Monday, March 1, 2004

March BMP Q&A

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

Q:  I recently inherited a tract just outside of Palestine.  The property has only one access road and over the years it has gotten in pretty bad shape becoming impassible.  The road has deep gullies running through it and appears to be below grade.  The road also travels across a bottom with moderate slopes (5-10%) and crosses a perennial stream.  I want to have permanent access to the tract so what options do I have to achieve this.  I also wanted to know if you are ever able to go out and give “on the ground” advice and suggestions concerning BMPs?

A:  First of all yes, loggers often call us and ask us to come out and give “on the ground” advice or suggestions regarding BMPs. 

Now lets get to your question about your access road.  It sounds like your road has gotten in pretty bad shape over the years.  I would like to start by saying that it is important that you consider using water control devices during any reconstruction of your road.  This is important because these devices will divert water off the roadway and help protect the site from excessive erosion.  Because the road will see a moderate amount of traffic during the reconstruction process and afterwards rolling dips should be used to divert the water and prevent excessive erosion.  Specifications for properly installing rolling dips can be found on pages 45 and 46 of the Bluebook.

A below grade road will constantly cause you problems.  In my opinion, the best thing to do is to have a dozer cut down the surrounding land and use this dirt to build up your road.  This will also help provide a natural outlet for diverted water.  Additional dirt may have to be brought in to finish building up the road to the desired height.  A mixture of dirt and rip rap may be used to build up the approaches.  This will make the approaches more stable and minimize any erosion on the approaches.  Crowning and seeding the road will also help stabilize it reducing the potential erosion hazard.  For proper seeding choices and rates see pages 64 and 65 of the Bluebook.

Lastly lets talk about what type of stream crossing you should install.  Since you want permanent access to the tract this means that you will have to install a permanent crossing. I would suggest installing a culvert if it will be able to handle the expected water flow.  To determine what size culvert to use refer to the Culvert Size Chart on page 50 of the Bluebook.  You want to make sure that you install the right size culvert because putting one in that is too small will eventually blow out.  A blown out culvert will cause more road problems, increased repair expenses, but more importantly it will impact the water quality of the stream through the high amount of sedimentation caused by the blown out culvert.  The Stream Crossings section on page 47 of the Bluebook also contains specifications on how to properly install a culvert.  If a culvert will not provide an adequate crossing then you may have to think about installing a bridge.  For this I would suggest that you get technical advice from someone specially trained in this area or contact your local NRCS office

Proper road construction and maintenance can be time consuming and expensive but are necessary if you want good access to your property.

If you need a copy of the Bluebook you can get a copy from your local Texas Forest Service office or you can view online at If you have any questions or comments about BMPs please call me at (936) 639-8180. 

* This article was published in the March 2004 issue of the Texas Logger                                                                                                                                                                                                                                                      

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