Thursday, May 8, 2014

May 2014 BMP Q&A

By: Todd Thomas, Water Resources Forester, Texas A&M Forest Service

Q: As a result of some of these spring time rains we have been experiencing, several of the permanent roads we use have stayed wet and become a major headache.  For future reference, what do you recommend to help decrease the amount of time it takes to dry these roads out?

A: After some of the dry weather we’ve had the last couple of years, there’s no doubt that the rain is welcome, but with it comes issues like the one you’ve brought up.  As they say, “the wetter the road, the weaker the road.”  One method that comes to mind for decreasing the amount of time it takes for a road to dry out is called “daylighting.”

Sun and wind are the primary agents needed to dry out a road.  Daylighting is a method that that entails clearing trees along the edge of the road in order to increase air circulation and allow more sunlight to hit the road surface.  The forest canopy intercepts quite a bit of wind and sunlight.  The more sun and wind that reach the road, the faster it will dry out, allowing you to work more efficiently, reducing erosion potential, and increasing the life span of your road.  How far you decide to remove these trees on the sides is up to your discretion, really just enough to get that sunlight and wind onto the road surface.  
This road is receiving optimum sunlight and air circulation now,
but later on these trees along the side may need to be removed.

Due to our location on the Earth’s surface, the southern side of east-west running roads should receive the most attention in order to maximize the amount of afternoon sun that hits the road.  Generally speaking, afternoon sun has a greater intensity than morning sun and a southern exposure will receive more direct sunlight than a northern exposure.  On a north-south running road, the west side should have more trees removed than the east side, to maximize the afternoon sun.  In areas with substantial curves in the road, go ahead and take several trees out of the inside of the curve to enhance the daylighting process and to increase visibility down the road as a safety precaution. 

In addition to allowing the road to dry faster, daylighting also helps to increase vegetative cover.  Increased grasses on the road surface when the road is not under heavy traffic loads will do two things.  The root structure of the grasses will do an excellent job of holding soil in place while the grasses themselves intercept rainfall and reduce soil particle displacement from raindrop impact.  The second benefit to the road is that the grasses will also aid in removing moisture.  As these grasses grow and conduct photosynthesis, they will remove moisture from the soil comprising the road bed and then transpire it into the atmosphere.  The increased number of grasses and forbs growing in the road and on the sides of the road will be of great benefit to wildlife as a food source.  So you are not only helping the road system but you are helping to feed our furry friends.  Who knows, maybe they’ll grow some bigger antlers and be more convenient to load into the back of the pickup since they are hanging out on the road! 

In conclusion, if your primary access roads are staying too wet, you may want to consider removing some trees along the side of the road in a process known as “daylighting.”  Remember, forest roads have the potential to severely degrade water quality and by keeping them in good shape, you are helping to keep our waters clean as well.  If you have any questions, feel free to call me at 936-639-8180, you can reach me by email at, or just swing by our office in Lufkin. 

*This article was published in the May 2014 edition of the Texas Logger

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