[Amended 6-12-1984 by Ord. No. 84-53]
In laying out a subdivision, the subdivider shall conform to:
A.
All applicable ordinances of the County.
C.
Applicable laws, rules, and regulations of the State of Illinois
and duly constituted agencies thereof.
D.
Current administrative policies (and all subsequent revisions) of
the Bureau of Local Roads of the State of Illinois for the various
road classifications and the minimum design standards for vertical
and horizontal alignment.
A.
Suitability of land. No land shall be subdivided which is unsuitable
for subdivision by reason of flooding, collecting of groundwater,
bad drainage, adverse earth or rock formation or topography, or any
other feature likely to be harmful to the health, safety, or welfare
of the future residents of the subdivision or of the community. Such
lands shall remain unsubdivided until such time as the conditions
causing unsuitability are corrected.
B.
Preservation of natural features. Natural features such as trees,
brooks, hilltops, and views shall be preserved wherever reasonably
possible.
C.
In the subdividing of any land within the County or within 1 1/2
miles of the corporate limits of any city or village, due 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 value to the proposed development.[1]
A.
General. All streets shall be designed in substantial relation to
(1) topographic conditions and drainage; (2) public convenience and
safety; (3) the proposed uses of land to be served by such streets.
A public street shall be provided for convenient access to all property
within the subdivision. Private streets shall not be permitted, except
where their control is definitely placed in the local governing body
under conditions approved by the Plat Officer.
B.
Publicly planned streets. Streets shall be laid out in conformity
to street or highway plans officially adopted by the County. If the
subdivision lies within 1 1/2 miles of the corporate limits of
a municipality, the streets shall be in conformity with the street
or highway plan officially adopted by the corporate authority of said
municipality or County, whichever is more restrictive. Wherever such
a planned street or highway runs through a proposed subdivision, it
shall be provided for in the place and with the width indicated on
said plan. Additional right-of-way specified on said plan shall be
reserved for circulation purposes by easement provisions to be acquired
at a later date by the public agency involved.[1]
C.
Alignment and continuation. Where streets are not a part of the Comprehensive
Plan or adopted street or highway plans, the arrangement of the streets
in a subdivision shall either provide for the alignment and continuation
or appropriate projection of existing principal street in surrounding
areas or conform to an approved plan for the neighborhood which meets
a particular situation where topography or other conditions make continuance
of, or conformance to, existing streets impracticable.
D.
Street classification.
(1)
Primary streets shall be those having intercity or regional importance
and shall be properly integrated with the existing and proposed system
of primary streets and highways.
(2)
Secondary streets shall be interneighborhood streets and shall be
properly related to specific traffic-generating facilities such as
schools, churches, shopping and employment centers; to population
densities; and to the primary streets into which they feed.
(3)
Collector and local streets shall be laid out to conform as much
as possible to topography; to discourage use by through traffic; to
permit efficient drainage and sewer systems; and to require the minimum
amount of street to provide convenient, safe access to adjacent property.
E.
Street widths. Where not otherwise specified, street right-of-way
widths shall be as follows:
(1)
Primary streets shall have a minimum right-of-way width as established
by the Official Map of not less than 100 feet.
(2)
Secondary streets shall have a minimum right-of-way width of 80 feet.
(3)
Collector and local streets shall have a minimum right-of-way width
of 60 feet in urban subdivisions and 66 feet in rural areas.
F.
Marginal access streets. Where a subdivision borders on or contains
a railroad right-of-way, limited access road right-of-way, or major
thoroughfare, a marginal access street not less than 60 feet in width
may be required to be located approximately parallel to such right-of-way.
The location of such marginal access street shall be determined with
due regard for the requirements of approach, grades, and future grade
separation.
G.
Reserve strips. Reserve or "spite" strips controlling access to streets
shall not be permitted.
H.
Half-streets. Half-streets shall not be permitted, except to provide
right-of-way for officially adopted planned streets or highways. Whenever
an existing half-street is adjacent to a tract to be subdivided, the
other half of the street shall be platted within such tract to be
subdivided, or the existing half-street shall be vacated prior to
final approval.
I.
Cul-de-sac or dead-end streets. Dead-end streets, as such, shall
not be permitted. Culs-de-sac, designed to be permanent, shall not
be longer than 500 feet, measured along the center line from the street
right-of-way to the end of the cul-de-sac, and shall be provided with
a turnaround right-of-way not less than 120 feet in diameter at the
closed end for rural and urban subdivisions.
J.
Street names. Streets that are extensions of or obviously in alignment
with existing streets shall bear the names of the existing streets;
however, no other streets shall bear names which duplicate, or so
nearly duplicate, so as to be confused with the names of existing
streets.
K.
Grades. The grade of primary and secondary streets shall not exceed
5% unless necessitated by exceptional topography and approved by the
Superintendent of Highways. The grade of all other streets shall not
exceed 7%. The minimum grade of all streets shall be 0.50%.
L.
Horizontal curves. A minimum sight distance with visibility, measured
along the center line, shall be provided of at least 300 feet on major
streets, 200 feet for secondary streets, and 100 feet on all other
streets.
M.
Vertical curves. All changes in street grades shall be connected
by vertical curves of a minimum length of 300 feet for major, secondary,
and collector streets and 200 feet for all other streets.
N.
Tangents. A tangent of adequate length to make proper transition
of the superelevation requirements, or 100 feet when no superelevation
is required, shall be introduced between reverse curves on major,
secondary, and collector streets.
A.
Alleys shall be provided in all commercial and industrial districts,
except that the Plat Officer 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.
B.
Alleys shall not be approved in residential areas unless necessary
because of topography or other exceptional circumstances.
C.
The width of alleys shall be not less than 20 feet when permitted
in residential subdivisions, and not less than 30 feet in all other
instances.
D.
Dead-end alleys are prohibited.
A.
The lengths, widths, and shapes of blocks shall be such as are appropriate
for the locality and the type of development contemplated, but block
length in residential areas shall not exceed 1,500 feet.
B.
Pedestrian crosswalks, not less than 10 feet wide, may be required
through the center of blocks more than 900 feet long where deemed
essential to provide circulation or access to schools, playgrounds,
shopping centers, transportation, and other community facilities.
A.
All lots shall be not less than 7,500 square feet in area and have
a width of not less than 70 feet when such lots are served by public
sewers and sewage treatment facilities and public water supply. Where
no public sewage facilities are provided, each lot shall not be less
than 20,000 square feet in area and have a width of not less than
100 feet.
B.
The size, shape, and orientation of lots shall be appropriate for
the location of the subdivision, and for the type of development and
use contemplated.
C.
Depth and width of properties reserved or laid out for commercial
and industrial purposes shall be adequate to provide for the off-street
service and parking facilities required by the type of use and development
contemplated.
D.
The fronting of residential lots onto major streets and highways
is to be discouraged; however, where this does occur, there shall
be provided a marginal access street.
E.
Excessive depth in relation to width shall be avoided. A proportion
of two to one shall normally be considered as desirable.
F.
In determining the minimum lot areas to meet the requirements of Chapter 400, Zoning, both of the following conditions must be met:
(1)
Ninety percent of the minimum lot area shall be at least two feet
above the approximate high-water elevation of any lake or stream affecting
the area; and
(2)
Eighty percent of the minimum lot area shall be at least three feet
above the highest groundwater level as estimated by the subdivider,
or his agent, from the soil boring test data.
G.
Corner lots for residential use shall have extra width to permit full building setbacks on both streets as required by applicable provisions of Chapter 400, Zoning.
H.
Every lot shall front or abut on a public street. Lots with an access
only to existing private drives or streets shall be permitted only
with the approval of the Plan Commission or as part of a planned development.
I.
Side lot lines shall be substantially at right angles or radial to
street lines.
J.
Double-frontage lots shall be avoided except where necessary to overcome
specific disadvantages of topography and orientation, and where a
limited-access highway, railroad right-of-way, major street, or similar
situation exists, in which case double-frontage lots are to be preferred,
provided suitable screen planting contained in a nonaccess reservation
along the property line and the right-of-way is provided.
K.
Subdivisions shall contain no leftover pieces, corners, or remnants
of land.
L.
Lot widths shall be measured at the building setback line.
M.
Where utility sewer and utility water are not provided, the minimum area of any residence lot shall be 30,000 square feet, except that the minimum area of any lot may be reduced to 20,000 square feet where the results of tests as on the table entitled "Absorption Areas for Individual Residences"[1] meet the minimum standards listed. This minimum area may
be further reduced to within 15,000 square feet where either utility
sewer or utility water is provided.
[1]
Editor's Note: The table is included at the end of this chapter.
A.
Utility easements shall be provided at the rear of all residential
lots and along the side lot lines where required, and shall provide
reasonable continuity from block to block. Such utility easement shall
be at least 10 feet wide, and normally centered upon the rear or side
lot line. Evidence shall be furnished to the Plat Officer that easements
and any easement provisions to be incorporated on the plat or in the
deeds have been reviewed by the individual utility companies or the
organizations responsible for furnishing the service involved.
B.
Where a subdivision is traversed by a watercourse, drainageway, channel
or stream, or other body of water, appropriate dedication or easement
provisions, with adequate width or construction to accommodate stormwater
drainage through and from the subdivision, shall be made. The width
of the easement or dedication shall be dependent on the area of land
drained by the watercourse, except that in no case shall the required
width be more than 300 feet.
C.
A screen planting easement may be required between residential and
commercial or industrial lots, or along lot lines to discourage the
undesirable development of residential lots fronting on traffic arteries.
