Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

3. Section-300
5. Protect the surface of drains/roadside ditches with turf cover or other suitable lining as shown on
the drawings. Consult the local agricultural department for selecting the appropriate species of
grass/vegetation.
6. Provide proper gradients and fix the invert for quick disposal of water to the outfall.
7. For any stretch of the rural road passing through a built-up area, ensure that any water coming
from the adjacent habitations discharges only into the drain and is not allowed to flow over the
road surface.
8. Any sharp edges, where cut/fill surfaces meet the ground level, should be rounded off to prevent
erosion and promote turfing.
9. Provide safe outlets to natural or artificial water courses.
10. Provide catch water/intercepting drains on hill slopes to intercept water from upper reaches,
such drains to be provided over stable slopes only, outside any slide or unstable areas.
B. Quality Control Requirements
1. Materials
(a) Where the soil is erodible, line the drain with random masonry coursed with 1:5 cementsand
mortar, as per subsection 700 or any other suitable material as shown on the drawings.
(b) The turf and variety of grass used for erosion control must meet the specified requirements
for use in the area.
(c) The materials used for other types of linings like brick masonry, stone masonry etc. must
meet the relevant specifications given in Sections 600 & 700 respectively.
2. Dimensions
The cross-section and side slopes should conform to the specified dimensions.
C. Do’s and Don’ts
Do’s Don’ts
1. Ensure that the gradients are adequate for free flow
of water to the outlet without overflowing or
ponding or undue siltation.
2. Do ensure that grass, when used as a lining forms a
firm dense turf.
3. Take special precautions in built-up areas to make
sure that water from any adjacent habitations does
not flow over the road.
4. Take care to see that a drain/roadside ditch is deep
enough to drain the sub-base/base course.
1. Do not provide ordinarily side slopes steeper than 2:1
to avoid damage by erosion.
2. Do not leave any roadside ditch/drain unlined even if
it be a grass lining.
3. Do not leave any sharp edges within the cross-section
to avoid damage by erosion.
4. Do not allow the bottom of roadside ditch/drain to be
below the bed of the cross-stream at an outlet.
5. Do not provide any catch water/ intercepting drain in
any slide area/unstable area.
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