area, about half of which is located in the Galveston Bay Region, was the fastest growing metropolitan area in the U.S in 1980.2 Despite a current economic slow-down, building continues as developers follow through on projects planned and funded ten years ago. Local urban complexes sprawl outward in all directions, but development west and southwest of Houston, and also on the west end of Galveston Island, is converting riparian and marsh habitats to a high density area of housing developments, condominiums, and beach front homes. Water, power, and sewer lines along with highways crisscross the area. Besides depleting wetlands directly through construction activities, urban development increases flood damage by replacing the absorption capacity of the wetlands with impermeable roofs and blacktop. Rushing water floods many areas around Houston after two or three-inch rains. The pollutant-laden runoff often contaminates water channels and ultimately degrades wetland areas.

Navigation projects along the Texas Gulf Coast include 720 miles of shallow draft channels, 260 miles of deep draft channels, and 12 deep water ports. Two navigation channels, the Gulf Intracoastal Waterway (GIWW) and the Houston Ship Channel (HSC), have had the greatest impact. The GIWW extends 426 miles along the Texas coast, a continuous swath, a minimum of 150-foot wide and 12-foot deep. The Houston Ship Channel is a deep draft waterway, 51 miles long, 400 feet wide, and 40 feet deep. Both channels have the same kinds of effects on wetlands, but the HSC's impact has been far greater. Construction and maintenance of the GIWW produced 51 million cubic yards of spoil from 1932-1972; the HSC generated 4 times as much, 220.5 million cubic yards. Much of this was originally deposited in surrounding wetlands although there is no estimate of the numbers of acres affected. Spoil is deposited on the bay bottom where it reduces biological productivity. Project planning has had little impact on the mode of moving products (e.g., pipe vs. channels), the location or size of channels, and the location and size of disposal areas.

In addition to creating upland out of wetland and smothering various life forms, dredging alters water flow and resuspends sediment pollutants. The spoil material is contaminated with oil, grease (hydrophobic carcinogens), heavy metals, and pesticides, which are transported out of the channels and into shallow bays. The growth of urban development and industrial activities increases the contaminant level. Biologists worry about the geometric accumulation of these pollutants as they progress up the food chain, but have yet to study it carefully. Contamination from spills of oil or chemicals would be severe. Wetlands adjacent to the channels are eroded by barge wakes and altered by the wedge of heavier saltwater that intrudes up the channels. Freshwater impoundments upstream on the Trinity and San Jacinto Rivers designed to meet Houston's future water demand will aggravate the saltwater intrusions by decreasing freshwater inflow.3

Flood control and multipurpose projects have also taken a toll on wetlands in the Galveston Bay Region. For example, all but a fraction of the 1000 square mile drainage area of the Buffalo Bayou and tributary channels have been cleared, straightened, enlarged, or concrete-lined for flood control. Only 19 miles have not been altered by channel work. These projects clear vegetation (often bottomland hardwoods) from the channel rights-of-way. Urban and agricultural activities then encroach on these areas, exacerbating habitat loss and, ironically, flood damage. In the five years from 1972 through 1977, Harris County lost five percent of the floodplain forests in the 100-year floodplain. With the loss of filtering vegetation and the increase of development, the water quality degrades rapidly. The channels also create islands out of wetlands, thus restricting the movement of organisms and the support systems available to them. Both of these consequences of isolation increase the vulnerability of the wetlands.

Agriculture has destroyed and altered thousands of wetland acres, many of which were drained for rice and soybean planting. Drainage ditches collect and concentrate agricultural runoff. The contribution of upstream drainage projects adds to the pollutant load. No nonpoint source pollution controls are now in effect to control this discharge. Modifying the watershed flow with drainage ditches has also meant that water no longer spreads in sheets across wetlands, nourishing marshes and settling contaminants, but instead flows rapidly into the bay via dredged channels.

Federal Programs and Projects  

Among the major Federal programs and activities that affect wetlands are multipurpose flood control, water supply, and navigation projects, as well as Federal programs that provide incentives for urban development. Although Federal programs to construct and advise on the construction of drainage ditches have destroyed wetlands in the past, these programs no longer seem to affect significant wetland acreage.

Water Projects

Multipurpose: A multipurpose project -- for salinity control, navigation, water supply, and fish and wildlife enhancement -- at Wallisville Lake is likely to have significant negative impacts on the Galveston Bay system. It will cost $352.6 million initially and $1.5 million each year to maintain. The project is heavily subsidized, with the Federal Government contributing about 40 percent of the construction cost and the annual O&M being shared equally.

In 1973, the district court enjoined the 75 percent completed project due to deficiencies in the Environmental Impact Statement (EIS). After the Corps redesigned the project, the district court refused to lift the ban. But on appeal in 1987, the circuit court allowed the redesigned project to go forward.

The Wallisville Lake Project will fill 75 acres of brackish marsh, and flood 588 acres of bottomland hardwoods and 3,103 acres of cypress swamp. By isolating habitat behind the dam and blocking sediment, nutrients, and freshwater input into the Galveston Bay and surrounding wetlands, the project will result in a $700,000 to $1 million (1974 dollars) annual loss of fisheries.4 Eventually, salinity increases in the bay and coastal marsh (because of the lack of freshwater inflow) will degrade nursery habitat for estuarine and downstream freshwater species. By preventing sediment flow to Galveston Bay, reservoirs contribute to marsh deterioration and conversion to open water habitat. These changes are particularly evident at the river delta of the Trinity and San Jacinto Rivers.

Navigation: Despite the problems from saltwater intrusion, the Corps is planning to enlarge the Houston Ship Channel from 400 feet wide by 40 feet deep to 600 feet wide and 50 feet deep. This will cost $197.86 million initially and $1.05 million each year thereafter to maintain. It would convert 892 acres of bay bottom to channel bottom. The Corps computed a favorable benefit-cost ratio based on transportation cost savings for imported crude oil and grain export. The FWS identified negative consequences for fisheries and estimated that 1900 acres would be required to mitigate oyster bed damage. The Corps' plans called for replacement of only 400 acres. As a result of the administrative appeals process, studies are underway which address hydrodynamic/salinity effects on oyster reefs, the rate of recovery of benthic communities, and possible beneficial uses of dredged material. The supplemental EIS for the HSC is due in early 1993.

Flood control: The Army Corps of Engineers is investigating the feasibility of flood control projects for ten major urban bayous and thirteen minor bayous and the feasibility of supplying water from ponds in two flood control reservoirs. These projects would destroy riparian habitat, reduce instream species diversity to foraging fish, and contribute to pollution and irregular flood flows into the bays. 

Urban Development 

A number of Federal programs are designed to encourage urban development. The tax deductibility of mortgage interest and local property tax together with HUD, VA, and FEMA programs provide several key incentives. HUD provides assistance for low income housing, and HUD, FmHA, and the VA provide mortgage insurance for homes. In addition, lending institutions benefit from being able to sell loans into the secondary market, a market which is facilitated by the activities of a number of federally sponsored agencies.5

In the Houston area HUD insures 5 to 10 percent of the housing developments. The Fish and Wildlife Service has registered concern about the adequacy and timing of HUD's EISs. A 1978 review of 56 different housing projects covering 58 square miles in the Houston area showed that 97 miles of stream were channelized or proposed to be channelized in conjunction with the HUD projects, resulting in a loss of 4000 acres of floodplains and degradation of 3000 acres of riparian habitat. The FWS also found that EISs are sometimes issued after land has been cleared or construction initiated. In 1978, because of heavy workload pressures, HUD decided to conduct an EIS investigation only for subdivisions over 2500 units, rather than for those over 500 units, as had been the policy. Since 1978, there has been a marked decrease in the EISs available for review and comment.

In the last few years, HUD has implemented new procedures under the Wetlands Executive Order. Before acting on applications for loan guarantees for proposed subdivisions in the 24 surrounding counties, HUD's Houston office requests a determination of wetland effects from the Corps. Projects have either been redesigned to avoid impacts, or mitigation has been undertaken where redesign has proven impractical.

Additional support for urban development comes from the Federal Emergency Management Agency (FEMA) which offers subsidized flood insurance to homeowners outside of the designated 100-year floodplain and within it if structures are elevated above it. In the five counties included within or overlapping the Galveston Bay Region, FEMA paid $241.6 million in claims during the first three months of 1986, a quarter of the claims statewide due to hurricanes and flooding. This subsidy reduces the risk of locating in the floodplain. As long as this program continues to underwrite urban developments that reduce wetlands and their flood attenuating capacity, insurance claims will continue to rise.


Construction and technical assistance for drainage projects was common in the 1950s and 1960s, but no new projects are underway. Rice and soybeans dominate production. The major impact of agriculture on wetlands today is water quality degradation from drainage. Neither Federal nor State regulations adequately address "nonpoint" source water pollution.

Status and Prospects 

Water quality degradation is the chief wetland problem facing the Galveston Bay Region. This results from having the largest petrochemical capacity in the world and the most important supply of natural gas in the nation. It also results from urban runoff in an area where population is expected to climb further and from agricultural runoff which could decline. The population pressure, however, will transform agricultural land into urban areas, exacerbating runoff problems by covering soil with blacktop. Although industrial and urban development receive some impetus from Federal funds, the major factor in the water quality problem is regulatory. Federal navigation and flood control channels, concentrate and speed contaminants to the bay system, and thus exacerbate the pollution problem.

Urban developments that take place in floodplains and along the coast often occur in the absence of a regional plan or local zoning. This destroys wetlands through construction, and degrades them by reducing their capacity to absorb floodwaters and purify contaminants. Flood insurance offered by FEMA serves to reduce the risks associated with such development. HUD may also encourage inappropriate development by not requiring adequate and timely environmental impact statements for projects receiving guaranteed loans.

Water projects also affect wetlands. The maintenance and expansion of existing navigation channels, the construction of additional flood control projects, and the creation of the Wallisville Lake project to offset the intrusion of saltwater up the Trinity River6 all destroy and degrade wetlands. Dredging channels stirs up and spreads contaminants. Water projects also displace wetlands and generate spoil that is often dumped in marshes and bays. Moreover, the project costs have been largely underwritten by the Federal Government, while the users of navigation channels and beneficiaries of flood control have contributed very little. The federally subsidized navigation and flood control facilities provided the infrastructure which has allowed much of the present industrial development and urban growth to take place in the Galveston Bay Region. The greater cost sharing required by the Water Resources Development Act could constrain the demand for new projects somewhat.


  1. Interagency Land and Resource Management:
    a. Federal environmental evaluation documents (Environmental Assessments and Environmental Impact Statements) should disclose whether the projects being evaluated are in compliance with the forthcoming Comprehensive Conservation and Management Plan for Galveston Bay.
    The Galveston Bay National Estuary Program is close to completing its Comprehensive Conservation and Management Plan (CCMP) which addresses all Federal, State, and local programs affecting the biological integrity of the Galveston Bay Estuary. The Galveston Bay Region has suffered from the lack of local or regional plans and possibly from failure on the part of the Federal Government to use existing authorities to protect wetlands to the fullest extent. Water pollution control, floodplain development, and urban growth in wetland areas are being addressed in the CCMP. The CCMP was mandated by the Water Quality Act of 1987, and when completed, will have the force of law. Federal projects which could affect the Galveston Bay must comply with the provisions of the CCMP.
    b. Consider requiring all Federal assistance programs to comply with conservation, mitigation, and reporting requirements like those contained in the Electric Consumers Protection Act.
    The ECPA requires that the following conditions must be met before a new construction project is entitled to PURPA tax benefits: (1) the project must not have significant adverse effects on the environment, including recreation and water quality; (2) the project cannot be located on a State or national wild or scenic river system which would be adversely affected; and (3) the project must comply with recommendations made by the resource protection agencies or explain why this is not possible in terms of primary agency mission. If these conditions have merit with respect to hydroelectric power development, perhaps they should apply to all Federal projects. Most, but not all agencies consult with the FWS if a project will have a major impact on wetlands. But they are not required to implement those recommendations or even to explain why the recommendations should not be implemented. This allows agencies a great deal of discretion in disregarding advice that would improve wetland quality. Requiring consultation and an explanation when the results of the consultation are not heeded could promote greater reflection and more thorough consideration of alternatives to projects with wetland impacts.
  2. Urban development:
    Restrict Federal funding for mortgage insurance and national flood insurance for urban development projects in wetlands.
    The population in the Galveston Bay Region is projected to increase by 34 percent between 1980 and 1995. This could increase contamination from urban runoff, destroy the vegetation that helps to absorb flood waters, and cause more draining and filling of wetlands. Existing mechanisms such as environmental impact statements and flood insurance rate maps have not substantially discouraged development in wetlands. A subsidy-free zone would correct market distortions which add inappropriately to developmental pressures in these wetlands.
  3. Water quality regulation:
    Examine the current approach to the regulation of water quality, particularly the National Pollution and Discharge Elimination System (NPDES), as it applies to wetland impacts and develop a more effective system of pollution control.
    In many areas, degradation of water quality is an even more serious problem than loss of wetland acreage. In the Galveston Bay, water quality is seriously impaired by oil refining processes that require 18 gallons of water per gallon of oil and by agricultural runoff. Problems with Section 402 of the Clean Water Act as it pertains to point sources are:
    • Contaminants concentrate in sediments at the disposal sites for brine and other effluents. Organisms living and feeding in the Bay sediments at these disposal sites are affected by the concentrated contaminants. Permittees should be required to monitor the concentration of contaminants in the sediment at discharge points.
    • Although EPA guidance requires that stress which lowers reproductive capacity be taken into account when determining water toxicity, stress test are infrequently required of permit applicants.
    • The Texas classification of stream segments according to different concentrations of pollutants relies on models that assume no impact beyond 200 feet, even though such impacts are significant.
    Nonpoint sources represent a major factor in the decline of wetland water quality. Agricultural drainage has an enormous impact on water quality not only in Texas, but in wetlands throughout the nation, including the Florida Everglades, the Delmarva Peninsula's drainage into the Chesapeake Bay, and the Central Valley in California. Stormwater discharges and return flows normally funnel out through carefully engineered collection systems and well-defined ditches, making them potentially accessible to water quality improvement measures.


Administration Position on Clean Water Act Reauthorization Issues, October 29, 1993.

Cain, B. W. 1986. Personal communication--Fish and Wildlife Service. Re: toxic waste and NPDES system in the Galveston Bay Region. Interview, August 20, 1986.

U.S. Congressional Budget Office. 1989. Reducing the Federal Deficit: Spending and Revenue Options, A report to the Senate and House Committees on the Budget--Part II, as required by P.L. 93-344, 1989 Annual Rept., Government Printing Office, Washington, DC, February.

Whitehead, E. Dawn. 1987. Impacts to Wetlands of the Galveston Bay Region and the Federal Role. Background Report. Office of Policy Analysis, U.S. Department of the Interior, Washington, DC, 31 pp.


1 The best available technology economically achievable as established by EPA.

2 In 1980, the population was about 3.1 million, and is projected to swell by 34 percent to 4.7 million by 1995. Immigration accounted for over half the growth.

3 The Congressional Budget Office has suggested two changes that could shift a greater portion of the costs of navigation projects from the general public to the users. First, noting that the Federal Government recovers only about 40 percent of the costs of channel dredging for harbor maintenance, the CBO states that raising the harbor maintenance tax from 0.04 percent to 0.12 percent of the cargo's value would lower the deficit by $1.5 billion from 1990-1994. Second, noting that in 1989, revenues from the Inland Waterways Fuel Tax will cover about 22 percent of waterway construction costs (about $200 million) but no O&M costs (about $300 million), the CBO states that imposing a user fee to cover O&M would save the Federal Treasury $1.775 billion from 1990-1994. Implementing these recommendations would mean that shippers would press only for those projects where benefits would be expected to exceed the fees thy would have to pay. Moreover, user fees on the inland waterways could encourage shippers to use existing capacity more efficiently, reducing the need for new construction to alleviate congestion. Less construction activity would reduce the amount of dredging and filling with their attendant negative wetland impacts. (CBO 1989)

4 National Marine Fisheries Service estimate.

5 Both federally insured lenders and conventional lenders benefit from being able to sell loans into the secondary market, which includes agencies and government sponsored enterprises such as the Government National Mortgage Association, the Federal National Mortgage Association, and the Federal Home Loan Mortgage Corporation. Such entities can package and securitize the loans, thereby attracting capital for housing from investors interested in mortgage backed securities. The securities are highly rated because of the backing of these entities.

6 The saltwater intrusion was exacerbated by the HSC, a channel which is scheduled for expansion.

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