The NH Method: Practical wetlands guide updated and online


New Hampshire communities, conservation groups and natural resources consultants now have an updated, practical method for evaluating wetland functions. The NH Method, originally published in 1991, has been updated for the first time in 20 years through the efforts of its two main authors from UNH Cooperative Extension and the NH Method Work Group.

Wetlands play a key role in maintaining water quality, reducing the amount and volume of stormwater runoff, and storing floodwater to prevent downstream property damage.

First update since 1991

First developed in 1991, the NH Method was long overdue for an update, according to one of the authors, Amanda Lindley Stone, UNH Cooperative Extension land and water conservation specialist.

"The NH Method is widely used in New Hampshire, so the update was needed to incorporate new information, studies and technologies. It also was an opportunity to incorporate feedback we have received from users over the years."

Officially known as the "Method for the Inventory and Evaluation of Freshwater Wetlands in New Hampshire," it has always been known as the NH Method, providing a science-based method designed that both professionals and non-professionals will find easy to use.

The format provides a step-by-step process that allows users to learn about wetlands and wetland evaluation. It is available only through its website and can be downloaded as one document or by chapters.

Over the past 20 years, the NH Method has been used frequently for community and watershed-based wetland assessments throughout the state and has been demonstrated as both useful and accurate.

Easy to use, educational, and objective

Its ease of use, educational value and the overall objectivity of the resulting function evaluations have contributed to its popularity. Since 1991, the NH DES Wetlands Bureau Prime Wetlands Regulations have recommended it as the preferred method for evaluating wetlands for the purpose of Prime Wetlands designation.

"The original NH Method was published before the wide availability of Geographic Information Systems (GIS), in the early days of desktop computers, before the availability of the Internet," Stone says.

"Eighteen years later, it was ripe for an update that included new information sources and technologies. In addition, the update incorporates changes suggested by past users."

The update includes the addition of new scientific information and new technologies, along with revisions that improve clarity and that incorporate new data from recent studies. Intended uses include:

• Educating members of conservation commissions, other town boards, non-wetland professionals and the public about wetland functions and values.
• Evaluating one or more wetlands in a study area, such as a town or a watershed.
• Evaluating Prime Wetlands (see: RSA 482-A:15)
• Collecting baseline information about the wetlands in a study area.
• Creating a database of the scores for the evaluated wetlands for a number of functions, as well as other data about the wetlands in a study area.
• Supporting local planning and decision-making.

Stone and Frank Mitchell, a UNH Cooperative Extension specialist emeritus, are the main editors. Contributing authors are listed within the document.

Check out the new resource. You can download it as one document or by chapters.