Water: Coastal Zone Act Reauthorization Amendments
II. Forestry Management Measures - A. Preharvest Planning Management Measure
Perform advance planning for forest harvesting that includes the following elements where appropriate:
- Identify the area to be harvested including location of waterbodies and sensitive areas such as wetlands, threatened or endangered aquatic species habitat areas, or high- erosion-hazard areas (landslide-prone areas) within the harvest unit.
- Time the activity for the season or moisture conditions when the least impact occurs.
- Consider potential water quality impacts and erosion and sedimentation control in the selection of silvicultural and regeneration systems, especially for harvesting and site preparation.
- Reduce the risk of occurrence of landslides and severe erosion by identifying high-erosion-hazard areas and avoiding harvesting in such areas to the extent practicable.
- Consider additional contributions from harvesting or roads to any known existing water quality impairments or problems in watersheds of concern.
Perform advance planning for forest road systems that includes the following elements where appropriate:
- Locate and design road systems to minimize, to the extent practicable, potential sediment generation and delivery to surface waters. Key components are:
- locate roads, landings, and skid trails to avoid to the extent practicable steep grades and steep hillslope areas, and to decrease the number of stream crossings;
- avoid to the extent practicable locating new roads and landings in Streamside Management Areas (SMAs); and
- determine road usage and select the appropriate road standard.
- Locate and design temporary and permanent stream crossings to prevent failure and control impacts from the road system. Key components are:
- size and site crossing structures to prevent failure;
- for fish-bearing streams, design crossings to facilitate fish passage.
- Ensure that the design of road prism and the road surface drainage are appropriate to the terrain and that road surface design is consistent with the road drainage structures.
- Use suitable materials to surface roads planned for all-weather use to support truck traffic.
- Design road systems to avoid high erosion or landslide hazard areas. Identify these areas and consult a qualified specialist for design of any roads that must be constructed through these areas.
Each State should develop a process (or utilize an existing process) that ensures that the management measures in this chapter are implemented. Such a process should include appropriate notification, compliance audits, or other mechanisms for forestry activities with the potential for significant adverse nonpoint source effects based on the type and size of operation and the presence of stream crossings or SMAs.
This management measure pertains to lands where silvicultural or forestry operations are planned or conducted. The planning process components of this management measure are intended to apply to commercial harvesting on areas greater than 5 acres and any associated road system construction or reconstruction conducted as part of normal silvicultural activities. The component for ensuring implementation of this management measure applies to harvesting and road construction activities that are determined by the State agency to be of a sufficient size to potentially impact the receiving water or that involve SMAs or stream crossings. On Federal lands, where notification of forestry activities is provided to the Federal land management agency, the provisions of the final paragraph of this measure may be implemented through a formal agreement between the State agency and the Federal land management agency. This measure does not apply to harvesting conducted for precommercial thinning or noncommercial firewood cutting.
Under the Coastal Zone Act Reauthorization Amendments of 1990, States are subject to a number of requirements as they develop coastal nonpoint source programs in conformity with this measure and will have some flexibility in doing so. The application of this management measure by States is described more fully in Coastal Nonpoint Pollution Control Program: Program Development and Approval Guidance, published jointly by the U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Department of Commerce.
The objective of this management measure is to ensure that silvicultural activities, including timber harvesting, site preparation, and associated road construction, are conducted without significant nonpoint source pollutant delivery to streams and coastal areas. Road system planning is an essential part of this management measure since roads have consistently been shown to be the largest cause of sedimentation resulting from forestry activities. Good road location and design can greatly reduce the sources and transport of sediment. Road systems should generally be designed to minimize the number of road miles/acres, the size and number of landings, the number of skid trail miles, and the number of watercourse crossings, especially in sensitive watersheds. Timing operations to take advantage of favorable seasons or conditions, avoiding wet seasons prone to severe erosion or spawning periods for fish, is effective in reducing impacts to water quality and aquatic organisms (Hynson et al., 1982). For example, timber harvesting might be timed to avoid periods of runoff, saturated soil conditions, and fish migration and spawning periods.
Preharvest planning should include provisions to identify unsuitable areas, which may have merchantable trees but pose unacceptable risks for landslides or high erosion hazard. These concerns are greatest for steep slopes in areas with high rainfall or snowpack or sensitive rock types. Decomposed granite, highly weathered sedimentary rocks, and fault zones in metamorphic rocks are potential rock types of concern for landslides. Deep soils derived from these rocks, colluvial hollows, and fine-textured clay soils are soil conditions that may also cause potential problems. Such areas usually have a history of landslides, either occurring naturally or related to earlier land-disturbing activities.
Potential water quality and habitat impacts should also be considered when planning silvicultural harvest systems as even-aged (e.g., clearcut, seedtree, shelterwood) or uneven-aged (e.g., group selection or individual tree selection) and planning the type of yarding system. While it may appear to be more beneficial to water quality to use uneven-aged silvicultural stand management because less ground disturbance and loss of canopy cover occur, these factors should also be weighed against the possible effects of harvesting more acres selectively to yield equivalent timber volumes. Such harvesting may require more miles of road construction, which can increase sediment generation and increase levels of road management.
In addition, for uneven-aged systems, yarding in moderately sloping areas is usually done with groundskidding equipment, which can cause much more soil disturbance than cable yarding. For even-aged systems, cable yarding may be used in sloping areas; cable yarding is not widely used for uneven-aged harvesting. Whichever silvicultural system is selected, planning will be required to minimize erosion and sediment delivery to waterbodies. Preharvest planning should address how harvested areas will be replanted or regenerated to prevent erosion and potential impact to waterbodies.
Cumulative effects to water quality from forest practices are related to several processes within a watershed (onsite mass erosion, onsite surface erosion, pollutant transport and routing, and receiving water effects) (Sidle, 1989). Cumulative effects are influenced by forest management activities, natural ecosystem processes, and the distribution of other land uses. Forestry operations such as timber harvesting, road construction, and chemical use may directly affect onsite delivery of nonpoint source pollutants as well as contribute to existing cumulative impairments of water quality.
In areas where existing cumulative effects problems have already been assessed for a watershed of concern, the potential for additional contributions to known water quality impairments or problems should be taken into account during preharvest planning. This does not imply that a separate cumulative effects assessment will be needed for each planned forestry activity. Instead, it points to the need to consider the potential for additional contributions to known water quality impairments based on information from previously conducted watershed or cumulative effects assessments. These types of water quality assessments, generally conducted by State or Federal agencies, may indicate water quality impairments in watersheds of concern caused by types of pollutants unrelated to forestry activities. In this case, there would be no potential for additional contributions of those pollutants from the planned forestry activity. However, if existing assessments attribute a water quality problem to the types of pollutants potentially generated by the planned forestry activity, then it is appropriate to consider this during the planning process. If additional contributions to this impairment are likely to occur as a result of the planned activity, this may necessitate adjustments in planned activities or implementation of additional measures. This may include selection of harvest units with low sedimentation risk, such as flat ridges or broad valleys; postponement of harvesting until existing erosion sources are stabilized; and selection of limited harvest areas using existing roads. The need for additional measures, as well as the appropriate type and extent, is best considered and addressed during the preharvest planning process.
Some important sediment sources related to roads are stream crossings, road fills on steep slopes, poorly designed road drainage structures, and road locations in close proximity to streams. Roads through high-erosion-hazard areas can also lead to serious water quality degradation. Some geographical areas have a high potential for serious erosion problems (landslides, major gullies, etc.) after road construction. Factors such as slope steepness, soil and rock characteristics, and local hydrology influence this potential. High-erosion-hazard areas may include badlands, loess deposits, steep and dissected terrain, and areas with existing landslides and are generally recognizable on the ground by trained personnel. Indications of hazard locations may include landslides, gullies, weak soils, unusually high ground water levels, very steep slopes, unvegetated shorelines and streambanks, and major geomorphic changes. Road system planning should identify and avoid these areas.
In most States, high-erosion-hazard areas are limited in extent. In the Pacific Coast States, however, road-related landslides are often the major source of sediment associated with forest management. Erosion hazard areas are often mapped, and these maps are one tool to use in identifying high-erosion-hazard sites. The U.S. Geological Survey has produced geologic hazard maps for some areas. The USDA Soil Conservation Service (SCS) and Agricultural Stabilization and Conservation Service (ASCS), as well as State and local agencies, may also have erosion-hazard-area maps.
Preplanning the timber harvest operation to ensure water quality protection will minimize NPS pollution generation and increase operation efficiency (Maine Forest Service, 1991; Connecticut RC&D Forestry Committee, 1990; Golden et al., 1984). The planning of streamside management area width and extent is also crucial because of SMAs potential to reduce pollutant delivery. Identification and avoidance of high-hazard areas can greatly reduce the risk of landslides and mass erosion (Golden et al., 1984). Careful planning of road and skid trail system locations will reduce the amount of land disturbance by minimizing the area in roads and trails, thereby reducing erosion and sedimentation (Rothwell, 1978). Studies at Fernow Experimental Forest, West Virginia, demonstrated that good planning reduced skid road area by as much as 40 percent (Kochenderfer, 1970).
Designing road systems prior to construction to minimize road widths, slopes, and slope lengths will also significantly reduce erosion and sedimentation (Larse, 1971). The most effective road system results from planning conducted to serve an entire basin, rather than arbitrarily constructing individual road projects to serve short-term needs (Swift, 1985). The key environmental factors involved in road design and location are soil texture, slope, aspect, climate, vegetation, and geology (Gardner, 1967).
Proper design of drainage systems and stream crossings can prevent system destruction by storms, thereby preventing severe erosion, sedimentation, and channel scouring (Swift, 1984). Removal of excess water from roads will also reduce the potential for grade weakening, surface erosion, and landslides. Drainage problems can be minimized when locating roads by avoiding clay beds, seeps, springs, concave slopes, muskegs, ravines, draws, and stream bottoms (Rothwell, 1978).
Developing a process, or utilizing an existing process, to ensure that the management measures in this chapter are implemented is an important component for forestry nonpoint source control programs. While silvicultural management of forests may extend over long stand rotation periods of 20 to 120 years and cover extensive areas of forestland, the forestry operations that generate nonpoint source pollution, like harvesting and road building, are of relatively short duration and occur in dispersed, often isolated locations in forested areas. Forest harvesting or road building operations are usually operational on a given site only for a period of weeks or months. These operational phases are then followed by the much longer period of regrowth of the stand or the rotation period. Since forestry operations are relatively dispersed and move from site to site within forested areas, it is essential to have some process to ensure implementation of management measures. For example, it is not possible to track the implementation of management measures or determine their effectiveness if there is no way of knowing where or when they might be applied. In the case of monitoring or water quality assessments, correlation of water quality conditions to forestry activities is not possible absent some ability to determine where and to what extent forestry operations are being conducted and whether management measures are being implemented. Because of the dispersed and episodic nature of forestry operations, many States have implemented programs that currently incorporate a process such as notification to ensure implementation and to facilitate evaluation of program implementation and assessment of water quality conditions.
This process has been shown to be a beneficial device for ensuring the implementation of water quality best management practices, particularly for forestry activities. In contrast to the typical forestry situation, nonpoint pollution from urban and agricultural sources is generated from areas and activities that are relatively stationary and repetitive. Because of this, these sources of nonpoint pollution are more apparent and readily addressed than more isolated and episodic forestry operations. Given the unique nature of forestry operations, it is necessary for States to have some mechanism for being apprised of forestry activities in order to uniformly address sources of nonpoint pollution.
This Forestry Management Measure component allows considerable flexibility to States for determining how this provision should be carried out in the coastal zone. For the purposes of this management measure, such a process should include appropriate notification mechanisms for forestry activities with the potential for nonpoint source impacts. It is important to point out that for the purposes of this management measure such a notification process might be either verbal or written and does not necessarily require submittal and approval of written preharvest plans (although those States that currently require submittal of a preharvest plan would also fulfill this management measure component for the coastal zone program). States also have flexibility in determining what information should be provided and how this should occur for notification mechanisms. Timing and location of the planned forestry operation are common elements of existing notification requirements and may serve as an acceptable minimum. Existing programs for forestry have found some type of notification of the planned activity to the appropriate State agency to be a very beneficial device for ensuring the implementation of water quality best management practices for silvicultural activities. At least 12 Coastal Zone Management Program States currently require some type of notification, associated with Forest Practices Acts, CWA section 404 requirements, tax incentive or cost share programs, State Forester technical assistance, severance tax filings, stream crossing permits, labor permits, erosion control permits, or land management agency agreements.
3. Management Measure Selection
The rationale for this measure is based on information on the effects of various harvesting practices and the effectiveness and costs of planning, design, and location components addressed in this measure. This measure is also based in part on the experience of some States in using preharvest planning as part of implementation of best management practices.
a. Effectiveness Information
Preharvest planning has been demonstrated to play an important role in the control of nonpoint source pollution and efficient forest management operations. A fundamental component to be considered in timber harvest planning is the selection of the silvicultural system. Research conducted by Beasley and Granillo (1985) demonstrated that selective cutting generated lower water yields and sediment yields than did clearcutting. This is important not only because of the sediment loss, but also because higher stormflows can undercut streambanks and scour channels, reducing channel stability. The data in Table 3-2 show that selective cutting results in sediment yields 2.5 to 20 times less and water yields 1.3 to 2.6 times less than those resulting from clearcutting. As stated previously, the amount and potential water quality impacts of roads needed for each system must also be taken into account.
Methods used for harvesting are closely related to the silvicultural system. Four harvesting methods combined with varying types of management practices to protect water quality, including road location, were compared in a study conducted by Eschner and Larmoyeux (1963) (Table 3-3 (10k)). Harvesting effects on water quality, as measured by turbidity, were shown to be clearly related to the care taken in logging and planning skid roads. The extensive selection method, combined with some NPS controls (20 percent road grade limits, no skidding in streams, water bars on skid roads), produced higher maximum levels of turbidity than did intensive selection with additional control practices (10 percent road grade limits; skid trails located away from streams). Harvesting by the diameter limit practice without any restrictions on road grades or stream restrictions increased maximum turbidity by 200 times over intensive selection, and commercial clearcutting with no controls increased maximum turbidity by over three orders of magnitude. This study concluded that care taken in preharvest planning of skid roads and logging operations can prevent most potential impairment to water quality.
McMinn (1984) compared a skidder logging system and a cable yarder for their relative effects on soil disturbance (Table 3-4). With the cable yarder, 99 percent of the soil remained undisturbed (the original litter still covered the mineral soil), while the amount of soil remaining undisturbed after logging by skidder was only 63 percent. Beasley, Miller, and Gough (1984) related sediment loss associated with forest roads to the average slope gradient of road segments (Table 3-5). The greater the average slope gradient, the greater the soil loss, ranging from a total of 6.8 tons/acre lost when the slope gradient was 1 percent, to 19.4 tons/acre at 4 percent, to 32.3 tons/acre at 6 percent, to 33.7 tons/acre at 7 percent.
Sidle (1980) found that the impacts of tractor skidding can be lessened through the use of preplanned skid roads and landings designed so that the area disturbed by road construction and the overall extent of sediment compaction at the site are minimized. Sidle (1980) described a study in North Carolina that showed that preplanning roads could result in a threefold decrease in soil compaction at the logging area.
Several researchers have emphasized that prevention is the most effective approach to erosion control for road activities (Megahan, 1980; Golden et al., 1984). Because roads are the greatest source of surface erosion from forestry operations, reducing road surface area while maintaining efficient access is a primary component of proper road design. Careful planning of road layout and design can minimize erosion by as much as 50 percent (Yoho, 1980; Weitzman and Trimble, 1952). This practice has the added benefits of reducing construction, maintenance, and transport costs and increasing forested area for production. Rice et al. (1972) found no increase in sedimentation from a well-designed logging road on gently sloping, stable soils in Oregon except for during the construction period.
Locating roads on low gradients is another planning component that can reduce the impacts of sedimentation. Trimble and Weitzman (1953) presented data showing that lower gradients and shorter road lengths reduce erosion. The same authors, in a 1952 journal article, also presented data showing that reduced gradients in conjunction with water bars can significantly reduce erosion from roads. The data from these two studies are presented in Table 3-6.
b. Cost Information
A cost-benefit analysis by Dissmeyer and others (USDA, 1987) reveals the dramatic, immediate savings from considering water quality during the design phase of a road reconstruction project (Table 3-7). Expertise on soil and water protection provided by a hydrologist resulted in 50 percent of the savings alone. Other long-term economic benefits of careful planning such as longer road life and reduced maintenance costs were not quantified in this analysis.
Kochenderfer, Wendel, and Smith (1984) determined the costs for locating four minimum standard roads in the Central Appalachians (Table 3-8). Road location costs increased as the terrain became more difficult (e.g., had a large number of rock outcrops or steep slopes) or required several location changes. Typically, road location costs accounted for approximately 8 percent of total costs.
Ellefson and Miles (1984) performed an economic evaluation of forest practices to curb nonpoint source water pollutants. They presented the cumulative decline in net revenue of 1.2 percent for the practices of skid trail and landing design for a sale with initial net revenue of $124,340.
As discussed more fully at the beginning of this chapter and in Chapter 1, the following practices are described for illustrative purposes only. State programs need not require implementation of these practices. However, as a practical matter, EPA anticipates that the management measure set forth above generally will be implemented by applying one or more management practices appropriate to the source, location, and climate. The practices set forth below have been found by EPA to be representative of the types of practices that can be applied successfully to achieve the management measure discussed above.
a. Harvesting Practices
Consider potential water quality and habitat impacts when selecting the silvicultural system as even-aged (clearcut, seedtree, or shelterwood) or uneven-aged (group or individual selection). The yarding system, site preparation method, and any pesticides that will be used should also be addressed in preharvest planning. As part of this practice the potential impacts from and extent of roads needed for each silvicultural system should be considered.
- In warmer regions, schedule harvest and construction operations during dry periods/seasons. In temperate regions, harvest and construction operations may be scheduled during the winter to take advantage of snow cover and frozen ground conditions.
- To minimize soil disturbance and road damage, limit operations to periods when soils are not highly saturated (Rothwell, 1978). Damage to forested slopes can also be minimized by not operating logging equipment when soils are saturated, during wet weather, or in periods of ground thawing.
- Planned harvest activities or chemical use should not contribute to problems of cumulative effects in watersheds of concern.
- Use topographic maps, aerial photography, soil surveys, geologic maps, and rainfall intensity charts to augment site reconnaissance to lay out and map harvest unit; identify and mark, as needed:
- Any sensitive habitat areas needing special protection such as threatened and endangered species nesting areas,
- Streamside management areas,
- Steep slopes, high-erosion-hazard areas, or landslide prone areas,
- In high-erosion-hazard areas, trained specialists (geologist, soil scientist, geotechnical engineer, wildland hydrologist) should identify sites that have high risk of landslides or that may become unstable after harvest and should recommend specific practices to control harvesting and protect water quality.
- Lay out harvest units to minimize the number of stream crossings.
- States are encouraged to adopt notification mechanisms that integrate and avoid duplicating existing requirements for notification including severance taxes, stream crossing permits, erosion control permits, labor permits, forest practice acts plans, etc. For example, States may require one preharvest plan that the landowner could submit to just one State or local office. The appropriate State agency might encourage forest landowners to develop a preharvest plan. The plan would address the components of this management measure including the area to be harvested, any forest roads to be constructed, and the timing of the activity.
b. Road System Practices
- Preplan skid trail and landing location on stable soils and avoid steep gradients, landslide-prone areas, high-erosion-hazard areas, and poor-drainage areas.
- Landings should not be located in SMAs.
- New roads and skid trails should not be located in SMAs, except at crossings. Existing roads and landings in the SMA will be closed unless the construction of new roads and landings to access an area will cause greater water quality impacts than the use of existing roads.
- Roads should not be located along stream channels where road fill extends within 50-100 horizontal feet of the annual high water level. (Bankfull stage is also used as reference point for this.)
- Systematically design transportation systems to minimize total mileage.
- Weigh skid trail length and number against haul road length and number.
- Locate landings to minimize skid trail and haul road mileage (Rothwell, 1978).
- Utilize natural log landing areas to reduce the potential for soil disturbance (Larse, 1971; Yee and Roelofs, 1980).
- Plot feasible routes and locations on an aerial photograph or topographic map to assist in the final determination of road locations.
Proper design will reduce the area of soil exposed by construction activities. Figure 3-3 presents a comparison of road systems.
- In moderately sloping terrain, plan for road grades of less than 10 percent, with an optimal grade between 3 percent and 5 percent. In steep terrain, short sections of road at steeper grades may be used if the grade is broken at regular intervals. Vary road grades frequently to reduce culvert and road drainage ditch flows, road surface erosion, and concentrated culvert discharges (Larse, 1971).
Gentle grades are desirable for proper drainage and economical construction (Ontario Ministry of Natural Resources, 1988). Steeper grades are acceptable for short distances (200-300 feet), but an increased number of drainage structures may be needed above, on, and below the steeper grade to reduce runoff potential and minimize erosion. In sloping terrain, no-grade road sections are difficult to drain properly and should be avoided when possible.
- Design skid trail grades to be 15 percent or less, with steeper grades only for short distances.
- Design roads and skid trails to follow the natural topography and contour, minimizing alteration of natural features.
This practice will reduce the amount of cut and fill required and will consequently reduce road failure potential. Ridge routes and hillside routes are good locations for ensuring stream protection because they are removed from stream channels and the intervening undisturbed vegetation acts as a sediment barrier. Wide valley bottoms are good routes if stream crossings are few and roads are located outside of SMAs (Rothwell, 1978).
- Roads in steep terrain should avoid the use of switchbacks through the use of more favorable locations. Avoid stacking roads above one another in steep terrain by using longer span cable harvest techniques.
- Design roads crossing low-lying areas so that water does not pond on the upslope side of the road.
- Use overlay construction techniques with suitable nonhazardous materials for roads crossing muskegs.
- Provide cross drains to allow free drainage and avoid ponding, especially in sloping areas.
- Do not locate and construct roads with fills on slopes greater than 60 percent. When necessary to construct roads across slopes that exceed the angle of repose, use full-bench construction and/or engineered bin walls or other stabilizing techniques.
- Use full-bench construction and removal of fill material to a suitable location when constructing road prisms on sideslopes greater than 60 percent.
- Design cut-and-fill slopes to be at stable angles, or less than the normal angle of repose, to minimize erosion and slope failure potential.
The degree of steepness that can be obtained is determined by the stability of the soil (Rothwell, 1978). Figure 3-4 depicts proper cut-and-fill construction. Table 3-9 presents an example of stable backslope and fill slope angles for different soil materials.
- Use retaining walls, with properly designed drainage, to reduce and contain excavation and embankment quantities (Larse, 1971). Vertical banks may be used without retaining walls if the soil is stable and water control structures are adequate.
- Balance excavation and embankments to minimize the need for supplemental building material and to maximize road stability.
- Do not use road fills at drainage crossings as water impoundments unless they have been designed as an earthfill dam that may be subject to section 404 requirements. These earthfill embankments should have outlet controls to allow draining prior to runoff periods and should be designed to pass flood flows.
- Allow time after construction for disturbed soil and fill material to stabilize prior to use (Huff and Deal, 1982). Roads should be compacted and stabilized prior to use. This will reduce the amount of maintenance needed during and after harvesting activities (Kochenderfer, 1970).
- Use existing roads, whenever practical, to minimize the total amount of construction necessary.
Do not plan and construct a road when access to an existing road is available on the opposite side of the drainage. This practice will minimize the amount of new road construction disturbance. However, avoid using existing or past road locations if they do not meet needed road standards (Swift, 1985).
- Minimize the number of stream crossings for roads and skid trails. Stream crossings should be designed and sited to cross drainages at 90ø to the streamflow.
- Locate stream crossings to minimize channel changes and the amount of excavation or fill needed at the crossing (Furniss et al., 1991). Apply the following criteria to determine the locations of stream crossings (Hynson et al., 1982):
- Use a streambed with a straight and uniform profile above, at, and below the crossing;
- Locate crossing so the stream and road alignment are straight in all four directions;
- Cross where the stream is relatively narrow with low banks and firm, rocky soil; and
- Avoid deeply cut streambanks and soft, muddy soil.
- Choose stream-crossing structures (bridges, culverts, or fords) with the structural capacity to safely handle expected vehicle loads with the least disturbance to the watercourse. Consider stream size, storm frequency and flow rates, intensity of use (permanent or temporary), water quality, and habitat value, and provide for fish passage.
- Select the waterway opening size to minimize the risk of washout during the expected life of the structure.
Bridges or arch culverts, which retain the natural stream bottom and slope, are preferred over pipe culverts for streams that are used for fish migrating or spawning areas (Figures 3-5 and 3-6). Fish passage may be provided in streams that have wide ranges of flow by providing multiple culverts (Figure 3-7).
- Design culverts and bridges for minimal impact on water quality. Size small culverts to pass the 25-year flood, and size major culverts to pass the 50-year flood. Design major bridges to pass the 100-year flood.
- The use of fords should be limited to areas where the streambed has a firm rock or gravel bottom (or where the bottom has been armored with stable material), where the approaches are both low and stable enough to support traffic, where fish are not present during low flow, and where the water depth is no more than 3 feet (Ontario Ministry of Natural Resources, 1988; Hynson et al., 1982).
- For small stream crossings on temporary roads, the use of temporary bridges is recommended.
Temporary bridges usually consist of logs bound together and suspended above the stream, with no part in contact with the stream itself. This prevents streambank erosion, disturbance of stream bottoms, and excessive turbidity (Hynson et al., 1982). Provide additional capacity to accommodate debris loading that may lodge in the structure opening and reduce its capacity.
- When temporary stream crossings are used, remove culverts and log crossings upon completion of operations.
- Springs flowing continuously for more than 1 month should have drainage structures rather than allowing road ditches to carry the flow to a drainage culvert.
- Most forest roads should be surfaced, and the type of road surface will usually be determined by the volume and composition of traffic, the maintenance objectives, the desired service life, and the stability and strength of the road foundation (subgrade) material (Larse, 1971).
Figure 3-8 compares roadbed erosion rates for different surfacing materials.
- Surface roads (with gravel, grass, wood chips, or crushed rocks) where grades increase the potential for surface erosion.
- Use appropriately sized aggregate, appropriate percent fines, and suitable particle hardness to protect road surfaces from rutting and erosion under heavy truck traffic during wet periods. Ditch runoff should not be visibly turbid during these conditions. Do not use aggregate containing hazardous materials or high sulfide ores.
- Plan water source developments, used for wetting and compacting roadbeds and surfaces, to prevent channel bank and streambed impacts. Access roads should not provide sediment to the water source.
- Many States currently utilize some process to ensure implementation of management practices. These processes are typically related to the planning phase of forestry operations and commonly involve some type of notification process. Some States have one or more processes in place which serve as notification mechanisms used to ensure implementation. These State processes are usually associated with either Forest Practices Acts, Erosion Control Acts, State Dredge and Fill or CWA Section 404 requirements, timber tax requirements, or State and Federal incentive and cost share programs. The examples of existing State processes below illustrate some of these which might also be used as mechanisms to ensure implementation of management measures.
Florida Water Management Districts require notification prior to conducting forestry operations that involve stream crossings. This is required in order to meet the requirements of a State Dredge and Fill general permit, comparable to a CWA section 404 requirement. This notification is usually done by mail, but at least one water management district also allows verbal notification for some types of operations by telephoning an answering machine. In Florida, notification is required for any crossing of "Waters of the State," including wetlands, intermittent streams and creeks, lakes, and ponds. If any of these waters in the State are to be crossed during forestry operations, either by haul roads or by groundskidding, then notification is needed and State BMPs are required by reference in the general permit. Notification is usually provided by mailing in a notification sheet, which says who will conduct the operation and where it will be conducted (see Appendix 3A, Example 3A-1). In addition, information on what type of operation will be conducted, the name of a contact person, and a sketch of the site are included. Use of pesticides for forestry applications in Florida also requires licensing by the State Bureau of Pesticides.
The Oregon Forest Practice Rules require that the landowner or operator notify the State Forester at least 15 days prior to commencement of the following activities: (1) harvesting of forest tree species; (2) construction, reconstruction and improvement of roads; (3) application of pesticides and fertilizers; (4) site preparation for reforestation involving clearing or use of heavy machinery; (5) clearing forest land for conversion to any non-forest use; (6) disposal or treatment of slash; (7) pre-commercial thinning; and (8) cutting of firewood, when the firewood will be sold or used for barter. The State must approve the activity within 15 days and may require the submittal of a written plan. In addition, the preparation and submittal of a written plan is required for all operation within 100 feet of Class I waters, which are waters that support game fish or domestic uses, or within 300 feet of wetlands and sensitive wildlife habitat areas. Appendix 3A, Example 3A-2 contains a copy of Oregon's Notification of Operation/Application for Permit form. Oregon has developed a system of prioritization for the review and approval of these written plans. In Oregon, notification of intent to harvest is provided to the Department of Revenue through the Department of Forestry for purposes of tax collection. Additional permits for operation of power-driven machinery and to clear rights-of-way for road systems are also required.
New Hampshire does not have a Forest Practices Act, but does have a number of other State processes that serve as notification mechanisms for forestry activities. Prior to conducting forest harvesting, an Intent to Cut Application must be submitted to the Department of Revenue Administration (see Appendix 3A, Example 3A-3). This is required for the timber yield tax, and is filed in order to get a certificate for intent to cut. The Intent to Cut Application must be accompanied by an application for Filling, Dredging or Construction of Structures for those operations that involve the crossing of any freshwater wetland, intermittent or perennial stream, or other surface water. If the activity is not considered a minimum impact, a written plan must be submitted and approved before work may begin. Signature of these applications by the owner or operator adopts by reference the provisions of the State Best Management Practice Handbook. The State Erosion Control Act also requires notification for obtaining a permit for ground-disturbing activities greater than 100,000 square feet. This permit is required prior to commencement of operations. Another State process that entails notification is the provisions for the prevention of pollution from terrain alteration. These provisions require the submission of a plan 30 days before conducting the transport of forest products in or on the border of the surface waters of the State or before significantly altering the characteristics of the terrain in such a manner as to impede the natural runoff or create an unnatural runoff. The State must grant written permission before operations of this type may take place. Each of these existing State mechanisms entails the notification of the State prior to conducting forestry operations. Pesticides licensing is also necessary if the forestry operation involves the application of herbicides or insecticides.