Technical Assistance

Explore data, learn about New Hampshire’s wetlands and find resources to plan your project.

NHDES offers technical assistance to all permit applicants with proposed projects that may impact protected areas such as wetlands. Project planning requires an understanding of wetland functions, values, and local natural processes. These resources are designed to help applicants avoid and minimize jurisdictional impacts, provide complete Wetlands Permit Applications, find information on identification and assessment, and screen for nearby natural resource areas.

Ask General Technical Questions, Including in Shoreland: For general questions on jurisdictional areas or permits, please call (603) 271-2147 and ask to speak with the Inspector of the Day (Monday-Friday, 8 AM - 4 PM).

Schedule Preapplication Meetings: If your proposed project involves 10,000 square feet or more of potential impacts to wetlands, or if otherwise required, please email to schedule a meeting. Please note that timing for such meetings depends on NHDES staff schedules as well as other state and federal agencies if applicable. Schedules are typically booked several weeks in advance.

Contact Regional Permit Reviewers: Pre-application meetings are not always necessary. Applicants may also call or email their regional permit reviewer directly. Applicants may be asked to answer additional specific questions, to share plans and photos, and to provide a brief project history. 

 A turbidity curtain containing suspended sediment. Photo shows turbid water on one side of the curtain and clean water on the other side.

"Avoidance and minimization" – as used here – means preservation wherever practicable. For permitting in or near wetlands, applicants must propose adequate avoidance and minimization of impacts. Avoidance and minimization in planning and design reduces costs and facilitates streamlined permit decisions. The Wetlands Best Management Practice - Techniques for Avoidance and Minimization Manual includes many descriptions and examples.

Project-Specific Resources


lily pads and flowersFind a state-certified professional wetlands scientist or learn more about how to identify and assess wetlands.

erosion controlThe resources listed below will help you visualize and access data and GIS information.

Prime Wetlands Designated by Municipalities

Under state statute RSA 482-A:15 and state administrative rules Env-Wt 700, municipalities may vote to designate wetlands as “prime wetlands” if, after thorough analysis, it is determined that high-quality wetlands are present. Typically, a wetland receives this designation because of its large size, unspoiled character and ability to sustain populations of rare or threatened plant and animal species. Field data and desktop data are used for the evaluations.

After high-value wetlands are identified, municipalities hold public hearings and vote on a designation. Once a municipality approves, it provides NHDES a copy of the study and tax maps with the designated prime wetlands identified. NHDES reviews to ensure it is complete and in accordance with Env-Wt 702.03.

Once the town's prime wetland is considered complete and approved, NHDES will apply the law and rules applicable to any future proposed projects within the prime wetland or the 100-foot prime wetland buffer.

Please consult the Wetlands Permit Planning Tool (WPPT) to determine if your proposed project is within a town-designated protected area. The original files can also be found at the town municipal offices.

Be aware that the town may have other local buffers or setbacks that are not addressed under the prime wetland or prime wetland buffer statute or rules.

Wetland Permit Applications: Tips for Your Planning and Design Phase

If you are a New Hampshire agent or homeowner in the planning and design phase of a proposed project in or near wetlands, here are some tips on getting better project results when filing your standard dredge and fill wetlands permit application. (Runtime 5:50)

Wetland Permit Planning Tool and Other Data Mapping Resources

Hour-long session introducing several NHDES online GIS mapping products, hosted by the New Hampshire Association of Conservation Commissions.

Introduction to OneStop Data Mapper 

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Vernal Pools

A vernal pool depicted in all four seasons.Vernal pools are those wetlands and temporary ponds that typically have ponded water only part of the year. Because the pools are temporary, they provide critical habitat for certain wildlife to breed and complete their life cycle. Many of the animals that breed in vernal pools live in the upland areas around the pool during the non-breeding season. When pools dry, wood frogs migrate to forested upland areas that are as much as 1,000 to more than 2,000 feet from their breeding pools. Mole salamanders will migrate to forested uplands that are 1,000 feet from their breeding pools. Vernal pools are a resource protected from unregulated alteration under the NHDES Wetlands law and rules. The rules provide definitions of vernal pool, primary vernal pool indicators and secondary vernal pool indicators.

Typically, a vernal pool:

  • Forms in a shallow depression or basin.
  • Holds water for at least 2 continuous months following spring ice-out.
  • Cycles annually from flooded to dry conditions, although the hydroperiod, size, and shape of the pool might vary from year to year.
  • Has no permanently flowing outlet.
  • Lacks a viable fish population.
  • Supports one or more primary vernal pool indicators, or three or more secondary vernal pool indicators.

Look at the USC Vernal Pool Field Guide for information on the many species considered vernal pool indicators.

The following documents can be used to identify and document vernal pools