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Compensatory Mitigation for Streams and Wetlands


Commercial, residential and agricultural land development, construction of linear transportation and utility systems, and other activities requiring State and Federal permits have the potential to impact and degrade Tennessee’s streams. These impacts often result in loss of aquatic resource values, including stream length, hydrology, available habitat, species composition, and other beneficial ecological and physical characteristics. Mitigation for certain stream impacts in Tennessee have been required since the passage of the Tennessee Water Quality Control Act by the Tennessee General Assembly in 1977. In July 2000, the Tennessee Water Quality Control Board adopted rules that more clearly specified the requirement that permits for the alteration of streams must not result in a net loss of water resource value, and established mitigation requirements. These Rules were further revised by the Board in October 2018.

The U.S. Army Corps of Engineers (USACE) and Tennessee Department of Environment and Conservation (TDEC) Division of Water Resources (Division) currently require compensatory mitigation for certain permitted impacts to Tennessee's streams. The Division may require compensatory mitigation to off-set unavoidable adverse impacts resulting in an appreciable permanent loss of aquatic resource value. The Division cannot issue an individual ARAP, with or without mitigation, unless an applicant has first demonstrated that there are no practicable alternatives to the proposed activity that would have less adverse impact on resource values, so long as the alternative does not have other significant adverse environmental consequences.

This page contains useful information for applicants who need access to the 2019 Stream Mitigation Guidelines, the TN Debit Tool, and other resources such as the TN Stream Quantification Tool (TN SQT), statewide, ecoregionally based regional curves, and other documents needed to prepare compensatory mitigation projects.

For large, complex proposals, applicants seeking a Tennessee Department of Environment and Conservation (TDEC) Aquatic Resource Alteration Permit (ARAP)/Section 401 Water Quality Certification and a U.S. Army Corps of Engineers (USACE) Clean Water Act Section 404 Permit can request a regulatory coordination meeting, especially those in which permittee-responsible mitigation (PRM) is proposed. If you have a project proposal that you think may meet these requirements please visit our regulatory coordination page to obtain additional information. 

  • Tennessee Stream Quantification Tool V.1- a Microsoft Excel Workbook described in the TN SQT User Manual; to assist in the calculation of functional change between an existing and proposed stream condition.
  • TN Rapid Data Collection Methods- Outlines the rapid assessment method for the TN SQT and TN Debit Tool
  • TN Debit Tool Workbook- The Microsoft Excel Workbook described in detail in the TN Stream Mitigation Guidelines (2019) and the TN SQT User Manual
  • TN SQT Rapid Data Assessment Form - printable version of the field form used in the collection of data for the rapid assessment
  • TN SQT Rapid Data Assessment Form - excel version of the field form used in the collection of data for the rapid assessment
  • TN SQT User’s Manual- Describes the TN SQT and all calculations performed by the workbook.
  • Example Restoration Projectusing the TN SQT Workbook- Populated versions of the TN SQT provided as an example.
  • Example Restoration Project with Biological Data using the TN SQT Workbook- Populated versions of the TN SQT (with biological data) provided as an example.
  • TN Stream Mitigation Guidelines- guidance on determining the amount of resource value loss associated with commonly authorized impacts and functional lift associated with compensatory mitigation of streams
  • TN SQT List of Metrics- A comprehensive list of the function-based parameters with their measurement methods, reference standards, stratification methods, and references.

 

  • The US Army Corps of Engineers Compensatory Mitigation Public Facing Mapviewer Database
    RIBITS (Regulatory In lieu fee and Bank Information Tracking System) was developed by the U.S. Army Corps of Engineers with support from the Environmental Protection Agency, the U.S. Fish and Wildlife Service, the Federal Highway Administration, and NOAA Fisheries to provide better information on mitigation and conservation banking and in-lieu fee programs across the country. RIBITS allows users to access information on the types and numbers of mitigation and conservation bank and in-lieu fee program sites, associated documents, mitigation credit availability, service areas, as well information on national and local policies and procedures that affect mitigation and conservation bank and in-lieu fee program development and operation.
  • TDOT Environmental Mitigation Office
    Compensatory mitigation is required for certain TDOT transportation projects, as part of the permitting process through the Tennessee Department of Environment and Conservation (TDEC) and the U.S. Army Corps of Engineers (USACE). The Tennessee Department of Transportation (TDOT) Environmental Mitigation Office is responsible for providing compensatory mitigation to offset unavoidable stream and wetland impacts from transportation projects through a process referred to as compensatory mitigation.
  • Regional Curves
    TDEC Division of Water Resources has worked (and continues to work) with Jennings Environmental, LLC to develop ecoregion based regional curves across the entire state. These regional curves were developed to assist practitioners in identifying the bankfull stage in ungaged watersheds and estimating the bankfull discharge and dimensions for river studies and natural channel designs. Regional curves relate bankfull channel dimensions (i.e., width, depth and cross-sectional area) and discharge to watershed drainage area. These tools can also be used as an aid in designing a pilot or low flow channel within flood control projects. TDEC Regional curves should only be applied where the project reach has the same Level III Ecoregion as the reaches that were used to generate the curve.
  • Tennessee Stream Quantification Tool Version 0.9 Public Notice Webinar (Jan 17, 2018)
  • Stream Permittee-Responsible Mitigation Guidance
Long term protection for compensatory mitigation sites is a requirement of federal rule and of Tennessee's Section 401 Water Quality Certifications and Aquatic Resource Alteration Permits. The following reference documents should be used to fulfill the site protection instrument requirements:
 

May 2019 - Joint Outreach Event Presentations & Videos

  • Tennessee Stream Mitigation Guidelines (Overview of the updated Stream Mitigation Guidelines for the State of Tennessee.)
  • General Permits and Aquatic Resource Alteration Permit Rule Changes (A review of revised General ARAPs that were issued in May 2019, and recent changes to the Aquatic Resource Alteration Permit Rules.)
  • Debit Tool Demonstration (Workshop demonstration involving impact project proposal examples and evaluating them using the new Stream Mitigation Guidelines and Debit Tool.)
    • VIDEO - Vena Jones, TDEC
  • Clean Water Act Section 404 and US Army Corps of Engineers Permitting Process (Defining regulatory program authorities and the scope of the Clean Water Act. This presentation reviews the Nashville District’s current practice for Jurisdictional Determinations and the processing procedure for Nationwide and Individual Permits. )
  • Dam Removal & Regulatory Guidance Letter 18-01 (This presentation explains Regulatory Guidance Letter (RGL) 18-01 and defines the permitting mechanisms for dam removals.)
  • US Army Corps of Engineers Mitigation Update (This presentation provides information to regulatory initiatives related to Compensatory Mitigation and reviews updates to guidance documents such as the Draft Prospectus Guidance for Stream and Wetland Mitigation Banks and ILF Projects, Permittee-Responsible Mitigation Guidance and other templates.)
  • US Army Corps of Engineers Regulatory Guidance Letter 19-01 (A review of Regulatory Guidance Letter (RGL) 19-01- Mitigation Bank Credit Release Schedules and Equivalency in Mitigation Bank and In-Lieu Fee Program Service Areas.)
  • Temporal Loss and Proximity Factor (This presentation summarizes Public Notice 18-40, temporal loss multiplier and proximity factor calculator. Temporal loss is the time lag between the loss of aquatic resource functions as a result of permitted impacts and the replacement of aquatic resource functions at the compensatory mitigation site.)

April 2017 - Joint Outreach Event Presentations


Water
Contacts

Jimmy Smith

Natural Resources Unit Manager
615-532-0648
Jimmy.R.Smith@tn.gov