Streamside Management Zones
An effort has been made to italicize technical words or phrases and clearly define them in the glossary.
Land adjacent to perennial, intermittent, and ephemeral streams and ponds or lakes requires special attention during forestry operations. These Streamside Management Zones (SMZs) are critical areas where NPS pollutants can enter the aquatic system .
- Perennial streams are identified by well-defined banks and natural channels, and have continuously flowing water most years.
- Intermittent streams also have well-defined banks and natural channels, but typically have flowing water from a headwater source for only a portion of the year.
- Ephemeral streams generally do not have well-defined channels, and flow only in response to localized precipitation.
Identifying the type of stream is important in prescribing the level of streamside protection. Usually a landowner or manager will be most familiar with a stream's flow characteristics and can make the determination. However, in some situations the landowner or manager may be uncertain or have little knowledge of a stream's flow characteristics. For example, braided streams with multiple interconnected channels can be difficult to identify. In these situations a licensed forester or other qualified professional should be consulted.
The SMZ is divided into two parts: the primary and the secondary. The primary SMZ is 40 feet wide on each side of the stream, except for designated trout waters with slopes greater than 5% where the primary SMZ is 80 feet. The width of the secondary SMZ depends on the average percent slope perpendicular to the stream. Minimum required widths of secondary SMZs under various conditions are listed in Figure 2.
Forest management activities are restricted within both the primary and secondary SMZs. These restrictions are listed below.
Perennial and Intermittent Streams
- On perennial streams, select individual trees for harvest, making sure to leave a minimum of 50 square feet of overstory basal area per acre evenly spaced throughout the zone. Leave all trees if less than 50 square feet of overstory basal area per acre exists. The intent is to maintain sufficient overstory and understory cover to provide shade, maintain bank stability, and protect water quality.
- On intermittent streams, permanent residual tree cover is not required as long as other vegetation and organic debris are left to protect the forest floor and stream banks.
- Fell trees away from the stream except where safety is a concern.
- Remove trees in a manner that minimizes disturbance of the forest floor, exposure of mineral soil, or degradation of stream bank stability. Under dry ground conditions, directional felling and removal of trees with mechanical equipment may be utilized.
- Hand plant or direct seed where artificial regeneration is desired.
- Remove tops or other logging debris dropped into stream channel.
- Handle and store toxic and hazardous material such as fuels, lubricants, and solvents outside of the SMZ.
- Logging debris in the stream.
- Mechanical site preparation or machine planting.
- Portable sawmills or log decks.
- Broadcast application of any pesticide
- Road construction except where necessary for stream crossing.
Perennial and Intermittent Streams
- Use all types of silvicultural harvest systems.
- Use site preparation practices that do not significantly disturb surface soil.
- Hand or machine plant or direct seed.
- Carefully use wheeled or tracked vehicles.
- Handle and store toxic and hazardous materials such as fuels, lubricants, and solvents outside of the SMZ.
- Portable sawmills and log decks.
- Road construction, except where necessary for stream crossing.
- Excessive rutting, especially where ruts run perpendicular to a stream.
- Exposing more than 15% of the mineral soil.
|Percent Slope Perpendicular to Stream||Width of SMZ on each side (feet)|
|Less than 5%||40||Trout|
|5% - 20%||40||80||40|
|21% - 40%||40||80||80|
|Greater than 40%||40||80||120|
Figure 2. Recommended primary and secondary Streamside Management Zone (SMZ) widths for perennial and intermittent streams.
Ephemeral streams generally flow in the upper reaches of a watershed following precipitation. Although well-defined channels may be present in unique situations, ephemeral streams (commonly referred to as drains) rarely carry enough runoff to displace soil, but they may displace the litter on top of the soil. They do flow directly into intermittent and perennial streams. Therefore, the forest floor in ephemeral areas should be protected so that sediment can be filtered out before runoff enters the watercourse. Handle and store toxic and hazardous material such as fuel, lubricants, and solvents outside the ephemeral area.
- Portable sawmills and log decks within the drain.
- Skidding logs during wet conditions within the drain except at infrequent planned crossings.
- Site preparation practices that significantly disturb the soil within the ephemeral area.
- Applying pesticides or fertilizers if surface water is present.
- Altering the flow of the runoff.
- Road construction except where necessary for crossings.
- Emptying road runoff directly into drains.
Trout require cool, clear streams. They, and the aquatic insects they feed on, are especially sensitive to increased sedimentation. Since South Carolina is near the southern limit of the trout's range, water temperature is also a critical factor. It is therefore important to take special precautions to minimize sedimentation and to maintain a shade cover to prevent excessive warming of the water.
- Increase the width of the primary SMZ from 40 feet to 80 feet on slopes over 5%.
- Drain water from roads and skid roads onto ridges and side slopes. Drainage structures should not divert water directly into streams.
- Revegetate exposed soils within the SMZ following road construction as soon as possible to take advantage of the loose soil conditions for seeding.
- Use mulch, gravel, and/or rock if needed to help stabilize fills where roads and skid roads cross streams.
Trout Waters in South Carolina
|Cox Camp Creek||Greenville||The entire creek tributary to the Middle Saluda River|
|East Fork Chattooga River||Oconee||That portion of the river from its confluence with Indian Camp Branch to the Chattooga River|
|Emory Creek||Pickens||The creek from the northern boundary of Table Rock Resort property to its confluence with the Oolenoy River|
|Lake Jocassee||Oconee||The entire lake|
|Matthews Creek||Greenville||From the end of State land in the Mountain Bridge Area to its confluence with the South Saluda River|
|Saluda River (main stem)||Lexington/Richland||That portion from the Lake Murray Dam to the confluence with the Broad River|
|Savannah River||Abbeville||From Lake Hartwell Dam to the head waters of Lake Russell|
|Swaford Creek||Oconee||The entire creek tributary to East Fork Chattooga River|
|Whetstone Creek||Oconee||The entire creek tributary to the Chattooga River|
|Willis Creek||Pickens||The creek from the northern boundary of Table Rock Resort property to its confluence with the Oolenoy River|
Stream Crossings / Forest Road Construction / Timber Harvesting / Site Preparation / Reforestation / Prescribed Burning / Pesticides / Fertilization / Minor Drainage / Endangered Species Act / Additional Management Options: Wildlife Management / Glossary