Town of Trenton, WI Article VII Design Standards

§ 350-38 Streets.

A. Compliance with statutes. In laying out a subdivision, the owner shall conform to the provisions of Ch. 236, Wis. Stats., and all applicable Town regulations. In all cases where the requirements of this chapter are different from the requirements of Ch. 236, Wis. Stats., the more restrictive provision shall apply.

B. Dedication. The subdivider shall dedicate land and improve streets as provided in this chapter and § 350-25. Streets shall be located with due regard for topographical conditions, natural features, existing and proposed streets, utilities and land uses and public convenience and safety. Streets shall conform to official maps adopted by the Town Board. The subdivision, certified survey parcel or land division shall be so designed as to provide each lot with satisfactory access to a public street or road.

C. Compliance with Comprehensive Plan. In any new subdivision, the street layout shall conform to the arrangement, width and location indicated on the Official Map, County Jurisdictional Highway System Plan, Comprehensive Plan or plan component or precise neighborhood unit development plan of the Town of Trenton, Washington County, Wisconsin. In areas for which such plans have not been completed, the street layout shall recognize the functional classification of the various types of streets and shall be developed and located in proper relation to existing and proposed streets, to the topography, to such natural features as streams and tree growth, to public convenience and safety, to the proposed use of the land to be served by such streets, to existing or planned utilities and to the most advantageous development of adjoining areas. The subdivision shall be designed so as to provide each lot with satisfactory access to a public street.

D. Areas not covered by Official Map. In areas not covered by a Town Comprehensive Plan, the layout of streets shall conform to the plan for the most advantageous development of adjoining areas of the neighborhood. Streets shall be designed and located in relation to existing and officially planned streets, topography and natural terrain, streams and lakes and existing tree growth, public convenience and safety and in their appropriate relation to the proposed use of the land to be served by such streets.

E. Street classifications. Streets shall be classified as indicated below:

(1) Arterial streets. Arterial streets, as hereinafter defined, shall be arranged so as to provide ready access to centers of employment, centers of governmental activity, community shopping areas, community recreation and points beyond the boundaries of the community. They shall also be properly integrated with and related to the existing and proposed system of major streets and highways and shall be, insofar as practicable, continuous and in alignment with existing or planned streets with which they are to connect.

(2) Collector streets. Collector streets shall be arranged so as to provide ready collection of traffic from commercial and residential areas and conveyance of this traffic to the major street and highway system and shall be properly related to special traffic generators such as schools, churches and shopping centers and other concentrations of population and to the major streets into which they feed.

(3) Minor streets. Minor streets shall be arranged to conform to the topography, to discourage use by through traffic, to permit the design of efficient storm and sanitary sewerage systems and to require the minimum street area necessary to provide safe and convenient access to abutting property.

(4) Proposed streets. Proposed streets shall extend to the boundary lines of the tract being subdivided unless prevented by topography or other physical conditions or unless, in the opinion of the Town Board, such extension is not necessary or desirable for the coordination of the layout of the subdivision or land division or for the advantageous development of the adjacent tracts.

F. Reserve strips. Reserve strips shall not be provided on any plat to control access to streets or alleys, except where control of such strips is placed with the Town under conditions approved by the Town Board.

G. Alleys.

(1) Commercial and industrial. Alleys shall be provided in all commercial and industrial districts for off-street loading and service access, except that the Town Board may waive this requirement where other definite and assured provision is made for service access, such as off-street loading and parking, consistent with and adequate for the uses proposed.

(2) Residential. Alleys shall not be approved in residential areas unless necessary because of topography or other exceptional circumstances.

(3) Width. The width of alleys shall not be less than 24 feet.

(4) Dead-end alleys. Dead-end alleys are prohibited, and crooked and "T" alleys shall be discouraged.

H. Continuation. Streets shall be laid out to provide for possible continuation wherever topographic and other physical conditions permit. Provision shall be made so that all proposed streets shall have a direct connection with, or be continuous and in line with, existing, planned or platted streets with which they are to connect. Proposed streets shall be extended to the boundary lines of the tract to be subdivided, unless prevented by topography or other physical conditions, or unless in the opinion of the Town Board, upon the recommendation of the Plan Commission, such extension is not necessary or desirable for the coordination of the layout of the subdivision with existing layout or the most advantageous future development of adjacent tracts. Dead-end streets not over 500 feet in length will be approved when necessitated by the topography.

I. Minor streets. Minor streets shall be so laid out so as to discourage their use by through traffic.

J. Number of intersections. The number of intersections of minor streets with major streets shall be reduced to the practical minimum consistent with circulation needs and safety requirements, preferably not more than two.

K. Frontage roads. Where a subdivision abuts or contains an existing or proposed arterial highway, the Town Board may require a frontage road, nonaccess reservation along the rear of the property contiguous to such highway or such other treatment as may be necessary to ensure safe, efficient traffic flow and adequate protection of residential properties.

L. Private streets. Private streets shall not be approved nor shall public improvements be approved for any private street; all streets shall be dedicated for public use.

M. Visibility. Streets shall afford maximum visibility and safety and shall intersect at right angles where practicable. As required by the Town Engineer, sufficient vision clearance triangles shall be provided at intersections.

N. Tangents. A tangent at least 100 feet long shall be required between reverse curves on arterial and collector streets.

O. Street grades.

(1) Unless necessitated by exceptional topography, subject to the approval of the Town Board, the maximum center-line grade of any street or public way shall not exceed the following:

(a) Arterial streets: 6%.

(b) Collector streets: 8%.

(c) Minor streets, alleys and frontage streets: 10%.

(d) Pedestrianways: 12% unless steps of acceptable design are provided.

(2) The grade of any street shall in no case exceed 12% or be less than 1/2 of 1%.

(3) Street grades shall be established wherever practicable so as to avoid excessive grading, the promiscuous removal of ground cover and tree growth, and general leveling of the topography.

P. Radii of curvature.

(1) When a continuous street center line deflects at any one point by more than 10°, a circular curve shall be introduced having a radius of curvature on said center line of not less than the following:

(a) Arterial streets and highways: 500 feet.

(b) Collector streets: 300 feet.

(c) Minor streets: 100 feet.

(2) Curves should be provided when center-line deflections exceed 1° in rural areas and in urban areas when deflection exceeds 3°.

Q. Half streets. Where an existing dedicated or platted half street is adjacent to the subdivision, the other half street shall be dedicated by the subdivider. The platting of half streets should be avoided where possible.

R. Intersections.

(1) Property lines at street intersections of major thoroughfares shall be rounded with a radius of 15 feet or of a greater radius where the Town Engineer considers it necessary.

(2) Streets shall intersect each other at as nearly right angles as topography and other limiting factors of good design permit.

(3) The number of streets converging at one intersection shall be reduced to a minimum, preferably not more than two.

(4) Minor and collector streets shall not necessarily continue across arterial streets. If the distance between the center-line intersection of any street with any other intersecting street is less than 250 feet, measured along the center line of the intersecting street, then the location shall be so adjusted that the distance is increased or the adjoinment across the intersecting street is continuous and a jog is avoided.

S. Street names. New street names shall not duplicate the names of existing streets, but streets that are continuations of others already in existence and named shall bear the names of the existing streets. Street names shall be subject to approval by the Plan Commission and Town Board.

T. Culs-de-sac.

(1) Cul-de-sac streets designed to have one end permanently closed shall not exceed 1,500 feet in length. All cul-de-sac streets designed to have one end permanently closed shall terminate in a circular turnaround having a minimum right-of-way radius of 78 feet and a minimum face of curb radius of 56 feet on urban sections and a minimum outside pavement radius of 56 feet on rural sections.

[Amended 5-1-2012 by Ord. No. 2012-01]

(2) Temporary termination of streets. Temporary termination of streets intended to be extended at a later date shall be accomplished with a temporary cul-de-sac in accordance with the standards set forth above, or by the construction of a temporary "T" intersection 34 feet in width and 66 feet in length abutting the right-of-way lines of the access street on each side.

(3) In the event a temporary termination of a street intended for extension at a later date under Subsection T(2) of this section has been established and said temporary termination exists for a period of 10 years or longer without permanent extension, the Town Board may, in its discretion, allow the construction of a permanent termination notwithstanding the length requirements of Subsection T(1) of this section.

U. Limited access highway and railroad right-of-way treatment. Whenever the proposed subdivision contains or is adjacent to a limited access highway, arterial street or railroad right-of-way, the design shall provide the following treatment:

(1) Subdivision lots. When lots within the proposed subdivision back upon the right-of-way of an existing or proposed limited access highway or a railroad, a planting strip at least 30 feet in depth shall be provided adjacent to the highway or railroad in addition to the normal lot depth. This strip shall be part of the platted lots but shall have the following restriction lettered on the face of the plat: "This strip reserved for the planting of trees and shrubs, the building of structures hereon prohibited."

(2) Commercial and industrial districts. Commercial and industrial properties shall have provided, on each side of the limited access highway, arterial street or railroad, streets approximately parallel to and at a suitable distance from such highway or railroad for the appropriate use of the land between such streets and highway or railroad, but not less than 150 feet.

(3) Streets parallel to a limited access highway. Streets parallel to a limited access highway or railroad right-of-way, when intersecting a major street and highway or collector street which crosses said railroad or highway, shall be located at a minimum distance of 250 feet from said highway or railroad right-of-way. Such distance, where desirable and practicable, shall be determined with due consideration of the minimum distance required for the future separation of grades by means of appropriate approach gradients.

(4) Minor streets. Minor streets immediately adjacent and parallel to railroad rights-of-way shall be avoided, and location of minor streets immediately adjacent to arterial streets and highways and to railroad rights-of-way shall be avoided in residential areas.

V. Width. The minimum right-of-way and roadway width of all proposed streets and alleys shall be as specified by the Comprehensive Plan, Comprehensive Plan component, Official Map, neighborhood development plan or jurisdictional highway system plan, or, if no width is specified therein, the minimum widths shall be as set forth in § 345-15 of this Code.

[Amended 2-6-2007 by Ord. No. 2-1-2007]

W. New and replacement bridges and culverts. All new and replacement bridges and culverts over perennial waterways, including pedestrian and other minor bridges, in addition to meeting other applicable requirements, shall be designed so as to accommodate the one-hundred-year recurrence interval flood event without raising the peak stage, either upstream or downstream, more than one 0.01 foot above the peak stage for the one-hundred-year recurrence interval flood, as established in the applicable federal flood insurance study. Larger permissible flood stage increases may be acceptable for reaches having topographic land use conditions which could accommodate the increased stage without creating additional flood damage potential upstream or downstream of the proposed structure. Such bridges and culverts shall be so designed and constructed as to facilitate the passage of ice flows and other debris. All new and replacement bridges shall be constructed in accordance with all applicable state statutes and codes and shall be submitted to the Department of Natural Resources to assure compliance therewith.

X. Stream and lake shores. Stream or lake shores shall have a minimum of 60 feet of public access platted to the low-water mark at intervals of not more than 1/2 mile as required by § 236.16(3), Wis. Stats.

§ 350-39 Blocks.

A. Length; arrangement. The lengths, widths and shapes of blocks shall be appropriate for the topography and the type of development contemplated, but block length in residential areas shall not exceed 1,200 feet nor have less than sufficient width to provide for two tiers of lots of appropriate depth between street lines. As a general rule, blocks shall not be less than 500 feet in length.

B. Pedestrian pathways. Pedestrian pathways, not less than 20 feet wide, may be required by the Town Board, upon the recommendation of the Plan Commission, through the center of a block more than 900 feet long, where deemed essential to provide circulation or access to schools, parks, churches, playgrounds, shopping centers, transportation and other community facilities.

C. Width. The width of blocks shall be wide enough to provide for two tiers of lots of appropriate depth except where otherwise required to separate residential development from through traffic. Width of lots or parcels reserved or laid out for commercial or industrial use shall be adequate to provide for off-street service and parking required by the use contemplated and the area zoning restrictions for such use.

D. Utility easements. Utility easements for electric power and telephone service shall, where practical, be placed on mid-block easements along rear lot lines, be not less than 10 feet centered on the property line and, where possible, be along rear lot lines for underground construction.

§ 350-40 Lots.

A. Size. The size, shape and orientation of lots shall be appropriate for the location or topography of the subdivision, the type of sewerage or septic system to be utilized, and for the type of development contemplated, provided that no lot shall be smaller in area than the minimum lot size for the appropriate zone as established by the Town of Trenton Zoning Code.[1]

[1] Editor's Note: See Ch. 380, Zoning.

B. Commercial lots. Depth and width of properties reserved or laid out for commercial or industrial purposes shall be adequate to provide for the off-street service and parking facilities required by the type of use and development contemplated, as required by the Town Zoning Code.

C. Lots where abutting major highway. Residential lots fronting on major streets and highways shall be platted with extra depth or design or alleviate the effect of major street traffic on residential occupancy.

D. Corner lots. Corner lots for residential use shall have extra width of 10 feet to permit full building setback from both streets.

E. Access to public streets. Every lot shall front or abut for a minimum distance of at least 66 feet on a public street. Lots with an access only to private drives or streets shall be permitted only with Town Board approval.

F. Side lots. Side lot lines shall be substantially at right angles to or radial to abutting street lines. Lot lines shall follow Town boundary lines.

G. Double and reversed frontage lots. Double frontage and reversed frontage lots shall be avoided except where necessary to provide separation of residential development from traffic arteries or to overcome specific disadvantages of topography and orientation.

H. Natural features. In the subdividing of any land, regard shall be shown for all natural features, such as tree growth, watercourses, historic spots or similar conditions which, if preserved, will add attractiveness and stability to the proposed development.

I. Land remnants. All remnants of lots below minimum size left over after subdividing of a larger tract must be added to adjacent lots, or a plan shown as to future use, rather than allowed to remain as unusable parcels.

J. Large lots. Where lots are created of a size larger than normal for the area, the Plan Commission may require that the plat be so designed as to allow for the possible future resubdivision of such lots into normal sizes compatible with the area.

K. Lot area and dimensions. Area and dimensions of all lots shall conform to the requirements of the Town of Trenton Zoning Code.

L. Lot depth. Depth of lots shall be a minimum of 100 feet. Excessive depth in relation to width shall be avoided and a proportion of two to one shall be considered a desirable ratio under normal conditions. Depth of lots or parcels reserved or laid out for commercial or industrial use shall be adequate to provide for off-street service and parking required by the use contemplated.

M. Lot width. Width of lots shall conform to the requirements of the Town Zoning Code, or other applicable ordinance, and in no case shall a lot be less than 125 feet in width at the building setback line.

§ 350-41 Drainage system.

A. Drainage system required. As required by § 350-29, a drainage system shall be designed and constructed by the subdivider to provide for the proper drainage of the surface water of the subdivision and the drainage area of which it is a part. A final plat shall not be approved until the subdivider shall submit plans, profiles and specifications as specified in this section, which have been prepared by a registered professional engineer and approved by the Town Board, upon the recommendations of the Plan Commission and Town Engineer.

B. Drainage system plans.

(1) The subdivider shall submit to the Town at the time of filing a preliminary plat a preliminary drainage plan or engineering report on the ability of existing watercourse channels, culverts and other improvements pertaining to drainage or flood control within the subdivision to handle the additional runoff which would be generated by the development of the land within the subdivision. Additional information shall be submitted to adequately indicate that provision has been made for disposal of surface water without any damage to the developed or undeveloped land downstream or below the proposed subdivision. The report shall also include:

(a) Estimates of the quantity of stormwater entering the subdivision naturally from areas outside the subdivision.

(b) Quantities of flow at each inlet or culvert.

(c) Location, sizes and grades of required culverts and other required appurtenances.

(2) A grading plan for the streets, blocks and lots shall be submitted by the subdivider for the area within the subdivision.

(3) The design criteria for storm drainage systems shall be based upon information provided by the Town Engineer.

(4) Material and construction specifications for all drainage projects (i.e., pipe, culverts, seed, sod, etc.) shall be in compliance with specifications provided by the Town Engineer.

C. Grading. The subdivider shall grade each subdivision in order to establish street, block and lot grades in proper relation to each other and to topography as follows:

(1) The subdivider shall grade the full width of the right-of-way of all proposed streets in accordance with the approved plans.

(2) Block grading shall be completed by one or more of the following methods:

(a) A ridge may be constructed along the rear lot lines which provides for drainage onto the streets.

(b) Parts of all lots may be graded to provide for drainage to the street or to a ditch along the rear lot line.

(c) Draining across rear or side lot lines may be permitted, provided that drainage onto adjoining properties is skillfully controlled.

D. Drainage system requirements. The subdivider shall install all the storm drainage facilities indicated on the plans required in Subsection A of this section.

(1) Street drainage. All streets shall be provided with an adequate storm drainage system. The street storm system shall serve as the primary drainage system and shall be designed to carry street, adjacent land and building stormwater drainage. No stormwater shall be permitted to be run into a sanitary sewer system within the proposed subdivision.

(2) Off-street drainage. The design of the off-street drainage system shall include the watershed affecting the subdivision and shall be extended to a watercourse or ditch adequate to receive the storm drainage. When the drainage system is outside of the street right-of-way, the subdivider shall make provisions for dedicating an easement to the Town to provide for the future maintenance of said system. Easements shall be a minimum of 20 feet, but the Town may require larger easements if more area is needed due to topography, size of watercourse, etc.

E. Protection of drainage systems. The subdivider shall adequately protect all ditches to the satisfaction of the Town Board and Town Engineer. Ditches and open channels shall be seeded, sodded or paved depending upon grades and soil types. (Generally ditches or channels with grades up to 1% shall be seeded, those with grades up to 4% shall be sodded and those with grades over 4% shall be paved.)

§ 350-42 Nonresidential subdivisions.

A. General.

(1) If a proposed subdivision includes land that is zoned for commercial or industrial purposes, the layout of the subdivision with respect to such land shall make such provisions as the Town may require.

(2) A nonresidential subdivision shall also be subject to all the requirements of site plan approval set forth in the Town Zoning and Building Codes.[1] A nonresidential subdivision shall be subject to all the requirements of this chapter, as well as such additional standards required by the Town, and shall conform to the proposed land use standards established by any Town Comprehensive Plan or Official Map and the Town Zoning Code.

[1] Editor's Note: See Ch. 174, Building Construction, and Ch. 380, Zoning.

B. Standards. In addition to the principles and standards in this chapter, which are appropriate to the planning of all subdivisions, the applicant shall demonstrate to the satisfaction of the Town Board that the street, parcel and block pattern proposed is specifically adapted to the uses anticipated and takes into account other uses in the vicinity. The following principles and standards shall be observed:

(1) Proposed industrial parcels shall be suitable in area and dimensions to the types of industrial development anticipated.

(2) Street rights-of-way and pavement shall be adequate to accommodate the type and volume of traffic anticipated to be generated thereupon.

(3) Special requirements may be imposed by the Town Board with respect to street, curb, gutter and sidewalk design and construction.

(4) Special requirements may be imposed by the Town Board with respect to the installation of public utilities, including water, sewer and stormwater drainage.

(5) Every effort shall be made to protect adjacent residential areas from potential nuisance from a proposed commercial or industrial subdivision, including the provision of extra depth in parcels backing up on existing or potential residential development and provisions for permanently landscaped buffer strips when necessary.

(6) Streets carrying nonresidential traffic, especially truck traffic, shall not normally be extended to the boundaries of adjacent existing or potential residential areas.