North Carolina

Sediment Controls Installed along Timbered Branch -
Common Sense Practices for Forest Roads

In 1992, the North Carolina Division of Water Quality asked the U.S. Forest Service to design simple, effective, low-cost methods for reducing chronic sediment loading from streamside gravel roads and to apply these best management practices on a demonstration site in the Nantahala National Forest. A section 319 program grant accompanied the request.

Project description

Timbered Branch, a tributary to Upper Creek in the Catawba basin, is closely paralleled for over two miles by Forest Service Road (FSR) 982, a historic travelway stabilized with gravel. Seven practices were used along this stretch of FSR 982 to infiltrate road runoff or reduce its sediment content. The best management practices (BMPs) were field-designed in less than a day, and all were easy to construct. They were able to capture about two- thirds of the road runoff, and effectively controlled sediment.

Common sense was the rule in applying the BMPs. For example, ditch outlets with or without sediment traps effectively dispersed concentrated ditch flow and runoff from trenched roads into available roadside infiltration areas. Weeps accomplished the same task on bermed roads.

Sediment traps were a useful option when distance to the stream channel was limited. Berms kept runoff on the roads until it reached a safe disposal area. Outslopes were used to allow sheet flow to adjacent infiltration areas. Humps diverted flow on down-sloping road surfaces. Quantitatively, the best management practices included 28 weeps, 19 sediment traps, 14 ditch outlets, 10 outslopes, nine berms, seven relief culverts, and five humps.

High ratings for Timbered Branch

Biological monitoring performed by the Division of Water Quality a year after the BMP installations showed improvement in water quality compared to a control stream and to two sampling events before BMP installation.

Benthic macroinvertebrate and total taxa richness values increased (from 38 to 48 and from 74 to 79, respectively); the biotic index value also improved, dropping from 3.01 to 2.68 on a scale of 10 to 1. Thus, largely as a result of the roadway BMPs, Timbered Branch received an excellent biological rating.

This rating creates the potential for including Timbered Branch in the Outstanding Resource Waters (ORW) supplemental classification currently in place on the rest of Upper Creek and its tributaries. An ORW classification can be considered if an outstanding trout population or fisheries habitat can be documented. At this time, fisheries monitoring has not been conducted.

Moving on

Since conducting the Timbered Branch project, the Forest Service has successfully used these techniques in other road reconstruction projects in North Carolina and Georgia, and has transferred the technology to other land managers, including a demonstration project in Mexico. A nontechnical pamphlet, Road Runoff Control, describing the method is available from either the Forest Service in Asheville, North Carolina, or the Division of Water Quality in Raleigh.

Practice Makes Perfect - The Long Creek Watershed Project

Land-use patterns in the Long Creek watershed in the southwestern Piedmont of North Carolina are agricultural, urban, and industrial. Nonpoint source pollution from all three sectors are a potential threat to Long Creek, which is a perennial stream and the primary water supply for Bessemer City (population about 4,888).

The Long Creek Watershed Project in Gaston County, North Carolina, began in 1994. The goal is to accelerate the implementation of best management practices (BMPs) that the Long Creek Nonpoint Source Monitoring Program Project had initiated in fiscal year 1992.

A major component of the watershed project is to quantify the effect of BMPs on water quality. BMPs that prevent or treat nonpoint source pollution have been developed to reduce nutrient and sediment loading to rivers and streams. These BMPs include nutrient management, waste management, livestock exclusion, riparian buffer restoration, field borders, grassed waterways, conservation tillage, urban stormwater wetlands, and waste storage structures.

Whether it is a farmer planting a vegetative buffer along a stream or a homeowner properly disposing of pesticides, these practices implemented by entire watershed communities over a period of time should reduce pollution and improve our environment. The following BMPs have been implemented:

• Three dairy farms (representing 75 percent of the watershed's dairies) have fenced their livestock or otherwise excluded them from the stream, installed alternative watering systems, stabilized streambanks, established riparian buffers, and used level spreaders, stream crossings, and proper nutrient and waste management practices.

• Two beef farms (representing about 20 percent of this industry) have fenced their livestock or otherwise excluded them from the stream, installed alternative watering systems, stabilized streambanks and established riparian buffers, and implemented proper nutrient and waste management.

• One horse farm (a boarding stable representing about 80 percent of this industry), has fenced its livestock or otherwise excluded them from a pond and stream, installed alternative watering systems, established riparian buffers, and implemented proper nutrient and waste management.

• One urban watershed site has been selected as a best management practice demonstration site. Its BMPs include streambank stabilization, construction of a stormwater wetland, and pollution prevention through education.

At least one value judgment follows from these figures, namely, that landowners in the watershed are keenly interested in participating in the project.

Phosphorus levels decline

Initial results illustrate that pathogens, nutrients, and sediment concentrations have decreased considerably since the installation of BMPs. The Kiser Dairy Farm was selected as a monitoring site to evaluate the effect of waste management and a riparian vegetated buffer on pathogens, nutrients, and sediment.

Weekly grab samples have been taken for the months of February through June since 1994 for total Kjeldahl nitrogen (organic nitrogen plus ammonium), total phosphorus, and total suspended solids. Organic nitrogen concentrations downstream of the farmstead have decreased considerably since the installation of the livestock exclusion fence in February 1996.

Similar decreases in total phosphorus and total suspended solid concentrations have also occurred. Before BMP installation, total phosphorus averaged above 0.5 mg/L and at least 20 mg/L for total suspended solids. After BMPs were installed, total suspended solids were slightly lower at downstream sites than at upstream sites. Total phosphorus levels downstream were at least 50 percent lower than those reported the previous year.

These improvements can be attributed to fencing out livestock and providing an alternate drinking water source for the cattle. Fencing out livestock prevents trampling, allows natural and planted vegetation to stabilize the soil in highly eroded areas, and ultimately results in less solids and sediment in the water. The combination of fencing and vegetative enhancement promises further improvements in the watershed.

Teaching watershed protection

The Long Creek project includes a strong education and community outreach program. Educational programs include an annual tour of the watershed and project sites and a workshop to update funding agencies, local officials, community leaders, scientists, engineers, environmental educators, and citizens. Nearly 80 individuals attended the third annual workshop in 1996.

Specific technical workshops are occasionally scheduled to teach bioengineering techniques for BMP implementation, monitoring designs for BMP evaluation, data analyses techniques, and water quality education programming.

Other educational events are scheduled periodically to publicize the project, encourage stewardship, and promote the use of BMPs. For example,

• A Stream Watch team was organized to expand monitoring in other watersheds within the county. Volunteers conduct stream monitoring on a monthly basis.
• One-on-one visits with watershed landowners provide technical assistance with BMP implementation.
• Water quality programs tailored to elementary, junior high, and high schools actively involve students in learning environmental stewardship. In 1996, 77 environmental education classes were taught to 2,011 students.

Forestry Nonpoint Source Pollution Management

In 1989, the North Carolina legislature amended the Sedimentation Pollution Control Act to limit its forestry exemption to only those operations that adhere to forest practice guidelines. The amendment required the Division of Forest Resources to develop performance standards known as the Forest Practices Guidelines Related to Water Quality.

Put into effect on January 1, 1990, the guidelines are nine performance standards for activities such as maintaining streamside management zones and applying fertilizers and pesticides. They are used to help the forest industry understand how its activities can be managed to control nonpoint sources in downstream waters. They can also determine if a forestry operation falls under the jurisdiction of the Division of Land Resources, which enforces the Sediment Pollution Control Act.

Memoranda of Agreement (MOAs) have been signed between the departments of Forest Resources and Land Resources and the Division of Water to coordinate their respective activities in the sedimentation control program. The Division of Water is the state's primary water quality agency, coordinating enforcement activities from a water quality perspective.

Site-disturbing forestry activities are inspected by local Forest Resources personnel as part of an ongoing training, mitigation, and monitoring program. Additional site inspections are conducted when a problem or potential problem is suspected. Forest Resources refers sites not brought into compliance within a reasonable time to Land Resources or the Division of Water Quality for appropriate enforcement action. The Division of Water Quality has an ongoing monitoring program in support of the Forest Practice Guidelines. This program has conducted 14,542 site evaluations since its inception in 1989. In recent years, the number of evaluations has averaged about 3,000 per year. In fiscal year 1995, 3,318 site evaluations were conducted, yielding 94.2 percent compliance and 9 enforcement referrals to the Division of Land Resources.

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