Amherst Wetland Assessment And Prime Wetland Designation Project Amherst, NH THE REPORT Return to Index

The Town of Amherst has been subject to unprecedented growth over the past two decades. Population projections have been exceeded, and the demand for clean drinking water has increased proportionally. Amherst is well endowed with stratified drift aquifers, and has been long recognized to harbor tremendous ground water use potential. However, as its population continues to expand, and "build out" is approached within the residential, commercial and industrial zones of Town, greater pressure will continue to be applied to the landscape’s natural ability to provide abundant, clean fresh water to the Town’s citizenry. Stringent zoning ordinances, regional planning activities, a high level of consumer awareness, and the water resource protection efforts of the Pennichuck Water Works Corporation has mitigated these impacts to a great degree. Further protection efforts are warranted, however, especially for those areas that serve as the best biogeochemical filters available, Amherst’s wetlands.

Amherst contains approximately 34.8 square miles or roughly 22,272 acres, most of which lies along the edge of the northern New England coastal plain. Fairly steep sided hills dominate the northern and western portion of Town, through which several perennial streams flow southeasterly towards the Souhegan River. Joe English and Pulpit Brooks drain the northern part of Amherst and support a chain of linearly arranged wetland complexes north of Baboosic Lake. Caesar’s Brook and Beaver Brook drain the western portion of Town and feed more directly into the Souhegan River. The latter waterway flows west to east in the southern part of Amherst, and is separated from the Pennichuck watershed to its south by a low ridge of outwash materials. From afar, the majority of Amherst’s wetlands appear to lie in a central "trough" running north-south above the Souhegan River. While the western half of Town is largely devoid of wetlands, the eastern portion contains several large wetland complexes surrounding open water bodies. The Baboosic Lake basin and Pond Parish drainage are two good examples of the latter.

Soils in the Town of Amherst are largely made of glacial tills in the higher elevation western sections, and outwash sands and gravels in the lower outwash areas. Although the latter types are somewhat to excessively drained and percolate surface water quite rapidly, these lower elevation sites also contain scattered pockets of very poorly drained glacial ice meltwater pockets. Ponemah Bog, Thibodeau Bog, and Homestead Fen are three examples of basin wetlands that formed in these "sink hole" type depressions.

Approximately 14.3% of the Town of Amherst contain hydric (poorly and very poorly drained) soils. Definitionally, these soils are inundated and/or saturated for a significant period during the growing season and develop anaerobic conditions in the upper part during most years. Typical to these soil types, plant communities that develop exhibit morphological adaptations to water saturation and anaerobia, and are therefore considered hydrophytes. The presence of the above saturation or inundation, hydric soils, and hydrophytes form the three constituents of jurisdictional wetlands in the United States.

Amherst recognizes the presence of wetlands in its Zoning Ordinance, and has protected them through the establishment of a Wetlands Conservation District in 1973. Subsequent revisions in 1980, 1991, and 1993 has provided the following four intents of the zoning overlay district:

1. To prevent the development of buildings and land use on naturally occurring wetlands, which would contribute to the pollution of surface and ground water;
2. To prevent the destruction of natural wetlands which provide flood protection, recharge of ground water supply, and augmentation of stream flow during dry periods;
3. To prevent unnecessary or excessive expenses to the Town to provide and maintain essential services and utilities which arise because of inharmonious uses of wetlands; and
4. To encourage those uses that can be appropriately and safely located in the wetland area.

Whereas the above ordinance recognizes wetlands and further protects them through setbacks of 75 feet for septic tanks and leachfields and 50 feet for "structures," all wetlands are treated the same, regardless of inherent differences in their functional capacity to serve the above purposes. Moreover, because of their well-known ability to filter pollutants from surface water as they enter ground water aquifers, even greater protection is recommended by the Pennichuck Water Works Corporation. Buffer zones of 400 feet from chain ponds and 200 feet from tributaries are recommended around all "sensitive water resources and wetlands."

This study arose from discussions between the Amherst Planning Board and the Town of Amherst Conservation Commission in 1998. Based upon the availability of matching funds for a statewide Local Initiatives Grants Program and a desire to better understand where the "sensitive water resources" were in Town, this project was created in early 1999. The following objectives were identified in the Project Agreement in accordance with the terms of the Local Water Protection Grant:

1. to initiate a comprehensive inventory of Amherst’s wetlands by reviewing existing mapped wetlands (NHDES Task 1);
2. to conduct a field inventory and inspection of each wetland using the "Method for the Comparative Evaluation of Non-tidal Wetlands in New Hampshire" (NHDES Task 2);
3. to prepare a ranked compendium of evaluated wetlands (NHDES Task 3);
4. to prepare a final report that include the findings of the wetlands evaluation, maps of the wetlands at a usable Town planning scale (1:12,000 to 1: 24,000), and recommendations for revisions to local land use regulations (NHDES Task 4).

This report represents Task 4 and provides the Town of Amherst with a Town-wide map of evaluated wetlands, a ranked assessment of same, and recommended revisions to the Town’s Wetland Conservation District ordinance. Additionally, it suggests a rationale for the nomination of 44 wetlands in Amherst for Prime Wetland designation in the subsequent year (or years).

 

This section is separated into two sections as reflected by the above objectives. Each section contains a description of the procedural steps followed while achieving the assigned tasks. Specific detail on the field parameters of the wetland evaluation section is provided in Appendix D.

Wetland Evaluation

The procedures outlined in the ‘NH Method’ detail a two-step process in the evaluation of selected wetlands. First, an office portion requires that the user obtain base maps and other remotely derived in order to prepare for field work and answer "office-based" questions associated with the 14 functions recognized by the method. The second step is the actual field evaluation of each attribute that is recognized within the 14 functions themselves. Questions are asked based on specific characteristics that are associated with a particular function. A value between 0 and 1.0 is assigned for each question, and tallied at the end of each set of functional attribute questions. The summary value, called a Functional Value Index (or FVI), is an average of the value assigned for each question, and therefore ranges between 0 (lowest) and 1.0 (highest). A second value is then computed, called the Wetland Value Unit (or WVU), that is equal to the FVI times the size in acres of the area associated with the particular function. In most case, the functional area is equal to the entire wetland acreage; however, for selected functions such as Educational Potential or Visual/Aesthetic Quality, functional areas tend to be much less than the entire wetland acreage.

Both the office and field steps require a working knowledge of wetlands on the landscape, as well as an understanding of where to find certain informational resources. Some guidance is given in the NH Method about whom to contact for information and how to develop base maps; however, a certain level of expertise is required in order to use the NH Method efficiently.

Having an extensive knowledge of wetlands, as well as having assisted in the development of the NH Method in 1990 and 1991, allowed this author to expedite the process of supervising the office and field assessment. This would not have been possible without the preparatory work of a Project Assistant, three Antioch students and the Amherst Conservation Commission, whose efforts in coordinating volunteers to assist in map generation, wetland identification, and field evaluation of 100 wetlands allowed for the rapid completion of Objective #2.

Thirteen of the fourteen functions that are recognized by the NH Method were assessed:

1) Ecological Integrity 2) Wetland Wildlife Habitat 3A & B) Finfish Habitat 4) Educational Potential 5) Visual/Aesthetic Quality 6) Water-based Recreation 7) Flood Control Potential

8) Ground Water Use Potential 9) Sediment Trapping 10) Nutrient Attenuation 11) Shoreline Anchoring & Dissipation of Erosive Forces 12) [Urban Quality of Life] 13) Historical Site Potential 14) Noteworthiness

Only the 12th function, Urban Quality of Life, was not assessed owing to the residential and light industrial nature of the Town of Amherst. In addition, the 3^rd function, finfish habitat, was maintained in the data analysis as two separate sub-functions, finfish habitat – A) streams & rivers, and finfish habitat – B) lakes & ponds.

Initial mapping was conducted with the assistance of John Vogel of the Nashua Regional Planning Commission, who provided the principal researcher with Arc/Info Geographic Information System (GIS) maps of the Town of Amherst. These maps were converted to ArcView shapefiles for easy viewing and then compared with paper copies of the National Wetlands Inventory maps for the New Boston, Pinardville, Milford, and Merrimack quads. Trudy Loy of the Amherst Conservation Commission made the initial estimate of wetland unit numbers based on the latter, whereupon it was determined that the number of wetlands in Amherst over 1 acre in size and with > 50% hydric A soils, ranged between 120 and 435. Fortunately for the field researchers, the actual number of wetlands in Amherst was closer to the former figure, as the hydrologic connectivity among wetland complexes reduced the overall number of distinct wetland units.

In late June and early July, two training sessions were held in Amherst for the purpose of instructing both Antioch interns and Amherst volunteers in the ‘NH Method.’ These were very useful sessions, which generated both commitment and support among over 20 Amherst citizens. Once the Governor and Council approved the grant appropriation on June 24^th, plans were immediately underway to schedule the field evaluations. Rhan Flatin of Antioch worked with students Kym Hall, Jeff Blecharzyck, and Robert Wood to undertake the task of preparing map and data sheet packets for each wetland to be evaluated.

All wetlands that were to be assessed required written permission from all abutting property owners, as per order of the Selectmen. Anne Krantz of the Amherst Conservation Commission provided invaluable assistance in checking Town tax maps, organizing the letter writing campaign, and soliciting verbal permission as necessary. In less than 5% of the wetland evaluations was property access denied. In most cases, these properties did not impede with the field assessment from abutting properties. In roughly six instances complete access was impossible and field evaluations were not completed.

Early in the assessment, a decision was made by Rhan Flatin to utilize the NWI maps for estimating the location and acreage of the individual wetlands. Base maps were comprised of NWI topographic quads that allowed the evaluator to estimate both wetland and watershed acreage. Site visits provided the determination of hydrologic connectivity, as well as any changes in overall wetland acreages based upon either changes in the landscape (i.e. through artificial disturbance) or actual field differences from the NWI map. These changes were entered into the ArcView map database upon completion of the field portion of the project.

Mapping was initiated by the principal author and Jeff Blecharzyck, and mostly carried out by Rhan Flatin. Andrew Toepfer and Peter Throop of Antioch New England provided invaluable assistance in the geo-referencing of the scanned NWI quads and in the printing of the large format maps. Quality control and assurance was performed by the principal author upon completion of the large format map layouts, within the standards of the source maps themselves. For a complete list of the latter, consult the Source Cites section of this report.

In approximately 90% of the wetland evaluations, the Antioch field teams either evaluated or supervised the evaluation of the wetlands in the field. Antioch intern Jeff Blecharzyck reviewed all of the data sheets and provided the initial spreadsheet entries. These were reviewed and corrected by the principal author. All data manipulations and chart creations were similarly performed by the author using Microsoft Excel v5.0.

The cumulative point ranking system was designed by the author, with modifications suggested by Town officials during a preliminary presentation on November 9, 1999. All wetlands with the highest three scores for each functional value for both WVU (Wetland Value Unit) and FVI (Functional Value Index) values initially received proportional points – i.e. 1 point for the third rank, 2 points for the second rank, and 3 points for the first rank. Points were assigned for both the overall ranking of the wetland in each category (WVU and FVI) and for each functional value within each category. These points were then summed and modified by three water quality attributes of the wetland. These three attributes were as follows:

1. location within the Pennichuck watershed
2. location above an aquifer as mapped by the NH Department of Environmental Services
3. location within .5 miles upstream of a public water supply system

The first attribute was derived from conversations with Don Ware of the Pennichuck Water Work Corporation owing to the particular water quality concerns of this water supply company in the southern part of Town. The second attribute also addressed water quality and was recommended by the Amherst Planning Board as reflected in the Amherst Master Plan and Amherst Water Resource Management Update. The last attribute, also emphasizing the unique and valuable water supply potential of over 35% of the Town, was prescribed by the ‘NH Method’ under the Ground Water Use Potential functional value (See Section V - 45).

Point rank modifications were established as follows:

Final Ranking = CPR x 1/(1+k)

Where CPR = cumulative point rank

k = sum of the attributes (1, 2 or 3)

Cumulative point ranks, k constants and the final ranking list can be reviewed in Appendix B.

Wetlands Ordinance Revisions

In the background description of the Local Initiatives Grant application, a rationale statement was given for the revision of the Amherst Zoning Ordinances. It cites the rapid population growth and the need to reassess the ability of the current regulations to "protect against non-point source pollution." It also points to the need for "better control over land use and setback consequences" and recognizes the fact that the current Amherst Zoning Ordinance "falls short" of the guidelines produced by the Audubon Society in "Buffers for Wetlands and Surface Waters" (revised May 1997). While existing regulations provide for both building and septic / leachfield setbacks, their adequacy was being questioned especially in areas where rapidly permeable soils pose a great risk to subsurface aquifer contamination.

In taking a look at the existing wetland ordinance, last revised on March 12, 1991, it was clear that several revisions were needed. Jurisdictional criteria for wetlands were not identified, source documents for delineating wetlands during cases of dispute were not cited, and no mitigation guidelines were outlined for unavoidable loss. These deficiencies stood out beyond the absence of a development setback or the recognition of Prime Wetlands. In preparing suggested revisions for the Conservation Commission, several sources were utilized: Pennichuck Water Works Watershed Management Plan (1998), the regional planning agencies, the NH Wetlands Bureau, and the NH Association of Conservation Commissions.

A first step was to enhance an existing file of municipal zoning ordinances with recent ones that contained wetland overlay districts. Six additional zoning ordinances were procured from diverse towns in the state. Both the Nashua Regional Planning Commission and the Southwest Regional Planning Commission provided assistance in this step. Secondly, updated wetlands rules were obtained from the NH Wetlands Bureau, as well as information from the NH DES web site at www.state.nh.us/des/482.htm. Marjorie Swope, Executive Director of the NH Association of Conservation Commissions, also contributed sample wetlands ordinances, and provided an estimate of the number of New Hampshire communities which have passed prime wetland designation in their towns. She also provided a database on wetland setbacks in the state for the various uses that are recognized in local ordinances.

All of this information was extremely useful when preparing a draft revision of the Amherst Zoning Ordinance, Section 4 -11. Appendix A – 1 contains the language in the existing ordinance, and pages A-3 to A-6 contain the suggested revision language for general provisions and prime wetlands, respectively. These revisions should be considered as DRAFT, since the process of Planning Board review and Town Hearings have yet to take place.

Wetland Evaluation

One hundred wetlands in the Town of Amherst were evaluated between June 27 and October 25, 1999. Teams of between two and five people utilized the Method for the Comparative Evaluation of Non-tidal Wetlands in New Hampshire (1991) to assess 13 functional values of all 100 wetlands. One project assistant and three Antioch interns performed the fieldwork, with the assistance of over 20 citizen volunteers from the Town. Anne Krantz was instrumental in mobilizing both the support of these volunteers as well as the cooperation of private residents and Town officials during the inventory process. Less than 5% of the Town private property owners denied permission to access their lands when completing the field portion. Approximately 2327 acres of jurisdictional wetlands were covered, 96.3% of which were within the Town boundaries. Roughly 85 acres of the wetland study area fell over Town lines in Merrimack (mostly Baboosic Lake) and Hollis (Witches Brook).

The overall evaluation process identified 100 distinct wetland units, some of which involved long, narrow wetland complexes (i.e. the Souhegan River). Sizes ranged between 1.0 acre and 230 acres, with a mean of 23.27 acres. Place names were arbitrarily given to each wetland for ease in relocation (see Frontspiece or accompanying large format map for mapped wetland names). Guidance in the ‘NH Method’ was utilized in determining the separation of discrete wetland complexes and in suggesting appropriate breaks in linear complexes (see ‘NH Method’ Section IV-1). National Wetland Inventory maps were used in conjunction NRCS soils maps to locate and confirm wetland boundaries. No attempt was made to carefully delineate the wetlands on the ground, although some revisions were made to rectify obvious boundary discrepancies.

Roughly 14.3 % of the Town of Amherst contained poorly and very poorly drained soils and open water according to the NRCS soils survey data. A slightly smaller amount, approximately 11.2 % of the Town, was found to be wet according to the NWI data. (See large format map overlay of NWI wetlands on top of hydric soils and water units). Slightly over 10% of the Town’s land area was evaluated, or roughly 90% of Amherst’s wetland area according to the NWI estimates and 78% of the Town’s wetland area according to the NRCS maps.

While the wetland evaluation area represented an overwhelming majority of the overall wetland area in Amherst, over 175 wetlands remain to be evaluated. With the exception of about a half dozen larger wetlands that were designated "off-limits" due to denial of access, all of these remaining wetlands involve small, isolated bodies of water, most of which are privately dug ponds of less than 1.5 acres in size. These latter wetlands are scattered throughout the Town, and with few exceptions do not represent significant contributions to the overall functions served by the wetland resources in Town. Notable exceptions occur in the industrially zoned section of the Pennichuck watershed and some of the newer residential areas in the central part of Town.

Thirteen wetlands exceeded 50 acres in extent, including Baboosic Lake, which entailed the entirety of the 230 acre open water body. Witches Brook was the largest and most complex wetland in the Town of Amherst and received the highest overall ranking for Wetland Value Units or WVU’s. It also received the highest cumulative point rank, as it sits in the Pennichuck watershed atop an aquifer and is less than .5 miles from a public water supply. It did not have the highest overall FVI average, however. Stump Pond scored the highest in this category with a mean FVI of .78. Weimont wetland and Terriault’s Marsh received the second and third highest FVI’s (.76 and .74 respectively), and were also highly ranked for water quality contribution and protection. (See Appendix B for FVI and WVU summary sheets and Appendix C for graphic representations of this data).

All functions but Urban Quality of Life was evaluated for all 100 wetlands. The latter function presumes a built-up downtown metropolitan area, which Amherst currently lacks. Functional value indices (FVI’s) ranged between .05 and 1.0, with an overall mean of .45. Certain functions received higher means individually, especially Flood Control Potential and Ground Water Use Potential, owing to the unique nature of Amherst’s wetlands in general (i.e. mostly with relatively large watersheds, small outlets, and close proximity to stratified drift aquifers). Whereas only three wetlands received a "perfect score" for Ecological Integrity (Remington Pond, Lorden, and Plume Forest), 18 wetlands received Noteworthiness values of 1.0, primarily for the presence of rare and endangered species or exemplary natural communities. Stump Pond, Souhegan Three, and Souhegan Two all contained 3 or more Noteworthiness attributes.

In terms of WVU’s, values ranged between .02 and 230 with a mean of 9.68. Overall mean WVU’s ranged between .24 for Bartlett Common and 119.05 for Baboosic Lake. All seven of the largest wetlands received first, second, or third ranked WVU scores among the thirteen functional values that were assessed. Baboosic Lake (119.05), Witches Brook (69.1), and Pulpit Meadow (55.37) represented the three highest values, followed by Pond Parish (45.38), Great Meadow (42.96), Ponemah Bog (40.9), and Horace Greeley Triangle (35.06). Of the eleven largest wetlands, only the Hodgman and Caputo wetlands did not receive any top scores for WVU’s. The remaining smaller wetlands with top scores for WVU’s included Stump Pond, Souhegan Two, Ice Pond, Souhegan Three, Belden’s Mill, and Souhegan One. It should be noted that Ice Pond and Belden’s Mill received high ranks only for their Historical Site Potential.

In analyzing the cumulative point rank (CPR) scores (Appendix B-5, 6) it is apparent that wetland size played a significant role in determining overall value. The ‘NH Method’ is designed to favor those larger wetland complexes that have a high degree of habitat interspersion, deep open water, and narrow outlets above an aquifer. Over half of the top ranked wetlands exceeded 25 acres in size and most were well above the mean size of 23.27 acres. Witches Brook (CPR = 3.5), Terriault’s Marsh (6.25), and Stump Pond (6.25) led the point ranked group, followed by Baboosic Lake (8.33), Pond Parish (8.5), Ponemah Bog (8.75), Horace Greeley Triangle (9.0), and Weimont (9.0). Stump Pond was the smallest of this group at 32 acres in size.

It was interesting to note that among the top 44 wetlands preliminarily selected for prime wetland nomination, several were smaller, isolated wet areas that play critical roles in water quality amelioration. Pocket wetlands in the midst of greater development, especially if they are within high yield aquifer areas, can have a greater positive influence on water purification than those wetlands that exist in forested or low-density residential areas. Thus, wetlands such as Nolan Pond, Maine RR Sandpit, and Corduroy / Dog Pound made the list of highest ranked areas.

Prime Wetlands Nomination

Forty-four wetlands have been noted for their high overall point ranks among the 13 functional values evaluated for 100 Amherst wetland areas. The cumulative point ranking system described above resulted in values that ranged between 3.5 and 157 with a mean of 57.79, a median value of 42.0 and a standard deviation of 43.52. The mean / median value differential reflects the slight skew attributable to the importance of wetland acreage, which typically contributes to higher overall values for larger wetlands. (See Chart C-10). However, the water quality contribution constant derived from wetland proximity to aquifers, wells, and the Pennichuck water system also skews the ranking towards those wetlands with beneficial locations, as demonstrated in Table B-10. Whereas standard deviation values appear greater for the wetland value units, the standard errors of Y/X for WVU versus wetland size are actually smaller. The cumulative point ranking system brings this into alignment, as illustrated by a standard error value that approximates that of the average FVI values.

Because of the statistical influence of the cumulative point ranking (CPR) data, it was possible to derive a mathematical threshold for the selection of prime wetland nominees. Chart C-11 suggests a threshold value of 48, at which a break occurs between wetlands that have two versus one water quality attribute. Table B-6 demonstrates this break numerically. Using this as a guide, wetlands were then sorted by the number of water quality attributes they had (Table B-8). Forty wetlands contained CPR values below 48 with two or more water quality attributes. The final selection of four candidate prime wetlands (bringing the total to 44) was made on the basis of low CPR scores in spite of a low (N = 1) number of water quality attributes. All four wetlands, Pond Parish, Pulpit Meadow, Little Baboosic, and Great Meadow, are fairly large and well-known wetlands that have already generated a great deal of support among the Amherst wetland evaluation volunteers for protection.

It is suggested that while the above rationale has attempted to summarize and consolidate a large amount of mathematical data on wetlands that are all individually unique, it is recognized that demonstrated statistical value versus perceived value will always vary. That said, the Amherst Conservation Commission, the Amherst Planning Board, and the citizens of Amherst are encouraged to review the enclosed data and test the viability of the statistics against personal judgement. The special nature and hard-to-describe attributes of specific wetlands need also be considered. Mitigation of future water quality impacts must also be factored in, especially for those wetlands that may serve a locally higher mitigation value by virtue of their proximity to development, as discussed above.

Additionally, current and future land use may dictate the prioritization of wetland protection through prime wetland designation. Areas that are currently protected, such as Ross Bird Sanctuary, Ponemah Bog, or Pond Parish, may not serve the immediate need for nomination. Similarly, wetlands in low-density residential areas may not require as great a protection status as those that face imminent threat due to contamination or destruction. Horace Greeley Triangle may not be as critical to protect as Currier Lumber, for example. Shoreland Act and NH Rivers Management protection measures may also alleviate the need to recognize the Souhegan River wetlands during this process.

Regardless of which wetlands end up on the nomination list, the Town officials of Amherst are encouraged to maintain the educational efforts of the Amherst Conservation Commission and its volunteer representatives. Only through greater awareness of the values of wetlands and their essential ecological role on the landscape will long-lasting protection be afforded. It is important to realize that prime wetland designation does NOT ultimately protect a particular resource – people protect a wetland resource. In that light, the following section suggests guidelines for the revision of the Wetland Conservation District language in an attempt to strengthen those measures that will help ensure that people prevent further wetland destruction.

Revisions to the Amherst Wetlands Ordinance

The process of suggesting the attached zoning ordinance revisions is well described under "Methods" above. The existing ordinance was found to be a significant foundation for wetland protection in Amherst, and appeared to only need moderate amounts of updating. Section A in the Appendix contains the wording of the existing ordinance, recommended language for the general provisions of the ordinance, and suggested language for an amendment to the ordinance that recognizes and protects prime wetlands. I have not attempted to modify the Flood Plain Conservation District, Aquifer Conservation District, or the Watershed Protection District ordinances, as they appear to be adequate and supportive of the intent of the Wetlands Conservation District. However, some clarification of what constitutes "bodies of water" may be needed within the Watershed Conservation District, as these may involve jurisdictional wetlands.

The principal revisions entail an updating of the wording that deals with the technical criteria of wetlands, a further recognition of multiplicity of functions that wetlands serve, the addition of a clause that emphasizes the District’s intent to protect potential water supplies and aquifers, and reference to the state guidelines on "Best Management Practices" in the event of activity in or near a wetland. Additionally, a fourth Special Provision was added that suggests the maintenance of a "natural vegetation buffer" of 25 feet, especially when general wetland buffers are being impacted by development. The latter suggestion arose from recommendations by the Pennichuck Water Works Corporation and from language in the Amherst Master Plan Executive Summary, dated 2-25-98. Whereas this setback may appear minimal, it is the largest buffer that is reasonable as long as a 50-foot building setback is maintained.

I have purposely not suggested increasing the latter buffer to one that is in line with the Water Protection District at this time. Whereas the Pennichuck Water Works Watershed Management Plan (1998) recommends a minimum buffer of 400 feet around "chain ponds" and 200 feet from the tributaries to these ponds, I believe such buffers should be created for those special areas that receive site specific protection. The latter could take place as part of the prime wetland designation process, or through a special protective warrant article. I suggest instead implementing the passage of prime wetland designation and the establishment of more restrictive buffers from development. You will note that I have suggested a minimum setback of 100 feet from all prime wetlands. These buffer areas should be maintained in their natural state.

I have listed all forty-four of the highest value wetlands named in this report as suitable candidates for prime. These are as follows:

Witches Brook Terriaults Marsh Stump Pond Ponemah Bog Glover Beds Homestead Commons Thibodeau Bog Ponemah Hill Complex J & J Party Outlet Nolan Pond Maine RR Sand Pit Baboosic Lake Horace Greeley Triangle Weimont Souhegan Three Beaver Brook South Meeting Place North Embankment Road Souhegan Two Souhegan One Ross Bird Sanctuary Pond Parish Outlet

Belden's Mill North Baboosic Jasper Valley Honey Pot Pond Curtis Well Holt Road Currier Land Corduroy/Dog Pound St. Patricks Cemetery Davis Hertzka Atherton Southfield Currier Lumber Boardman Baboosic Forested Black Forest House of Faith Souhegan Street Pond Parish Pulpit Meadow Little Baboosic Great Meadow

As mentioned above, these wetlands should be reviewed for their overall functional attributes, and some consensus by Town officials should be reached prior to nominating them to the state of New Hampshire Department of Environmental Services. The first step in this process involves the approval by a Town vote that prime wetland designation is desirable for those areas that "because of their size, unspoiled character, fragile condition or other relevant factors, make them of substantial significance." Once the Town is found to be in support of this action, then official nomination can be sought through the state, as outlined in the NH Code of Administrative Rules Chapter Wt700. Subsequent approval of all or a selection of these nominated prime wetlands can then take place the following year, again through a Town vote. The Town will have at least a year in which to garner support for the passage of a prime wetlands amendment.

The Town of Amherst, New Hampshire has a unique set of water resources that help shape and regulate growth within its borders. In a period of unprecedented growth and development, it is imperative that greater protection be afforded for those saturated and inundated areas that serve the general purpose of water quality enhancement. Wetlands provide a host of life-giving attributes for both the ecosystem at large and its human inhabitants. Town citizens would be remiss if in their shortsighted attempts to cope with a burgeoning population they would overlook the protection of the very resource by which they are able to expand and thrive.

For almost three decades the Town officials of Amherst have demonstrated their support for wetlands and general water resource protection, and have passed and amended in this time three critical ordinances that place a high value on water resources. Whereas this wetland inventory and evaluation process is consistent with this general effort, it is now up to the Town and its elected officials to strengthen these protective measures in the face of increasing contamination and encroachment. Prime wetland designation may appear to the majority of the populace as a restrictive measure that will inhibit growth and justifiable use of private property, yet when it is viewed in the light of the alternative of no protection, it can only be looked at as a sound measure of insurance for future generations. In a world of nearly incalculable yet finite natural resources, it is necessary to step back and consider the consequences of improper land use practices. Given the multiplicity of values that wetlands serve human population, their protection can only be regarded as an essential part of the legacy of wise stewardship we are attempting to create.

1999 Amherst Zoning Regulations. March 1999.

Ammann, A., and A.L. Stone. 1991. Method for Comparative Evaluation of Non-tidal Wetlands in New Hampshire. Concord, NH: NH Department of Environmental Services.

Castello, Lomansky & de Napoli, Inc. 1986. Town of Amherst, New Hampshire Sewer Study Phase I Aquifer Evaluation. Unpublished Draft.

Chase, V., L. Deming, and F. Latawiec. 1995. Buffers for Wetlands and Surface Waters: A Guidebook for New Hampshire Municipalities. Concord, NH: Audubon Society of New Hampshire.

Comprehensive Environmental Inc. 1998. Pennichuck Water Works Watershed Management Plan. Nashua, NH: Pennichuck Water Works Corporation. August.

Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Fish and Wildlife Service. FWS/OBS – 79/31. Washington, D.C.: Government Printing Office.

Howard, Needles, Tammen, and Bergendoff. 1973. Comprehensive Regional Water Quality Management Plan. Nashua: NH: Nashua Regional Planning Commission.

Local Water Protection Grant application, Town of Amherst Conservation Commission

Nashua Regional Planning Commission. 1990. Amherst Water Resource Management Update. Nashua, NH: Nashua Regional Planning Commission. October.

Nashua Regional Planning Commission. 1994. Souhegan River Corridor Study. Nashua and Concord, NH: Nashua Regional Planning Commission, NH Office of State Planning, and the NH Division of Historical Resources. June.

New England Interstate Water Pollution Control Commission. 1998. Field Identification of Hydric Soils. v2. Concord, MA: NEIWPCC.

New Hampshire GRANIT Database. Complex Systems Research Center, University of New Hampshire, Durham, NH.

Revised Statutes Annotated. 1999. RSA 482-A:15 Local Option; Prime Wetlands. www.state.nh.us/des/482.htm.

U.S. Army Corps of Engineers. 1987. Wetlands Delineation Manual. Technical Report 1-3-87. Washington, D.C.: Government Printing Office.

USDA Soil Conservation Service. 1983. Hillsborough County Soil Survey – Eastern Part. Washington, D.C.: USDA Natural Resource Conservation Service.

U.S. Department of Housing & Urban Development. 1979. Flood Insurance Study – Town of Amherst, New Hampshire Hillsborough County. Washington, D.C.: Federal Insurance Administration. January.

USGS Topographic Quads: New Boston, Pinardville, Milford, and Merrimack

USFWS National Wetland Inventory. 1971 - 1986. NWI maps of the New Boston, Pinardville, Milford, and Merrimack quads.