Article 5 Design Standards

Article 5.  Design Standards

§12-501  DESIGN STANDARDS; CONFORMANCE TO THE GENERAL PLAN.  In subdividing property, consideration shall be given to suitable sites for schools, parks, playgrounds, and other common areas for public use so as to best conform with any recommendations of the General Plan.  Any provisions for schools, parks, and playgrounds should be indicated on the preliminary plat in order that it may be determined when and in what manner such areas will be provided or acquired by an appropriate agency.

§12-502   DESIGN STANDARDS: CONFORMANCE TO GENERAL STREET PLAN.  Unless otherwise approved by the Commission and Governing Body, provision must be made for the extension of major and collector streets as shown on the General Street Plan of the Municipality and local street must provide free circulation within the subdivision.

The system of streets designated for the subdivision, except in unusual cases, must align with street already dedicated in adjacent subdivision, and where no adjacent connections are platted, must in general be the reasonable projection of streets in the nearest subdivisions, and must be continued to the boundaries of the tract subdivided, so that other subdivisions may connect therewith.

Rights-of-way providing for the future opening and extension of such streets as outlined herein may, at the discretion of the Commission, be made a requirement of the plat.

Off-center street intersections will not be approved except in unusual cases.

In general, streets shall be of a width at least as great as that of the streets so continued or projected.

Local streets shall be arranged so as to discourage through traffic.

Streets shall be logically related to the topography to produce usable lots and reasonable grades.

Proposed streets shall be extended to provide access to adjoining property where necessary.

Where a subdivision abuts or contains an existing or proposed major traffic street, the Commission may require marginal access streets, rear service alleys, reverse frontage lots, or such other treatment as will provide protection for abutting properties, reduction in the number of intersections with the major street, and separation of local and through traffic.

§12-503   DESIGN STANDARDS; CUL-DE-SACS; DEAD END STREET.  No dedication of a half-street will be permitted except where essential to reasonable subdivision of a tract in conformance with the other requirements and standards contained in this Chapter.  Whenever subdivided property adjoins a half-street, the remainder of the street shall be dedicated to the Municipality.  Cul-de-Sacs may be permitted where the form or contour of the land makes it difficult to plat with connected streets.  Cul-de-Sacs shall provide proper access to not more than twenty (20) dwelling units, shall not exceed five hundred feet (500') in length, and shall be terminated with a turn-around having a minimum right-of-way radius of fifty feet (50').  Unless future extension is clearly impractical or undesirable, a street right-of-way shall be carried to the property line in such a way as to permit future extension of the street into the adjoining tract.

§12-504   DESIGN STANDARDS; INTERSECTIONS AND JOGS.  Street intersections shall be as nearly at right angles as possible, and no intersection shall be at an angle less than sixty (60) degrees.  The intersecting right-of-way lines at all minor street intersection shall be rounded by a minimum radius of fifteen feet (15'), for all other street intersections the minimum radius shall not be less than twenty-five feet (25').  A greater radius may be required by the Governing Body.  Detailed designs of intersections may be required.  Street jogs with centerline off-sets of one hundred and twenty-five feet (125') or less shall not be permitted.

Multiple intersections involving junction of more than two (2) streets shall be avoided.  Where this proves impossible, such intersections shall be designed with extreme care for both pedestrian and vehicular safety.

Clear sight triangle of thirty feet (30') measured along street lot lines from their point of junction shall be provided at all intersections, and no building shall be permitted within such sight triangles.

To the fullest extent possible, intersections with major traffic streets shall be located not less than eight hundred feet (800') apart, measured from centerline to centerline.

Where the grade of any street at the approach to an intersection exceed seven percent (7%), a leveling area shall be provided having not greater than four percent (4%) grades for a distance of twenty-five feet (25') measured from the nearest right-of-way line of the intersecting street.

§12-505 DESIGN STANDARDS; LOT ACCESS. Every lot within a subdivision shall front on a publicly dedicated street.

§12-506 DESIGN STANDARDS; BLOCKS.  Residential blocks shall not be less than three hundred feet (300') nor more than twelve hundred feet (1,200') in length, except as the Governing Body considers necessary to secure efficient use of land or to achieve desired features of the street system.  In blocks over eight hundred feet (800') long, the Governing Body may require public crosswalks at locations other than intersections.  Such crosswalks shall have a minimum easement width of ten feet (10').  The Commission may also require the reservation of a twenty foot (20') wide easement through the block to provide for underground utilities and pedestrian traffic in those blocks exceeding eight hundred feet (800') in length.  A four foot (4') wide pedestrian foot path shall be provided when required by the Commission.  Residential blocks shall be deep enough to provide two (2) tiers of lots at least minimum depth, except where prevented by topographical conditions or size of the property, in which case the Commission may recommend to the Governing Body a single tier of lots of at least minimum depth.  The length, width, and shape of blocks shall be determined with due regard to the following:

1.   Provision of adequate sites for buildings of the type proposed.

2.   Zoning requirements.

3.   Topography.

4. Requirement for safe and convenient vehicular and pedestrian circulation.

§12-507 DESIGN STANDARDS; LOTS.  The lot arrangement and design shall be such that all lots will provide satisfactory and desirable building sites properly related to topography, drainage, sanitation, and the character of adjacent development.  Insofar as practical, side lot lines shall be perpendicular or radial to street right-of-way lines.

§12-508   DESIGN STANDARDS; MINIMUM LOT DIMENSIONS. The minimum dimensions for lots shall conform to the Zoning Regulations unless the Governing Body, for special reasons, including absence of utilities, approves otherwise.  The following shall apply solely to subdivisions:

A.   The size, shape, and orientation of every lot shall be subject to approval of the Governing Body for the type of development and use contemplated.  No lot shall be more than two and one-half (2½) times as deep as it is wide, except as provided in the Zoning Chapter.

B.   The minimum corner lots size in Residential Districts shall be nine thousand (9,000) square feet with a minimum width of seventy-five feet (75') and a minimum depth of one hundred twenty feet (120').

C.   Where either or both water supply and sanitary sewage disposal are provided by individual on-lot facilities, and evidence indicates that the requirements of the Zoning Chapter are not adequate, the Commission may require test, in accordance with the rules and regulations of the State Departments of Environmental Quality and Health and Human Services System, undertaken at the expense of the developer, to determine the adequacy of the proposed lot size and existing grade and soil conditions. 

In all such cases where the tests indicate a large lot size to be necessary, the Commission may employ the services of a registered and qualified independent sanitary engineer for advice as to the minimum lot size and/or facilities necessary to prevent unsanitary conditions and hazards to the public health.  In such cases, the cost of retaining the services of a qualified engineer shall be borne by the developer.

D.   Where commercial subdivisions are proposed to be served by either or both on-lot sanitary sewage disposal and water supply facilities, the lots area and dimensions required to prevent health hazards shall be subject to individual review and determination by the Planning Commission, Nebraska State Departments of Environmental Quality, and Health and Human Services System and/or the County Board of Health.

E.   If remnants of land exist after subdividing, they shall be incorporated in existing or proposed lots, or dedicated to public use if acceptable to the Municipality.

F.   Double frontage lots are prohibited, except where employed to prevent vehicular access to major traffic streets.

G.   Depth and width of parcels laid out or reserved for nonresidential use shall be sufficient to provide satisfactory space for off-street parking and loading as required by the provisions of the Zoning Chapter.  (Amended by Ord.  No.  83-105, 4/18/83)

§12-509   DESIGN STANDARDS; EASEMENTS.  Where there are no streets or alleys, easements of at least ten feet (10') in width shall be provided on each side of all rear lot lines and along side lot lines where necessary for poles, wires, conduits, storm and sanitary sewers, gas, water and heat mains, or other utilities.  An adequate easement as approved by the City Engineer, may be dedicated along all well defined water courses for the purpose of widening, sloping, improving, deepening or protecting the stream for future drainage or recreational purposes.

§12-510   DESIGN STANDARDS; SCHOOL AND PARK LAND DEDICATION. Dedication or reservation of land for schools or parks should be required in all major subdivisions, with the location of such lands as preferably recommended by the General Plan for the Municipality.  Further:

A.   In reviewing subdivision plats, the Commission will consider the adequacy of existing or proposed community facilities to serve the additional dwellings proposed by the subdivision.

B.   Where a proposed park, playground, school, or other public use shown in the General Plan is located in whole or in part in a subdivision, the Commission may require the reservation of such area as may be deemed reasonable.  Where said area is not dedicated, it shall be reserved for acquisition by the Municipality for a period of three (3) years.

C.   Areas provided or reserved for such community facilities should be adequate to provide for building sites, landscaping, and off-street parking as appropriate to the use proposed.

D.   In the event that an area to be used for a park or playground is required to be so shown, the subdivider shall submit, prior to final approval, to the Commission, three (3) prints (one (1) on cloth) drawn in ink showing, at a scale of not less than thirty feet (30') to the inch, such area and the following features thereof:

1. The boundaries of the said area, giving lengths and bearings of all straight lines, radii, lengths, central angles, and tangent distances of all curves.

2. Existing features such as brooks, ponds, clusters of trees, rock outcrops, and structures.

3.  Existing, and if applicable, proposed changes in grade and contours of the said area and of area immediately adjacent.