Modified Charleston Method
(MCM)
Brenda A. Archer, Regulatory Program
U.S. Army Corps of Engineers,
New Orleans District (CEMVN)
What is the MCM?
Modified Charleston Method (MCM)
An Assessment Methodology for evaluating
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unavoidable wetland impacts
associated with Section 404 Clean
Water Act permits and
projects that are proposed as mitigation
for those unavoidable impacts
MCM – Conditional Assessment Model
 Measures wetland functional loss indirectly by
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considering the quality of wetland functions of
the impacted site weighed against
the perceived increases of wetland functions
of the mitigation project.
 Evaluates only the site as it exists at the time
of evaluation.
History of the MCM
Regulatory was tasked with developing
an assessment model that:
 Produced comparable mitigation
requirements as other Corps Districts in
Louisiana and
 Promoted consistency among New Orleans
District regulatory project managers with
diverse backgrounds
Interagency Review Team
 Federal and state resource/regulatory
agencies involved in the decisions for the
assessment model included:
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US Environmental Protection Agency
US Fish and Wildlife Service
National Marine Fisheries Service
Louisiana Department of Wildlife and
Fisheries
Louisiana Department of Natural
Resources, Office of Coastal Management
Modified Charleston Method
 The Charleston Method was developed by the Charleston
District in collaboration with an Interagency Review Team in that
District; Used by Vicksburg District
 Provides comparable mitigation requirements from the other
Districts adjacent to the New Orleans District.
 After minimal training and practice, project managers are able to
easily apply the method with a minimal about of field data
collection and a high degree of consistency.
 Allows unlimited mixing of mitigation locations, and types (e.g.
restoration, preservation, enhancement).
 Allows mixing of mitigation banks and permittee-responsible
mitigation projects.
Modified Charleston Method (conti-)
• Only required slight modifications for it to be used in
the New Orleans District. These modifications were
to account for
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Regional wetland differences
CEMVN Mitigation Standard Operating
Procedures
33 CFR 332: New Mitigation Rule
Who can use the MCM?
MCM Operators
 CEMVN permit and mitigation bank project
managers for Section 404 CWA permits
including restoration and/or enhancement
projects
 Applicants/agents
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to estimate the amount of mitigation that will
be required to compensate for various project
scenarios (avoidance and minimization), and
to compare mitigation options
How does the MCM work?
MCM Factors
 MCM evaluates a suite of factors that are used to
assess the potential of the site to perform wetland
functions.
 A factor is an element, circumstance, or influence
which contributes to the overall quality of the site.
 Each factor is defined by a list of options that qualify
the factor based on conditions at the evaluated site.
 The functional value of the site is determined by
selecting the options that best fit the site conditions
for each factor and then summing all the factor
values.
MCM Workbook
 MCM workbook is an excel spreadsheet
consisting of four worksheets:
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“Summary Worksheet”,
“Adverse Impact Worksheet”,
“Mitigation from Bank Worksheet”, and
“Proposed Restoration/Enhancement
Mitigation Worksheet”.
MCM Guidebook
 Definitions of terms used in the model
 Discussions of the use of each worksheet
 Definitions for each factor and option
associated with that worksheet, and
 Examples using each worksheet.
1. Assessment of Adverse Impacts
 The model considers;
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The habitat rarity or difficulty to replace,
Site wetland quality,
Work involved and the extent to which that
work will impact wetland functions,
Duration of the impact
Potential for project to result in cumulative
impacts.
Adverse Impacts Worksheet
2. Assessment of Mitigation Project
The model considers:
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Net improvement
Negative impacts on the site that can not be
remediated,
Protection type,
Temporal loss,
Credit availability versus Credit use.
Replacement with in-kind/out-of-kind
Location of impact versus mitigation.
Restoration Worksheet
3. Kind and Location Factors

These factors are included when evaluating an
permit project with a particular mitigation bank
and/or permittee responsible mitigation project

The value for these Factors adjust the required
mitigation amount depending upon the degree of
variance from the most to least preferred option of
in-kind/on-site to out-of-kind/out-of-watershed.
Additional Information
Resource for MCM Guidebook and Workbook
 Located in the Regulatory In-Lieu Fee and Bank
Information Tracking System (RIBITS)
 Go to RIBITS from the following website:
https://ribits.usace.army.mil
 Once in RIBITS, Choose “New Orleans District” in the
lower, left-hand side of the screen and then the
“Assessment Tools” tab in the upper, left-hand side of
the screen.
Contact Information
Dr. James A. Barlow, Section Chief
Special Projects and Policy Team
(504) 862-2250 or
james.a.barlow@usace.army.mil
QUESTIONS??