Culvert location guide can be discussed as follows as it located in various geographical conditions and climate variation.
(a) In general, the flow line of a culvert should conform as nearly as practicable to the gradient and direction in the stream bed or channel.
(b) The stream should have a direst any an entrance and exit on the culvert. Abrupt adjustments to direct can cause turbulence and the probability of scouring in some aspects of the stream and silting in other.
(c) Generally the stream should pass underneath the road in the first opportunity.
The ideal grade line for a culvert is one that produces neither silting nor excessive velocities and sour. Normally the grade type of the culvert should coincide while using stream bed, however, in most circumstances it may be desirable to deviate from it e.g.:-
• Where sedimentation is anticipated that occurs the culvert invert may be set several inches higher compared to the stream bed, but on a single slope.
• Where headroom is limited, setting a culvert below stream bed grade is likely to result in sedimentation and reduced waterway area. This should be avoided either by using a low, wide culvert say for example a box culvert or a pipe arch, or by raising the street grade.
• In steeply slopping areas, as on hillsides, it’s not always necessary to put the culvert on the same steep grade. The culvert can be put on the ‘critical’ slope and then a spillway provided in the outlet in order to avoid scouring. This prevents the culvert shorter and under shallower cover.
• At times a shorter length of culvert can be used and/or a better foundation obtained by shifting the culvert to one side of the natural channel. When this is done, care should be arrive at construct the inlet and outlet channels to supply for a smooth flow from the water, particularly around the downstream side in order to minimize or prevent erosion.
Not only above, as culvert location guide but also varied conditions apply with different kind of project around the world.