|
|
MODEL SHOULDER/DITCHING SPECIFICATIONS
- Shoulders will be lower and graded at a slightly steeper cross-slope
to provide positive drainage toward the ditch.
-
If possible, all inslopes will be no steeper than
2:1 (Horizontal to Vertical) and all backslopes will be no steeper
than 1:1.
- The depth of ditch should be at least 12" below the bottom
of the roadway gravel. If the depth of base gravel is unknown
then the ditch should be a minimum of 18" below the shoulder elevation.
Care should be given to avoid excessively deep ditches which could
create safety and liability concerns to motorists and/or pedestrians,
especially with steep side slopes.
- All ditches will be shaped with no hard transitions in slopes.
The shape should be rounded (parabolic) to minimize erosion and
water velocities. V-ditches should be avoided.
- The slope of the graded ditch should be a minimum of 1%. In
difficult situations, it should never be less than .5%.
- No gravel of sod berm or windrow will be left in-between the
road and the ditch slope.
-
Prior to any grading, the Contractor or Town will
call Dig-Safe toll-free number 1-888-DIG SAFE (344-7233) to protect
against possible damage. Comments like "I know there's nothing
there" are not acceptable. The 72-hour waiting period will be
adhered to in ALL CASES, except emergencies.
- All work will be protected by proper work zone devices and
procedures. The standards presented in the latest edition of Part
6 of the Manual on Uniform Traffic Control Devices (MUTCD) will
serve as minimum standards.
- All culverts or obstructions will be flagged or marked prior
to grading to ensure no damage to the culverts or equipment.
- All "ditch spoils" will be properly disposed of by the operator
in accordance with all environmental considerations. An easement
will be obtained to dump excavated material onto private property.
- Any ditch drainage onto private property can only occur after
a drainage easement is on file with the Town.
-
All work will be performed under the direction of
the Road Commissioner (Town Manager or Board of Selectmen).
-
Any inconveniences to residents or to adjacent driveways
shall be avoided by prior notification.
- All culverts, geotextiles, and erosion control materials will
be approved of and/or bought by the Town for use.
- All unstable ditches and slopes will be properly protected
against erosion according to current best management practices
and State law.
|