November BMP Q&A

By: Chris Duncan, BMP Forester (Ret.), Texas Forest Service

Q: A few months ago you wrote a couple of articles about the planning process which is necessary prior to constructing a forest road. I found these articles to be very helpful, and I would like to know if you have any other information on forest roads.

A: In the August issue I wrote about several tools which should be used when available to help aid in you in the planning process.  Most of these tools are available at little to no cost to you.  In the September issue, I listed several factors to consider when planning your forest road layout.  This month I would like to address the construction phase for new forest roads.

Well-constructed forest roads are essential to forest management activities and are critical in reducing pollution impacts to forest streams.  Poorly constructed forest roads will always be problematic, and are often very costly to maintain or repair.  Improperly constructed forest roads are also usually the main cause of sedimentation into forest streams.  The following guidelines should be used to ensure that roads are constructed properly and to reduce the chances for costly repairs in the future.

Deposits of road building materials are an important resource for forest management activities.  Excavation of these materials represents a potential for pollution into forest streams.  When possible, balance cuts and fills so that the excavated material will be deposited in the roadway fill sections and thereby minimizing the need for borrow pits. To minimize erosion, cut and fill slopes should be designed at the normal angle of repose or less.

Example of a "below grade" road

When constructing a new road, it is important to avoid cutting down to deep and creating a below grade road.  Below grade roads occur when the road’s surface becomes lower than the sides (shoulders) of the road.  Below grade roads act as conduits for rainfall runoff, thereby increasing the chances for erosion and risks to water quality.  Below grade roads are often very problematic, and can be very costly to repair or maintain.

Another important guideline is to implement necessary BMPs during the construction phase.  Following this simple guideline will ensure that the road has maximum protection from erosion both during construction and after construction is complete.  It can be costly to come back in after construction has been completed to fix an erosion problem that may have been averted by installing the proper BMPs during construction.  Installing the proper BMPs during the construction phase will also help to minimize the adverse effects of rain during the construction.

Depending on the sites topography, soil type, streams, and other features; one or more of the following BMPs may need to be installed during the construction phase: crown and ditch, cross drain culverts, wing ditches, rolling dips or broad based dips, water bars, rock or other aggregate materials.

These are just a few of the guidelines that should be considered before any road construction begins.  I encourage you to attend one of our upcoming BMP Forest Roads Logger Training Workshops for more information.

For more information on forest road BMPs and other BMPs visit the Texas Forest Service webpage at http://texasforestservice.tamu.edu/water, contact me at (903) 297-3910.

* This article was published in the November issue of the Texas Logger