Chapter 17.20
PLATS AND DATA FOR PRELIMINARY APPROVAL
Sections:
17.20.020 Storm drainage analysis plan.
17.20.010 Preliminary plat.
The preliminary plat shall be at a minimum scale of one inch equals 100 feet. In no case shall it be on less than 18-inch by 24-inch sheets of paper. It shall show existing conditions and all proposals, including the following:
A. Name of proposed subdivision, name and address of subdivider, agent, and principal persons preparing the preliminary plat.
B. Scale and north arrow.
C. Proposed benchmark locations, proposed location of and method of tie to permanent survey monuments, and proposed location and type of subdivision control monuments. Descriptions of all monuments found or set.
D. Plat boundary lines: bearing in degrees, minutes, and seconds; distances in feet and hundredths.
E. Existing conditions of the site and its environs shall include the following:
1. Present site designation or subdivision name.
2. Easements on site: location, width and purpose.
3. Public right-of-way on and within 150 feet of the site: name, type, and width of paving.
4. Utilities on and adjacent to the site: location and size of water wells, water reservoirs, water line, sanitary and storm sewers; location of gas lines, fire hydrants, electric and telephone poles, and street lights. If water mains and sewers are not on or adjacent to the tract, indicate the direction, distance, and size of nearest lines.
5. Ground elevation on the side based on mean sea level datum as established by the U.S. Coast and Geodetic Survey:
a. For land that slopes less than approximately one percent, show contour lines at intervals of not more than one foot and spot elevations at all breaks in grade along all drainage channels or swales, and at selected points not more than 100 feet apart in all directions.
b. For land that slopes approximately between two percent to five percent, show contour lines at intervals of not more than two feet.
c. For land that slopes more than five percent, show contour lines at intervals of not more than five feet.
6. Existing storm drainage facilities on and adjacent to the site.
7. Conditions on adjacent land significantly affecting design of the subdivision. Approximate direction and gradients of ground slope, character and location of development, and building types.
8. Zoning on and adjacent to the site. If the area proposed to be subdivided is zoned Single-Family Residential, Historical Residential, Commercial or Historical Commercial and is adjacent to active agricultural operations, then the subdivider shall be responsible for the installation of a wall or fencing between the subdivision and the agricultural operation. The planning and zoning commission shall determine if the standards proposed for the wall/fence are adequate during the preliminary plat stage of development. Cross reference: MTC 18.45.040(N), Perimeter wall or fencing.
9. A statement of ownership, signed by the subdivider.
10. Total area of the proposed plat to the nearest one-tenth acre.
F. Location map showing location of the site in relation to well-known landmarks and town boundaries.
G. Proposed lot lines and public right-of-way lines; street names; right-of-way and street widths; indicate roadways intended to be private, rights-of-way for public services or utilities, and any limitations thereof.
H. All lots in any subdivision shall meet the requirements of the zoning ordinance and each lot shall be dimensioned in such a manner that setbacks as required by the ordinance shall be met for any structure or building that may be or will be constructed on the lot. No platted lot within a subdivision shall contain less square footage than that required by MTC Title 18, Zoning.
I. Number or letter to identify each proposed lot and block.
J. Locations, dimensions, approximate areas, and purpose of lots proposed to be reserved for the public.
K. Sites and approximate area for any multifamily dwellings or nonresidential uses.
L. Every lot shall front on or have access to a public street.
M. All public entity easements and improvements. [Ord. 2001-09 § 2; Ord. 89-01; prior code § 11-5-4.A]
17.20.020 Storm drainage analysis plan.
A storm drainage analysis and plat shall be prepared and signed by a professional engineer registered in New Mexico to include the following:
A. An up-to-date topographic survey or contour map of the area to be subdivided and contributing watershed showing existing structures and pavement and denoting existing elevations above mean sea level of all land features and improvements that would affect drainage.
B. An aerial photograph at the scale of one inch equals 100 feet or one inch equals 200 feet showing the area to be subdivided.
C. A drainage report with a map identifying and locating all rivers, creeks, arroyos, draws, washes or any other channel having definite banks and bed with visible evidence of the occasional flow of water. It shall include computations of the watershed area draining into each watercourse, identification and analysis of permeability of soils in each watershed, and calculations based on the S.C.S. Engineering Field Manual procedures for estimating runoff from a 100-year frequency storm of:
1. The volume and peak discharge of storm surface waters emanating from higher lands and drainage through the area to be subdivided (external drainage).
2. The volumes and peak discharges of internal drainage originating from the land to be subdivided prior to and after completion of the proposed development.
D. A detailed storm drainage plan showing how the runoff from a 100-year frequency storm will be maintained on the property being subdivided. Means of detention basins, retention basins, swales on lots or any other method approved by the commission so as to insure that new development will not increase the peak discharge load on the existing drainage system or cause damage to properties at lower elevations. A map submitted with the plan shall indicate all points of entry and discharge of storm runoff prior to and after development, as well as proposed easements and structures provided for containment or controlled discharge of storm drainage. Points of discharge of natural watercourses shall not be altered by the development.
E. A grading plan showing any proposed alteration, including finished elevations of areas to be graded, paved areas, building sites, retention or detention areas retaining walls and other structures. It shall be accompanied by a signed agreement by the owner of the lands being platted binding on his heirs or subsequent owners, that no grading, land filling, excavating or other alteration will be done except pursuant to the approved or amended grading plan.
F. The plan shall show that all property within the subdivision is developed in such a manner the flood damage will be minimized and that construction and substantial improvements are elevated to the 100-year flood level, if the property lies in an area which has been designated a floodplain under the National Flood Insurance Program. New water and sewer systems (including on-site systems) shall be located to avoid impairment or contamination during flooding.
G. Areas which will be inundated by runoff from a 100-year or greater frequency storm shall not be divided into lots for sale in any proposed subdivision.
H. A copy of the subdivision plat and drainage plan will be provided to any public entity with holdings in the area for their review in order to avoid urban conflicts with the operation and maintenance of utility systems. Their review shall be advisory only. [Ord. 89-01; prior code § 11-5-4.B]
17.20.030 Improvements.
A report on the proposed method of installing utilities, street paving, curb and gutter, sidewalks, and sewer service shall be prepared and submitted to include the approximate time for accomplishing such improvements. Such improvements shall be based on the maximum population density allowed in the zoning district in which the subdivision is located. [Ord. 89-01; prior code § 11-5-4.C]