500:000    ROAD CONSTRUCTION STANDARDS
500:100    TOWNSHIP ROAD STANDARDS
500:200    DRAINAGE
500:300    INSPECTION OF IMPROVEMENTS

500:000      ROAD CONSTRUCTION STANDARDS.

500:100      TOWNSHIP ROAD STANDARDS.

Prior to acceptance by the Township Board, roads constructed for public use shall meet the following minimum specifications:

    1.      The minimum road right-of-way width shall be sixty-six (66) feet,

    2.      The right-of-way shall be cleared of all brush, trees and stumps and all debris shall be removed from the right-of-way.

    3.      The roadway shall conform to the typical rural or urban section attached to these standards.  All available topsoil shall be replaced on the road inslopes, backslopes and ditch bottoms and seeded with rye and brome grass.

    4.      The ditch depth and width shall conform to the typical street section attached to these standards.  Any exceptions to the standard section will require a Certified Civil Engineer's Plan, approved by the Town Board, assuring adequate drainage of water from the road surface and ditches.

    5.      Dead end roads shall have a minimum cleared right-of-way diameter and a bituminous road surface diameter as shown on the road details.  For roads that are laid out to be continued at a later date, there shall be a temporary turnaround built in the same manner as previously outlined.  Due to high maintenance costs, cul-de-sacs are to be kept to the minimum number possible.  Temporary cul-de-sacs shall be constructed within temporary easements outside the sixty-six (66) foot right-of-way rather than in platted right-of-way.

    6.      Roads shall be designed for a minimum thirty (30) miles per hour design speed. All finished grades shall be reasonable and justified, with a minimum one-half (½) percent and maximum eight (8) percent grade.  A maximum two (2) percent grade shall extend one-hundred (100) feet from all intersections.  The Town Board reserves the right to request a lesser grade when deemed necessary to assure safety and efficient road maintenance.  This will be determined during the plan review process.  A road profile and drainage plan shall be furnished to the Town Board in conformance to the Developer's Agreement.  Exceptions to these design criteria will be allowed only when conditions justify and the Town Board approves the exception for public safety and/or environmental considerations.  Before Class 5 aggregate base work is started, the edge of the road shall be staked and a test roll of the subgrade performed.

    7.      Class 5 aggregate base with a minimum five (5) percent binder (subject to testing) shall be placed with a minimum thickness as per the typical street section. Additional thickness may be required depending on the soil conditions. All base work shall be  inspected, test rolled and approved by the Town's representative prior  to placement of the bituminous surface.  Class 5 shall be compacted to a minimum ninety-five (95) percent of the Modified Proctor Density and shall be tested by the Developer at locations specified by the Town's representative.  The minimum test frequency shall be every three-hundred (300) feet.

    8.      A plant-mixed bituminous surface shall be placed in accordance with MnDot Standard Specifications for Construction 2360, latest revision.  Bituminous wear course shall be LVWE 35030 B.  Bituminous non-wear course shall be LVNW 35030 B.  The bituminous shall be placed as per the typical street section. There shall be a twelve (12) inch wide apron thirty (30) feet long where driveways or mailboxes are already established.  All bituminous placement shall be inspected and approved by the Town's engineer.  The bituminous shall be compacted according to the “Ordinary Compaction Method”.  Pavement smoothness shall be waived.

    9.      Shouldering, Class 5 (with a minimum five (5) percent binder, subject to testing) shall be placed beyond the edge of the bituminous mat and brought up to the level of the bituminous surface.  All shouldering shall be inspected by the Town's representative prior to acceptance.

    10.    All storm sewer work shall be in accordance with Sections 2501, 2503, 2506, and 2511 of the current Minnesota Department of Transportation Specifications, latest revision, and as shown on the detail plates.  All concrete storm sewer pipe joints shall be of the rubber "O" ring gasket type.  Corrugated polyethylene pipe (CPP) may be used in green area.  All CPP shall have "water-tight" joints.

    11.    All concrete curbing shall be in accordance with Section 2531 of the current Minnesota Department of Transportation specifications, latest revisions, and as shown on the details.

    12.     Geotextile fabric shall conform to Minnesota Department of Transportation 3733 requirements, latest revisions.  Geotextile shall be Type V, non-woven fabric.

500:200      DRAINAGE.

    1.      Rural design streets shall be built to be free of snow traps and flooding.  All ditches shall provide for the ten (10) year frequency storm event in accordance with the  “Rational Formula” method of design without flood encroachment on the road shoulder or bituminous surface.  Culverts under roadways and driveways shall be designed for the fifty (50) year storm event without overtopping of the roadway; except when they are the outlet from a detention pond and then they shall be designed for the one-hundred (100) year frequency, twenty-four (24) hour duration storm event in accordance with the “Soil Conservation Service” (SCS) method of design, without overtopping the driveway.

    2.      Urban design streets shall have storm sewer systems installed to provide for surface water runoff.  Storm sewers shall be designed for a ten (10) year frequency storm event in conformance with the “Rational Formula” method of design.  All detention pond areas and all storm sewers providing outlets for detention pond areas shall be designed for the one-hundred (100) year frequency, twenty-four (24) hour duration storm event in accordance with the “Soil Conservation Service” (SCS) method of design.  Combination pipe and ditch pond outlets will be considered based upon suitable design data being furnished by the Developer's Engineer and approval by the Town Board or Town's representative.

    3.      All landlocked ponding areas without outlets shall be provided with drainage easements to encompass the elevation of the water surface computed by using a three (3) inch, frozen ground rainfall amount and post development runoff conditions in accordance with the “Soil Conservation Service” (SCS) method of design.  Drainage easements shall be provided or all retention and detention areas to provide for expected flood high water elevation.

    4.      Culverts are required as follows:

        a.      All private driveways shall have a minimum twelve (12) inch diameter and thirty (30)  foot length, sixteen (16) gauge metal culvert with aprons installed in the roadway ditch alignment.

        b.      All public roadway cross culverts shall be a minimum eighteen (18) inch diameter, sixteen (16) gauge metal culverts with aprons of the length required to match the roadway ditch and embankment conditions.

500:300      INSPECTION OF IMPROVEMENTS.

    1.      It shall be the responsibility of the Developer and/or Contractor to notify the Town or the Town's representative so that adequate tests and inspections can be accomplished on the road improvements.  Failure to notify Town or the Town's representative in time to perform proper inspection of the aggregate base or bituminous surface will result in one of the following:

        a.      The right of the Town Board to refuse acceptance of said proposed road.

        b.      The right of the Town Board to require test core-boring as requested by the Town's representative to determine if the specified gravel and bituminous depth, meeting the specifications were installed, together with density tests and oil content tests.  Test core-borings for the entire project to average one (1) boring every five-thousand (5,000) square feet and are to be paid by the Developer.  The Town Board reserves the right to select the company to provide test core-borings.  All borings and sample holes shall be repaired at the Developer's expense.