Although a particular individual permit may impose stewardship conditions, such as an endowment fund for corrective action after sign-off and the transfer of an easement or title to a conservation entity, nothing in Corps and EPA regulations or guidance documents requires that permittee-responsible mitigation account for the long-term stewardship of compensatory sites. Indeed, the 1990 Corps and EPA mitigation MOA, which provides the most comprehensive guidance with respect to permittee-specific mitigation, is silent on the matter.

In contrast, a mitigation bank's banking instrument should provide for long-term stewardship. For example, the 1995 mitigation banking guidance states that the bank operator is responsible for securing adequate funds for “long-term management” of the bank site. Additionally, to assist in protecting the bank site in perpetuity, the banking instrument should specify that title or a conservation easement will be transferred to a government agency or nonprofit conservation organization.

Prior to the October 2000 in-lieu fee guidance, agencies had not clearly articulated the long-term stewardship responsibilities of in-lieu fee administrators. On the other hand, most in-lieu fee administrators were entities that were philosophically oriented to long-term stewardship of protected lands. The guidance suggests that these in-lieu sponsors should secure adequate funds for site maintenance and arrange for the site to be protected in perpetuity by conveying an easement or title to a government agency or nonprofit conservation organization.

The committee found it instructive to develop a taxonomy of compensatory mitigation mechanisms (Table 5–1) to discuss differences among the alternative mechanisms for achieving compensatory mitigation. There are two main categories: permittee-responsible mitigation and third-party-responsible mitigation. Permittee-responsible mitigation includes permit-specific mitigation and single-user mitigation banks, and third-party-responsible mitigation includes commercial mitigation banks, inlieu fees, cash donations, and revolving funds. The differences in mechanisms turn primarily on the factors listed on the left side of the table and discussed in detail in this chapter. Other descriptors, such as in-kind or use of restoration, creation, enhancement, or preservation, are not necessarily specific to a type of mitigation mechanism. Instead, differences in mitigation practices are attributed to site-specific conditions and not to the mitigation mechanism used.