Skip to Main Content
Wetlands and Waterways Home
Nontidal Wetland Mitigation Overview
What is mitigation? When is mitigation required?
What are the acreage requirements for mitigation?
What are the procedures for mitigation?
Maryland Nontidal Wetland Mitigation Guidance
A comprehensive guide to the regulations, procedures and information sources relevant to wetlands mitigation.
What is mitigation?
Nontidal wetland mitigation is the creation, restoration, or enhancement of nontidal wetlands, to compensate for nontidal wetlands that were or will be lost due to regulated activities or non-exempt agricultural activities. The State definition of wetlands corresponds to the Federal definition of compensatory mitigation.
projects establish nontidal wetlands on upland sites. These projects usually involve lowering the elevations of uplands by grading the soil for the purpose of increasing the frequency of soil saturation, flooding, and ponding.
projects reestablish nontidal wetlands on sites where they were formerly located. For example, the removal of drainage structures from agricultural fields can result in nontidal wetland restoration.
projects improve the functions of existing nontidal wetlands. Planting wetlands that are farmed or dominated by lawn grass is the most common type of enhancement project. Stream restoration projects that reconnect the floodplain can enhance existing nontidal wetlands. Enhancement projects do not, however, increase the acreage of nontidal wetlands.
When is nontidal wetland mitigation required?
Mitigation is required to compensate for authorized activities which will cause unavoidable losses of nontidal wetlands.
What activities require nontidal wetland mitigation?
Removal, excavation, or dredging of soil, sand, gravel, minerals, organic matter, or materials of any kind.
Changing existing drainage characteristics, sedimentation patterns, flow patterns, or flood retention characteristics.
Disturbance of the water level or water table by drainage, impoundment, or other means.
Dumping, discharging of material, or filling with material, including the driving of piles and placing of obstructions.
Grading or removal of plant life that would alter the character of a nontidal wetland.
Agricultural activities in undisturbed wetlands.
What activities do not require nontidal wetland mitigation?
Traditional agricultural activities such as plowing and cultivating, which do not drain, dredge, fill, or otherwise convert undisturbed nontidal wetlands.
Development activities with minimal impacts to nontidal wetlands, and which are exempt or qualify for a Letter of Authorization, except Letters of Authorization for activities in the Chesapeake Bay Critical Area.
Mitigation is not required for temporary impacts to wetlands or impacts to the wetland buffer or expanded buffer.
What are the acreage requirements for nontidal wetland mitigation?
Acreage replacement ratios are used to determine the amount of mitigation required. Before any nontidal wetlands have been impacted by a project, the amount of each type of wetland to be lost (emergent, scrub-shrub, or forested) must be determined. Acreage replacement ratios are expressed as a relationship between two numbers. The first number specifies the acreage to be mitigated and the second number specifies the acreage of nontidal wetlands impacted. The acreage replacement ratios are:
REPLACEMENT RATIO FOR PERMANENT IMPACTS
Scrub-shrub to emergent conversion
Forested to emergent conversion
Forested to scrub-shrub
Emergent (of special State concern)
Scrub-shrub (of special State concern)
Forested, (of special state concern)
What are the procedures for mitigation?
Nontidal Wetland Mitigation for Development Activities
What is the procedure for mitigating for the loss of nontidal wetlands due to development activities?
If mitigation will be required for a development activity, a Phase I (conceptual) Mitigation Plan must be developed. The following steps should be taken:
Determine the acreage of each type of wetland (emergent, scrub-shrub, or forested) to be impacted, based on a delineation consistent with the
Regional Supplements to the Corps of Engineers (Corps) Wetland Delineation Manual
Determine wetland mitigation type being proposed: 1) purchase of available credits from an approved
having a service area overlapping with the area of impacts, 2) payment into the
MDE ILF Program
(for mitigation not required by the Corps), or 3) completing a
If proposing a permittee-responsible mitigation project, locate appropriate mitigation site(s).
Develop and submit a Phase I Mitigation Plan.
Do not proceed with a Phase II (design) Mitigation Plan until the Phase I has been approved by the Department.
If requesting to purchase credit from a mitigation bank or pay into the ILF Program, this should be proposed as the Phase I Mitigation Plan. If proposing a permittee-responsible mitigation project, the Phase I Mitigation Plan should include all elements in the
Phase I Mitigation Plan checklist
For permittee-responsible mitigation, demonstrate that you have the right to use the site for mitigation.
MDE will review the Phase I Mitigation Plan and provide feedback, but cannot officially approve the Phase I Mitigation Plan until after completion of the Public Notice period (for projects where Public Notice is required). The Department will render a decision on the acceptability of the Phase I as part of the final permit decision. The Phase I Mitigation Plan must be approved by the Department prior to issuance of authorization. If payment into a mitigation bank is approved by the Department, a copy of the signed contract showing the purchase of required mitigation credits must be received prior to issuance of authorization. If payment into the ILF Program is approved by the Department, payment must be received prior to issuance of authorization.
If necessary, obtain a mitigation surety bond or other Department-approved financial assurance prior to issuance of authorization. The financial assurance will be released after the Department determines that the mitigation project has been successfully completed and is developing into an acceptable wetland system.
The applicant should submit the Phase II Mitigation Plan to MDE as part of the permit application, to the maximum extent practicable. The Corps may require that projects requiring an Individual Permit have an approved Phase II Mitigation Plan prior to issuance of authorization. For all other projects, the Phase II Mitigation Plan must be approved prior to commencing authorized impacts. The applicant should send all the information to MDE at the same time as the Corps, so MDE is able to comment on the Phase II plan in conjunction with the Corps.
If the project is not exempt from mitigation requirements, and the permittee is proposing to conduct permittee-responsible mitigation, the following mitigation steps are required as permit conditions:
After the Phase I Mitigation Plan has been approved, develop a Phase II Mitigation Plan, being sure to include all elements of the
Phase II Mitigation Plan checklist
Submit Phase II of the Mitigation Plan to the Department within 3 months of receiving a favorable permit decision, unless otherwise determined by the Department. The Phase II Mitigation Plan must be approved by the Department prior to commencing authorized impacts. The Department will render a decision within 45 days of receipt of a complete Phase II mitigation plan. If necessary, revise the mitigation plan based on comments by the Department.
After the Phase II Mitigation Plan is approved by the Department, create, restore, and/or enhance nontidal wetlands at the mitigation site(s). The mitigation project should be successfully constructed in advance or concurrently with the authorized impacts. Notify the Department upon the start of grading and the completion of planting of the mitigation project. Submit an "as-built" site design plan to the Department within 120 days of the completion (including grading, planting, and/or vegetative stabilization) of the mitigation project.
Demonstrate that the site has been protected in perpetuity through a
Declaration of Restrictive Covenants
(PDF) or other site protection mechanism acceptable to the Department.or other site protection mechanism acceptable to the Department.
Monitor the mitigation project for the period of time specified in the permit condition to ensure the site is meeting
(PDF). Submit monitoring reports to the Department. Conduct maintenance and remediation activities, as appropriate to meet Performance Standards.
The original permittee or authorized person, as stated in the authorization, must notify the Department if the authorization is transferred to another party. If the mitigation obligation has not yet been completed to the Department’s satisfaction (through payment into an approved mitigation bank, payment into the ILF Program, or termination of mitigation monitoring by the Department), and the permittee or authorized person listed on the authorization transfers responsibility for the mitigation obligation to another party, the permittee or authorized person listed on the authorization must notify the Department.
Nontidal Wetland Mitigation for Agricultural Activities
What is the procedure for mitigating for the loss of nontidal wetlands due to agricultural activities?
A person conducting an agricultural activity within nontidal wetlands is exempt from the requirement to obtain a nontidal wetlands permit according to the Code of Maryland Regulations (COMAR). Agricultural exemptions are further described in the MDE factsheet entitled
Nontidal Wetland Regulations and Agriculture
While these projects do not require a permit, the farmer may be required to implement best management practices (BMPs) to protect nontidal wetlands and provide mitigation for any loss of nontidal wetlands through a soil conservation and water quality plan submitted to, and approved by, a Soil Conservation District (SCD). BMPs are conservation measures that control soil loss, reduce water quality degradation, and/or minimize adverse impacts to water quality and flow, and the chemical, physical, and biological characteristics of nontidal wetlands. Examples of BMPs include filter strips, field borders, conservation cropping sequences, nutrient and pesticide management, and irrigation water management.
Mitigation is required if nontidal wetland impacts associated with these projects meet any of the following criteria:
Any amount of impacts to nontidal wetlands within the Critical Area
Any amount of impacts to nontidal wetlands having significant plant or wildlife value, as defined in COMAR 26.23.01.01. These include wetlands: of unusual or unique community types; with water discharge that maintains minimum stream base flow important for maintaining plant and wildlife species; with threatened or endangered species, or species in need of conservation; adjacent to Class III or Class IV waters; of Special State Concern; supporting vernal pools; and areas that are regularly or periodically influenced by tidal waters.
Impacts to 5,000 square feet or more of connected nontidal wetlands
Impacts to 1 acre or more of isolated nontidal wetlands
Before conducting agricultural activities in nontidal wetlands, a farmer must:
Contact the SCD to identify or verify the extent of nontidal wetlands, the presence or absence of significant plant or wildlife value, and the status of the wetlands as connected or isolated. A
SCD Certification/MDE Concurrence Form
must be approved for the project.
Submit a soil conservation and water quality plan with BMPs to the SCD for approval before beginning the activity.
Determine the wetland mitigation type being proposed: 1) completing a
project, 2) purchase of available credits from an approved
having a service area overlapping with the area of impacts, or 3) payment into the
MDE ILF Program
Submit the mitigation components of the soil conservation and water quality plan to MDE, Wetlands and Waterways Program, Mitigation Section, 1800 Washington Boulevard, Suite 430, Baltimore, Maryland 21230. For permittee-responsible mitigation proposals the mitigation component should include the Phase I and Phase II Wetland Mitigation Plans, consistent with requirements in the documents entitled
Phase I Mitigation Plan
– Required Information and
Phase II Mitigation Plan
– Required Information, and COMAR 26.23.04.03 through 26.23.04.07. The Phase I Wetland Mitigation Plan should be submitted to the Mitigation Section for approval before preparing and submitting the detailed Phase II Wetland Mitigation Plan. Within 60 days from receipt, MDE shall determine whether or not the mitigation component is consistent with regulations. The mitigation component must be approved by the Mitigation Section, as documented by a MDE Phase II Wetland Mitigation Plan Approval Letter, prior to commencing impacts.
Receive SCD approval of a soil conservation and water quality plan that is consistent with regulations.
Unless the mitigation is completed in advance of the impacts, a bond or other financial assurance for the mitigation project will be required within sixty days after the soil conservation and water quality plan is approved.
Mitigation must be completed according to the Phase II Wetland Mitigation Plan Approval Letter within three years of the impacts. For five years from the completion of the mitigation project, the farmer shall submit annual monitoring reports to show how the mitigation is meeting the Performance Standards, unless otherwise determined in the Phase II Wetland Mitigation Plan Approval Letter.
1800 Washington Boulevard, Baltimore, MD 21230