Protecting water quality during a timber harvest isn’t always straightforward. Access roads, which allow log trucks to reach the landing, sometimes follow the stream channel up the valley. These valley bottom roads followed stream channels to avoid steep side-hill construction. The problem is that roads are effective conduits for surface runoff and sediment, and for valley bottom roads, runoff has a short path to the stream. One could build a new road section further upslope, but this creates additional soil disturbance and the added cost could make logging unprofitable for a small woodlot.
In early December 2018, I visited a logging site near Hamden, NY that posed such a challenge. The timber harvest was just starting and it would take roughly 1.5 months to complete. Some 40 truckloads would need to come down the valley bottom road, which included one ford stream crossing. On frozen ground, this access route had minimal water quality risks, but we know better than to expect frozen ground conditions for 6 weeks straight. A key component of logger economic viability is having access roads, skid trails, and landings that are built to keep production going and protect water quality during adverse weather.
Road conditions were muddy when logging started in early December 2018. Visible ruts and sediment pathways to the stream were evident after only a handful of truckloads had come off the hill.
With these things in mind, WAC’s Forestry Program team discussed what could be done. Research has shown that problem roads for water quality have some common characteristics. They include being too steep, having poor water control, and/or inadequate surface cover. Re-locating this road segment was problematic because logging had already started and the proposed re-route would have required the neighboring landowner’s permission to send log trucks over their driveway. Similarly, water control was difficult due to the road’s proximity to the stream. Surface cover was the main thing that we could change in this situation.
We decided to use geotextile fabric and gravel on soft road segments or otherwise sensitive areas, such as the stream crossing approaches. The geotextile acts as a separation layer between the gravel and the soft ground. Otherwise, the gravel would simply be pushed down into the soil under loading. We also used seven water bars to control surface runoff volume in small amounts, thereby preventing scouring of the road surface.
Geotextile fabric was used as a separation layer between the original road surface and fresh gravel layer.
Straw wattles were placed in the outlets of water bars during geotextile installation and gravel application. Note that conditions were quite wet during BMP installation.
Gravel spreading began at the start of the access road, working towards the landing at the top of the hill. Here, the driver is beginning to back over a section of geotextile fabric in preparation for a downhill dump. Each gravel truck carried 15 yards of gravel.
It took 2.5 work days to install the BMPs. About 180 yards (twelve truckloads) of gravel were used to surface 800 ft of road. WAC Watershed Foresters Karl VonBerg, Andrew Krutz, and I worked with logger Keith Clark to lay the geotextile fabric and place straw wattles at the outlets of the water bars to trap sediment coming off the road. Keith used a bulldozer to build the water bars and to uniformly distribute and compact the gravel layer. Keith completed an application to WAC’s BMP cost-share program for technical and financial assistance to implement these BMPs. Keith will be reimbursed around $6000 for this project. As a Trained Logger Certified (TLC) Logger, Keith gets better cost-share rates on BMPs like water bars and regrading (i.e. removing ruts from) skid trails. The WAC Forestry Program cost-shares around 45 BMP projects annually.
This project was successful in that we worked with an innovative, water quality-conscious logger to upgrade a difficult truck road. The geotextile and gravel helped the road to support log truck traffic during the harvest. As such, the road was in good condition at the end of the harvest. Also, by implementing BMPs on site with the logger, we can learn a lot about things like BMP effectiveness to protect water quality, time and effort required to implement BMPs, and how BMPs affect logging productivity and economic viability.
The uphill stream crossing approach before (top) and after (bottom) it was upgraded with gravel and geotextile. Photos were taken in early December 2018 and mid-Jan. 2019, respectively. These BMPs improved the road’s ability to support logging truck traffic and helped to reduce erosion.
A water bar before (top photo) and after (bottom photo) it was upgraded with gravel, geotextile fabric, and a straw wattle.
Implementing these BMPs was not without impact, however. Gravel application occurred during wet conditions that were not ideal for compacting the road and keeping sediment out of the stream. Also, Keith Clark’s logging production likely took a dive over the 2.5 days that he helped to implement BMPs. Looking to the future, we think that an improved process involves: 1) identifying woodlot harvests having high-risk infrastructure (i.e. truck roads and skid trails next to streams); 2) knowing when loggers plan to start logging those potential problem sites; and 3) upgrade problem roads and trails during the right soil moisture conditions and well before logging starts. When it comes to protecting water quality during a timber harvest, pre-harvest planning is arguably the most important BMP.
If you are a landowner interested in learning more about protecting your roads, trails, and streams during logging, check out MyWoodlot.com. If you are a logger interested to learn more about WAC’s BMP cost-share program, click here: https://www.nycwatershed.org/bmp-program.