Borough of Green Tree, PA Article VI Principles and Standards of Construction

§ 300-31 Compliance required; conflicts of laws.

The plats of a subdivision shall substantially conform to the principles and standards enumerated in this chapter. If there is a discrepancy between any of the minimum standards or dimensions noted in this chapter and a standard or dimension contained in the Uniform Construction Code, or any other official regulation, the highest standard shall apply. All construction shall comply with all applicable codes.

§ 300-32 Streets and alleys.

A. All street and alley layouts shall take into consideration prospective plans made by the Borough, the County and the Pennsylvania Department of Transportation. Also, the subdivider shall comply with any plan officially adopted by the Borough.

B. Wherever there exists a dedicated or platted portion of a street or alley along a boundary of the tract being subdivided, the remainder of such street or alley, to the prescribed width, shall be platted within the proposed development.

C. Service streets may be considered only in planned developments.

D. Culs-de-sac shall not be longer than 600 feet, which shall include a turnaround at the closed end. The turnaround shall have a maximum grade of 5%.

E. Alleys shall not be provided in residential districts but may be included in commercial, industrial or institutional areas where needed for loading and unloading or access purposes.

F. The minimum distance between center lines of parallel or approximately parallel streets intersecting a cross street from opposite directions shall be 125 feet.

G. Intersections of more than two streets at one point are prohibited. Street intersections shall be spaced not less than 300 feet apart.

H. Sight triangles for intersections shall be free of all obstruction, including embankments and shrubbery, which obstruct vision between any point on the streets and any other point on the streets within the triangle. The clear vertical area shall permit unobstructed visual access to the area between 1 1/2 feet and eight feet above the opposing street but shall not be interpreted to prohibit street signs, utility poles, tree trunks, etc.

I. Council may, when it deems it advisable, require a right-of-way in excess of the width of that required in this chapter. Such increased width shall be under the advisement of the Planning Commission and the Borough Engineer.

J. Minimum right-of-way widths, paving widths, angles of intersection, distances along sides of sight triangles, required sidewalks, horizontal alignments, vertical alignments and maximum and minimum grades, shall be in accordance with Table I, following this chapter.

K. Design standards of streets are as shown in such Table I.

§ 300-33 Blocks.

Blocks shall ordinarily not exceed 1,000 feet in length. Where it is necessary for blocks to exceed such length, pedestrianways and/or easements may be required near the center of the block.

§ 300-34 Lots.

A. Every lot shall be accessible for the use of public safety vehicles and other public and private purposes and shall be served by a public or private street system, improved in accordance with this chapter and connected to the general street system.

B. Side lines of lots shall be approximately at right angles to straight streets and to radial lines on curved streets. Some variation from this rule is permissible, but pointed or very irregular lots shall be avoided unless it is clearly evident that such variation will improve the overall neighborhood design.

C. Double-frontage shall be avoided.

D. Lot width, building setback and lot area shall be as specified in the Zoning Code.

E. When a tract is subdivided into larger than required building lots, such lots or parcels shall be so arranged as to permit a logical location and opening of future streets and resubdividing, with provision for adequate utility connections for each subdivision.

§ 300-35 Location of structures.

The placement of structures on a lot shall be as specified or permitted in the Zoning Code.

§ 300-36 Easements.

Sewer and utility easements shall be required at a minimum width of 15 feet. Where a subdivision is, or will be, traversed by a watercourse, there shall be provided a stormwater easement or drainage right-of-way of a width sufficient for the purpose, but no less than 20 feet.

§ 300-37 Stormwater drainage.

A. Design and construction of facilities. Storm sewers, stream enclosures, bridges, culverts and channel changes shall be designed and constructed in conformity with accepted engineering practice. Where regulated waters of the commonwealth are involved, a permit shall be obtained from the Pennsylvania Department of Environmental Protection in conformity with Chapter 105 of its regulations, as amended.

B. Design and construction criteria. All construction, alteration, enlargement, repair or removal of the water obstructions specified in Subsection A hereof shall be in accordance with the following criteria:

(1) The structure shall not create or constitute a hazard to life or property.

(2) The structure shall not materially alter the natural regimen of the stream.

(3) The structure shall not cause an increase in velocity or direct flow so as to cause erosion of the streambed or banks.

(4) The structure shall pass flood flows without loss of stability.

(5) The structure shall include adequate entrance and outfall appurtenances for efficient flow characteristics.

(6) The design capacity of the structure shall be based on the degree of development of the tributary watershed throughout the lifetime of the structure.

(7) The determination of flows for design shall be made with consideration of the runoff characteristics in the design year. Specific hydraulic design criteria shall fit the conditions at the site.

(8) Adequate means of access shall be provided for maintenance of the structure.

C. Report and analysis. The design of the structure shall be prepared by a registered engineer in conformity with the PennDOT Design Manual, Part 2, Chapter 12. The report and analysis shall include:

(1) The location, type, size and height of the proposed structure;

(2) A profile of the stream for a reasonable distance above and below the proposed site, showing slopes of bed, normal water surface and floodwater surface;

(3) Estimates of flood frequencies and flood flows at the site of the proposed structure, including such information as can be reasonably obtained regarding actual rainfall and flood flow records on the stream;

(4) An analysis of the hydraulic capacity of the proposed structure;

(5) A description of the purposes of the proposed structure;

(6) A listing and description of all other enclosures and all culverts, bridges, dams and other water obstructions located upstream and downstream of the proposed enclosure;

(7) Proof of title or adequate flowage and other easements for all lands included in the site of the proposed structure, including all lands which may be subject to flooding by backwater from such structure during a one-hundred-year flood; and

(8) Such other information as the Borough may require.

D. Effects of runoff.

(1) Where the intense development of any tract or parcel of land will cause increased and unnatural stormwater runoff, the effects of such increased runoff shall be analyzed through the downstream portions of the storm sewer or watercourse system. In considering such effects, the reasonable ultimate development of the total tributary area shall be considered.

(2) On-site stormwater detention shall be required as a stormwater management technique where detrimental effects may be caused downstream.

(3) The analysis shall be prepared by a registered engineer and shall indicate by hydrographs and other evaluations the effects of the increased flows and retained flows at critical points on the downstream system.

§ 300-38 Erosion control facilities.

Erosion control facilities shall be designed and constructed in accordance with the Borough's Standards for Construction, [1] the U.S. Soil Conservation Service's Standards and Specifications, or equivalent standards.

[1] Editor's Note: The Borough's Standards for Construction are included as an attachment to this chapter; drawings of specific standards are available in the Borough offices.