Here's the Dirt on Rural Roads

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A tractor or truck with a blade can be used to create or reshape a crown. Surface materials should be redistributed evenly afterward.

Instead of a crown, some roads will drain better if they're graded to slope all to one side. Woody Colbert of the Pennsylvania Conservation Commission said a road can be side-sloped when the slope of adjacent land is moderate and water flow can be maintained over the road and into that land. Sharply curved roads often are good candidates for sloping inward, which also forces traffic to slow. Such roads require an inside ditch.

Banking a road outward is trickier, since the far edge from which water is draining will have a tendency to erode. Almost every country dweller has seen a crack in the roadside enlarge over time until a bank gives way. On suitable sites, however, outsloped roads are generally cheaper to install, less expensive to maintain and have fewer erosion and drainage issues.

Before & After

The primary outlet of drainage is usually the roadside ditch. But not all ditches are created (or maintained) equal. To handle the most water, a ditch should have a parabolic or flat bottom, not a "V" shape. Strong vegetation or a rock lining will help prevent erosion. (Tip: Use rocks the size of those left behind by storm water.) A ditch that's constructed and operating effectively should be carrying fairly clear water that never gets closer than a foot from the roadside. Culverts-metal, plastic or concrete pipes installed under roadbeds to channel runoff - are not always the best solution for drainage, but they are common and sometimes necessary. Unless you have heavy equipment and some expertise at road building, you'll probably need to hire someone to install a culvert.

"Always oversize culverts," Casale said. Sedimentation can reduce water - carrying capacity significantly, and debris can block culverts, so bigger is always better. The water will find its way beyond a culvert, and if the pipe is too small or blocked, excess flow will destroy the culvert and might wash out the roadbed. On the downstream side of culverts, it's important to provide some means of energy dissipation - something that will break up the force of the water, such as some large rocks - or the water you've channeled can destroy the roadside ditch and/or the surrounding landscape. Anything that slows the water down without blocking it entirely will help. To prevent storm debris from blocking the upstream side of a culvert, create a debris barrier - but not at the mouth of the pipe, Casale said. If a barrier is too close to the culvert mouth, it can promote damming of debris. Instead, walk upstream from the culvert 5 or 6 feet. Drive lengths of steel pipes or fence posts into the ditch base at regular intervals across its width, the aim being to block large pieces of debris. For a 24 - inch culvert, place the barriers 12 to 15 inches apart; for a 36-inch culvert, install 18 to 24 inches apart at approximately the depth of the ditch; and so on.

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