The overall goals of the project are to: Build a Geographic Information System (GIS) model of the Merrimack River watershed and apply that model to: Identify wetlands that may be impacted by past land uses and would therefore be good candidates for restoration; and Understand which of those wetlands would provide the most function and benefit once restored, and which would be most likely to sustain that increased function over a long term. Conduct field inspections of a limited number of high priority sites and develop conceptual restoration plans for each. Use the information generated by this project to help educate the public about wetland restoration, and to stimulate interest in the ARM Fund Grant opportunity.

Methodology
Because of the large scale of this watershed (1,672 square miles), the development and application of an automated geospatial model to identify and prioritize potential wetland restoration sites was necessary. The project aimed to develop a model that is specific enough to provide reliable results in the Merrimack River Watershed, but general enough so that it can be applied to other watersheds in New Hampshire in the future. This model will be called the Wetland Restoration Assessment Model (WRAM), and comprises two components: the "Site ID Model" and the "Site Assessment Model." The methodology for this model was fashioned through a collaborative process using a Technical Advisory Group (TAG) comprising various state agencies, regional planning commissions, and nonprofit groups.

Site ID Model
The purpose of the Site ID Model is to identify impacted wetlands that could serve as a set of candidate sites for input into the Site Assessment portion of the WRAM. The Site ID Model is relatively straight forward, and involved a basic screening method as follows. In order to be included in the set of "Candidate Sites," a wetland must meet the following criteria:

1. Some portion of the wetland is identified by the National Wetlands Inventory (NWI) as being drained/ditched (Cowardin modifier "d"), diked/impounded (modifier "h"), or excavated (modifier "x"); or
2. Any portion of the wetland intersects an area mapped as "agricultural," "disturbed," or ""other cleared" land cover classifications using the most recent NH Land Cover Classification coverage (Justice, et al. 2001).
3. Finally, Candidate Sites less than five acres in size were excluded. This criterion was based on a review of the literature which suggests that restoration success is most likely when working in or adjacent to wetlands at least five acres in size.

Site Assessment Model
The purpose of the Site Assessment Model is to categorize each of the Candidate Sites according to its potential benefit. It comprises three components which calculate the following quantities for each of the 951 Candidate Sites:

• Net Functional Benefit, which attempts to measure the amount of wetland function and value that could be gained by restoration of a particular site;
• Sustainability, which attempts to measure the likelihood that a site, once restored, will retain increased function over the long-term; and
• Landscape Position, which assigns value to sites which are located in certain locations which would be of benefit to the restoration (e.g., close to existing conservation land, higher in the watershed).

Figure 1: Wetland Restoration Assessment Model: Site Prioritization Model Schematic

These three components are weighted independently to derive a final assessment score that could range from a value of 0 (low priority) to 100 (very high priority) - see Figure 1 at right. Using this Assessment Score, it is possible to place each site in a category according to whether it should be considered a "high priority," "priority," or "other opportunity" to reflect its overall potential relative to the other 950 sites in the watershed. Maps showing all of the 951 Candidate Sites can be downloaded here.

Restoration Concept Plans
Once the WRAM was completed and sites were prioritized, about 60 high priority sites were reviewed and visited in the field. The project team completed Restoration Concept Plans for 30 of these sites. The Restoration Concept Plans must be considered very preliminary, since the access and amount of field investigation was very limited. But, they provide a good idea of the potential for a site. Additional study, planning and engineering may be required to make the restoration plan a reality. And, obviously, the restoration of any wetland depends on the participation of the property owner.