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A Primer on Inland Wetlands Creation and Restoration for Design Professionals

Patrick C. Garner, PLS, Wetland Scientist

Course Outline

This course is a supplement to A WETLAND PRIMER FOR DESIGN PROFESSIONALS and ADVANCED WETLANDS PRIMER: FIELD EVALUATION & PERMITTING by the same author. Although a basic understanding of wetlands—crucial for architects, engineers, land surveyors, contractors and landscape architects—is presented in those two courses, design professionals are often expected to understand the fundamentals of wetland creation and restoration.

Today numerous projects are coupled with wetland creation or restoration permitting conditions . Fulfilling these conditions is no easy task, given that a project must meet certain criteria for success—for instance, a 75% success rate for plantings after two or three growing seasons.

Further, the disquieting fact is that more than 50% of created or restored wetlands nationwide fail within a few years. New wetlands may be subject to massive plant die-off, invasions by unintended or non-native plants and insects, or are planted with incorrect species (usually as the result of poor monitoring during initial construction). Other factors can impact them as well.

Upon completing A PRIMER ON INLAND WETLANDS CREATION AND RESTORATION FOR DESIGN PROFESSIONALS, you will understand the basic parameters required for all successful inland wetland creation. You will also be introduced to a sample report of a proposed restoration project, and learn how to approach a problem site. Finally, you will have been exposed to the obvious pitfalls and the critical tools necessary to design a successful wetland.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

A PRIMER ON INLAND WETLANDS CREATION AND RESTORATION FOR DESIGN PROFESSIONALS examines the basic parameters required for successful inland wetland creation. You will become acquainted with the science, art and terminology of wetland creation as it is currently practiced in America.

Upon completion of the course, you will have learned about the basic principles of wetland creation, including

You will be familiar with

The course also examines unexpected challenges, including creation and restoration of forested wetlands.

Upon completion of the course, you will understand the basic parameters required for all successful inland wetland creation. Obvious pitfalls are highlighted and the critical tools needed to plan and permit a successful wetland are examined. A sample report of a proposed restoration project is included. Problem sites—as well as common problems—are also discussed.

Intended Audience

This course is intended for Architects, Engineers, Land Surveyors, Contractors and Landscape Architects .

Benefit to Attendees

An attendee of this course will learn the principles and techniques of wetland creation and restoration. First, wetland science and the scientific components of wetlands are reviewed. Then critical principles necessary to creating wetlands—and having them succeed—are discussed at length. A sample report of a restoration project is included. Commonly encountered problems are discussed. Upon completion of this course, the attendee will have a working knowledge about the nuances of created wetlands.

Course Introduction

The practice of the art and science of wetland creation and restoration is a new phenomenon. Note that I use the words “art” and “science” purposely, because successful wetland creation requires a certain amount of aesthetic sensibility, as well as a knowledgeable application of science.

The creation of wetlands was given little respect in the design field until the mid-1980s. When landowners were required to “restore” areas they had illegally filled, many simply dug a depression beside existing wetlands and planted seed. When developers were required to replicate wetlands lost in a large project, they often replaced a forested swamp with a cattail marsh.

Federal and state regulations often require mitigation to occur when wetlands are impacted, but have provided minimal technical guidance regarding replication methodology. In addition, some states have issued replication directions that are so vague that they effectively allow shrub swamp wetlands to be replaced with odd pockets of soft rush and loosestrife. This pattern of inept and careless replacement is well documented in the Brown and Veneman report, Compensatory Wetland Mitigation in Massachusetts (Sept 1998). Bad science, careless construction, basic misunderstandings and inadequate supervision have all contributed to the long history of these failures across the United States.

The wetland regulatory and private consultant community was slow to acknowledge these failures, but mounting evidence, both specific and anecdotal, have made it impossible to ignore. Increasingly, like-kind wetlands are being required.

In short, recognition of the biochemical, biological and habitat values of different types of wetlands are now part of regulation. Forested wetland swamps are recognized as vastly different from monocultural wetland meadows. Professionals now understand that many marsh “restorations” five years after planting became, at best, shrub-scrub depressions. Taken cumulatively, these “junk” replications were finally recognized by the regulatory community as, simply, continued wetland losses. The bar has been raised in the 21st century on how successful restoration is measured.


Course Content

The course content is contained in the following PDF file:

A Primer on Inland Wetlands Creation and Restoration for Design Professionals

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Course Summary

The emphasis throughout this course has been on properly estimating and calibrating site hydrology to successfully create or restore wetlands. Soils and vegetation play a role, but that role is secondary to hydrology. If groundwater (usually the predominant source of hydrology) is estimated too low, plants that are dependent on a certain period of saturation are likely to die. Similarly, if there is too much saturation, long periods of anaerobic conditions may cause a similar vegetative failure. The most important fieldwork before construction should be to accurately determine seasonal high groundwater.

A thorough understanding of the three components that define a wetland is also crucial. Those components are hydrology, soils and vegetation. As important as hydrology may be, proper use of hydric soils and wetland plants are particularly necessary for short-term success. Accidental or ignorant use of invasive species can rapidly destroy the most careful restorations. Similarly, improper contact of hydric soils with untilled substrates can prevent healthy root growth.

The course has also emphasized the importance of initial discussions of goals and requirements with regulatory authorities. Pre-planning wetland creation with permit granting authorities is almost always fruitful. Such input may require changes in project design; it is always better to have such feedback before expensive, definitive design takes place.

As we have seen, there are many distinct varieties of inland wetlands, including marshes, bogs, bordering vegetative wetlands and shrub-scrub or emergent swamps. Using the principles emphasized in this course, these wetlands are easily created or restored.

Recreating forested wetlands, on the other hand, is always problematic. A project should attempt to avoid impacting such areas. Be aware of like-kind requirements, and be certain that you can provide restoration or wetland creation that meets regulatory requirements.

In addition, if reports and plans are required, providing the necessary basic data is to your advantage. Working through those requirements early in project planning can help you design a better project. Further, reviewers use checklists, so if data is missing from an application, you have cost yourself time and your client money. Above all, design with the understanding that the underlying components that define a wetland must exist in any successful wetland creation or restoration.

Related Links

US Corps of Engineers

US Environmental Protection Agency--Wetlands


Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.