Texas A&M Forest Service: Water Resources

Monday, November 1, 2010

The Texas Water Source - November 2010

November Issue of the Texas Water Source Now Available

November BMP Q&A

By: Chuck Coup, BMP Forester (Ret.), Texas Forest Service

Q: The Blue Book mentions rutting on roads but not so much about rutting in the harvest area. Are there BMP guidelines for rutting that apply across the harvest area as well? What are the concerns for rutting in the harvest area and how would you evaluate a site if you were conducting a voluntary site evaluation?

A: Great question, and one that could really use some clarification, especially as we move into the wet season!

Rutting is one of those situations where everybody loses. A skidder slogging through the mud certainly does not increase the efficiency of a logger’s operation, and landowners know that extensive rutting can lead to erosion and soil compaction, which can have a substantial impact on future tree growth. Rutting can also lead to environmental and water quality issues, especially if it occurs on steep slopes.

Rutting generally results from the tires of vehicles such as skidders, log trucks, pickups, ATVs, etc., operating under wet conditions. Most of the rutting occurring in the harvest area (i.e., off the established roads) will be caused by skidder traffic and to a lesser degree the shear. The BMP guidelines do not specifically mention the shear, but it would be considered part of the skidding operation since it travels over essentially the same area.

So, are there guidelines that cover rutting in the harvest area? I think that question can be answered by mentioning one point; skidding operations occur on skid trails. Skid trails are defined as a route over which logs are moved to a landing or road. So if a skidder passes over an area, any rutting that it causes would be considered occurring on a skid trail, and therefore be addressed by BMPs for skid trails. Make sense?

Rutting on skid trails is covered under the recommended specifications for skid trails in Part II of the Blue Book. The guidelines recommend that when soils are saturated, skidding should be restricted to prevent excessive soil compaction and channelized erosion. The general rule of thumb for determining excessive rutting is no deeper than six inches for no more than 50 feet (or about two skidder lengths). That comes from number 18 under the recommended specifications for haul roads in your BMP Blue Book. Certainly there are things you can do to minimize rutting during your operation. Using high flotation tires, keeping skidder loads light, or shovel logging extremely wet sites are all possible options.

But, don’t get the impression that when we do a site evaluation we come with ruler and tape measure in hand ready to measure every rut we see. Remember that BMP guidelines are for reducing impacts to water quality. When determining if rutting is too extensive, there are several factors to consider. Look to see if the ruts will change the direction of water flow, or cause it to puddle the next time it rains. Soil type and slope are both very important factors to consider. Look to see if the ruts will in some way channel rainwater so that it may deliver sediment to a stream. If you notice these things happening, then it may be time to head to drier ground. Our evaluations take the entire site into consideration, so if it is obvious to us that you pulled off when you noticed rutting started to occur, our evaluation will certainly reflect that.

For more information on BMPs visit the Texas Forest Service webpage at http://txforestservice.tamu.edu/water, contact me at (936) 639-8180.

* This article was published in the November 2010 issue of the Texas Logger

Friday, October 1, 2010

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. Which of the following characteristics are fairly unique to intermittent streams?

A. Soils with gray colors down to a depth of 24 inches with a loamy to clay texture.
B. A channel that is almost always sinuous.
C. Evidence of leaf litter and/or small debris jams in the flow area.
D. Water pools absent during dry conditions but present during wet conditions. E. Considered “waters of the United States."

Click on "comments" below and post your answers.

Wednesday, September 1, 2010

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

Sunday, August 1, 2010

The Texas Water Source - August 2010

August Issue of the Texas Water Source Now Available

August BMP Q&A

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

Q: I have a tract of timber which was clearcut last fall. The logger who harvested the tract did a bang up job on installing necessary BMPs where they were needed. My consulting forester has recommended that I conduct a site preparation burn later this summer to prepare the site for planting. The tract has a stream on it that usually runs for about 3 months in a typical year. Are there any special BMPs in regards to prescribed burning that should be implemented to ensure the water quality of the stream is not adversely affected?

A: Glad to hear that you were happy with the job your logger did in implementing BMPs where they were needed. Prescribed burning can be a beneficial management tool when used properly with trained personnel. Site preparation burns are often the hottest type burn and can remove a substantial amount of the surface organic material. This type of burn would have the greatest potential for increased surface runoff or soil erosion, particularly on steeper slopes. Use the following guidelines to help reduce the risks to water quality and soil erosion on your tract.

Site preparation burning creates the potential for soil movement. A significant amount of soil movement can be caused by the preparation for the burns, i.e., firebreaks. Firebreaks should have water control structures that divert runoff away from water bodies in order to minimize erosion. Site prep burns on steep slopes or highly erodible soils should only be conducted when they are absolutely necessary and should be as "cold" as possible. Stabilize and revegetate firelines, if needed, on grades in excess of 5% or areas subject to accelerated erosion or known sensitive areas.

Firelines should be constructed on the perimeter of the burn area and along the boundary of the Streamside Management Zone (SMZ). The purpose of protecting the SMZ from fire is to safeguard the filtering effects of the litter and organic matter. All efforts should be made to minimize the impact from site-prep burning within an SMZ. Firelines should follow the guidelines established for logging trails and skid trails with respect to waterbars and wing ditches, and should be only as wide and as deep as needed to permit safe site preparation burns. Firelines which may cross a drainage should be turned parallel to the stream or have a wing ditch or other structure allowing runoff in the line to be dispersed rather than channeled directly into the stream.

Finally, make plans to maintain your firelanes after the burn has been completed. Firelanes on highly erodible sites or other problem areas should be inspected periodically to correct erosion problems by installing dips, wing ditches, waterbars, etc. and/or by seeding. Mowing, rather than blading, should be used to maintain firelanes in order to avoid exposing mineral soil to potential erosion.

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 August 2010 issue of the Texas Logger

Thursday, July 1, 2010