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Chapter 8: Coastal Louisiana


Physical Description: Coastal Louisiana embraces one of the most wetland-rich regions of the world, with 2.5 million acres of marshes (fresh, brackish, and saline) and 637,400 acres of forested wetlands. It contains about 40 percent of the coastal marshes in the coterminous United States. Wetlands border the entire Gulf of Mexico shoreline and extend inland more than 60 miles in some places. Coastal Louisiana's wetlands are bordered and interspersed with 1.8 million acres of ponds and lakes, 2.2 million acres of bays and sounds, and 8,200 miles of navigation, drainage, and petroleum access canals. Two physiographic units comprise the area: the Deltaic Plain on the east, formed by sediments from the Mississippi and Atchafalaya Rivers and the Chenier Plain on the west, formed by sediments from ocean currents. (See Figure VIII-1.)

Figure VIII-1: Physiography of Louisiana

Physiography of Louisiana

Characteristics and Functions: Coastal Louisiana influenced by its rich network of wetlands.

  • Contributes 28 percent to the total volume of U.S. fisheries ($321.5 million at dockside in 1986);
  • Leads the nation in trapping of fur-bearing animals and operates a highly regulated harvest of alligator skins;
  • Provides winter habitat for one-half to two-thirds of the Mississippi Flyway waterfowl population;
  • Contains one national park, seven national wildlife refuges, and fourteen State wildlife refuges and management areas; about 22 percent of the region is in public ownership;
  • Provides habitat for six federally-listed threatened and endangered species, including the bald eagle and the brown pelican.1
  • Reduces storm and erosion damage by curtailing tidal surge and wind velocities;2
  • Maintains water quality by filtering pollutants.3
Original Acreage: Coastal Louisiana contained 4.07 million acres of wetlands at the turn of the century.

Current Acreage: From 1900 to 1978, Louisiana lost about 22 percent (901,200 acres) of its coastal wetlands, with 3.17 million acres remaining in 1978. Conservatively, an additional 300,000 acres have been lost since then. Current loss rates are estimated to be about 0.75 percent per year.

Trends: From the mid-1950s through the late 1970s, Louisiana averaged a loss of 48 square miles of coastal wetlands per year. Recent figures suggest that the loss may have slowed to between 35 and 37 square miles per year. These figures contrast with the 6000 years prior to 1900 when Coastal Louisiana had an overall net gain of wetlands. At current rates, half of Louisiana's coastal wetlands (representing 20% of the coastal wetlands in the coterminous United States) could disappear over the next 100 years.

Factors Adversely Affecting Wetlands 

A combination of natural and human factors have caused the wetland decline. Natural factors include subsidence, erosion due to storms, and a change in sea level due to recovery from the last ice age and tectonic motion. Historically, sediment deposition from the Mississippi River largely offset any losses, but in the last century human activities have altered this process. Dams and levees along the Mississippi River now trap sediments before they reach the coastal plains. Exacerbating the problem is the threat of sea level rise due to global warming. Because of the interrelationship of factors responsible for wetland loss in Coastal Louisiana, accurate estimates of losses attributable to each factor are difficult to derive. Estimates span a broad range and suggest more about relative influence of the factors than their precise impact. The most recent study (Turner and Cahoon 1988) identified the causes of between 43-73 percent of wetlands losses. Canals and spoil banks (related to activities within and outside of the outer continental shelf (OCS)) accounted for 30-59 percent of the losses and land use changes for about 13 percent.4 The remaining 28-57 percent of the losses "may also be caused by OCS or non-OCS economic development, agricultural and urban expansion, and canals and spoil banks, but are likely to involve the more non-manageable influences, particularly water level rise, geological factors, and the decreased sediment content of the Mississippi River" (Turner and Cahoon 1988). About three-fourths of Louisiana's coastal wetland losses are conversions to openwater.

The single most important factor affecting wetlands has been the construction of levees to reduce the frequency and duration of flooding throughout much of the lower Mississippi River Valley. Levees have allowed for the large-scale conversion of forested wetlands to agriculture, the growth of urban areas, and industrial expansion in areas formerly plagued by frequent flooding. The levees have benefitted navigation by confining the river's flow to a smaller area, thereby scouring the bottom of sediment buildup more efficiently and raising water levels between the levees. The net result has been a deeper navigation channel with much less channel dredging than would have been required if the levees had not been built.

The hydrologic changes that made this economic development possible took their toll on wetlands. Levees prevent the historic overbank flow that transported huge quantities of fresh water and sediment to adjacent wetlands. The 961 miles of levees associated with the Mississippi River and Tributaries Project (MR&T) have largely halted the delta building process (except in Atchafalaya Bay). The delta building process is also affected by upstream reservoirs and flood control projects, resulting in the Mississippi River carrying about 60 percent less sediment than in the 1950s. Much of the sediment that does make it to the coast is shunted by the confined Mississippi River and dredged canals into deeper water where no delta-building takes place. In addition to restricting sediment replenishment, the flood control also deprives wetlands of freshwater, which served to dilute and keep the saltwater at bay. The cutoff of the riverine inflow allows for the intrusion of saltwater, which, in combination with the deep canals which allow for stratification and intrusion, hastens conversion of low-salinity marshes and forested wetlands to unvegetated, open water.

Whereas Mississippi River levees protect against riverine flooding, dikes protect against tidal flooding brought on by hurricanes. Dikes often enclose undeveloped wetlands; pumps are then installed to reclaim the wetlands. The increased flood protection and drainage leads to increased development of the enclosed wetlands. Three major Federal hurricane protection projects, when completed, will have enclosed over 19,000 acres and destroyed about 5800 acres of coastal wetlands directly via construction of dikes and excavation of material used in dike construction. Plans to mitigate some of these losses are underway.

Canal dredging occurs to create or deepen channels for navigation and to embed oil and gas pipelines. The dredging digs up sediment that is then deposited as spoil banks along the canals, thus filling existing wetlands. Canal dredging and spoil deposits accounted for between 30 and 59 percent of the coastal wetland losses in Louisiana from 1956-1978 (Turner and Cahoon 1988; Turner 1987). About 8200 miles of canals traverse the coastal wetlands.

The Corps dredges some of the navigation canals. About 550 miles of Federal navigation canals traverse Coastal Louisiana and range from 12 to 45 feet deep and 150 to 500 feet wide. The 302-mile Gulf Intracoastal Waterway is the largest of the seven main canals. Together these projects converted 17,878 acres of wetlands to open water due to excavation and another 76,676 acres due to filling with dredged material. About 274,000 additional acres disappeared in the affected drainage basins, largely as a result of the canals' indirect effects. The indirect effects are several times larger than the direct effects. (See discussion below.)

The oil and gas industry dredges other canals to transport barge-mounted oil and gas exploration and production equipment and to house pipelines. Although prior to World War II oil and gas fields were few, today more than 70 percent of the oil and 90 percent of the gas from U.S. coastal water comes from the Louisiana Coastal zone. (See Figure VIII-2.) In 1985, $27.1 billion in crude petroleum and natural gas was extracted from the wetlands. This amounted to 16 percent of the nation's total petroleum production and 29 percent of the natural gas production.

Figure VIII-2: Oil and Gas Fields in Southern Louisiana in 1941, 1964, and 1981

Oil and Gas Fields in Southern Louisiana in 1941, 1964, and 1981

Source: Turner, 1987.

In addition, over 152 pipelines come ashore from the outer continental shelf to the Louisiana Coast. Additional pipelines originating from State (near-shore) waters also traverse Louisiana's coastal wetlands. The Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) recently estimated that canal dredging and the concomitant levee construction due to offshore oil and gas activity accounts for 8-17 percent of total wetland loss in Coastal Louisiana (Turner and Cahoon 1988). The placement of onshore facilities supporting offshore oil and gas activities and access roads in wetland areas causes additional losses.

While the loss from the initial construction of canals is significant, the greatest damage occurs over the longer run. Canals widen over time converting wetlands to open water. It appears that boat traffic hastens canal widening; widening occurs less frequently with pipeline canals. The doubling rate for navigation canals averages from 5 to 35 years; the annual enlargement of the older canals now approximates the area of newly constructed canals. Hence, even if no new canals were built, those in existence will exert a continuing influence.

The indirect impacts of canals are considered to be significantly more important than canal widening. These impacts result from hydrological alterations brought on by canal dredging and spoilbank creation, leading to saltwater intrusion and the subsequent conversion of vegetated wetlands to open water or to more saline wetland types. Impoundment of wetlands deprives them of nutrients, sediments, and freshwater, thereby compacting soils and altering the flora and fauna. Pollutants from shipping and oil and gas development impair the water quality in the coastal wetlands. These impacts can occur away from the immediate area of the canal project, can manifest themselves years after canal construction, and can persist for a long period of time.

Although the Mississippi River levees, hurricane protection projects, and the canals for navigation and pipelines contribute most to wetland losses, filling for highway projects and agricultural and urban development have a significant impact in some areas. For example, between 1967 and 1984, four major Federal or federally aided highway projects in Coastal Louisiana destroyed 2640 acres of wetlands, and helped create the opportunity for additional development with attendant indirect wetland losses. In the Chenier Plain agriculture has accounted for 10.8 percent of the wetland loss and urban development for 2.5 percent. Between 1952 and 1974, agricultural land increased by 14,000 acres in southwestern Louisiana and southeastern Texas mainly at the expense of coastal wetlands. Urban development remains an important factor in wetland conversion in southeastern Louisiana. Between the mid-50s and 1978, developed land increased by 59,000 acres in the Deltaic Plain largely by diking, draining, and filling wetlands. Jefferson Parish experienced the greatest increase at 14,500 acres. The Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) estimates that together agricultural and urban development account for about 13 percent of Coastal Louisiana's wetland decline (Turner and Cahoon 1988).

Nearly all of this agricultural, urban, and highway development occurred without any action to offset wetland losses. The advent of Swampbuster has greatly diminished agricultural losses, however, and compensatory mitigation is now routinely required for urban development in wetlands as a condition for State and Federal permits. The recent experience of the Fish and Wildlife Service is that the FHWA and the Corps have become more responsive to wetland mitigation recommendations.

Federal Programs and Projects 

Federal flood control and navigation projects have had a major impact on the loss of Louisiana wetlands. Federal hurricane protection and highway projects have had a lesser impact, but are nonetheless important. Economic incentives offered by the Federal Government for oil and gas development, urban growth, and agriculture have also served to increase profits and led to conversion of wetlands.

Water Projects

The Federal Government has assumed responsibility for the planning, construction, and maintenance of an extensive system of flood control, hurricane protection, and navigation in Coastal Louisiana. Local interests have been the chief beneficiaries of flood control and hurricane protection projects. These projects not only protect existing development, but also create the opportunity for the conversion of additional coastal wetlands. Project beneficiaries typically have contributed only land and rights-of-way to the projects, a relatively small portion of the overall costs. However, the Water Resources Development Act of 1986 (WRDA), which requires greater cost-sharing by local beneficiaries, should reduce pressure for additional projects.

Flood control: Through 1985 the Federal Government invested over $5.9 billion on the Mississippi River and Tributaries Project throughout the Mississippi Valley.5 Almost 1000 miles of levees and other features comprising the Mississippi River Levees and Associated Works projects were constructed. This massive public works endeavor was constructed to prevent flooding of towns, cities, and agricultural lands, improve navigation, and facilitate commerce and trade. Almost all project benefits accrued locally, and there was very little mitigation of environmental damage.

With passage of the WRDA, Congress made substantial progress toward eliminating the subsidization of flood control, drainage, and navigation projects, as well as reducing the construction of inefficient projects. The WRDA assigns a greater share of the financial burden to those directly profiting from Corps projects.6 Future project beneficiaries will have to assume half the cost of development and design studies, at least 25 percent of construction cost (including mitigation costs),7 and all operating and maintenance expenses.

Hurricane Protection: The Corps is conducting design studies on the "West Bank of the Mississippi River in the vicinity of New Orleans" Project. The project would destroy 814 acres of wetlands and cost $65.8 million to build. The "Larose to Golden Meadow Hurricane Protection" Project is nearing completion, at an estimated cost of $91.4 million.8 That project will result in the loss of nearly 2500 acres of wetlands through construction and drainage. Mitigation of wetland losses is underway.

Navigation: The Federal Government has spent over $280 million9 for a system of over 500 miles of navigation channels and continues to spend $40 million annually for maintenance. The WRDA will shift some of the cost of navigation projects from Federal taxpayers to the shipping industry and other project users.

The Corps has the authority to maintain existing waterways and to enlarge the Gulf Intracoastal Waterway. The Fish and Wildlife Service estimates that by the year 2026, maintenance dredging along the Gulf Intracoastal Waterway will eliminate between 500 and 2,600 more acres of wetlands in Coastal Louisiana. The total would rise substantially if authorized enlargements of that waterway are completed. As of 1992, however, the Corps does not intend to undertake these enlargements. Congress has authorized the Corps to deepen the Mississippi River Ship Channel from Baton Rouge to the Gulf at a construction cost of $454.2 million and an annual maintenance cost of $139.1 million. The channel was deepened to an interim depth of 45 feet in 1987; further deepening to the authorized 55-foot depth is not currently planned. Although the Corps proposes to create marsh with dredged material, the project (especially the 55-foot deep channel) could increase the intrusion of saltwater and threaten the water supplies of communities along the lower Mississippi River. Because of this threat to water supplies, resistance may develop to diverting river flow to enhance wetlands, as called for by the diversion projects described next.

Freshwater Diversion Projects: A major Federal effort designed to help restore freshwater inflow to coastal wetlands is planned for Southern Louisiana. This effort consists of a set of three diversion projects that would install water flow gates in the levees to divert river water into adjacent wetlands. The effort would freshen water influenced by saltwater intrusion, but have little land-building impact. The three Congressionally authorized projects include the recently completed Caernarvon Freshwater Diversion ($25.9 million), the Davis Pond Freshwater Diversion ($70.0 million), and the Freshwater Diversion to Lake Pontchartrain Basin and Mississippi Sound ($77.0 million). Together, these three enhancement projects would reduce marsh loss by 110,000 acres over the next 50 years, or about 2200 acres per year, and would improve the value of the remaining wetlands for fish and wildlife. Under the authority of the Coastal Wetlands Planning, Protection, and Restoration Act, the Corps will construct the West Bay Sediment Diversion project ($8.5 million) to create 9800 acres of coastal marsh by funneling Mississippi River sediment through a diversion channel into West Bay in the active delta of the river.

Mitigation: Prior to the 1980s, mitigation of wetland losses caused by Federal navigation, flood control, and hurricane protection projects in Coastal Louisiana consisted of relatively minor project changes designed to reduce habitat losses. Such features might include building of spoil retention dikes to reduce the runoff of dredged material onto adjacent wetlands. During the past few years, however, the Corps has been including more substantial mitigation measures into its project plans. Compensation measures have included prevention of shoreline erosion on existing public lands, creation of new wetlands by careful placement of dredged material, formation of small wetlands by excavating artificial crevasses in the active Mississippi River Delta, and intensive management of existing public lands to reduce wetland loss and enhance wildlife habitat values. The improved mitigation planning approach should help to reduce future losses of wetlands associated with new proposals for Federal navigation, flood control, and hurricane protection projects. The Fish and Wildlife Service has acknowledged that newer projects are better mitigated than in the past.

Oil and Gas Development

A dense network of canals for navigation and pipelines has been dredged in Coastal Louisiana by the oil and gas industry. Two provisions of the Federal tax code, specific to the industry, have made development more lucrative: the oil and gas depletion allowance and the expensing, as opposed to capitalizing, of intangible drilling costs. Critics contend that industry oversight by the Corps and the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) has not been sufficiently sensitive to wetland impacts. BOEMRE disputes this. Moreover, BOEMRE does not have direct regulatory authority over coastal wetlands which are controlled by the State. Industry activities in support of OCS exploration and development (such as pipeline and navigation canals) that affect coastal wetlands are regulated by State and other Federal agencies.

Income Tax Code: From 1926 to 1975, the oil and gas industry was entitled to a tax subsidy: the depletion allowance. The allowance set an arbitrary percentage for depreciating the value of a well as its oil or gas was pumped out. The arbitrary allowance (27.5 percent of gross income through 1968 and 22 percent until 1975) was unrelated to costs, and permitted tax-free recovery, often exceeding the amount invested in the property. Producers could deduct the allowable percentage of gross income from taxable income with a limit on the deduction equal to 50 percent of taxable income. This provision encouraged the development of otherwise marginal wells with the attendant pipelines and support facilities.

In 1975, this deduction was eliminated for all but independent producers, who are now entitled to a 15 percent depletion allowance for the first 1,000 barrels of oil and the first 6 million cubic feet of gas produced daily. Louisiana's Association of Independent Producers and Royalty Owners claims 1200 members. The oil depletion allowance influences their drilling decisions about marginal areas.

A second tax code provision aids the industry by allowing deductions for intangible costs related to oil and gas exploration and production. The deduction allows producers to take an immediate tax deduction for "intangible" expenses -- those without salvage value -- on labor, fuel, power, materials, supplies, and tools. No rapid write off is allowed for "tangible" costs such as expenditures for pipe, tanks, and pumps used in an oil or gas rig. Whereas tangible costs are depreciated and deducted over the number of years the facility is in use, the tax code allows a full deduction for intangible costs in the year the expenditures are made.10 These deductions are a significant factor in offsetting the costs of canal dredging and access road construction. These deductions can make the development of marginal wells profitable, and provide the incentive for development that affects wetlands.

Regulation: Two Federal agencies (the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE)and the Corps of Engineers) regulate oil and gas activities that can affect Louisiana's coastal wetlands.

The BOEMRE leases Federal tracts on the outer continental shelf (OCS) to winning bidders. However, BOEMRE does not have the authority to regulate the activities that occur on coastal wetlands, even when those activities are conducted in support of OCS oil and gas development. Industry activities in support of OCS exploration and development that affect coastal wetlands are regulated by State and other Federal agencies. BOEMRE does address secondary impacts of OCS activities (i.e., onshore effects) in its EISs, and it can formally notify lessees of responsibilities and procedures under other Federal and State laws in clauses included in oil and gas leases (called "Information to Lessee" clauses). However, BOEMRE does not have the authority to regulate activities of lessees that do not occur on the OCS.

Under section 404 of the Clean Water Act, the Army Corps of Engineers issues permits for discharge of dredged or fill material into U.S. waters, including wetlands. Such discharges can be associated with the installation of structures in navigable waters. The Corps can condition permits required to install pipelines used to transport oil or gas from the OCS through coastal wetlands.

There are two distinct approaches that could be used to modify the 404 program in Louisiana and make mitigation of wetland losses due to oil and gas activities more effective. One is performance-based; the other involves attaching additional command-and-control provisions to permits. The economic ideal is the establishment of environmental standards for permittees to meet in whatever way they deem most efficient, while simultaneously requiring permittees to post performance bonds. The bonds must be of sufficient magnitude to cover the cost of restoration in the event the standards are not met, together with any increased governmental administrative costs and penalties. In situations where the performance-bond approach proves unmanageable, the alternative is the specification of procedures and techniques that must be observed in conducting the permitted activities. Some of the suggestions often offered for improving the effectiveness of mitigation for wetland losses due to oil and gas activities in Louisiana are:

  • If directional drilling is technically feasible, it could be used to reduce wetland damages caused by drilling in State waters and onshore.
  • As permit conditions, the Corps could require the use of other technologies that reduce wetland loss and degradation. Examples include using jet-spray dredges to minimize spoil buildup along channels dug in wetlands; using board road access for drilling rigs instead of channels; re-injecting brine instead of discharging these pollutants into adjacent wetlands; using closed drilling fluid systems to minimize impacts on wetlands due to drilling fluids and associated reserve pits; and using air cushioned vehicles instead of canals and marsh buggies for marsh access.
  • The Corps could require oil companies to fully compensate for unavoidable wetland damages associated with individual proposals requiring Sections 10 and 404 permits. One way that this can be accomplished off-site is through wetland enhancement projects. Historically, the Corps rarely required off-site mitigation of damages associated with oil and gas activities in wetlands, and on occasion did not even include on-site mitigation measures recommended by resource agencies as conditions of issued permits. Recently, however, the Corps has been accepting most of the resource agencies' recommendations and has been conditioning permits with appropriate on- and off-site mitigation measures.
Urban Development

Although many factors contribute to the urban sprawl felt most intensely in Jefferson Parish in the Deltaic Plain, 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 and the VA provide mortgage insurance for homes. FEMA offers flood insurance for urban developments in Jefferson Parish and other Coastal Louisiana parishes under the National Flood Insurance Program for approximately 30 percent of the actual cost. The program is supposed to avoid flood damage by limiting development in flood prone areas or requiring flood-proofing of structures in such areas. As was evident in the aftermath of Hurricane Juan (1985), local governments have often done a poor job of enforcing local ordinances and codes which restrict development and of meeting the intended goals of the program (FEMA 1985).11 This failure has led to otherwise unnecessary Federal expenditures for flood insurance claims and disaster relief payments. It has also spurred public demand for expanded Federal hurricane protection to enclose former wetlands, now converted to urban development. The West Bank project discussed above is a case in point.


Between 1967 and 1976, almost 60 miles of Federal highways were built in Coastal Louisiana at a cost of $65.8 million. The construction destroyed 1886 acres of wetlands and created greater development pressures on the remaining wetlands. New construction is underway on Interstate 310 and is proposed for Interstate 10. The State provides the Fish and Wildlife Service with an opportunity for early input on all highway projects, including those which are federally funded. The State and Federal Highway Administrations have also been fairly good at mitigating recent losses.


Various Department of Agriculture programs and Federal tax incentives have encouraged the conversion of wetlands to croplands. USDA programs include price supports for rice, soybeans, and other crops; low interest loans issued by the Farmers Home Administration; disaster payments for crop losses; and technical assistance by the Soil Conservation Service and the Agricultural Stabilization and Conservation Service on issues such as developing drainage plans. Swampbuster should reduce the loss of wetlands to croplands.

12 Further, legislative reforms in the 1985 and 1990 Farm Bills made it much more difficult for new acreage to qualify for price and income supports, and hence, significantly diminished the incentives in Federal agricultural law to convert wetlands to cropland.

Until passage of the Tax Reform Act of 1986, the Federal income tax code contained several provisions specific to agriculture which treated expenses for land clearing, drainage, and other types of alteration liberally. Although tax reform eliminated the accelerated deductibility for these items, wetland alteration and development costs continue to be tax deductible, like any normal business outlay.

Status and Prospects 

Without aggressive action to reverse the trend, the rate of loss of coastal wetlands in Louisiana is expected to continue. If the losses are not reduced, another 167,000 acres of wetlands will disappear or be converted by the year 2000. The Gulf shoreline will advance inland as much as 33 miles in some areas, jeopardizing public and private investments. State waters will become outer continental shelf lands, subject to Federal control, and private lands will become water bottoms, subject to State control. About 1200 businesses, residences, camps, schools, storage tanks, electric power substations, water control structures, and pumping stations will require protection or relocation. The Corps estimates that commercial fish and shellfish harvests will decline by 30 percent by the year 2040 without action to reverse projected wetland losses. The loss of income and assets will run into the billions of dollars.

Historically, the natural factors depleting wetlands (subsidence, compaction, erosion, hurricanes, and the rise in sea level) have been offset by delta-building sedimentation by the Mississippi River, so that prior to 1900 the deltaic land area was stable or expanding. Since 1900, flood control dams and levees along the Mississippi River have dramatically reduced sediment deposition and delta renewal. Moreover, flood control has facilitated private land development along the river, so now the Federal Government is committed to protecting this investment by trying to prevent the Mississippi River from shifting to its desired course where it could build delta land efficiently and by trying to prevent subsidence in sediment-depleted areas. In addition, the dredging of an extensive canal system has directly consumed coastal wetlands. And the canal widening that occurs as a result of erosion and the indirect effects from dredging (saltwater intrusion, impoundment and water logging of wetland soils as well as pollution) will exert an ongoing, negative influence on Louisiana's coastal wetlands, even if new dredging were halted. Finally, urban and agricultural development diminishes wetlands.

As a result of the Coastal Wetlands Planning, Protection, and Restoration Act of 1990, various State and Federal agencies are working together to prepare a comprehensive plan to address problem of coastal wetland loss in Louisiana. Section 303 of the Act requires establishment of a task force to i) identify a list of priority wetlands restoration projects for Coastal Louisiana (due November 28, 1991) and ii) develop a comprehensive wetlands restoration plan for the area (due November 18, 1993).13 The Act also provides for funding to implement wetland restoration projects approved by the task force. The Administration considers this Act to be a major improvement in Federal programs affecting wetlands in Louisiana.

The freshwater diversion projects (Caernarvon, Davis Pond, and the Diversion to Lake Pontchartrain basin and Mississippi Sound) could restore a modest amount of fresh water from the lower Mississippi River to adjacent marshes, swamps, and shallow estuarine waters, reducing wetland loss by an estimated 110,000 acres over a 50-year period.

Section 1135 of the WRDA authorizes the Secretary of the Army to modify water resource projects for the improvement of environmental quality. That authority was extended by the WRDA of 1988. The Fish and Wildlife Service and the Corps have identified several projects that could restore or create wetlands under that authority. The first project to make use of that funding source in Coastal Louisiana was initiated in FY 1991. Using dredged material to restore wetlands and help offset the sediment losses from levees is one of the more promising mitigation strategies.

Ongoing oil and gas development also affects wetlands. Although production has leveled off, the majority of the oil and gas produced in the coastal waters of the United States will continue to come from offshore Louisiana. This continued development could create the need for additional canals and construction of ancillary facilities. To reduce the damage, Federal regulatory oversight by the Corps in cooperation with the State could specifically encourage:

  • Minimizing additional canal construction and making greater use of existing canals;
  • Drilling directionally to several targets from one well-head location (as is now done in the Alaskan tundra and offshore Louisiana);
  • Leaving breaks where needed in the canal spoil banks to maintain hydrologic patterns;
  • Backfilling or plugging canals;
  • Using hovercraft (air-cushioned vehicles that can traverse uneven terrain with very slight impact on the ground) as is done in Alaska.
A cooperative, State/Federal program could devise a strategy to apply in Coastal Louisiana innovations which were developed in Alaska to minimize wetlands losses and mitigate the effects of past activities.

The threat to wetlands from oil and gas activities might also be reduced by eliminating certain tax-expenditure subsidies for the oil and gas industry. In particular, oil depletion allowances granted to independent producers and the deductions for (rather than capitalization and depreciation of) intangible costs associated with drilling (such as canal dredging and access road construction) are difficult to justify on economic grounds. Absent such deductions, some wells that involve marginal returns might not go forward.

Urban development remains an important threat to the wetlands in Southern Louisiana. Enforcement of the Floodplain Management and Wetland Protection Executive Orders could help to alleviate urban development problems. Moreover wetland loss could also be stayed by denying Federal subsidies -- low income housing funds, mortgage insurance, and National Flood Insurance -- to developments in floodplains and other wetlands. This could be facilitated by having regulatory agencies and project sponsors routinely coordinate with FEMA and HUD on Sections 10 and 404 permit applications involving residential and industrial developments in wetland areas. Such notification would alert these agencies to proposed development plans, and forewarn developers that Federal funding cannot be provided to support such developments.

Agricultural conversion, once a serous threat to Louisiana's coastal wetlands, no longer appears as such because of the 1985 FSA and the 1990 amendments to the FSA in FACTA.


  1. Water resource projects:
    a. Congress should continue funding the construction by the Corps of two authorized but uncompleted water diversion projects: Lake Pontchartrain ($57.8 million Federal share) and Davis Pond ($52.5 million Federal share).
    In conjunction with Caernarvon, which is operational, these projects would restore a small percentage of the freshwater inflows lost as a result of the MR&T Project, and may restore a portion of the sediment lost. They constitute a first step in reducing the estimated 35 to 37 square miles of Coastal Louisiana wetlands which are disappearing annually.
    b. Consider expanding the Corps' Civil Works Program to protect, create, restore, and enhance wetlands in Coastal Louisiana.
    The Corps now has numerous authorities to construct or modify projects to benefit wetlands. Examples are marsh creation with dredged material, sediment and freshwater diversion, and shoreline protection.
  2. Oil and gas industry:
    a. Evaluate the impact on Federal tax revenues and the industry of eliminating the Federal income tax deductions in wetland areas for oil depletion allowances granted to independent producers and for intangible costs associated with drilling.
    The threat to wetlands from oil and gas activities could be reduced by making these tax subsidies unavailable in wetland areas. Both tax provisions amount to special subsidies for the industry, are difficult to justify on economic grounds, and promote drilling of marginal wells in important wetlands.
    b. Consider expanding the use of performance-bonds for the mitigation of wetland losses.
    Performance bonds create an incentive for developers to complete work in a timely manner. In the event of noncompliance, the Government is relieved of the need to pursue costly enforcement action, and the bond provides a ready source of funding to restore the environment quickly. BLM already utilizes performance bonds on lands which it administers. To be fully effective, the bonds must be of sufficient magnitude to cover the cost of restoration in the event the standards are not met, together with any increased governmental administrative costs and penalties. Congress should consider whether a performance-bond approach could be utilized more widely in the wetland regulatory programs.
    c. Establish stronger mitigation requirements within the programs regulating oil and gas development in Coastal Louisiana.
    The Army Corps of Engineers and the State regulate oil and gas development in Coastal Louisiana. The Corps could work in cooperation with State and local authorities to attach more effective wetland mitigation requirements to permits for installing pipelines and drilling equipment. Specific techniques for achieving this include: making greater use of existing canals, minimizing construction of new ones, and backfilling and plugging abandoned ones; requiring directional drilling and other extraction technologies that reduce wetland loss and degradation whenever technically feasible;14 and leaving breaks in levees where needed to maintain hydrologic patterns. Where wetland damage is unavoidable, full compensation should be required, reflecting the quality and functional value of the affected wetlands. Off-site wetland enhancement and restoration projects could be developed as a compensatory technique.
  3. Urban development:
    a. Suspend Federal subsidies such as funds for low income housing, mortgage insurance, and National Flood Insurance for urban development projects in environmentally significant wetlands.
    These expenditures offer significant incentives for development in important wetlands. They also set the stage for future Federal outlays for damages caused by storms to developments located in naturally flood-prone areas. Environmental considerations aside, strictly on economic grounds, it is sound public policy to withhold incentives for developing areas subject to high flooding risks.
    b. Encourage enforcement of the Floodplain Management and Wetland Protection Executive Orders and the regulations implementing them.
    These executive orders direct Federal agencies to avoid, to the extent possible, adverse impacts associated with the occupancy and modification of wetlands and floodplains. Their purpose is to reduce the loss of life and property due to floods and to diminish environmental damage due to imprudent planning and development. Most Federal agencies have promulgated regulations implementing these executive orders.
  4. Wetland restoration:
    a. Encourage the Army Corps of Engineers and EPA to work with the State of Louisiana to identify opportunities for beneficial use of dredged material for wetlands restoration, and review the Federal standard for selecting disposal alternatives, giving greater weight to disposal alternatives that include environmental benefits.
    The Corps of Engineers currently uses a least-cost criterion to select sites for disposal of dredged material. This often results in the material being dumped offshore. The State of Louisiana has expressed concerns about ocean dumping and a preference for the dredged material to be used to restore sediment-starved wetlands. Alternatives that restore wetlands are often more costly than ocean dumping, and the Corps has been reluctant to incur the additional costs. The current Federal standard calls for maintenance of waterways in the least costly manner consistent with engineering practices and in compliance with environmental laws and regulations. The Corps, EPA, and the State should explore cost-sharing options, and develop a procedure for identifying additional opportunities for beneficial use of dredged material for wetlands restoration.
    b. Encourage the Soil Conservation Service to continue to put emphasis on wetland protection and restoration through the PL-566 Watershed Program.
    In 1990, Congress amended PL-566, authorizing cost-sharing assistance for the acquisition of perpetual wetland or floodplain conservation easements to retain floodwaters, improve water quality and quantity, and provide habitat for fish and wildlife. Several watershed projects are currently being planned that are expected to use this new authority to enhance and protect wetlands. The SCS has already developed and begun implementing watershed project plans for the West Fork Bayou L'Ours and Bayou Penchant/Lake Penchant Watersheds in Louisiana. These two watershed projects provide accelerated technical assistance and/or financial assistance to prevent destruction of approximately 20,000 acres of valuable marshland due to saltwater intrusion. SCS is involved in a similar project for the Sabine Black Bayou Watershed.


Craig, N.J., R.E. Turner, and J.W. Day, Jr. 1979. "Land Loss in Coastal Louisiana." Proceeding of the Third Coastal March and Estuary Management Symposium, Day, et. al., eds., Louisiana State University, Division of Continuing Education, Baton Rouge, pp. 227-254.

Davis, D. W. 1973. Louisiana Canals and Their Influence on Wetland Development. Ph.D. dissertation, Louisiana State University, Baton Rouge, 199 pp.

Federal Emergency Management Agency. 1985. Interagency Hazard Mitigation Report. Prepared by Region VI, Interagency Flood Hazard Mitigation Team, Denton, Texas, 24+ pp.

Fruge, D. W. 1986. The Impact of Federal Programs on Wetlands of the Louisiana Coastal Region. Background Report. Office of Policy Analysis, U.S. Department of the Interior, Washington, DC, 32 pp.

Gagliano, S. M. 1973. Canals, Dredging, and Land Reclamation in the Louisiana Coastal Zone. Hydrologic and Geologic Studies of Coastal Louisiana. Report No. 14. Center for Wetland Resources, Louisiana State University, Baton Rouge, 104 pp.

Michot, T. C. 1984. Louisiana Coastal Area Study, Interim Report on Land Loss and Marsh Creation. Planning Aid Report submitted to New Orleans District, U.S. Army Corps of Engineers, New Orleans, LA. U.S. Fish and Wildlife Service, Division of Ecological Services, Lafayette, LA.

Morgan, J. P. 1973. "Impact of Subsidence and Erosion on Louisiana Coastal Marshes and Estuaries." Proceedings of the Second Coastal Marsh and Estuary Management Symposium, Chabreck, R.H. ed. Louisiana State University, Baton Rouge, pp. 217-233.

Turner, R. E. 1987. Relationship Between Canal and Levee Density and Coastal Land Loss in Louisiana. Fish and Wildlife Service, U.S. Department of the Interior, Washington, DC, 58 pp.

Turner, R. E. and D. R. Cahoon, eds. 1988. Causes of Wetland Loss in the Coastal Central Gulf of Mexico, Vol. 1: Executive Summary. Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE), U.S. Department of the Interior, New Orleans, LA, 32 pp.

U.S. Army Corps of Engineers in cooperation with the State of Louisiana. 1987. Crisis on Louisiana's Coast...America's Loss. New Orleans, LA, 14 pp.


1 This excludes several listed species of sea turtles and marine mammals that may occur in Louisiana's coastal waters, but not in its coastal wetlands.

2 Along the coast of Terrebonne Parish wetlands were estimated in 1985 to have an estimated present value for hurricane protection of $1,604-$1,712 per acre.

3 The loss of wetlands fringing the Lake Pontchartrain Basin and the dredging of canals in the Barataria Basin have contributed to water quality declines.

4 OCS lands are those seaward of the territorial seas over which the States have jurisdiction. Generally, the OCS begins three nautical miles from the coastline.

5 This figure merely sums the project expenditures. It is not stated in constant dollars, and does not correct for inflation. The figure would be much higher if it were stated in the dollars of a recent year.

6 The WRDA applies only to projects constructed by the Corps. The Reagan Administration recommended that for equity and efficiency all future water projects be financed in accordance with the benefit principle of public finance. See recommendation 1 in Volume I of this report.

7 Under the WRDA, the cost of all lands, easements, and rights-of-way remain the responsibility of the non-Federal sponsors, but are credited against the 25 percent obligation. The WRDA requires a minimum, non-Federal cash contribution of 5 percent.

8 Sum of total dollars spent and projected cost to complete in current dollars, not corrected for inflation.

9 See previous footnote.

10 The immediate deduction for intangibles applies to the following: transporting drilling rigs to location, including canal dredging and rig up costs; building roads for use during drilling; dredging on location; surveying and seismic studies to locate well sites; supplying water, fuel, and other resources needed for drilling; drilling on a footage or daily basis; compensating for technical services rendered by engineers, geologists, and fluid technicians; removing rigs and equipment from location.

11 Establishing and enforcing these local ordinances are a statutory requirement for eligibility in the Federal flood insurance program.

12 See chapter 3 for a discussion and critique of Swampbuster.

13 The task force is chaired by the District Engineer, representing the Secretary of the Army. Other task force members include the Governor of Louisiana, the Administrator of the EPA, and the Secretaries of Agriculture, Commerce, and the Interior.

14 Examples include use of jet-spray dredges to minimize spoil buildup along channels dug in wetlands; use of board road access for drilling rigs instead of channels; re-injecting brine instead of discharging these pollutants into adjacent wetlands; and use of closed drilling fluid systems to minimize impacts on wetlands due to drilling fluids and associated reserve pits.

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For more information on the impact of Federal programs on wetlands,
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