§ 17.25-6. Standards for development.
(a)
Lots.
(1)
Insofar as practical side lot lines shall be at right angles to straight street lines or radial to curve street lines. Each lot must front upon a street which is not less than fifty (50) feet in width and which is connected with the public street system. Lots on major street intersections and at acute angle intersections will be designed to provide an adequate sightflare.
(2)
Within the jurisdiction of the town the size and shape of residential lots shall be such as the mayor and council or its representative deems appropriate for the type of building development contemplated. Lots shall have a minimum width of fifty (50) feet at the building setback line and a minimum area of six thousand (6,000) square feet.
(3)
Commercial and industrial lots shall be of the size and shape as the planning commission and the mayor and council deems appropriate in order to accommodate the development.
(4)
Fences, walls, hedges or shrub planting shall be in compliance with the town zoning ordinance.
(b)
Blocks. No blocks shall be acceptable longer than one thousand five hundred (1,500) linear feet between cross streets except as adjacent development or terrain may dictate or, in the opinion of the mayor and council or its representative, would enhance the public safety. The mayor and council or its representatives may require, where blocks exceed the maximum distance, pedestrian crosswalk with a ten-foot minimum right-of-way where the nearest portion of the block is more than one thousand five hundred (1,500) feet from a public or semipublic building or facility.
(c)
Streets.
(1)
Proposed new streets shall extend existing streets or their projections at the same or greater width and constructed of the same material, but in no case less than the minimum required width unless variations are deemed necessary by the mayor and council or its representatives for reasons of topography or design. The mayor and council or its representatives may require the dedication of additional right-of-way width. Proposed streets shall extend to boundary lines where needed for future development of adjacent properties, as shall be determined by the mayor and council.
(2)
Insofar as practical, acute angles at street intersections shall be avoided. Where an acute angle of less than seventy-five (75) degrees occurs between streets at their intersection, the mayor and council or its representatives may require the property lines to be rounded or otherwise set back to permit curb construction of desirable radius without curtailing the sidewalk at the street corner to less than normal width.
(3)
Culs-de-sac shall be provided at the closed end with a turnaround with a minimum right-of-way radius of fifty (50) feet, and a minimum driving surface radius of thirty-five (35) feet. A cul-de-sac shall not be more than five hundred (500) feet in length unless approved by the mayor and council or its representatives for specific reasons of topography or design. A turning "T" may be used where future extension is planned for a street(s) perpendicular to primary streets.
(4)
Street names. Proposed street names shall be checked by the St. Mary Parish 911 addressing staff so as to avoid any duplication thereof. In no case shall the name for the proposed streets duplicate existing street names irrespective of the suffix used. Proposed streets obviously in alignment with existing and named streets shall bear the names of existing streets.
(d)
Street and drainage improvements—Residential.
(1)
Streets shall have a minimum right-of-way of fifty (50) feet or an additional right-of-way width where the mayor and council deem necessary.
(2)
All streets shall be hard surfaced with curb and gutters and subsurface drainage. Open ditch construction is expressly prohibited.
(3)
Wherever drainage channels exist within a subdivision, adequate servitudes shall be dedicated on both sides of the facility for construction improvements and future maintenance. The widths of servitude shall be approved by the mayor and council. Lots sold along the servitudes shall be subject to the servitudes and the protective covenants shall so stipulate.
(4)
Open drainage channels, when required to facilitate the adequate and proper drainage of the overall development, will be designed to provide a minimum fall of fifteen one-hundredths (0.15) feet per one hundred (100) feet. All drainage facilities shall be designed in accordance with "The Louisiana Department of Highway Drainage Manual" issued August 14, 1975. Minimum channel flow velocity shall be a minimum two (2) feet per second.
a.
Any owner, developer, subdivider or their agents who apply to, develop, improve or build upon any residential, industrial or commercial development or subdivision must, in addition to any other requirement of law or ordinance, submit a drainage impact study as determined appropriate for drainage safety and engineering by the town's engineer. An exemption from submission of a drainage impact study may be granted by the mayor based upon written certification by the building inspector of the town that the proposed development will not significantly impact any drainage.
(5)
Street improvements shall consist of hard surface pavement with curb and gutter and subsurface drainage and the following minimum requirements will apply:
a.
In residential areas, all streets shall have curbs and gutters with subsurface drainage with hard surfacing of Portland cement concrete pavement, six (6) inches thick, with a minimum width of twenty-seven (27) feet measured from back-to-back curbs. The design engineer shall submit his recommendations for the design of the subbase for approval by the mayor and council.
b.
Subsurface drainage will be designed to accommodate a five-year recurrent storm interval. Roughness coefficients and Manning's Formula will be utilized. A rational method for design will be used (Q-C.I.A.). For additional information, see Chapter V of the U.S. Bureau of Public Road Publication Design Charts for Open Channel Flows, Hydraulic Designs Series No. 3.
The maximum grade will be one that will produce a velocity of eight (8) feet per second.
The minimum grade that will be used will produce a velocity of three (3) feet per second.
Minimum size pipe of twelve (12) inches will be utilized.
The maximum length of pipe between catch basin and/or manhole will be:
12 inches and fifteen inches ..... 150 feet
18 inches ..... 300 feet
24 inches and 36 inches ..... 400 feet
42 inches and larger ..... 600 feet
A minimum time of five (5) minutes will be used for overland flow based on a minimum duration of five (5) minutes.
Roll over catch basins shall be placed at or near property lines in midblock and at the intersection as the grades may dictate.
(6)
Street signs bearing the names of the streets shall be provided and installed at each street intersection in the subdivision. Street signs shall be located eight (8) feet above the ground with a minimum height of four (4) inches, and shall conform to the town standards.
(7)
Traffic-control signs shall be installed in accordance with the regulations set forth in the Louisiana Manual on Uniform Traffic-Control Devices, as required in Section 235 of Act 310 of the 1962 legislature and as amended by Act 182, Section 1 of the 1968 legislature.
(8)
Sidewalks are required and shall be in accordance with the specifications of the mayor and council or their authorized representative.
(e)
Street and drainage improvements—Commercial and/or light industry.
(1)
Right-of-way width shall be a minimum of sixty (60) feet.
(2)
All streets shall be hard-surfaced with adequate drainage and conform to the following standards:
a.
Shall consist of streets with curb and gutter and subsurface drainage and six (6) inch thick Portland cement concrete pavement with a structural equivalent design on a stabilized base measuring twenty-seven (27) feet back-to-back of curb. Subsurface drainage shall be designed as provided in subsection (D)(5)(b).
b.
The design of the stabilized subbase in subsection a. above shall be submitted by the design engineer to the mayor and council for approval.
(3)
Street and traffic-control signs shall be as provided in subsections (d)(6) and (7).
(4)
Any owner, developer, subdivider or their agents who apply to, develop, improve or build upon any residential, industrial or commercial development or subdivision must, in addition to any other requirement of law or ordinance, submit a drainage impact study as determined appropriate for drainage safety and engineering by the town's engineer. An exemption from submission of a drainage impact study may be granted by the mayor based upon written certification by the building inspector of the town that the proposed development will not significantly impact any drainage.
(f)
Street and drainage improvements—Industrial.
(1)
Rights-of-way in an industrial subdivision shall be a minimum width of eighty (80) feet.
(2)
Roadways will be constructed of Portland cement concrete pavement to the following minimum requirements:
(a)
Portland cement concrete pavement must be a minimum of eight (8) inches thick and twenty-eight (28) feet in width placed on a subgrade compacted to a minimum of ninety-five (95) percent of the maximum theoretical density. The existing materials may be conditioned with lime, where feasible, to conform to these specifications.
(b)
The design of the stabilized subbase in subsection (a) shall be submitted by the design engineer to the mayor and council for approval.
(3)
Open roadside drainage is expressly prohibited. Subsurface drainage shall be designed as provided in section 17.25-6, paragraph (d)(5)(b).
(4)
Street and traffic-control signs shall be as provided in section 17.25-6, paragraph (d)(6) and (7).
(5)
Any owner, developer, subdivider or their agents who apply to, develop, improve or build upon any residential, industrial or commercial development or subdivision must, in addition to any other requirement of law or ordinance, submit a drainage impact study as determined appropriate for drainage safety and engineering by the town's engineer. An exemption from submission of a drainage impact study may be granted by the mayor based upon written certification by the building inspector of the town that the proposed development will not significantly impact any drainage.
(g)
Utility improvements; residential, commercial and/or light industry and industrial.
(1)
Servitudes. In general servitudes shall be located along the front property line adjacent to the street.
a.
All water and gas lines shall be placed in servitudes adjacent to the street, no less than five (5) feet in width. This servitude may be shared with other utilities.
1.
On streets running generally north and south, the water main shall be placed in the east side of the street and the gas main on the west side of the street.
2.
On streets running generally east and west, the water main shall be placed on the north side of the street and the gas main on the south side of the street.
b.
Sewers shall be constructed within the street right-of-way.
c.
Local telephone service shall be generally placed on a front lot line shared servitude as required by the telephone company.
d.
Electrical service shall generally be placed on a front lot line servitude as required by the electrical company.
(2)
Water distribution system. All developments shall be provided with a water distribution system designed in accordance with good engineering practice that:
a.
Consists of the size watermains as recommended by the American Insurance Association. In any development, the minimum size line shall be eight (8) inches, however, a six-inch line may be approved on runs of six hundred (600) feet or less, connected on each end to an eight-inch line. In residential developments, the mayor and council reserve the right to request larger mains when deemed necessary for future development, however, should mains larger than eight (8) inches be required, the developer shall pay the cost of the eight-inch system, and the town will pay the additional cost required to furnish the larger mains. In commercial or industrial developments, the line size may be larger in accordance with the requirements of the American Insurance Association.
b.
In residential areas, provide fire hydrants on property lines with the maximum hydrant spacing not to exceed five hundred (500) feet on any street. This spacing may be altered slightly to conform to the location of lot lines.
c.
The system shall be provided with sufficient valves as approved by the mayor and council.
d.
The minimum cover on all water mains shall be thirty-six (36) inches.
e.
Unless otherwise approved by the mayor and council, all water mains shall be of polychloride Class 150 PVC C-900 pipe.
f.
Water mains shall extend to the end of all deductible street servitudes as shown on the finally approved subdivision plat.
(3)
Gas distribution system. All development shall be provided with a gas distribution system designed in accordance with good engineering practice that:
a.
Complies with the requirements of the office of pipeline safety, department of transportation as listed in Parts 191 and 192 of Title 49 of the Code of Federal Regulations revised as of October 1, 1973 or latest revisions, and/or state and local codes.
b.
All design and construction shall be for Class 3 location, as determined in the above regulations.
c.
In any development, the minimum main size shall be two (2) inches, however, the mayor and council reserve the right to require larger or additional mains when deemed necessary for future development, or in commercial and industrial developments.
d.
Unless otherwise approved by the mayor and council, all gas mains shall be polyethalene plexco (chevron) or an approved equal.
e.
The mayor and council reserve the right to require additional valves if it is deemed necessary for the mere safe and efficient operation of the system.
(4)
Sewerage collection system. All developments shall be provided with a sanitary sewerage collection system designed in accordance with good engineering practice that:
a.
Is consistent with the "Recommended Standards for Sewerage Works"—Ten (10) states' standards.
The minimum slope of small diameter lines may be as follows:
SEWER SIZE MINIMUM SLOPE IN FEET PER 100 FEET 8 inch (first 600 feet high end) 0.36 8 inch (after first 600 feet) 0.32 10 inch 0.24 12 inch 0.20 b.
The minimum cut at the high end of the collection system shall be four and five-tenths (4.5/10) feet. The sewage collection system shall be designed so that the house service and mains do not conflict with subsurface drainage lines.
c.
The gravity collection system construction shall either tie-in directly to either existing gravity mains by method of manhole insertion, or if gravity mains are not available a new sewage pump station and force main may be required to connect the development to the existing facilities of the town.
d.
The mayor and council reserve the right to require additional capacity when deemed necessary for future development or for commercial or industrial developments.
(5)
Electrical distribution system.
a.
All development shall be provided with an electrical distribution system sufficient to serve the needs of the development. The proposed electrical system layout for this service shall be included with the submittals for engineering approval.
b.
All subdivisions shall be furnished with light standards located within the street servitude and of a type and at the locations approved by the mayor and council. There shall be one standard at each intersection and the spacing of standards shall not exceed two hundred fifty (250) feet and shall not be less than two hundred (200) feet except as approved by the mayor and council. Standard shall be located at a property line.
c.
Local distribution lines will be constructed underground with pad-mounted transformers.
(6)
Telephone service.
a.
All development shall be provided with a telephone system sufficient to serve the needs of the development. The proposed telephone company layout for this service shall be included with the submittals for engineering approval.
b.
All local distribution lines within the subdivision shall be underground with distribution boxes located on the front property lines.
(h)
Building restrictions and setback lines. No final plat shall be approved or subdivision accepted unless building restrictions embodying at least the following minimum restrictions or established as covenants to run with the land:
All sales of residential lots, plots or building sites shall stipulate that no residence or building shall be constructed unless in accordance with the height, area and yard requirements of the zoning ordinance for the town.
(Ord. No. 580, 6-10-08; Ord. No. 665 , 5-12-15)