The requirements in this section are intended to provide for a subdivision design that is more efficient and better suited to the natural features of the land. Conservation design allows smaller and less costly networks of roads and utilities, encourages closer-knit and potentially safer neighborhoods, preserves sensitive farmland, woodlands, scenic views and open space, and reduces the amount of impervious surface and resulting stormwater runoff. The open space provided by conservation design can be used to provide recreational opportunities for the subdivision's residents or employees, to conserve and protect significant natural areas and environmentally sensitive areas, to conserve important historic resources, and/or to conserve productive farming and forestry uses.
(1) Compliance required. Subdivisions containing 20 or more acres shall utilize conservation design in accordance with the requirements of this section. Notwithstanding the foregoing, subdivisions of land situated entirely within the R-1 zoning classification containing at least five contiguous acres may utilize conservation design but are not required to do so.
(2) Contiguous subdivisions. It is the intent of this section to preclude any attempt to avoid conservation design by the sequential subdivision of land into two or more subdivisions containing less than 20 acres. To that end, two or more subdivisions shall be aggregated and treated as a single subdivision under this article when they are contiguous to property owned or controlled by person owning or controlling the land to be subdivided.
(3) General design requirements. In addition to the other standards contained in these regulations, conservation design subdivisions shall comply with the following design requirements:
a. Minimum conservation design subdivision site size. The minimum land area within a parcel to create a conservation design subdivision shall be at least five contiguous acres.
b. Maximum number of lots in conservation design subdivision. The maximum number of lots allowed within a conservation design subdivision shall be determined by dividing the total acreage in the tract, excluding state road and town street rights-of-way and primary conservation areas, by the lot size requirement for zoning classification of the property contained in section 36-70.
c. Lot design and dimensional requirements for subdivisions. Lots shall be clustered in one or more contiguous areas. Furthermore, provided the arrangement, design and shape of lots is such that lots provide satisfactory and desirable sites for building and contribute to the overall preservation of open space and all other requirements in this section and applicable local, state and federal requirements are met, the minimum lot area, lot width and yard requirements as shown in section 36-70 for the applicable zoning classification may be reduced as stated herein. Any reduction in the yard requirements as shown in section 36-70 shall be approved by the zoning and planning board during the preliminary and final plat process and clearly stated on the final plat for the approved conservation subdivision. If the reduced setback is not stated on the final plat, the standard setbacks noted in section 36-70 shall apply.
1. The minimum lot area shall not be less than 75 percent of the lot area required in the underlying zoning district, or 10,000 square feet, whichever is greater.
2. The minimum lot width requirement at the building site may be reduced by 50 percent, but shall not be less than 45 feet.
3. The minimum front yard requirement may be reduced by 40 percent.
4. The minimum rear yard requirements may be reduced by 40 percent, but shall be no less than ten feet.
5. The minimum side yard requirements may be reduced to zero feet.
6. When buildings are separated, they shall be separated a minimum of 20 feet.
7. Yards abutting the perimeter boundaries of a conservation subdivision shall be no less than the minimum requirements contained in section 36-70.
(4) Required open space. Land within the subdivision site that is not contained in lots or in rights-of-way or parcels devoted to accommodating necessary streets and utilities shall be in one or more connected parcels dedicated or reserved as permanent open space as specified herein. Lands identified as primary conservation areas pursuant to subsection (5)a of this section shall be deemed permanent open space in accordance with this article. In addition to primary conservation areas, 25 percent of the remaining land area of the subdivision shall be included in permanent open space. Secondary conservation areas shall be included in open space to the extent they do not exceed 25 percent of the remaining land area. In the event secondary conservation areas do not equal or exceed 25 percent of the remaining land area of the subdivision, additional open space shall be designated so that at least 25 percent of the remaining land area of the subdivision is made permanent open space.
(5) Open space use, location and design. Design requirements for open space use, location and design are contained in this section.
a. Primary conservation areas. The following areas are considered primary conservation areas and shall be designated as open space on the plat of any major subdivision:
1. Natural watercourses and any adjoining areas required to be maintained in a natural vegetated and unaltered state by this article.
2. Any identified sensitive natural area as defined herein.
3. Other areas specified in section 28-76(a)(1).
b. Secondary conservation areas. The following areas are considered secondary conservation areas and should be considered for designation as open space on the plat of any conservation design subdivision:
1. Any environmentally sensitive areas where land clearing, land disturbance and/or development might threaten water quality or ecosystems (e.g., stream buffers, groundwater recharge areas).
2. Any identified important historic resources (e.g., homesteads, mills, barns, archeological sites) identified from a local archeological or architectural survey or an individual site survey.
3. Productive farmland or forest land intended for continued agricultural and/or forestry use.
4. Steep slopes (those exceeding 30 percent).
c. Open space which is not situated within a primary conservation area may be used to provide active and/or passive outdoor recreation opportunities (e.g., ballfields, playgrounds, tennis courts, swimming pools, basketball courts, bikeways, walking trails, nature trails, and picnic areas), either for the general public or for the subdivision's residents or employees and their guests. Note: This does not preclude a membership requirement or monetary charge for use of recreation facilities, such as a swim or tennis club, as long as subdivision residents have an opportunity to join the club or pay to use club facilities. No more than ten percent of such additional open space shall be covered with impervious surfaces.
d. Open space situated within a primary conservation area may be used for limited passive recreational activities, such as nature trails, so long as such activities do not impair the functionality of the area.
e. Sidewalks may be provided by the developer, if approved by the subdivision administrator, as leading to a pedestrian destination point, such as a school, park, etc., and may constitute part of the open space requirements.
f. The location, size, character, and shape of required open space shall be appropriate to its intended use (e.g., open space proposed to be used for recreation, particularly active recreation, shall be located and designed so as to be conveniently and safely reached and used by those persons it is intended to serve, and open space proposed to be used for ballfields, playing fields, or other extensive active recreational facilities should be located on land that is relatively flat and dry).
g. Phasing. When a conservation design subdivision is developed in phases, it shall be designed and developed in such a manner that total open space is never less than 25 percent of the total land area in any such phase and all previously approved phases.
h. No portion of any required primary or secondary areas may be used for septic drain fields.
(6) Open space dedication or reservation. Open space shall be dedicated or reserved in accordance with the standards contained herein.
a. Subdivision occupants shall be ensured direct access to and use of the subdivision's open space, by conveying that portion of open space to a homeowners' association, property owners' association, or similar legal entity or to a public agency or nonprofit organization that is organized for, capable of, and willing to accept responsibility for managing the open space for its intended purpose and that will ensure subdivision occupants direct access to and use of the open space. Any other open space provided may be conveyed to such organizations or to any agency, organization, person, or other legal entity that is organized for, capable of, and willing to accept responsibility for managing the open space for its intended purpose, provided such conveyance is restricted to ensure continued open space use and maintenance.
b. Each dedicated or reserved open space parcel shall be shown on all subdivision plans and on a record plat recorded with the county register of deeds, with a notation of its area and its intended open space use, as identified herein. The owner of an open space parcel may rededicate or re-reserve the parcel for another open space use allowed under this subsection by recording a record plat showing the parcel and its new intended open space use.
c. The land clearing, land disturbance and/or development area for any lot in a conservation design subdivision shall be delineated on subdivision plats. Those areas described in subsection (4) of this section shall not be included in the area of any lot intended for development and shall be set aside for the common use and enjoyment of occupants of the subdivision, and arrangements for maintenance by a homeowners' association, management group or other acceptable arrangement shall be made. These areas shall be designated for permanent protection on the subdivision plat and recorded deeds, with appropriate recorded deed restrictions for the use and protection of these areas stipulated, and all management responsibilities set forth in homeowners' association bylaws or other appropriate and binding documents for the development.
(7) Open space maintenance. The owner of the open space shall be responsible for maintaining the open space so that it continues to effectively function for its intended use, and any dedication or conveyance of an open space parcel shall provide for such responsibility. Where the subdivision is located within a watershed protection district, retention of undeveloped open space in a vegetated or natural state shall be ensured by maintenance provisions filed with the county register of deeds, either as part of recorded documentation providing for establishment of a homeowners' association or similar legal entity that is to be responsible for maintenance and control of open space or in a maintenance agreement recorded with the property deeds.
(8) Design procedure. The following conservation design procedures shall be used in evaluating conservation design subdivision applications:
a. Existing features/site analysis. An existing features/site analysis map shall be submitted to the planning director. The map shall indicate all features that exist on the subject site as described in this subsection (8).
b. Identification of open space conservation areas. Open space areas shall be identified. Guidance as to which parts to classify as open space areas shall be based upon the following three factors:
1. On-site visits by the subdivision administrator, the subdivider and the site designer.
2. The open space standards contained in this section.
3. The evaluation criteria as shown in subsection (9) of this section.
c. Principal structure setback from open spaces. Any principal structures must be set back a minimum of 30 feet from all open space lot lines. Provided, however, the planning director may reduce this setback requirement when, due to soil types, topography or other site considerations, strict compliance would result in practical difficulty or unnecessary hardship and when adequate assurances have been given for the protection of the open space.
d. Street, trail and sidewalk locations and alignments. All streets, sidewalks and trails shall be located and aligned on the site in the most reasonable, economical, and environmentally protective manner. Trails shall be provided from housing clusters to the designated open space.
(9) Evaluation criteria. For any given site, resources may vary widely by importance. Likewise, for each type of resource, there should be examples of greater or lesser significance. In evaluating the layout of a site, the following evaluation criteria will be considered in determining the site's features and allowing for site design flexibility:
a. The open space shall be reasonably contiguous and shall abut existing open space on adjacent sites.
b. Wetlands, flood hazard areas and natural watercourses with associated stream buffers shall not be cleared, filled or graded except as authorized by state, federal and other applicable regulations and as may be approved by the planning director. Water features shall constitute no more than 50 percent of the open space area.
c. Dwellings shall be located in unwooded parts of the site to prevent unnecessary clearing practices. Exceptions may be made when a site investigation reveals all or part of wooded areas are not worth saving due to tree decay/disease or unsightly overgrowth.
d. The impacts on larger woodlands over two acres shall be minimized as much as practical.
e. Where farmland preservation is the goal of a site design, dwellings shall be located away from active farming areas, as is practical.
f. Where preserving scenic views is the goal of a site design, such scenic views shall remain unblocked and uninterrupted. In wooded areas, where enclosure (i.e., a tree canopy) is a feature to be maintained, a no-cut and no-build buffer strip shall be considered along the public roadway.
g. Where historic or archeological preservation is the goal of a site design, new streets, driveways, fences and/or utilities shall not interfere with the historic site. Building designs of the new homes shall reflect the qualities and designs of the historic buildings, as much as is practical.
h. Where power line rights-of-way are proposed to be included as part of the open space, the right-of-way shall not exceed 50 percent of the required permanent open space.
(10) Estate lot subdivisions. Estate lot subdivisions exist as an alternative to conservation design subdivisions as regulated herein. In addition to other applicable standards of this article and other applicable regulations, estate lot subdivisions shall comply with the standards contained in this subsection.
a. Minimum lot size. Each lot within an estate lot subdivision shall contain at least five acres of land area.
b. Maximum disturbed area. No more than 25 percent of the area of a lot within an estate lot subdivision may be cleared of natural vegetation or otherwise disturbed.
c. Maximum impervious surface. No more than ten percent of the area of a lot within an estate lot subdivision may be covered with impervious surfaces.
d. Protection of primary conservation areas. Primary conservation areas, as specified in subsection (5)a of this section shall be protected in accordance with the standards of this article with the exception that such areas need not be included within the open space of the subdivision and may be included within the boundaries of an estate lot.
e. Plats and restrictive covenants. The plat of an estate lot subdivision shall bear a notation concerning the maximum disturbed area, the maximum impervious surface and the protection of primary conservation areas, and restrictive covenants so limiting the use, land clearing, land disturbance and/or development of any such lot shall be recorded in the office of the county register of deeds. The restrictive covenants shall be reviewed and approved by the town prior to recordation.
(Code 1989, § 91.44; Ord. of 10-9-2007; Ord. of 6-10-2008)