Aluminum culverts and concrete cylinder pipe are available for surface water routing under road surfaces and down slopes. Culvert pipes are usually purchased in diameters of 12 inches or greater. Rigid pipe is sold in short lengths of approximately 10 to 20 feet and requires good connections at each end. Pipe sold in coils requires fewer connections which is a benefit but may have a low strength for wall crushing or buckling depending on the pipe manufacturer's specifications. Ask your pipe supplier about pipe details.
Perforated pipe allows water to enter or exit through small openings along a length of a pipe.
The openings can be circular or slots. The more opening space per foot of pipe, the greater the capacity of the pipe to collect and move water. Slotted pipes have an advantage over pipes with small holes because they tend to reduce the amount of fine soil particles that get pulled into a drainage system and discharged downstream. Solid pipe has no openings in the walls and is commonly referred to as tightline pipe in drainage applications. Geotextile A geotextile is a permeable fabric material made from synthetic polymers.