September BMP Q&A

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

Q:   I ‘m getting ready to move onto a fairly large tract for a timber harvest.  This particular tract doesn’t have much in the way of an established road system, so I will be constructing most of the roads for the harvest.  The landowner wants me to make part of the road system a permanent road which he will be able to use for access to his tract in the future.  I anticipate that I will need to have at least 1 and maybe 2 material borrow sites to complete this permanent road as the landowner has requested.  What I would like to know if there any guidelines for road material sites that pertain to best management practices?

A:   This is a very good question.  We have written several articles in the past about road BMPs, but have not mentioned a whole lot about what should be done if there is a need to “borrow” materials from the site.  Deposits of surfacing, fill, and site stabilization materials located on the tract are an extremely important resource for forest management activities.  Excavation of these deposits represents a potential for nonpoint source pollution.  Proper planning, layout, maintenance, and reclamation are critical to ensure maximum utilization of materials while minimizing soil movement and impacts to water quality.

Carefully assess the tracts natural drainage patterns, soil types, slopes, and any adjacent streamside management zones (SMZ) to determine the best location, size, and shape of the needed material site.  Deposits covering large areas should be divided and worked in stages, maintaining a minimum size working area and accomplishing partial or complete reclamation of the disturbed area before moving on.  Avoid leaving large areas disturbed for extended periods, active or not.  Road material sites should not be located within an SMZ.  They should be located a minimum of 50 feet from the SMZ edge, but if they must be closer than 50 feet make sure to plan for control measures that will protect water quality.

While material sites are active; use settling basins, waterbars and/or terraces to slow runoff and disperse surface flow.  When extended periods of inactivity are expected, use temporary erosion control measures such as silt fences or straw bales to control surface runoff.  When possible, do site work during dry weather to eliminate excessive runoff and accelerated erosion of freshly disturbed areas.

Upon completion of pit operations and depletion of the deposit; redeposit and shape the overburden in a uniform layer over the pit area.  Make sure the pit has adequate drainage to prevent soil movement and stream sedimentation.  Finally, reclaim the site to aid the future use of the area and implement control measures to minimize surface runoff for each case.  Consider the area's slope, soil erosiveness, and capability to naturally revegetate and then fertilize and reseed all disturbed areas as needed.

For more information on forest road material site 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 September 2010 issue of the Texas Logger

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