Monday, January 1, 2007

January BMP Q&A

By: Shane Harrington, BMP Forester (Ret.), Texas Forest Service

Q:    I have heard you mention various products such as logging mats, culverts, and geo-textile fabrics in past articles.  I wanted to know where these types of products can be purchased and what do they typically cost.

A:    A variety of products are used in the management of forestlands and some of these products can be difficult to find.  The Texas Forest Service BMP Project Office maintains a product/vendor guide which lists a variety of products and the vendors who sell or manufacture them.  Prices are also listed with these products but the vendor should be contacted to ensure prices have not changed.

Products such as logging mats or drag line mats can be found in the BMP Product/Vendor Guide.  Logging mats are used when access across a stream or wet area is only needed for a short time during the harvest or planting of a tract.  These temporary crossings are relatively inexpensive, can be used multiple times, and when installed correctly greatly minimize or prevent any negative impacts to water quality.  Most logging mats when cared for properly can last anywhere from five to seven years and can be transported easily from operation to operation.  Logging mats are typically made of several hardwood cants that are bolted together and provide a secure and stable crossing for equipment.  Depending on the size logging mat purchased to price can range anywhere from $300 to $1200 each.   

Another common product that can be found in the BMP Product/Vendor Guide is culverts.  Culverts are used when permanent access is needed across a stream or the stream is too large for logging mats.  When installing culverts care should be taken to ensure that the proper size culvert is used and that it is installed correctly.  Soil type and topography greatly influence the size of culvert that is needed to adequately handle expected water flow through a stream.  A topographic map and soil survey can be used to determine the amount of water being drained from a watershed and the soil type of the area drained.  Culverts not properly installed can negatively impact water quality and can be very costly to repair.  There are several types of culverts and they come in various sizes ranging from 18 inches in diameter and larger and range widely in price depending on the size

Geo-textile products such as Geoweb are listed as well.  Geoweb is used for shallow stream crossings or low water crossings.  These crossings are permanent crossings on streams that have relatively flat approaches and shallow stream channels.  The purpose of using a product such as Geoweb is to provide a stable low water crossing and to prevent rutting up the stream channel for passing vehicles.  The stream must have a stable bottom for this type of crossing to be effective.  When purchasing Geoweb it is important to purchase enough material so that it stretches several feet out past the edge of the stream channel.  This is to ensure that the approaches do not become washed out and rutted which can increase the amount of erosion and sediment entering the stream.  Geoweb, when installed correctly, can provide a stable low water crossing that can last for many years.  Several companies sell Geoweb or products that are similar and they come in various sizes and range in price from $150 to $500 per unit.

For more information concerning these products or other products please consult the BMP Product/Vendor Guide which can be viewed by visiting the Texas Forest Service website at  If you have any questions concerning the BMP Product/Vendor Guide or BMPs in general please contact me by calling (936) 639-8180. 

* This article was published in the January 2007 issue of the Texas Logger