March BMP Q&A

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

Q:  I have a client in East Texas whose timberland was damaged by the 2011 fires. The streamside management zones (SMZs) were damaged as well, and I am trying to give some advice on restoring these areas in order to continue protecting water quality. Would it be better to allow these areas to naturally heal or should I recommend taking action? 

A:  That is a really good question, and I would imagine that many of you might have been wondering the same thing.  As we all know, the two primary purposes of an SMZ are to reduce or eliminate the potential for nonpoint source pollution, like sediment and logging debris, from reaching streams, and to maintain cool water temperatures. Of course, they also provide other important benefits like maintaining the integrity and function of the stream, providing habitat and cover for wildlife, and helping with the aesthetics of the site. We all know that SMZs are important areas that serve important functions, so what do we do if they are burned in a wildfire?  Do we stand back or take action?

It can be a tricky situation, so here is what I would suggest:

First, start by making an initial assessment of the impacted SMZ to determine the severity of the damage, the density of surviving trees, the potential for regeneration, and the immediate threat to water quality. Once you have done that, you just might have enough information to conclude that the SMZ can heal itself on its own in a reasonable amount of time. That would certainly be the case in less severely burned areas where the basal area of surviving trees is at or near the recommended 50 square feet per acre and evenly distributed (refer to your BMP handbook if you need a refresher on basal area), the SMZ is still at least 50 feet wide on either side of the stream channel, the canopy trees are mostly intact or likely to survive, new tree seedlings and other vegetation are sprouting across the ground, and erosion does not appear to be a significant problem. However, these can be very tricky things to judge, especially if you don’t have much experience. In that case, I would certainly recommend getting some help from a professional forester.

In some situations it might be necessary to salvage at least part of the SMZ and possibly even replant it. This might be the case where the fire was severe, killing most of the trees and leaving very little vegetation, the SMZ does not appear to be re-growing on its own, and the lack of vegetation has led to substantial erosion concerns. Again, get help from a professional forester if you are unsure. If salvage and artificial regeneration are necessary I would strongly recommend that you take appropriate precautions and follow all applicable BMPs. Be especially careful to minimize the amount of ground disturbance resulting from your operations. As always, keep haul roads, skid trails, and landings outside the SMZ and avoid or minimize stream crossings. Trees and tops should not be felled across or pushed into the channel, and every effort should be made to protect and leave trees in the SMZ that are not severely damaged.

If re-planting is deemed necessary after evaluating the regeneration potential of the SMZ, then site preparation and machine planting should be avoided within the SMZ. When replanting, every effort should be made to ensure that the number of seedlings planted will meet the minimum recommended basal area of 50 square feet per acre and that the SMZ will encompass the standard 50 foot width on either side of the stream channel. Herbicide and fertilizer use should be limited within the SMZ and applied with extreme caution. Seeding or other erosion control practices could be installed to temporarily control short-term erosion issues until the SMZ becomes re-established.

The initial assessment should help you decided on a strategy for restoring the various conditions across the SMZ. In some situations it might make sense to stand back and let nature take its course, while prudent management might be appropriate for others. Either way, make sure you consider the potential impacts to water quality and follow all appropriate Best Management Practices. For a copy of the BMP handbook visit your local Texas Forest Service office or view online at http://txforestservice.tamu.edu/water.  For questions regarding repairing damaged SMZs or BMPs in general please contact me by calling (936) 639-8180. 

*This article was published in the March 2012 issue of the Texas Logger