Chapter 5: Compensatory Mitigation

How is Compensatory Mitigation Implemented?

Updated September 01, 2021

The U.S. Fish & Wildlife Service may require that wind energy developers create compensatory mitigation plans as a condition of obtaining an incidental take permit for projects predicted to adversely impact a protected species. Wind developers may also undertake compensatory measures voluntarily. These may be part of larger-scale conservation strategies that take into account not just individual project boundaries but entire biomes or species ranges.

When compensatory mitigation is required

Compensatory mitigation is required specifically for species protected by the Endangered Species Act or Bald and Golden Eagle Protection Act. Learn more about the regulatory context of wind energy development.

Endangered Species Act (ESA)

The Endangered Species Act (ESA) authorizes the listing of species that are threatened or endangered, and “take” of any listed species is a violation of the federal statute. The term “take” covers not only fatalities, such as result from collision with turbines, but also “harm,” which includes “significant habitat modification” that results in impairing protected species’ essential behavior such as breeding, feeding, or sheltering. Wind projects that anticipate incidental take (take that occurs due to an otherwise lawful activity) of species listed under the ESA may choose to obtain an incidental take permit (ITP) to avoid risk of enforcement if take does occur.

The central component of an ITP application is a habitat conservation plan (HCP) designed to conserve the ecosystems upon which species listed as threatened or endangered depend, thus contributing to the conservation and recovery of listed species. Wind developers are responsible for determining whether species of concern (defined in the U.S. Fish & Wildlife Service Land-Based Wind Energy Guidelines as species formally protected such as by law or other regulation, defined or managed by a relevant entity such as a state agency, that have been shown to be significantly adversely affected by wind energy development; or are determined to be possibly affected by a specific wind energy project) are likely to be affected by a project and for quantifying those impacts. Other key components include a description of compensatory (and other) mitigation measures and procedures for monitoring for compliance and effectiveness.

Compensatory mitigation measures may take many forms. Which type of mitigation measure is used for a specific HCP is determined on a case-by-case basis and depends on the needs of the species and type of impacts anticipated.

While individual wind projects may create project-specific mitigation plans, the Midwest Wind Energy (“MWE”) HCP was created to provide a coordinated regional solution to wind energy impacts affecting three species of bats, bald eagles, and three other bird species across large portions of their ranges. Developed collaboratively by the Service and its Midwest regional office, the natural resources and conservation agencies of seven of the eight states, the American Wind Energy Association (now the American Clean Power Association), a group of wind energy companies, and a nonprofit conservation organization, the MWE serves to authorize incidental take (including habitat as well as collision fatality impacts) of the covered species that may occur in connection with the development and operation of proposed and existing wind energy facilities within the eight-state region. By taking a regional approach, MWE proponents seek to enhance conservation of species and streamline regulatory compliance for proposed and existing wind energy facilities.

Bald and Golden Eagle Protection Act (BGEPA)

Eagles have special protection under the Bald and Golden Eagle Protection Act (BGEPA). Like the ESA, BGEPA prohibits take of individual eagles as well as destruction of their nests. Under BGEPA, take is defined to include “pursue, shoot at, poison, wound, kill, capture, trap, collect, molest or disturb,” and the term “disturb” is further defined by regulation as “to agitate or bother a bald or golden eagle to a degree that causes, or is likely to cause …injury to an eagle, a decrease in productivity, or nest abandonment.”

While eagles may be included in a habitat conservation plan, wind project proponents in areas with eagle activity are advised to seek a specific type of incidental take permit first authorized by the 2009 Eagle Permit Rule, which was updated in 2016. Under the rule, the Service can issue a “programmatic take” permit for projects (such as wind energy facilities) that may occasionally result in eagle collision fatalities or other forms of incidental take.

BGEPA conservation standards stipulate that permitted eagle take must be “consistent with the goal of stable or increasing breeding populations.” Acceptable take thresholds are determined by the Service on a regional basis, with additional measures taken to ensure that local-area eagle populations are not negatively affected. For bald eagles, population recovery in most regional management areas is such that acceptable take thresholds are greater than zero. For golden eagles, however, no net loss is considered compatible with stabilizing breeding populations; every golden eagle fatality must be compensated by a commensurate reduction in golden eagle fatalities from another source of mortality.

An eagle conservation plan (ECP) is required to show how anticipated incidental take (via direct mortality, disturbance, or territory loss) of eagles will be offset. Unlike HCPs, mitigation strategies for ECPs are limited to Service-approved options. To date, power pole retrofits are the only approved mitigation option, but others have been developed, including models for lead poisoning abatement and reducing vehicle collisions published by AWWI. Additional types of mitigation such as preserving habitat – actions that would not by themselves lead to increased numbers of eagles but would assist eagle conservation – may also be advised to offset other detrimental effects of permits on eagles.

Voluntary compensatory mitigation approaches

HCPs, including compensatory mitigation efforts, can be applied to non-listed species to help prevent them from reaching the point of being listed under the ESA. For example, although not currently listed under the ESA, the greater sage-grouse is considered by some experts to be an umbrella species whose conservation helps not only to prevent it being considered for listing, but also is thought to support a wide array of species that rely on the same landscape.

Examples of voluntary compensatory mitigation plans – Greater Sage-Grouse Conservation Bank

The Service partnered with the State of Wyoming and the Sweetwater River Conservancy to launch the nation’s first Greater Sage-Grouse Conservation Bank in 2015. Wind energy and other land developers use wildlife habitat credits, generated by the conservation or restoration of habitat, to offset their overall habitat impact. This approach may be more cost effective than a project developer or owner completing land protection and restoration work themselves. Quantifying conservation value is a key component to the development and monitoring of a conservation bank.