(A) General: The following standards are hereby required for all subdivision improvements. The subdivision plans shall conform to standards that will encourage good development patterns adopting the principles and standards which are generally exhibited in the Comprehensive Plan.
(B) Water Distribution System: The water distribution system shall be installed to serve all properties within the subdivision and will include pipes, fittings, hydrants with auxiliary valve, valves and valve vaults, water service lines with a buffalo box or shut-off valve for the property to property line for each lot.
1. Water Mains: Water mains shall be installed to conform with the Comprehensive Water Plan of the City of Darien as adopted by the City Council or as may be adopted or amended from time to time. All mains shall be a minimum of six inch (6") diameter. Water main lines of eight inch (8") diameter or greater are to be ductile iron pipe, cement lined or equal material as approved by the City. Water mains will be located south of the north right- of-way line or east of the west right-of-way line within the road right of way or on dedicated easements. Water mains shall be buried not less than five feet (5') below surface of the final grade as measured to the top of the pipe. A copy of the water district system, including all mains, sizes, valve locations and hydrants, shall be provided as built.
2. Water Hydrants: Water hydrants with auxiliary valves shall be installed at intervals not to exceed four hundred feet (400'). Hydrants shall be located south of the north right-of-way line or east of the west right-of-way line within the road right of way. Valve boxes will be placed on all auxiliary valves.
3. Valves: Valves shall be installed on mains at locations to minimize inconvenience to customers served but in no case shall they be spaced greater than eight hundred feet (800') apart. All valves must be placed in valve vaults: valves of six inches to ten inches (6" to 10") in diameter, inclusive, to be installed in a five foot (5') diameter vault; twelve inch (12") diameter and above to be installed in a five foot (5') diameter vault. Valves shall be located at the extension of the right of way at its intersection with the water main wherever possible.
4. Curb Stops, Cocks And Boxes: Curb stops, cocks and boxes shall be approved pattern of the inverted key type and extension type, respectively.
5. Water Service Pipe: All service pipe shall be Type K copper soft tubing and joints shall be flared or wedged. Diameter of service shall be one inch (1") minimum. Materials other than copper may be used if approval is given by the Plan Commission and City Engineer.
6. Water Improvements: Construction of water improvements shall be in accordance with the existing "Standard Specifications for Water and Sewer Main Construction in Illinois", and as amended and adopted by the City Council.
(C) Sanitary Sewer System: Sanitary sewer lines, including house service sewer stubs to the property line for each lot, shall be installed to adequately service all property in the subdivision.
1. Location Of Sanitary Sewer Lines: All sanitary sewer lines shall conform to the Comprehensive Sanitary Sewer Plan of DuPage County. The sanitary sewer lines will be located eight feet (8') north of the south right-of-way line or eight feet (8') west of the east right-of-way line within the roadway or on dedicated easements.
2. Design: Design of sanitary sewers shall conform to standards of the Illinois Environmental Protection Agency as amended. Risers on house services shall be provided where the sewer is greater than ten feet (10') below the proposed ground elevation and shall be brought up to a depth minimum of ten feet (10') below the proposed ground line.
3. Inspection: The City requires inspection by air tests and lamping of all sanitary trucks and laterals. This inspection shall be conducted by an independent contractor and shall be approved by the DuPage County Public Works Department. Complete written reports shall be submitted to the City Engineer and Public Works Supervisor for permanent records. Any and all expenses incurred for this work shall be the responsibility of the owner. Records shall include duplicate sets of photographs, sewer size, type, location, distance, location of infiltration, sources of unsatisfactory joints and grade, all services, etc.
4. Construction: Construction of sanitary sewer improvements shall be in accordance with the existing "Standard Specifications for Water and Sewer Main Construction in Illinois", and as required by DuPage County. (Ord. 0-21-71, 11-15-1971, as amended 1-25-1975)
(D) Storm Drainage System: An adequate storm water management system shall be designed and constructed to service the entire subdivision. It shall also address all runoff upstream and tributary to the proposed development.
The design criteria for the proposed storm water management system and required engineering criteria to be submitted for review is stated in Title 6B, Chapter 1 of this Code.
All materials used in conjunction with the proposed storm water management system shall comply to the Standard Specifications for Public Improvements in the City of Darien, Illinois, as amended from time to time. (Ord. 0-08-92, 2-3-1992)
(E) Public Utilities System:
1. Utilities Underground: All utility distribution lines for telephone, electric and gas service in the subdivision shall be placed underground. Any aboveground facilities shall require prior approval of the Plan Commission. Installation of such facilities shall be made in compliance with the applicable orders, rules and regulations of the Illinois Commerce Commission now or hereafter effective and the owner shall be responsible for compliance with rules and regulations, now and hereafter effective and filed with said Commission pursuant to the Illinois Public Utilities Act, of any public utility whose services shall be required for the subdivision with respect to the provision of such underground facilities.
2. Underground Utilities In Easements: Underground telephone, electric and gas service shall be placed within easements or dedicated public ways in a manner which shall not conflict with other underground services. Further, all transformer boxes shall be located so as not to be unsightly or hazardous to the public.
3. Permits: Permits shall be obtained from the City of Darien and other governing bodies having jurisdiction for the installation of communication, electric power, gas and other utility services in public or private rights of way or easements, as shown on the final plat.
(F) Sidewalk System: Sidewalks of minimum widths as required shall be constructed and shall have a thickness of four inches (4"). Construction of sidewalks shall be in accordance with existing "Standard Specifications for Road and Bridge Construction, Illinois Department of Transportation" and with the additional requirements of the City of Darien.
(G) Street System: All streets within the subdivision shall be improved with a durable hard surface roadway. The pavement shall be equal to or superior to a pavement consisting of the following requirements:
1. Street Plan: The arrangement, character, extent, width, grade and location of all streets shall conform to the Official Plan and shall be considered in their relation to existing and planned streets; to reasonable circulation of traffic within the subdivision and adjoining lands; to topographical conditions; to runoff of sewer water; to public convenience and safety; and in their appropriate relations to the proposed uses of the area to be served. Streets and right-of-way widths shall conform to the Official Master Plan adopted by the City.
(a) Curve Radius; Horizontal Center Lines: Where there is a deflection in horizontal center lines within a given block at any given point in excess of ten degrees (10°), a curve shall be inserted with a radius of not less than:
Collector streets | 300 feet |
Minor streets | 150 feet |
(b) Curve Radius; Vertical Center Lines: Where there is a difference in vertical center lines within a given block at any point in excess of six degrees (6°), a curve shall be inserted with a radius of not less than:
Collector streets | 300 feet |
Minor streets | 150 feet |
(c) Alignment Of Minor Streets: Minor streets shall be so aligned that their use by through traffic will be discouraged.
(d) Street Jogs: Street jogs with center line offsets of less than one hundred twenty five feet (125') shall be avoided.
(e) Intersections: It must be evidenced that all street intersections and confluences encourage safe and efficient traffic flow and, in general, be at or near right angles, avoiding acute angles. An intersection of more than two (2) streets shall be avoided unless specific conditions of design indicate otherwise.
(f) Residential Alleys: Alleys are not permitted in residential areas unless deemed necessary and approved by the Plan Commission.
(g) Cul-De-Sacs: Cul-de-sac streets in single-family residential districts shall be not more than five hundred feet (500') in length, measured along their center lines from the streets of origin to the end of their rights of way, or may be longer than five hundred (500) lineal feet provided not more than twenty (20) lots abut upon their right-of-way lines. In multiple-family residential districts such streets shall not exceed three hundred feet (300') in length. Roadway pavements in cul-de-sac street turnarounds shall have a minimum diameter measured from faces of the outside curb or outside edges of roadway pavement of one hundred feet (100') for all subdivisions and roadway pavements in "T" type or other variations of the circular type terminus as approved by the Plan Commission and the City Engineer.
(h) Half Streets: Half streets shall be prohibited except where the City Council finds it practicable to require the dedication of the other half of such street. Wherever an existing or dedicated half street is adjacent to a tract to be subdivided, the other half of the street shall be platted within such tract. A half street, where included, shall be graded at one level and the regrading or new construction of any half street shall conform to the grade and pavement of the adjacent half street.
(i) Access To Residential Property: Provisions shall be made for vehicular and pedestrian access to residential property abutting arterial streets either by providing: 1) marginal access streets, or 2) by backing lots to the arterial street and providing access by a collector, minor or cul-de-sac street one lot depth removed and with a visual barrier established in a nonaccess reservation strip along the rear property line (abutting the arterial street). These standards are established for the purpose of providing protection to residential properties and to separate through and local traffic.
(j) Gradients: Gradients of streets shall be at least one-half percent (0.5%) and not to exceed:
Collector streets | 5 percent |
Minor streets | 7 percent |
(k) Tangents: Tangents at least fifty feet (50') long shall be introduced between reverse curves on collector streets.
2. Excavations: Sub-base earth excavation construction in accordance with approved engineering plans to provide a stable sub-base no less than a CBR value of 3.0; CBR tests shall be performed if, in the opinion of the City Engineer, they are necessary to evaluate sub-base material.
3. Paving Standards:
(a) Types Of Construction Permitted: The following general types of construction shall be permitted, according to the individual standards for street classes indicated in subsections (G)3(b), (G)3(c) and (G)3(d) of this Section.
Type 1 | Portland cement concrete (PCC) with integral curb and gutter. |
Type 2 | Bituminous aggregate material base course with bituminous concrete binder and surface, Class I, and PCC combination curb and gutter. |
Type 3 | Stabilized aggregate base with bituminous concrete binder and surface, Class I, and PCC combination curb and gutter (aggregate may be stabilized by the addition of Portland Cement, asphaltic material or hydrated lime and fly ash). |
Type 4 | Gravel or crushed stone base course, Type A, with bituminous concrete binder and surface. Class I and PCC combination curb and gutter. |
(b) Construction Standards For Major Streets:
Type 1 Portland cement concrete with integral curb and gutter shall have a minimum thickness of eight inches (8") reinforced with pavement fabric. The subgrade shall be compacted.
Type 2 Bituminous aggregate material base course shall have a minimum compacted thickness of nine inches (9") and shall have two inches (2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course and Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted nongranular select borrow, with a depth as required.
Type 3 Stabilized aggregate base shall have a minimum compacted thickness of ten inches (10") and shall have two inches (2") of bituminous concrete binder and one and one- half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted nongranular select borrow, with a depth as required.
Type 4 Shall not be allowed.
(c) Construction Standards For Collector Streets:
Type 1 Portland cement concrete with integral curb and gutter shall have a minimum thickness of seven inches (7"). The subgrade shall be compacted.
Type 2 Bituminous aggregate material base course shall have a minimum compacted thickness of seven inches (7") and shall have one and one- half inches (11/2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted.
Type 3 Stabilized aggregate base shall have a minimum compacted thickness of eight inches (8") and shall have one and one-half inches (11/2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course of Class I with Portland cement concrete combination curb and gutter with compacted subgrade.
Type 4 Gravel or crushed stone base course. Base course Type A or B shall have a minimum compacted thickness of twelve inches (12") and shall have one and one-half inches (11/2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted.
(d) Construction Standards For Minor Streets:
Type 1 Portland cement concrete with integral curb and gutter shall have a minimum thickness of six inches (6"). The subgrade shall be compacted.
Type 2 Bituminous aggregate material base course shall have a minimum compacted thickness of five inches (5") and shall have one and one- half inches (11/2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted.
Type 3 Stabilized aggregate base shall have a minimum compacted thickness of six inches (6") and shall have one and one-half inches (11/2") of bituminous concrete binder and one and one-half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted.
Type 4 Gravel or crushed stone base course. Base course Type A or B shall have a minimum compacted thickness of nine inches (9") and shall have one and one-half inches (11/2") of bituminous concrete binder and one and one- half inches (11/2") of bituminous concrete surface course of Class I with a Portland cement concrete combination curb and gutter. The subgrade shall be compacted.
(e) Concrete Curb And Gutter Standards: Portland cement concrete combination curb and gutter shall be not less than nineteen inches (19") in width, measured from back of curb to flag of gutter. The curb shall be a minimum of six inches (6") in height above the gutter. Curb and gutter shall conform to State of Illinois Standard Design, Department of Transportation.
(f) Other Standards Required: The construction of streets and combination concrete curb and gutter shall be in accordance with existing "Standard Specifications for Road and Bridge Construction, State of Illinois, Department of Transportation".
Detail standards for street cross section and combination concrete curb and gutter and all appurtenances shall conform to the Highway Standards adopted by the State of Illinois, Department of Public Works and Buildings, Division of Highway Bureau of Design. (Ord. 0-21-71, 11-15-1971, as amended 1-25-1975)
(H) Street Lighting System: All public ways within the subdivision shall be adequately lighted by luminaries constructed in accordance with the lighting standards set forth herein. The lighting system shall be designed and constructed by the developer. The system shall be based on the following criteria:
1. Horizontal Illumination:
Street Classification
|
Average Foot-Candles Value
|
Major and minor arterial | 1.2 |
Collector | 0.6 |
Minor | 0.4 |
2. Height And Fixture: Lighting standards shall be of a stress- spun concrete precast butt type with the following requirements for height and fixture:
Height | ||
Street Classification
|
In Feet
|
Fixture
|
Major and minor arterials | 30-33 | 25,000-45,000 lumens, HP sodium, bracket-arm mounted, wattage 250-400 maximum |
Collector | 23 | 13,000-25,000 lumens, HP sodium, bracket-arm mounted, wattage 150-250 maximum |
Minor | 23 | 8,000-13,000 lumens, HP sodium, bracket-arm mounted, wattage 100-150 maximum |
3. Circuits: The street lighting circuits shall be of the 120-240 volt single-phase; triplexed; cross-linked polyethylene, 600 volt type insulation; direct burial cable type, with the pedestal to lamp runs not smaller than #6 AWG (AL). The triplexed conductor shall run from the pedestal to the lamp standard and shall run in a random lay method at a minimal depth of thirty two inches (32") below the final established grade line and shall follow the back lot lines, established side lot line easement or one foot (1') from the back of curb outside of the pavement area on either side of the street or where such installations would not be feasible at such other location as is approved in writing by the City Engineer, but in all cases shall remain within the dedicated right of way when laid parallel with the street. (Ord. 0-27-80, 8-4-1980)
(I) Street Signs Identification: Street signs shall be erected so as to identify every street within the subdivision and shall be so designed and constructed as to conform with existing street sign standards. They shall be installed at a height not less than seven feet (7') and shall be placed not less than two feet (2') nor more than ten feet (10') from the edge of the pavement. When a curved street blends into another street, street signs shall be erected to identify each street.
(J) Landscape Development:
1. All unpaved or otherwise unimproved areas within the public right of way or public use areas shall be graded and seeded in an approved manner.
2. Street trees shall be provided by the owner along all streets where trees do not exist. Trees shall be of a species suitable for local soil and climate conditions and adapted to street use at least two inch (2") caliper. At street corners the trees shall be located a minimum of twenty five feet (25') from the intersection of the street right-of-way lines. They shall be located so as not to interfere with utilities or sidewalks and placed fifty feet (50') apart. Trees shall be placed in the grassed area between curb and sidewalk unless the space is less than six feet (6') wide or the City Engineer shall determine they will interfere with sewers, water lines or underground utilities, in which case the trees shall be planted on the lot.
3. In informal type street patterns, informal planting of street trees in accordance with approved landscape development plans may be permitted.
4. All residential lots shall have an appropriate cover of undisturbed existing vegetation, seeding, fresh cut sod, plugs or spot sod.
5. Median strips may be planted with trees and shrubs in accordance with a landscaping plan approved by the Plan Commission.
(K) Monuments And Markers:
1. Permanent monuments consisting of steel pipes or bars not less than three-quarters of an inch (3/4") in diameter and thirty six inches (36") long encased in concrete at least four inches (4") in diameter and thirty six inches (36") long shall be located as follows:
(a) At the intersection of all lines forming angles in boundaries of the subdivision.
(b) At the intersection of street property lines and at the beginning and end of all curves along street property lines.
(c) In slope areas at principal changes in alignment in the boundaries of the subdivision.
2. Markers consisting of steel pipe or bars not less than three- quarters of an inch (3/4") in diameter and thirty inches (30") long shall be located as follows:
(a) At all points where lot lines intersect street right-of-way lines.
(b) At all angles in the lot property lines.
(c) At all other lot corners.
3. Monuments and markers shall be provided by the owner and so placed that the center point shall coincide with the intersection of lines to be marked and the top level with the surface of the surrounding ground after final grading. (Ord. 0-21-71, 11-15-1971, as amended 1-25-1975)