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Interceptor Swales

Interceptor swales capture uncontrolled surface water flows above steep and unstable slopes and convey flow to a stable discharge point. Swales can be excavated to form a channel and then seeded with a hearty erosion control grass mix. It is a very economical drainage technique that can also be used as a temporary erosion control measure. Figure 15 shows a typical swale system.

Figure 15. Typical swale system.

Limitations:

Swales should not be sloped greater than 5 percent. Needs a minimum 1 foot width at the bottom with 1 foot minimum depth and 2H:1V maximum side slopes.

Advantages:

Available construction materials and inexpensive construction. Easy to place many swales at different locations. Easy to landscape around.

Disadvantages:

If permeable (sand and gravel) soils are crossed by the swale, conveyed water could infiltrate into the soils adding to local groundwater.

	Applicability	Compatibility

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