A Big Step in the Right Direction: U.S. Army Corps of Engineers 2013 Regional Mitigation and Monitoring Guidelines

Fall/Winter 2013 Ecesis, Volume 23, Issue 3

In August 2013, the South Pacific Division of the U.S. Army Corps of Engineers (Corps) released draft Regional Compensatory Mitigation and Monitoring Guidelines (Guidelines) for unavoidable impacts to aquatic resources. The Guidelines were designed to help the regulated public and mitigation/restoration practitioners comply with the 2008 national regulations (“Mitigation Rule”). The South Pacific Division encompasses a large geographic area — Arizona, California, Nevada, Utah, New Mexico and parts of Colorado and Texas. The Los Angeles, Sacramento, San Francisco, and Albuquerque Districts have been working together for several years to develop these Guidelines, as well as other tools to aid in the identification, design, implementation, and monitoring of compensatory mitigation sites. These efforts have been led by Dr. Daniel Swenson, North Coast Section Chief, Los Angeles District. It was an enormous effort corralling busy State and Federal regulators to participate in meetings and then facilitate discussions between people with varying degrees of restoration and mitigation experience. In addition, the large geographic area complicated the effort due to the vast diversity of ecological conditions, aquatic resources and sometimes conflicting regional goals and state regulations that govern land and water uses. So although not perfect, these Guidelines are a big step in the right direction.

The Guidelines supplement the Mitigation Rule by providing regionally-specific information and tools for developing the twelve required elements of a Compensatory Mitigation Plan. Of particular interest to SERCAL members may be Sections 3.4 and 4.2.2, Amount of Compensatory Mitigation; Section 4.3, Site Selection; and Section 4.4, Design, including subsections on recommendations and potential pitfalls. Historically, the amount (e.g. mitigation ratio) of compensatory mitigation required by regulatory agencies has been inconsistent, particularly when ratios have varied greatly across districts or between regulators within a single district. Section 3.4 describes the eight variables Corps regulators will consider in setting mitigation requirements. The standardized approach for evaluating these variables is provided in a separate guidance document referred to as the Standard Operating Procedure for Determination of Mitigation Ratios (“Mitigation Ratio Checklist”). The Mitigation Ratio Checklist is a tool for comparing the impact site to the proposed mitigation site(s). Supporting information is provided for each variable in the Guidelines, expressing why each should be considered in developing a mitigation plan. These include the type, condition, and location of the affected jurisdictional resources at the impact site relative to those at the proposed mitigation site; the risk and uncertainty of successfully implementing the mitigation site; and whether the temporal and indirect jurisdictional impacts are adequately addressed.

Site selection, as required in Section 4.3, is a key part of the process needed to restore or establish a natural and sustainable aquatic resource. As referenced in the Guidelines, it is well documented that the type of aquatic resource proposed should be ecologically suitable to the location, taking into consideration the physical, hydrological, and biological processes needed for the aquatic resource to function naturally. Unfortunately, this has not frequently been the practice for proposed mitigation sites. Often, mitigation sites are proposed on landscapes that are convenient or available and cost-effective to the permittee, with little consideration to landscape position, physical or hydrological processes, and surrounding land uses. Based on my recent experience as a Corps regulator in the Los Angeles District, it is my opinion that poor site selection is the primary reason for mitigation failure. These Guidelines should help to reverse that trend.

Section 4.4 of the Guidelines discusses design and the development of the mitigation site work plan, including basic recommendations for design approach. Although it does not cover all of the information needed to design a successful mitigation site — or an exhaustive list of all the problems that practitioners can experience — it does cover some of the most common mistakes. There is a statement that a conceptual design needs to provide enough site-specific data to provide the Corps with confidence the proposed project would fulfill its objectives. After the conceptual plan is approved, the final work plan must include grading and planting designs which require substantial site-specific data. The design recommendations include choosing a location and design with buffer areas, connectivity with other aquatic resources or natural open space, sources of natural hydrology, and soils conducive to the type of aquatic resource and target vegetation community. Reference sites in proximity to the mitigation site are recommended for use in setting realistic performance standards and to provide a basis for comparison during site development, particularly during abnormal weather years or in the face of a changing climate.

The Guidelines are intended to standardize compensatory mitigation procedures throughout the SPD region by providing definitions for commonly used terms and simple guidance for mitigation plan requirements in the Mitigation Rule. Also provided is an outline for developing mitigation plans that, if followed, will address the 12 elements required by the Mitigation Rule, and example tables for reporting data that SPD requires. These Guidelines are a substantial step in the right direction to providing both regulators and the regulated public with clear expectations for planning and implementing successful compensatory mitigation. — by Michelle Mattson, Southern California Biology Team Manager, ICF International.