This information was adapted from the 'Shiawassee & Huron Headwaters Preservation Project' developed by Oakland County Planning and Carlisle Wortman & Associates.
Overlay districts are an effective way to reflect the unique characteristics of a given area. Furthermore, the overlay approach avoids the need to rezone a multitude of properties that either exhibit unique characteristics or require additional protection.
The following language represents a comprehensive approach which gives the community and developer the opportunity to formulate a plan based on the characteristics of a given parcel. Furthermore, it requires that regulation is based on factual ecological information. Where it exists, the MNFI information is to be used. In the absence of the MNFI studies, or other appropriate data, the overlay ordinance requires the developer to conduct ecological studies to provide a sound basis for a development plan.
Section _______. Resource Protection Overlay District.
(a.) Purpose. The purpose of this Section is to ensure that property is developed in a manner consistent with its zoning designation, and the proposed physical elements are designed and arranged to protect the priority resource protection areas both on the site and in the vicinity of the site as identified by the (community). The Overlay District establishes procedures to enable the applicant and (community) to achieve the mutually compatible objectives of reasonable use of land and protection of vital natural resources.
(b.) Applicability. To the maximum extent feasible, any development plan (i.e. site plan, subdivision plat, and site condominium plan) shall be designed and arranged to ensure that disturbance to any priority resource protection area as a result of the development, and that impacts and disturbance to such areas and the plants and wildlife inhabiting those areas, shall be minimized through the use of natural area buffers, conservation easements, and creative land development techniques. To that end, the (community) has identified areas to be regulated on a Priority Resource Protection Map, which is attached to and made part of this Ordinance. (Such a map will need to be produced for each community based on available data from the S&H Project).
(c.) Ecological Characterization. It is intended that these Ordinance requirements be applied based upon reliable and factual data. Applicants are encouraged to consult the Michigan Natural Features database. Where detailed studies have been prepared by the Michigan Natural Features Inventory no other additional ecological study is required. If a development site is determined by the (community), upon information or from inspection, that the site likely includes areas with wildlife, plant life, and/or other natural characteristics in need of protection, and if the (community) does not then possess the information required to apply review standards, then the developer shall provide to the (community) a report prepared by a professional qualified in the areas of ecology, botany, wildlife biology, or other relevant discipline that describes, without limitation, the following:
(1) the wildlife use and habitat showing the species of wildlife using the area, the times or seasons that the area is used by those species, and the "value" (meaning feeding, watering, cover, nesting, roosting, perching) that the area provides for such wildlife species;
(2) the boundary of wetlands in the area and a description of the ecological functions and characteristics provided by those wetlands;
(3) any prominent views from or across the site;
(4) the pattern, species, and location of any significant native trees and other native site vegetation;
(5) the bank, shoreline, and high water mark of any stream or body of water on the site;
(6) wildlife movement corridors; and
(7) the general ecological functions provided by the site and its features.
The (community) may employ their own consultants with the relevant expertise to review materials submitted by the applicant.
(d.) Establishment of Priority Protection. For every development subject to this Ordinance, the applicant shall propose, and the (community) shall establish on the project development plan, areas of priority protection. The development plan shall establish the development capability of the site and indicate the specific area(s) of a site within which the developed project may be constructed and within which the development activity shall be contained. In establishing the development capability of a site, the (community) shall consider and apply the following criteria:
(1) The actual boundary of development capability designation to be shown on a development plan shall be proposed by the applicant, and established by the (community) through site evaluations and reconnaissance, and shall be based on the ecological characterization of the area.
(2) In establishing the development capability of the site, the following shall be taken into account:
a. visual impacts, including but not limited to ridgeline protection areas and protection of scenic views.
b. erosion prevention and control, including but not limited to protection of natural drainage channels and compliance with an approved stormwater drainage management plan.
c. preservation of significant native trees and other native site vegetation, including protection of natural area buffers zones.
d. conservation of water, including but not limited to preservation of existing native vegetation, reduction in amounts of irrigated areas, and similar considerations.
e. stream corridor and wetland protection and buffering.
f. site topography, including but not limited to such characteristics as steepness of slopes, existing drainage features, rock outcroppings, river and stream terraces, valley walls, ridgelines, and scenic topographic features.
g. floodplains and floodways.
h. wildlife movement corridors.
i. natural area buffer zones as delineated below.
j. the practical needs of approved construction activity in terms of ingress and egress to the developed project and necessary staging and operational areas.
k. hydrology and groundwater flow.
(e.) Development Standards and Guidelines.
(1) To the maximum extent feasible, no construction activity, including, without limitation, grading, excavation, or stockpiling of fill material shall be permitted within priority protection areas whether to provide for a building site, on-site utilities or services, or for any roads or driveways except as provided for below.
a. mitigation of development activities;
b. restoration of previously disturbed or degraded areas;
c. emergency public safety activities and utility installations when such activities and installations cannot reasonably be contained to areas outside of those identified as significant;
d. construction of trails or pedestrian walkways that will provide access in an environmentally appropriate manner;
e. the enhancement of the habitat values and/or other natural resource values of a natural area.
(2) Establishment of Buffer Zones. Buffer zones shall be established adjacent to areas of priority protection. Such buffers may range in width from _________ feet to ________ feet. The (community) may increase or decrease the buffer zone requirement as reasonably appropriate under such circumstances. In establishing the buffer zone(s), the (community) shall consider and apply the following criteria:
a. the foreseeable impacts of development on the wildlife usage or ecological character or function of the natural area.
b. the ecological and wildlife use characterization of the natural area.
c. the existence of wildlife movement corridors.
d. the extent of floodplains and floodways.
e. the type, amount, and extent of existing vegetation on the site.
f. the existence of special wildlife habitat features.
h. site topography, including but not limited to such characteristics as steepness of slopes, existing drainage features, ridgelines, and scenic topographic features.
(3) Mitigation of Disturbance. While development is anticipated outside of priority protection areas, the applicant shall avoid disturbance to priority protection areas and undertake mitigation measures to restore any damaged or lost natural resource. Any such mitigation or restoration shall be roughly equivalent to the loss suffered by the community because of the disturbance, and shall be based on such mitigation and restoration plans and reports as have been requested, reviewed and approved by the (community).
(4) Connections. If the development site contains priority protection areas that connect to other off-site areas of a similar nature, to the maximum extent feasible, the development plan shall preserve such connections. If priority protection areas lie adjacent to the development site, but such areas are not presently connected across the development site, then the development plan shall, to the extent reasonably feasible, provide such connection. Such connections shall be designed and constructed to allow for the continuance of existing wildlife movement between natural areas and to enhance the opportunity for the establishment of new connections between areas for the movement of wildlife.
(5) Lakes, Reservoirs, and Ponds. If the development site contains a lake, reservoir, or pond, the development plan shall include such enhancements and restoration as are necessary to provide reasonable wildlife habitat and improve aesthetic quality in areas of shoreline transition and areas subject to wave erosion. The development plan shall also include a design that requires uniform and ecologically and aesthetically compatible treatment among the lots or tracts surrounding a lake, reservoir, or pond with regard to the establishment of erosion control protection and shoreline landscaping on or adjacent to such lots or tracts.
(6) Design and Aesthetics. Projects located within the Overlay District, shall be designed to complement the visual context of the natural area. Techniques such as architectural design, site design, the use of native landscaping, and choice of colors and building materials shall be utilized in such manner that scenic views across or through the site are protected, and manmade facilities are screened from off-site observers and blend with the natural visual character of the area.
(7) Stormwater Drainage/Erosion Control. All stormwater drainage and erosion control plans shall meet the standards adopted by the (community) for design and construction and shall, to the maximum extent feasible, utilize nonstructural control techniques, including but not limited to:
a. limitation of land disturbance and grading;
b. maintenance of vegetated buffers and natural vegetation;
c. minimization of impervious surfaces;
d. use of terraces, contoured landscapes, runoff spreaders, grass or rock-lined swales;
e. use of infiltration devices.