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 http://txforestservice.tamu.edu/water. 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                                                                                                                                                                                                                                                      

February BMP Q&A

By: Jake Donellan, BMP Forester (Ret.), Texas Forest Service

Q:   I am a road contractor for a large timber company and I was looking at my bluebook the other day and I noticed that in Part II - Recommended Specifications, you make a distinction between Broad-Based Dips and Rolling Dips. I was under the impression that these two were basically the same thing. Can you explain the difference in these two and when you might use one over the other?

A:   Don't feel bad about not knowing the difference between these two BMPs, we are asked this question quite often. At first glance these two practices are very similar and both are designed to accomplish basically the same goal: provide cross drainage on in-sloped roads. The differences between these practices are very subtle but despite these minor differences, the benefits of these BMPs can be a very valuable during road and skid trail construction and/or maintenance.

Both rolling dips (Pg. 45 in the blue book) and broad-based dips (Pg. 42 in the blue book) are dips and reverse slopes in the road surface with an outslope for natural cross drainage. Rolling dips are designed to be used on haul roads and heavily used skid trails. Broad-based dips differ in that they are designed for use primarily on heavily used haul roads. Rolling dips can be used on roads with up to a 15% grade while broad-based dips should be used on roads that do not exceed a 12% grade. The spacing on broad-based dips should change with every 2% change in gradient, while the spacing with rolling dips changes with every 5% change in gradient.

With broad-based dips, the reverse grade should always be 3% and near 20 feet in length.

Rolling dips are a little more flexible in that the reverse grade can be 3% to 8% and can range from 10 feet to 15 feet in length. These differences allow higher vehicle speeds on broadbased dips than on rolling dips.

Since broad-based dips are used on high traffic roads some other considerations may be necessary; on some soils the dip and reverse grade section may require bedding with crushed stone to avoid rutting the road surface, also, energy absorbers such as rip rap and, in some cases, a level area should be installed at the outfall of the dip to reduce water velocity thus assuring no erosion of cast materials.

With both types of dips, neither the dip nor the hump should have a sharp, angular break, but should be rounded to allow smooth flow of traffic. Properly constructed dips require minimal annual maintenance and continue to function years after abandonment.

You can get a copy of the blue book at yourlocal Texas Forest Service office or you can view it online at http://txforestservice.tamu.edu/water. If you have any questions regarding BMPs please contact me.

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

BMP Trivia Question

Streams are classified into 3 categories; perennial, intermittent, and ephemeral. Knowing the difference between these three categories can mean the difference in leaving an SMZ or not. Can you match the definitions (A,B,C) to the stream categories listed below? (Hint) All of these stream types are defined in the BMP handbook.


 _______ Perennial Stream                   
 _______ Intermittent Stream
 _______ Ephemeral Stream



A. Drain that carries water less than 30% of the year and water flow is usually rain-dependent. An SMZ may need to be left but is not always necessary.

B. A stream that flows 90% of the year or more in a continuous, well-defined channel. An SMZ should be left.

C. A stream that flows 30-90% of the year in a continuous, well-defined channel. An SMZ should be left.


Click on "comments" below and post your answers.

December BMP Q&A

By: Jake Donellan, BMP Forester (Ret.), Texas Forest Service

Q: I am an industry forester and my company believes in and adheres to the Texas forestry BMP guidelines. I am conducting a harvest in a bottomland area and need some clarification on a specific situation we have encountered. Years ago when this stand was planted, the land was low and saturated for long periods of time so we installed drainage ditches to help get the stand established. These ditches have, over the years, apparently become the primary drains for this area of land. These ditches carry water most of the year and now they look more like streams than ditches. My question is, "Do we need to protect this ditch/stream with a streamside management zone (SMZ) or is it still just a ditch?"

A: Wow, this sounds like a complicated situation you have on your hands. The first thing I would recommend on a situation like this is that you find out if you are operating in a wetland. If you are not sure, you can always ask for assistance from the Natural Resource Conservation Service (NRCS formerly the Soil Conservation Service or SCS). Those folks are experts in the area of wetland delineation and should be able to tell you for sure if you are operating in a wetland. The reason this is important is because there are 15 mandatory road BMPs that you must follow when operating in a wetland. Those 15 mandatory BMPs can be found in the bluebook in the Forest Wetlands section on pages 93 & 94.

This is an interesting situation and it is difficult to make recommendations without visiting the site for myself however, this is an area that is covered in the bluebook. The Forest Wetlands section mentioned previously also covers drainage ditches (on page 92). The book says,

"Drainage ditches that were formerly natural streams and have dredged and/or straightened need the protection of an SMZ only if they meet the flowing water criteria for a perennial or intermittent stream."

You may or may not know whether these ditches were formerly natural streams but, based on the situation you described, it sounds like you have, at the very least, an intermittent stream. An intermittent stream is defined as a stream that flows for at least 4 months of a typical year. Given that you have what sounds like an intermittent stream then I would say that you should leave an SMZ. Since this ditch has apparently become the natural stream then it should definitely be protected by a SMZ.

You can get a copy of the Blue book at your local Texas Forest Service office or you can view it online at http://txforestservice.tamu.edu/water. If you have any questions regarding BMPs please contact me.

* This article was published in the December 2003 issue of the Texas Logger

BMP Trivia Question

The BMP handbook contains plenty of useful information including a helpful Culvert Sizing Chart. Using that chart, what is the proper culvert diameter needed at a crossing that drains 75 acres on light, sandy soils, and that has an average slope of 10%?

Click on "comments" below and post your answers.

BMP Informer - October 2003

October Issue of the BMP Informer Now Available

• Remember BMPs When Planting
• Seedlings On-line!
• Improving My Land - Permanent Stream Crossings
• How Do I Know What Size Culvert I Should Use?
• Forestry and Water Quality Protection in East Texas
• Culvert Installation

October BMP Q&A

By: Jake Donellan, BMP Forester (Ret.), Texas Forest Service

Q:   I recently got a chemical applicator’s license and plan on offering chemical site preparation to landowners as part of my service. I don’t have a pilot’s license, so all of the site prep will be done from the ground with an ATV and a skidder modified for chemical applications. Are there any special BMPs that I need to follow when I spray?

A:   As many of you probably guessed, there is a section in the Bluebook that deals the application of silvicultural chemicals. Silvicultural Chemicals are addressed in section 8.0 and begin on page 24 of the Bluebook. This section provides information on both ground and aerial application of chemicals.

The first thing you want to do is to familiarize yourself with the chemical’s characteristics. You should read the label and the Materials Safety Data Sheet (MSDS) for the chemical you are working with and follow all instructions. The next part of the planning process is to be familiar with the topography, soils, and drainage pattern of the land you will be working on in addition to any other factors that might be important for preventing water pollution during application.

You need to inspect your equipment for leaks. Leaks can lead to areas of high concentration of the chemical you are using and present a danger of direct chemical application into surface waters.

During ground application, carefully plan applications to avoid direct and indirect entry of chemicals into streams and other impoundments. Use extreme caution in areas immediately adjacent to open water. Special care should be taken when chemicals are used in the streamside management zone (SMZ). Avoid applying chemicals to vegetation protecting eroded slopes, gullies, drainages, and other fragile areas subject to erosion. Exercise care not to exceed intended or allowable dosages. Avoid chemical application during windy conditions that may cause unintended drift.

Aerial application guidelines are very similar to those of ground application. When conducting an aerial application you should also carefully plan application to avoid direct and indirect entry of chemicals into streams and other water bodies. Leave well-marked buffer zones between the target area and surface water. Realize that significant portions of the SMZ will probably be left untreated. Chemicals should not be applied when stream pollution is likely to occur through aerial drift. A spray device capable of immediate shutoff should be used. Shut off chemical application during turns and over open water.

During any type of application of chemicals, should a spill occur, shovel up a dike around the spill. Use absorbent materials (kitty litter, slaked lime, sawdust, soil, etc.) to soak up fluids. Keep the spill from flowing into streams or bodies of water. Some spills will require that you notify the appropriate authorities.

You can get a copy of the Bluebook at your local Texas Forest Service office or you can view it online at http://txforestservice.tamu.edu/water. If you have any questions regarding BMPs please contact me.

* This article was published in the October 2003 issue of the Texas Logger