Useful Links

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 Los Angeles District (SPL) SOP for Evaluation of Proposed Compensatory Mitigation Sites
 In-Lieu Fee Program Mitigation Projects
 Mitigation Resources
 Policies and Procedures

Regional Compensatory Mitigation and Monitoring Guidelines (2015 Final), regarding procedures for compensatory mitigation as required for processing of Department of the Army (DA) permits under Section 404 of the Clean Water Act, Section 10 of the Rivers and Harbors Act, and Section 103 of the Marine Protection, Research, and Sanctuaries Act.

Regulatory Guidance Letter 08-03, Minimum Monitoring Requirements for Compensatory Mitigation Projects 
Habitat Mitigation and Monitoring Proposal Guidelines
Contents of Mitigation Monitoring Reports


 Related Regulations
 South Pacific Division (SPD) Mitigation Ratio & Requirements


Mitigation Overview

Mitigation as a whole consists of three factors; avoidance, minimization and compensation.  Prior to issuing a Department of the Army (DA) permit, we must analyze the impacts to aquatic resources and determine that the applicant has avoided and minimized impacts to aquatic resources, to the maximum extent practicable. Only after impacts to aquatic resources are avoided and minimized, will we consider the requirements for compensatory mitigation for unavoidable losses of waters of the U.S. The Corps’ regulations required that a DA permit application include a statement describing how impacts to waters of the U.S. are to be avoided and minimized, and a statement describing how impacts to waters of the U.S. are to be compensated for, or a statement explaining why compensatory mitigation should not be required (33 CFR 325.1(d)(7)).

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 Section 404(b)(1) Guidelines
As part of Section 404 of the Clean Water Act, the Corps is required to ensure compliance with the U.S. Environmental Protection Agency’s (USEPA) Section 404(b)(1) Guidelines for the Specification of Disposal Sites of Dredged or Fill Material (Guidelines)(40 CFR 230). In accordance with the Guidelines, no discharge of dredged or fill material shall be permitted if there is a practicable alternative to the proposed discharge which would have less adverse impact on the aquatic ecosystem, so long as the alternative does not have other significant adverse environmental consequences. Practicable alternatives include activities which do not involve a discharge of dredged or fill material into waters of the U.S. and discharges at other locations in waters of the U.S. The Corps will evaluate each permit application/pre-construction notification received for compliance with the Guidelines. An alternative is practicable if it is available and capable of being done after taking into consideration cost, existing technology and logistics in light of the overall project purpose. Both on-site and off-site alternatives are considered. If the proposed activity would involve a discharge into a special aquatic site (i.e. wetland, mudflat, riffle and pool complex, sanctuary, refuge, vegetated shallow or coral reef) and does not require access or proximity to or sitting within the special aquatic site to fulfill its basic purpose (i.e. is not ‘water dependent’), the Corps assumes practicable alternatives exist that do not involve special aquatic sites unless clearly demonstrated otherwise by the applicant. It is recommended that all permit applications/pre-construction notifications contain alternatives information sufficient for the Corps to determine compliance with the Guidelines.
 Mitigation Types - Avoidance
Avoidance of impacts to aquatic resources would occur if project activities would not result in the placement of fill material into the resource. In many cases however, simply avoiding an aquatic feature may not ensure that impacts are avoided altogether, and is possible that indirect adverse effects may occur.
 Mitigation Types - Minimization

Minimization of impacts to aquatic resources would occur if measures are taken to ensure the amount and duration of impacts are limited and that no indirect impacts would occur. There are many minimization measures that could be implemented, prior to, during, or after the proposed activity, to ensure impacts are minimized, including, but not limited to:

    • Permanent preservation of avoided aquatic features, in perpetuity. In these cases the preserve would be under a conservation easement and managed by conservation oriented third-party manager;

    • Utilization of best management practices (BMPs) to ensure impacts are limited, and do not result in adverse impacts to the integrity and long-term functions of preserved/avoided features;

    • Construction of permanent exclusionary fencing surrounding all preserved/avoided features, and;

    • Implementing development away from the preserved/avoided areas and providing sufficient buffer habitat to protect and sustain the integrity of the preserved/avoided features.

 Mitigation Types - Compensatory Mitigation
Compensatory mitigation is required for all activities in which the impacts to the aquatic resources have been avoided and minimized to the maximum extent practicable, but would still result in unavoidable adverse effects.
 Compensatory Mitigation Overview

The Corps strives to achieve a goal of no net loss of aquatic resource functions and services. The purpose of compensatory mitigation is to develop long term self-sustaining aquatic resources that offset adverse effects and are not dependent on human intervention after the establishment period. The methods of compensatory mitigation include:

    • Establishment: manipulation of the physical, chemical or biological characteristics present to develop an aquatic resource that did not previously exist at an upland site. Establishment results in a net gain in aquatic resource area and functions.

    • Re-establishment: the manipulation of the physical, chemical, or biological characteristics of a site with the goal of returning natural/historic functions to a former aquatic resource. Re-establishment results in rebuilding a former aquatic resource and results in a gain in aquatic resource area and functions.

    • Enhancement: the manipulation of the physical, chemical, or biological characteristics of an aquatic resource to heighten, intensify, or improve a specific aquatic resource function(s). Enhancement results in the gain of selected aquatic resource function(s), but may also lead to a decline in other aquatic resource function(s). Enhancement does not result in a gain in aquatic resource area.

    • Rehabilitation: the manipulation of the physical, chemical, or biological characteristics of a site with the goal of repairing natural/historic functions to a degraded aquatic resource. Rehabilitation results in a gain in aquatic resource function, but does not result in a gain in aquatic resource area.

    • Preservation: the removal of a threat to, or preventing the decline of, aquatic resources by an action in or near those aquatic resources. This term includes activities commonly associated with the protection and maintenance of aquatic resources through the implementation of appropriate legal and physical mechanisms. Preservation does not result in a gain of aquatic resource area or functions.

The preferred type of compensatory mitigation is re-establishment, and sometimes establishment, as these result in a net gain in both aquatic resource area and function(s). Compensatory mitigation that results in a net gain of aquatic resource function but not area (enhancement and rehabilitation) may also be a viable option provided functional gain would be sufficient to off-set functional loss. Only in rare instances will the Corps accept preservation as an acceptable form of compensatory mitigation.

Compensatory mitigation may be accomplished through:

    • Purchase of appropriate credits at a Corps approved mitigation bank

    • Payment into a Corps approved in-lieu fee fund, or

    • Permittee responsible on-site/off-site; establishment, re-establishment, enhancement, rehabilitation, and/or preservation.

Generally, the use of Corps approved mitigation banks, to fulfill compensatory mitigation requirements, is preferred. However, in many cases the payment into an in-lieu fee fund and/or permittee responsible compensatory mitigation may provide greater benefits to the aquatic environment and/or watershed as a whole. The appropriate method, type, and amount of compensatory mitigation required to off-set unavoidable adverse effects to the aquatic environment is determined by the Corps, and is made on a project-by-project basis.

 Compensatory Mitigation Ratios

The Corps determines the appropriate compensatory mitigation ratio after reviewing recommendations from the applicant and appropriate resource agencies, and by evaluating and comparing the functions and services of the aquatic resources to be compensated for to the functions and services of the proposed aquatic resources to be compensated with - as well as the likelihood of success of the proposed aquatic resource mitigation.

Often, the replacement acreage is greater than the acreage lost when taking into consideration; a qualitative assessment of functional loss at the impact site versus expected functional gain at the mitigation site, mitigation site location, net loss of aquatic resource surface area, type conversion, risk and uncertainty, and/or temporal loss of habitat. Typically, implementation of compensatory mitigation is completed in advance of or concurrent with the authorized impacts.  For additional information, see South Pacific Division (SPD) SOP 12501 above.

 Mitigation Monitoring

Monitoring of compensatory mitigation is a requirement of most DA permits and is used to assess the attainment of yearly and final success criteria, as well as any remedial actions or contingency measures needed in the event of non-compliance or failure. Typically, mitigation monitoring commences upon completion of mitigation construction or implementation, and annual progress reports (monitoring reports) will be required thereafter. Yearly monitoring reports should describe progress to date and include monitoring results from control areas, if applicable.

For more information, see the Habitat Mitigation and Monitoring Proposal Guideline.

 Mitigation Banks
Mitigation Banks are sites approved by the Corps to sell compensatory mitigation credits for projects resulting in unavoidable impacts to waters of the U.S. When a permit is issued that required compensatory mitigation, the permit will specify how many credits are required to be purchased at an approved mitigation bank. It is the responsibility of the permittee to provide proof of the purchase of these credits prior to any work within waters of the U.S. A list of Los Angeles District approved mitigation banks and their service area can be found on the Regulatory In-Lieu Fee and Bank Information Tracking System (RIBITS).
 In-Lieu Fee Programs

In-Lieu Fee Programs involve the restoration, establishment, enhancement, and/or preservation of aquatic resources through funds paid to a governmental or non-profit natural resources management entity to satisfy compensatory mitigation requirements for Department of the Army permits.

In-lieu fee programs, which are described in the Corps regulations [Compensatory Mitigation for Losses of Aquatic Resources, dated April 10, 2008 (Title 33 CFR Part 332)], are similar to mitigation banks in that they sell compensatory mitigation credits to permittees whose obligation to provide compensatory mitigation is then transferred to the in-lieu fee program sponsor.  Los Angeles District is currently working to establish in-lieu fee programs which are consistent with 33 CFR Part 332. Information on the status of these programs is available in RIBITS.

Instead of selling mitigation credits, the primary purpose of the Fund is to collect and manage monies generated by in-lieu fee funding requirements under Section 404 of the Clean Water Act or Section 10 of the Rivers and Harbors Act for authorized activities, as well as enforcement and compliance actions initiated by the Los Angeles District.

In order for the Fund to provide compensatory mitigation, the Los Angeles District must solicit, review, and approve aquatic resource restoration, establishment, and enhancement project proposals.

 Compensatory Mitigation Map

ArcGIS USACE SPL Regulatory Division PR Compensatory Mitigation Map (v.1)

The following map is a non-comprehensive compilation of permittee-responsible compensatory mitigation sites in Southern California and Arizona. To access this map via the ArcGIS Online web portal click here.

GIS data downloads for the Compensatory Mitigation Map are provided below: