By the authority granted in RSA 674:16-17 and 674:20-21, and in the interest of public health, convenience, safety, and the general welfare, the Wetlands Conservation Overlay District is established in order to regulate the use of land areas subject to extended periods of high water table, flooding, or standing water. It is the intent of this district to:
A. 
Prevent the development of structures or other land uses on naturally occurring wetlands which would contribute to the pollution of surface water and groundwater.
B. 
Prevent the alteration of natural wetlands which provide flood protection, recharge of groundwater supply, or augmentation of stream flow during dry periods.
C. 
Prevent unnecessary or excessive expenses to the Town to provide and maintain essential services and utilities which could arise because of inharmonious use of wetlands.
D. 
Encourage those uses that can be appropriately and safely located in wetland areas.
E. 
Create an undisturbed and natural buffer to the prime wetlands.
F. 
Protect unique and unusual natural areas.
G. 
Protect wildlife habitats and maintain ecological balances.
The limits of the Wetlands Conservation Overlay District are hereby determined to be the following:
A. 
All areas of very poorly drained soils.
B. 
Areas of poorly drained soils 2,000 square feet or more in size and that exhibit a predominance of 50% or more wetland vegetation.
C. 
Areas of any wetland of any size if contiguous to surface waters such as lakes, ponds and streams.
D. 
Areas designated as bogs regardless of any size.
Words and terms used in this article are defined as follows:
BOGS
Highly acidic wetlands that have usually developed in undrained glacial depressions and are generally underlaid by thick layers of saturated organic soils called peat, or as further defined by the New Hampshire Wetlands Board.
HIGH-INTENSITY SOIL MAPS FOR NEW HAMPSHIRE
The most recent document prepared by the Society of Soil Scientists of Northern New England detailing the standard for making high-intensity soils maps on file with the Rockingham County Conservation District.
MARSHES, FRESHWATER
Characterized by herbaceous (soft-stemmed) vegetation, or as further defined by the New Hampshire Wetlands Board.
POORLY DRAINED SOILS
Soils with a moderately high water table as described in the report titled "Soils Information for Resource Planning for the Town of Derry," dated March 1980, or as further defined by High-Intensity Soils Maps for New Hampshire on file with the Rockingham County Conservation District.
PRIME WETLANDS
Those areas designated "prime wetlands" within the scope of RSA 483-A and the New Hampshire Code of Administrative Rules, Part WT-700. These wetlands are described in the Derry Prime Wetlands Report dated November 11, 1986. The topographic definition of each prime wetland is included in separate maps correlated to the report. Both the aforementioned maps and report are incorporated in this chapter by reference. The mapped locations of the prime wetlands are identified on maps which are on file with the Derry Planning Office. They are as follows:
Wetland Number
Location
Map Number
A/1
North of Hood Pond, off Franklin Street
122
A/6
West of By-pass 28, east of Scobie Pond Road/Shields Brook
134
A/9
East of By-pass 28, South of English Range Road
140
A/11
Abuts Eleanor Avenue, east of By-pass 28
150
A/15
East of Pingree Hill Road, Auburn line
151
B/6
Southwest intersection of Adams Pond and Hampstead Roads
130
B/7
Southwest intersection of Cross and Adams Pond Roads
136
B/8
Southeast of Worthley Road
142
B/9
North of intersection of Beaver Lake and North Shore Roads
142
B/12
North of 102; west of English Range Road
141
B/15
East of Back Chester Road, south of Chester line
149
B/16
West of Back Chester Road, east of Pioneer Circle
149
C/3
Between Gulf and Island Pond Roads
106
C/4
South of Hampstead Road, east of Oleson Road
132
C/7
West of Damren Road and north of Hampstead Road
132, 138
C/9
North of Walnut Hill between Damren and Adams Pond Roads
143, 137
C/10
North of Walnut Hill Road, east of Partridge Lane
110, 137
D/5
Feeds into Ballard Pond
110
D/7
Island Pond Road south of Drew Road
120
D/8A
Drew Brook; crossed by Drew Road
121, 127
D/8B
Drew Brook; Drew Road
121
D/14
Leavitt Brook, railroad bed, Jackman Road
126
E/1
Windham Line, west of Frost Road
102
E/8
Windham Road
108
F/6
Northeast of Beacon Hill Road on I-93
101, 102, 108
F/7
East of Fordway Extension and south of Bowers Road
107, 108
F/11
Along Berry Road south of Claire Avenue
114
F/13
North of Pierce Avenue and along the brook
123, 117
PRIME WETLANDS BUFFER ZONE
That area extending 150 feet beyond the boundary of each prime wetland as defined above.
QUALIFIED SOIL SCIENTIST
A person qualified in soil classification and mapping who is recommended or approved by the State Board of Natural Scientists.
SWAMPS
Contain predominantly woody vegetation (shrubs and trees) and range in wetness from occasionally flooded to standing water most of the year, or as further defined by the New Hampshire Wetlands Board.
VERY POORLY DRAINED SOILS
Soils with a permanent high water table as described in the report titled "Soils Information for Resource Planning for the Town of Derry," dated March 1980, or as further defined by High-Intensity Soils Maps for New Hampshire on file with the Rockingham County Conservation District.
WETLANDS
Areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal conditions do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. They include, but are not limited to, swamps, bogs, marshes, ponds, and lakes, as well as soils that are defined as poorly or very poorly drained.
A. 
When a boundary of the Wetlands Conservation Overlay District is disputed, or in the event that an area is incorrectly designated as being poorly drained or very poorly drained on the Town of Derry, New Hampshire, Soils Information for Resource Planning Map, March 1980, the Planning Board and/or the Conservation Commission, at the applicant's expense, may engage a professional biologist and/or soils scientist qualified in field analysis to determine the precise location of the Wetlands Conservation Overlay District boundaries of the properties affected. A report of his findings shall be submitted to the Planning Board and shall include, but not be limited to, a revised soils map of the area in question prepared by a qualified soils scientist along with a written report.
B. 
The Planning Board shall adjust the boundary of this district, if necessary, based on the evidence provided as set forth above. If the evidence indicates that the boundary or area in question has been incorrectly designated, the restrictions contained in this article shall not apply. Conversely, in the event that an area has poorly drained or very poorly drained soils within the meaning of the aforementioned definitions, then the restrictions contained in this article shall apply. The Planning Board shall reserve the right to withhold action on any plat pending the results of an on-site inspection by the Board or its appointed agent.
The following general provisions shall apply with respect to all permitted, special exception, and conditional use applications pertinent to this district:
A. 
Environmental assessment. The Planning Board, with the concurrence of the Conservation Commission, may require the applicant to submit an environmental impact assessment when necessary to evaluate an application made under this article. The cost of this assessment shall be borne by the applicant. The Planning Board may also assess the applicant reasonable fees to cover the costs of other special investigative studies and for the review of documents required by particular applications.
B. 
Compliance with conditions. The Zoning Board of Adjustment may itself, in cases where it has jurisdiction, or upon petition from the Building Inspector, Conservation Commission or the abutters, hire a qualified consultant or consultants to prepare such studies as are necessary to determine whether the conditions set forth in this article have been met. The costs of such studies shall be borne by the applicant.
C. 
Performance security. Prior to the granting of a conditional use permit under this article, the applicant shall agree to submit a performance security to the Planning Board. The security shall be submitted and approved prior to issuance of any permit authorizing construction. The security shall be submitted in a form and amount with surety and conditions satisfactory to the Conservation Commission and approved by the Planning Board to ensure the construction has been carried out in accordance with the approved design.
D. 
Filled lands and preexisting uses.
(1) 
Lands which may have been wetlands but which were filled under properly issued state and Town permits granted prior to the adoption of this article shall be judged according to the soils and flora existing at the site at the time application for a building permit or subdivision is made.
(2) 
Structures and uses existing at the time of the adoption of this article may be continued, provided that such use shall not be expanded to encroach further upon the wetlands or designated setback areas.
E. 
Exemption for residential structures. Notwithstanding other provisions of this article, the construction of additions and extensions to one- and two-family dwellings shall be permitted within the Wetlands Conservation Overlay District provided that:
(1) 
The dwelling lawfully existed prior to February 4, 1988; and
(2) 
The proposed construction conforms to all other applicable ordinances and regulations of the Town of Derry.
F. 
Special exceptions; vacant lots of record. Other provisions of this article notwithstanding, upon application to the Board of Adjustment, a special exception shall be granted to permit the erection of a structure within the Wetlands Conservation Overlay District on vacant lots, provided that all of the following conditions are found to exist:
(1) 
The lot upon which an exception is sought was an official lot of record as recorded in the Rockingham County Registry of Deeds prior to the date of the first legal notice pertaining to this chapter, posted and published in the Town of Derry, New Hampshire.
(2) 
The use for which the exception is sought cannot feasibly be carried out on a portion or portions of the lot which are outside the Wetlands Conservation Overlay District.
(3) 
Due to the provisions of this chapter, no reasonable and economically viable use of the lot can be made without the exception.
(4) 
The design and construction of the proposed use will, to the extent practical, be consistent with the purpose and intent of this article.
(5) 
The proposed use will not create a hazard to individual or public health, safety, and welfare due to the loss of wetlands, the contamination of groundwater or other reason.
G. 
Conflicting regulations. In all cases where the Wetlands Conservation Overlay District is superimposed over another zoning district in the Town of Derry, that district whose regulations are the more restrictive shall apply.
A. 
Prime wetlands and prime wetlands buffer zones.
(1) 
Permitted uses. Permitted uses in areas designated as prime wetlands and/or prime wetlands buffer zones are as follows:
(a) 
Wildlife habitat development and management.
(b) 
Conservation areas and nature trails.
(c) 
Cultivation and harvesting of crops according to recognized soil conservation practices, including the protection of the prime wetlands from pollution caused by fertilizers, pesticides, and herbicides used in such cultivation.
(2) 
Conditional uses. A conditional use permit may be granted by the Planning Board (RSA 674:21, II) for the following purposes:
(a) 
Forestry and tree farming within the buffer zone, using best management practices in order to protect prime wetlands from damage, to prevent sedimentation, and to prevent destruction of wildlife habitats, provided that any forestry and/or tree farming activities shall first be reviewed and approved by the Conservation Commission. Final approval shall be given by the Planning Board.
(b) 
The construction of fences, footbridges, catwalks, and wharves only, provided:
[1] 
Said structures are constructed on posts or pilings so as to permit the unobstructed flow of water;
[2] 
The natural contour of the prime wetland is preserved;
[3] 
The Conservation Commission has first reviewed and approved the proposed construction; and
[4] 
The Planning Board has received Conservation Commission approval in writing and has reviewed the proposed construction.
(3) 
Prohibited use. No dredging or filling shall be permitted in the prime wetlands.
(4) 
Special exception in prime wetlands buffer zones.
(a) 
Upon application to the Zoning Board of Adjustment, a special exception shall be granted for uses in the outermost 75 feet of the prime wetlands buffer zones, provided that all of the following conditions are found to exist:
[1] 
The proposed special exception is essential to the productive use of land not within the prime wetlands buffer zone.
[2] 
Design and construction methods will be such as to minimize detrimental impact upon the prime wetland and the seventy-five-foot buffer nearest the prime wetland. The site will be restored as nearly as possible to its original condition.
[3] 
Economic advantage alone is not reason for the proposed construction.
[4] 
The use for which the exception is sought cannot feasibly be carried out on a portion or portions of the lot which are outside the prime wetlands buffer zone.
[5] 
The design and construction of the proposed use will, to the extent practical, be consistent with the purpose and intent of this article.
[6] 
The proposed use will not create a hazard to individual or public health, safety, and welfare due to the loss of the prime wetlands buffer zones, the contamination of groundwater or other reason.
[7] 
Any special exception granted shall not disturb the 75 feet of the prime wetlands buffer zone nearest the prime wetland.
[8] 
When a parcel is being developed, no landlocked land or unbuildable lot shall be created that would require a special exception or variance under this article.
(b) 
Studies/reports that may be required:
[1] 
Botanist.
[2] 
Biologist.
[3] 
Soil scientist.
[4] 
Sediment/erosion control plan.
[5] 
Impact on the wetland, water quality and habitat.
[6] 
Drainage calculations.
[7] 
Amount of area to be disturbed.
(c) 
Appropriate escrow shall be established for construction and inspection.
(d) 
No special exception shall be granted in the prime wetlands.
(e) 
The hearing for the special exception shall require a joint meeting of the Zoning Board of Adjustment, Planning Board, and the Conservation Commission, provided there is a significant and substantial impact to the productive use of the land defined as landlocked or unbuildable lots caused by the creation of the prime buffer zones.
(5) 
Preexisting use in the prime wetland buffer zones.
(a) 
Structures and uses existing at the time of the adoption of this chapter may be continued.
(b) 
Where an existing use within the buffer is destroyed or in need of extensive repair it may be rebuilt, provided that such rebuilding is completed within one year of the event causing destruction, and the new or rebuilt use shall not extend further into the buffer area than the original use.
(c) 
Expansion of an existing use shall require a permit from the Code Enforcement Officer (CEO).
[1] 
The application for a permit shall be accompanied by two copies of a drawing of the proposal prepared to scale, or so that dimensions are clearly defined. One copy shall be retained by the CEO and one copy shall be forwarded (by the CEO) to the Conservation Commission a minimum of five working days prior to the issuance of the permit.
[2] 
If the proposed expansion of use is found to be detrimental to any function of the wetland, the CEO shall not issue the permit.
B. 
Poorly drained and very poorly drained soils, other than prime wetlands.
(1) 
Permitted uses: any of the following uses that do not result in the erection of any buildings and that are otherwise permitted by this chapter.
(a) 
Poorly drained soils. Permitted uses in areas of poorly drained soil are as follows:
[1] 
Any use otherwise permitted by this chapter and state and federal laws that does not involve the erection of a structure and that does not alter the surface configuration of the land by the addition of fill or by dredging, except as a common treatment associated with a permitted use.
[2] 
Cultivation and harvesting of crops according to recognized soil conservation practices, including the protection of the wetlands from pollution caused by fertilizers, pesticides and herbicides used in such cultivation.
[3] 
Forestry and tree farming, using best management practices in order to protect poorly drained soils and streams from damage and to prevent sedimentation.
[4] 
Wildlife habitat development and management.
[5] 
Recreational uses consistent with the purpose and intent of this article.
(b) 
Very poorly drained soils. Permitted uses in areas containing very poorly drained soils, marshes, open water, and perennial streams are as follows:
[1] 
Uses specified under Subsection B(1)(a)[1] through shall be permitted except that:
[a] 
There shall be no alteration of the surface configuration of the land by filling or dredging; and
[b] 
There shall be no use which results in the erection of a structure, except as provided for in Subsection B(1)(b)[2] below, in accordance with the same provisions which apply to those uses.
[2] 
The construction of fences, footbridges, catwalks and wharves only, provided that:
[a] 
Said structures are constructed on posts or pilings so as to permit the unobstructed flow of water;
[b] 
The natural contour of the wetland is preserved;
[c] 
The Conservation Commission has first reviewed and approved the proposed construction; and
[d] 
The Planning Board has received Conservation Commission approval in writing and has reviewed and approved the proposed construction.
(c) 
Bogs. Permitted uses in bogs shall be limited to only those uses specified in Subsection B(1)(b)[2] above, and then only in accordance with the same provisions as apply to those uses.
(2) 
Conditional uses. A conditional use permit may be granted by the Planning Board (RSA 674:21, II) for:
(a) 
The construction of roads, access drives and other accessways;
[Amended 6-5-2007]
(b) 
Pipelines, power lines and other transmission lines;
(c) 
Water impoundment and the construction of well water supplies;
(d) 
Drainageways, to include streams, creeks or other paths of normal runoff water; and
(e) 
Common agricultural land drainage.
(3) 
Conditional use provisions. Such uses, for which a conditional use permit may be granted, may be permitted provided that all of the following conditions are found to exist:
(a) 
The proposed construction is essential to the productive use of land not within the Wetlands Conservation Overlay District.
(b) 
Design and construction methods will be such as to minimize detrimental impact upon the wetland, and the site will be restored as nearly as possible to its original condition.
(c) 
No alternative which does not cross a wetland, or has less detrimental impact on the wetland, is feasible.
(d) 
Economic advantage alone is not reason for the proposed construction.