Texas Environmental Almanac




Mitigation is the attempt to offset potential adverse effects of human activity on the environment. The development of mitigation measures has become an integral part of the regulatory process and of conservation planning efforts.

The National Environmental Policy Act of 1969 requires that mitigation measures be included in environmental impact statements (EIS) - the detailed studies of the environmental effects of major actions undertaken, funded or permitted by the federal government.

Texas also has established state mitigation policies. For example, the Texas Parks and Wildlife Department and the General Land Office require mitigation for adverse impacts on wetlands.(1) There is also a statutory requirement for mitigation for fish and wildlife habitat lost to large reservoir development projects.(2) The General Land Office has an informal policy requiring at least a three-to-one compensation ratio for unavoidable adverse impacts to natural resources on state-owned submerged land.(3) Many state natural resource regulations, moreover, must meet minimum federal standards, which often include mitigation requirements. For example, regulations governing highway construction require revegetation of lands damaged by road development.

Most federal or state legislation requiring mitigation measures does not prescribe the specific mitigation activity that must take place, and mitigation can take many forms. Unfortunately, enforcement of mitigation commitments is sometimes sporadic.(4) For instance, rarely does anyone monitor to see if a developer or an agency has kept its promise to replace a natural wetland with a man-made one.

The National Environmental Policy Act regulations define mitigation as follows:(5)

  1. Avoiding adverse impacts by not taking an action. (For example, the Texas State Department of Transportation rerouted a section of State Highway 71 to avoid destroying large old oak trees.)

  2. Minimizing impacts by limiting the degree of action. (For example, the state has built several Austin freeways that cross aquifer recharge areas without frontage roads. This approach is intended to help limit development near the freeway in order to help protect water quality in the aquifer.)

  3. Rectifying by repairing, rehabilitating, or restoring the affected environment. (For example, coal companies operating in some parts of the state are required to design reclamation projects, including revegetation of mined areas.)

  4. Reducing or eliminating impacts over time through preservation and maintenance activities.

  5. Compensating for an impact by replacing or providing substitute resources or environments. In most mitigation agreements, more of a resource or habitat must be provided than was originally present. Ratios greater than 1:1 are required in part to compensate for unrealized losses and the inability of technology to completely restore the natural environment. (For example, if a developer wants to build a planned community in Houston that will destroy 100 acres of wetlands, the developer can propose to create 400 acres of wetlands in a nearby site.)

Except for the avoidance option, most mitigation efforts assume that some loss of natural resources is permissible. Options two, three and four above assume a level of human expertise in designing natural environments and/or funding that in some situations can be unrealistic. Option five suffers from the same risk. Replacement activities, such as creating a wetland, assume that man-made environments are equal to natural ones and can serve the same valuable functions. There is still much dispute among scientists about whether this is actually the case. No one really knows how to mimick natural systems. This is particularly true with respect to complex systems such as wetlands. A five-year study conducted in Oregon to see how restored and created wetlands measured up to natural ones found that the initial designs were inadequate, that the designs outlined in the permit were not adhered to and that overall the wetland projects were "fundamentally different" from the wetlands they were supposed to replace.(6) On the other hand, compensation may indeed be a viable option for mitigation activities that involve less complex ecosystem decisions.



  1. Texas Parks and Wildlife Code, Section 14.002

  2. Texas Water Code, Section 11.152.

  3. Texas General Land Office, Texas Coastal Management Program: Public Comment Document (Austin: GLO, March 1994), IX-21-22.

  4. John E. Bonine and Thomas O. McGarity, The Law of Environmental Protection (St. Paul, MN.: West Publishing Company. 1984), 203. For example, in Texas the Army Corps of Engineers does not monitor its mitigation agreements.

  5. 40 CFR 1508.20

  6. Leslie Roberts, "Wetlands Trading Is a Loser's Game, Say Ecologists" (Science, Vol. 260. June 25, 1993).

Texas Environmental Almanac, Environmental Focus: Mitigation

Almanac Table of Contents TEC Home Page

Please send questions, comments, or problems with this page to ltarver@mail.utexas.edu..