Glen Osborne City Zoning Code
ARTICLE V
Natural Resource Protection Overlay
§ 155-501 Purpose.
A.
Protect the public health and safety by mitigating potential hazards such as land subsidence that may arise due to the inappropriate development of lands with sensitive natural resources.
B.
Safeguard the public welfare by guiding future development patterns to prevent potential impacts on the region's water and stream quality.
C.
Preserve the public health safety and welfare by protecting private property from potential damages that may occur due to uncontrolled development of lands with sensitive natural resources.
D.
Promote and protect the community's existing level of quality of life by restricting development that could alter the quality and availability of groundwater.
§ 155-502 Intent.
A.
The Resource Protection Overlay provides a rational methodology for:
(1)
Inventorying, mapping, and evaluating the carrying capacity of a lot based on the existing natural resources found on said lot.
(2)
Establishing standards to define and determine the amount of development that a lot can reasonably support. The net buildable area, as determined by this overlay process, is the total acreage and general location(s) of permitted disturbance on a lot. Disturbance includes the portions of a lot where grading, construction activities, and, subsequently, development occur.
B.
The use of the Resource Protection Overlay process is intended to enable:
(1)
Developers to identify, early in the development process, the lot's development capacity and, subsequently, its development opportunities.
(2)
Protection of persons and lots from hazards resulting from the inappropriate development of land in areas that contain sensitive existing natural resources.
§ 155-503 Applicability.
A.
For the purpose of carrying out the provisions of this chapter, a Resource Protection Analysis shall be completed and submitted as part of any minor or major land development, subdivision, and/or any activity requiring excavation as defined by the Borough. Said information shall be accompanied by a sealed and signed letter by an engineer and/or landscape architect licensed within the commonwealth acknowledging the review and submission of the related site information.
B.
Development within the Natural Resource Protection Overlay requiring only a building permit and no other land development, subdivision, or zoning approval, including, but not limited to, new buildings or any building addition, shall not be required to meet the minimum standards of this article, but shall be reviewed using the provisions of Article VIII, Steep Slopes Regulations, of this chapter.
C.
The Resource Protection Analysis shall be completed on the official Borough forms provided by the Borough Zoning Officer. The official forms required by this article and other applicable analyses defined by the Borough shall be completed and submitted as part of any application for land development (preliminary approval). No application shall be processed or accepted as administratively complete unless or until the Borough Zoning Officer determines that the Resource Protection Analysis has been properly completed.
D.
The granting of any permit pursuant to the regulations of this section shall not constitute a representation, guarantee, or warranty of any kind by the Borough, or by any official or employee thereof, of the practicability or safety of the proposed use and shall create no liability upon the Borough, its officials, or employees.
E.
This section does not imply that areas outside those encumbered by steep slopes will always be totally free from the adverse effects of erosion or other effects of nearby steep slopes.
G.
If a developer/property owner does not wish to utilize the cluster development regulations as outlined in § 155-508, the net density for a land development contained within the boundaries of the Natural Resource Protection Overlay shall be calculated by multiplying the net buildable area, as defined by the Natural Resource Protection Worksheet, by the permitted gross density stated within the applicable base zoning district regulations.
§ 155-504 Existing natural resources.
A.
This chapter protects specific natural resources that are sensitive to development. These existing natural resources include:
B.
Refer to the following agencies for information regarding the location of resources listed in Subsection A for previous land disturbances of a lot. Additional contact information is available at the Borough office; however, the applicant is responsible for contacting or referencing all sources, listed below or otherwise, to obtain information related to the assessment of existing natural resources.
(1)
Commonwealth of Pennsylvania;
(2)
PA Department of Conservation and Natural Resources Bureau of Geological Survey;
(3)
Pennsylvania Department of Environmental Protection, Southwest Regional Offices;
(4)
Allegheny County Division of Computer Sciences Geographic Information Systems Groups; and
(5)
National Wetland Inventory.
§ 155-505 Initial development ratios.
A.
Protection of the Borough's existing natural resources is governed by the development ratio for each sensitive existing natural resource. Initial development ratios represent the maximum amount of disturbance or alteration that a sensitive existing natural resource can sustain without posing a hazard to persons or a lot. Development ratios are specific to the existing natural resources and are further affected by the slope of the natural topography where a sensitive existing natural resource may be found.
B.
For the purposes of this article, slopes used in Table 9, Resource Protection Worksheet, shall be at least 25 feet in length, measured on a horizontal plane.
§ 155-506 Analysis procedures and implementation.
A.
The Resource Protection Analysis is designed to determine the location and amount of development permitted within any given lot or contiguous lots under common ownership or control, which shall be determined in the following manner:
(1)
Create a one inch equals 100 feet scale slope map based on a contour interval of not more two feet. The slope map shall delineate the location and extent of the following four slope categories:
(2)
Inventory floodways and wetlands/hydric soils,
(3)
Inventory natural drainageways, streams and lakes/water bodies including all land within 50 feet from the centerline of any natural drainageways or 50 feet from the normal pool elevation of any lakes or water bodies, whichever is greater.
(4)
Inventory natural springs and vernal pools including all land within 50 feet from the waterline as established from a normal pool elevation.
(5)
Inventory any areas containing colluvial soils and red bed soils.
(7)
Official copies of Table 9, Resource Protection Worksheet, of this chapter, as available through the Borough, shall be completed to determine the initial net buildable area of the lot.
B.
The layout of all proposed buildings, structures, streets, and utilities shall occur only within the portions of a lot that do not contain sensitive existing natural resources documented as part of this article as well as determined by the Borough represented by the individual permitted disturbance ratios and the total net buildable area (Table 9: Resource Protection Worksheet).
Table 9: Resource Protection Worksheet | ||||||
|---|---|---|---|---|---|---|
Sensitive Existing Conditions | Gross Lot/Site Area (acres) | Permitted Disturbance Ratio | Net Buildable Area (acres) | |||
Line 1 | All floodplains, wetlands, and hydric soils | _____x | 0.0 | = | 0.00 | |
Line 2 | All lakes and water bodies, and natural drainageways/streams | _____x | 0.0 | = | 0.00 | |
Line 3 | All springs and vernal pools (including 100 ft. buffer) | _____x | 0.0 | = | 0.00 | |
Line 4 | Colluvial soils and red beds on slopes | <25% | _____x | 0.4 | = | 0.00 |
>25% | _____x | 0.1 | 0.00 | |||
Line 5 | Other areas on slopes 0%–25% not calculated as part of Lines 1 through 4 above | _____x | 1.0 | = | 0.00 | |
Line 6 | Other areas on slopes >25% but <40% not calculated as part of Lines 1 through 4 above | _____x | 0.4 | = | 0.00 | |
Line 7 | Other area on slopes >40% not calculated as part of Lines 1 through 4 above | _____x | 0.1 | = | 0.00 | |
Line 8 | Sum of Lines 1+2+3+4+5+6+7 | 0.00 (Total Gross Lot/Site Area) | 0.00 (Total Net Buildable Area) | |||
§ 155-507 Net buildable area increases.
A.
Purpose. To promote the efficient use of land, infrastructure, and economic resources; to provide development flexibility; and to enhance development quality and longevity, two methods of increasing the net buildable area of a lot shall be available to a developer and/or landowner. Net buildable area increases shall be granted in return for development enhancements. The two methods include the following:
B.
Applicability.
(1)
Net buildable area increases shall be permitted only in areas located on slopes between 0% and 25% in gradient. Net buildable area increases shall utilize the existing natural resources in reverse order of sensitivity in accordance with Table 9 of this chapter, whereas least sensitive resource areas shall be utilized first.
(2)
A developer and/or landowner may incorporate one or more of the methods outlined in Subsection C to a land development plan.
(3)
When multiple methods are combined as prescribed in § 155-507C, the combined total net buildable area increase shall not exceed 25% of the lot's total net buildable area as calculated in Line 8 of the Resource Protection Worksheet.
(4)
Net buildable area increases shall occur on the same lot where the development enhancement(s) are provided.
(5)
Prior to receiving Planning Commission approval of a green roof-related buildable area increase, the developer and/or landowner shall complete a preliminary and/or final slope stability investigation report in conformance with Borough standards.
C.
Methods.
(1)
Stormwater runoff reduction measures. Upon incorporating any two of the following stormwater runoff reduction measures into a land development, a developer and/or landowner shall receive a maximum 10% net buildable area increase. No preliminary or final slope stability investigation report shall be required to obtain the 10% net buildable area increase.
(a)
Provide area(s) for groundwater recharge through on-site stormwater infiltration for an amount of impervious area equal to one times the net buildable area increase. Unless otherwise defined by the Borough's Subdivision and Land Development Ordinance,[1] the minimum required recharge volume shall be equal to 1 1/2 inches of runoff for the area defined.
(b)
Preserve existing trees whose combined canopy area is equal to one times the net buildable area increase. A preserved tree shall be a minimum of 10 inches in diameter at breast height (dbh).
(c)
Install additional landscaping area(s) equal to 1 1/2 times the net buildable area increase. This additional landscaping may be used to treat any cut or fill slopes; to increase the habitat value of any on-site stormwater management facility; to re-establish streamside buffers or for other on-site uses. Lawn or turf areas shall not constitute additional landscaping.
(d)
Utilize porous pavement to reduce stormwater runoff. Porous paving, with proof by engineering calculation/soils analysis, may be used if the developer/landowner can demonstrate that this method will produce zero increased stormwater runoff. The Borough shall review proposed design and engineering of the pavement to verify construction is in accordance with acceptable industry standards and United States Environmental Protection Agency's (EPA) Porous Pavements Phase I — Design and Operational Criteria.
(e)
Propose on-site environmental mitigation of equal or greater environmental value. Mitigation shall include but may not be limited to the removal of landfilled hazardous materials, the remediation and treatment of abandoned mine drainage, or the establishment of quality wetlands. When such mitigation measures are proposed, the Borough shall review the proposed mitigation measures and shall make a recommendation on the relative value of the proposed mitigation to the Planning Commission and the Borough Council.
(2)
Green roof construction.
(a)
A developer and/or landowner that utilizes green roof construction in a building design may receive a buildable area increase equal to a maximum of 40% of the total surface area of the green roof.
(b)
Green roof construction shall be in accordance with the standards defined by the United States Green Building Council's Leadership in Energy and Environmental Design (LEED) program or equivalent as standards may be modified in the future.
(c)
All green roofs shall be incorporated into the principal building of the lot.
§ 155-508 Cluster lot development.
A.
Cluster lot development shall be permitted only within the boundaries of the Natural Resource Protection Overlay.
(1)
No portion of any cluster lot development shall be outside the boundary of the Natural Resource Protection Overlay.
(2)
If a lot is situated in such a manner that only a portion of that lot is within the Natural Resource Protection Overlay only that portion located within the overlay may utilize cluster lot development as described in this section.
(3)
In no case may a lot contain more units than is prescribed by the base zoning district's maximum density regulations.
B.
Cluster lot development is voluntary and not required.
C.
Density requirements.
(1)
Cluster lot developments shall utilize the development standards in Table 10 as to net density, minimum lot area, minimum lot frontage and minimum setbacks.
Table 10: Cluster Lot Development Standards | |||
|---|---|---|---|
Proposed Cluster Development | R1 | R2 | R3 |
Gross density | 1.2 | 2.2 | SFR - 5.8 2 Fam - 4.4 Twnhs - 7.9 MF - 7.9 |
Net density | 1.7 | 3 | 7.9 |
Min. lot area | 26,000 | 14,500 | 5,500 |
Min. lot frontage | 75 | 75 | SFR - 60 2 Fam - 65 Twnhs - 25 MF - 80 |
Setbacks (F/S/R) | 40/15/40 | 20/10/20 | 20/5/15 |
D.
Flag lots shall be permitted where necessary to provide ingress/egress access within a cluster development.
E.
No more than two flag lots shall be permitted per land development.
F.
A flag lot shall meet minimum lot frontage requirements no further than 100 feet from the roadway in which it gains its access. The "pole" portion of a flag lot shall not be less than 50 feet in width in order to provide adequate spacing for driveways.
G.
The front setback requirement for flag lots shall be measured at the point where the lot meets the minimum lot frontage requirement.
H.
Cul-de-sacs shall be permitted to access cluster developments within the Natural Resource Protection Overlay boundaries. Roadways ending in a cul-de-sac shall be no longer than 400 feet in length unless otherwise determined by the Borough to be safe and adequate distance for emergency service and firefighting purposes in context of topography and site visibility.
I.
The balance of the land not utilized for residential lots shall be reserved as common open space. Ownership of the common open space shall be determined prior to final application approval.