British Columbia Mine Reclamation Symposia

Soil erosion and sediment control planning for managed forest watersheds : a case study on the Queen.. Carr, William W., 1952- 1991

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata


1991 - Carr - Soil Erosion and Sediment Control Planning.pdf [ 310.51kB ]
JSON: 1.0042195.json
JSON-LD: 1.0042195+ld.json
RDF/XML (Pretty): 1.0042195.xml
RDF/JSON: 1.0042195+rdf.json
Turtle: 1.0042195+rdf-turtle.txt
N-Triples: 1.0042195+rdf-ntriples.txt
Original Record: 1.0042195 +original-record.json
Full Text

Full Text

th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  SOIL EROSION AND SEDIMENT CONTROL PLANNING FOR MANAGED FOREST WATERSHEDS - A CASE STUDY ON THE QUEEN CHARLOTTE ISLANDS.  William W. Carr, PhD. (CPESC)  TERRASOL. 1637 Columbia Street, North Vancouver, B.C. V7J 1A5  Abstract  Public and professional awareness of the impacts of forest resource development on fishery and watershed values has increased dramatically over the past decade. Proper planning and implementation of soil erosion and sediment control procedures must be an integral part of forest resource management. In cooperation with the Ministry of Forests and Fletcher Challenge Canada Ltd., Terrasol has completed the development of a formal approach to soil erosion and sediment control planning for managed forest watersheds in British Columbia. The approach presented in this paper has been implemented on an operational basis in B.C., and moves sediment and erosion control operations from being post-damage "band-aid" treatments into an active cost-effective mitigation program.  La stabilisation des rives -le besoin d'une surveillance à long terme  Au cours des dernières années, le nombre d'études portant sur la stabilisation des rives a beaucoup augmenté, particulièrement celles qui mettent l'emphase sur l'inclusion d'une composante végétale pour répondre aux besoins des populations faunigues et ichtyologiques. Ces études utilisent soit des techniques de bioingénierie, soit une combinaison de ces dernières à des approches d'ingénierie plus conventionnelles. Comme ces études sont relativement nouvelles, il devient nécessaire de maintenir une surveillance continue de l'efficacité des techniques qu'elles proposent. Il est important de répondre aux exigences du contrôle de l'érosion de même qu'à celles de l'écologie des cours d'eau. Cette communication passe en revue plusieurs études de stabilisation des rives effectuées en ColombieBritannique, ainsi que dans l'état de Washington, et résume leur niveau de succès ou d'échecs, à la lumière de leurs objectifs à long terme.  70  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Biographical Sketch William W. Carr, Ph.D.(CPESC) William W. Carr is currently the manager of the Environmental Consulting Division of Terrasol in Vancouver, B.C. He received a B.Sc. in Forest Management from Oregon State University in 1975, and his M.Sc. and Ph.D. in Forest Soils from the University of British Columbia in 1977 and 1984, respectively. Bill was one of the first Certified Professional Soil Erosion and Sediment Control Specialists in western Canada. As a researcher and environmental consultant, he has specialized in soil erosion and sediment control, soil compaction, and site degradation associated with resource development. His clientele include a wide range of government agencies, forest companies, crown corporations, and engineering firms. Over the past two years, he has been serving on the consulting team that is developing a comprehensive watershed management plan for the Greater Vancouver Regional District, represented the Department of Fisheries and Oceans in the development of the erosion and sediment control policy for Westwood Plateau, and developed detailed soil erosion and sediment control plans for urban developments in the lower mainland. Dr. Carr has published over 30 major reports and papers on various aspects of soil erosion and soil degradation, and is currently giving workshops throughout British Columbia on the potential impacts of timber harvesting on the soil resource.  71  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Introduction Public and professional awareness of the potential negative impacts of timber harvesting on fishery and watershed values has increased dramatically over the past decade. This awareness has increased the pressure on forest managers to minimize these potential impacts on both existing and future forestry operations. Watershed research projects have not only documented the potential for detrimental processes to occur in managed forest watersheds, but also point out that the opportunity exists to prevent or alleviate resource damage. Road development and timber harvesting operations have been identified as principal causes of soil degradation. Such degradation may lead to accelerated surface erosion and mass wasting, which can adversely affect fishery values, water quality, and future site productivity. Fortunately, many of the erosion and water quality problems associated with forest resource development can be alleviated, if not prevented, through proper planning and implementation of soil erosion and sediment control procedures. However, sediment and erosion control planning must be an integral part of forest resource management, along with a commitment to carry the plan through to final implementation. The undertaking of this type of approach moves sediment and erosion control from a post-damage, "band-aid" treatment into an active, cost effective mitigation program. The results from the Redwood Park Restoration Program of the U.S. National Park Service in California have demonstrated the success achievable with such a program. An erosion and sediment control plan, often referred to as a watershed "rehab" plan, must be compatible with the management objectives of the area. Current and future road development and timber harvesting plans, water quality, recreation potential, and fishery values are among those factors that provide the focus of the plan. An inventory of active and potential problem areas is needed, in conjunction with prioritization criteria to direct future activities. Management solutions and/or treatment options should be developed for each problem area, along with an implementation schedule. The schedule should promote an orderly and logical undertaking of rehab treatment options based on available funding. This type of soil erosion and sediment control planning system can provide the land manager with a valuable tool for optimizing forest development in sensitive watersheds while minimizing the potential negative impacts on other resource values.  Objectives There are two objectives for this report. The first is to formalize the approach and procedures for developing a comprehensive, operational soil erosion and sediment control plan (rehabilitation or "rehab" plan) for managed forest: watersheds in British Columbia. The second objective is to present example portions from an operational field test of the planning system. The documentation of the planning process, combined with the operational examples, should serve as a template for expansion of this concept to other managed forest watersheds. The individual components of a rehab plan are developed in response to management concerns within a watershed. As such, they may be simple or very complex, and the structure of the plan must be flexible to meet a range of management needs. In the demonstration watershed  72  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  used for this report, Shomar Creek, the management concerns were directed solely at the impacts of timber harvesting development on slope stability and downstream fishery values. In other watersheds, additional concerns such as recreational value, visual impact, and community water supply could be incorporated into the planning system. Operational Study Area The Shomar Creek watershed is centrally located along the northern edge of Moresby Island, part of the Queen Charlotte Islands in northern B.C. The creek enters the Deena River, a major salmon spawning and rearing river, approximately (5km from the South Bay estuary. Shomar Creek is a class IV stream with no fish population due to a major blockage caused by an old bridge failure. However, it is important to downstream fish habitat due to a relatively high flow capacity and substantial sediment delivery potential. Encompassing approximately 900ha of good and medium site forest land, Shomar Creek is an integral part of forest management in Tree Farm License (TFL) 42, Fletcher Challange Ltd. As part of the Coastal Western Hemlock - wet hypermaritime (CWH-whl) biogeoclimatic zone, old growth stands are composed of western red cedar, western hemlock, and Sitka spruce. Second growth stands are predominantly Sitka spruce and western hemlock. This steep-sided drainage basin is a complex of terrain units. The lower portions of the watershed are predominantly glaciofluvial and morainal materials. Both the middle and upper slopes are dominated by morainal blankets and/or colluvial veneer, and exhibit substantial bedrock influence. Often exceeding 100% in steepness, the upper slopes are characterized by steep, unstable gully systems. Harvesting activity began in the watershed during the mid-1960's. Initial operations concentrated on the flatter areas and the west side of the basin, while more recent and current logging activities have concentrated on the steeper east slopes. Future plans include continued old-growth logging, and the reopening of the west side road system for stand management access. Soil Erosion and Sediment Control Plan Structure A soil erosion and sediment control (or rehab) plan should be developed under the direction of a soil erosion and sediment control specialist (e.g. Certified Professional Soil Erosion and Sediment Control Specialist or CPESC) in close cooperation with the forest licensee and appropriate resource agencies. Public participation in the planning process may also be included should it be warranted by resource concerns. The plan structure for managed forest land must also be flexible enough to address the range of conditions and concerns that may occur in any given watershed. Small, informal soil erosion and sediment control plans for specific forest road development projects are not uncommon in British Columbia forestry and require only minimal time to develop. However, for large projects that may require months of development time, a more structured format is necessary to maintain the project focus. The more formal approach has been used on such projects as the 15,000 ha Redwood Creek restoration program in  73  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  California (Belows 1984) and the watershed rehab plan for a 5,000 ha management unit at Stewardson Inlet, British Columbia (Carr and Wright 1987, unpublished). The time required to develop a soil erosion and sediment control plan is dependent upon the project scale, complexity of the management concerns, and the number of problem sites. As such, total watershed area should not be the primary determinant in plan budgeting. These other factors can play an overriding role in time requirements, particularly the number or frequency of problem sites. As is true in most planning exercises, accuracy in the costing process is dependent on the background information available. Regardless of the project scale, a soil erosion and sediment control plan generally includes five major components: 1. Definition of objectives, 2. Inventory of active and potential problems, 3. Prioritization, 4. Treatment options, 5. Cost and scheduling. The plan objectives (or resource concerns) and information gathered in the area inventory combine to determine the priority assigned to each specific problem site. This priority assignment and relevant inventory data assist the specialist (CPESC) in selecting appropriate treatment options, including operational specifications. In general, the more sophisticated (and usually more expensive) methods can only be justified on the higher priority sites. All these components, plus other factors such as access and season, contribute to the eventual project budget and scheduling. Where the available funding for the program is limited, the priority assignment and general costing data can provide a basis for the final selection of sites to be treated. Plan Components Definition of Plan Objectives Various resource agencies and public groups participate with the forest manager in this first component of the project. Both timber and non-timber resources are to be considered in defining the objectives of the soil erosion and sediment control plan. Some of the various factors to be included are: - forest development and management plans - fish habitat protection - water quality concerns - potential slope stability and mass wasting - integrity and capability of drainage structures - long-term road maintenance planning - visual impact and aesthetics - recreational use.  74  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Rehabilitation objectives for the project area must be clearly stated and ranked as to overall importance. These objectives are not only important to effective integrated resource management, but also play an important role in the latter sections of the rehab plan. Objectives of the Shomar Creek plan Fletcher Challenge plans to continue forestry operations in the Shomar drainage in accordance with the overall management plans for TFL 42. These operations include road building, timber harvesting, and stand tending. In recognition of the potential impact of such activities on slope stability and down stream fishery values, the Sandspit Division has adopted a progressive approach toward watershed management in the Shomar Creek area through the development of a soil erosion and sediment control plan. The objectives of the plan are: to address active and potential soil erosion sediment problems associated with existing forest development through repair, upgrading, and/or rehabilitation, and to plan and implement future forestry operations so as to prevent or minimize potential negative impacts. Logging related and road initiated erosion and sediment problems are present in this watershed, many of which are still active and must be addressed. These problems will be treated in the manner prescribed in the plan as funding becomes available. As well, future forest development plans in this area will take into consideration the information gathered in the inventory regarding the cause and location of problem sites. This additional information, when combined with high operational standards and an aggressive mitigation program, should minimize the potential impacts of road building and timber harvesting operations on other resource values. Inventory of Active and Potential Problem Sites The second component of the plan is an inventory of problem sites within the watershed, or area of concern. The inventory is conducted using both air photographs and on-site inspection. Active erosion sites and sediment delivery routes are identified on air photographs (preferably recent colour photos at 1:10,000 scale), classified as to origin or cause, measured and catalogued. An initial assessment of the impact of each site in relation to the management objectives is also made. Potential erosion and slope stability problems are included in the inventory. To facilitate the on-site verification of the airphoto inventory and to up-date recent erosion activity, all problem sites are located (at scale) on available area maps. These maps, preferably at a scale of 1:5,000 or 1:2,500, should also include pertinent area information; such as logging history, future development plans, soil and terrain type, fishery and other resource values, etc. During the on-site inspection, the accuracy of airphoto identification should be validated and evidence of recent erosion activity noted. Information required for the assigning of priorities (defined later in this report) is also gathered. The inspection also provides the sediment and erosion control specialist with an opportunity to begin the formulation of rehab or treatment options.  75  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Shomar Creek inventory The disturbance inventory of erosion sites was initially conducted using 1987 colour air photographs (1:10,000). However, it was necessary to update the inventory with an extensive, on-site inspection of the entire watershed. Recent road development and timber harvesting activity (1987-88) had created numerous new erosion sites. Most of these were associated with logging within a V-notch gully complex. The older road system also needed ground inspection to identify potential road-related problems that were obscured in the photos by second-growth regeneration. The disturbance inventory is summarized in a format similar to Table 1, with all sites also located on the operational 1:5000 rehab mylar. Each problem site is categorized as to its origin and/or cause (type) with additional information in the other columns. Table 1. Shomar Creek disturbance inventory  (Note: Definitions of disturbance type follow in the text.)  Although the categories selected for this project may be simplistic compared to some slope stability inventory systems, they convey enough information to direct the rehab program. The category selection and definitions are flexible, and may be modified in future rehab plans to parallel other surveys as long as the needs of the rehab program are met. Road associated problems (R) include major cut and fill/sidecast slopes, as well as road initiated mass wasting. The slide category (S) implies open slope failures that are generally related to yarding damage. Gully failure (G) applies to debris torrent/avalanche activity in steepsided, V-notch gullies. Debris torrented stream channels (Str) were separated from the gully category to denote extensive in-channel scouring. The configuration (size) and area of each problem site is also included, along with relevant specific comments. Prioritization Upon the completion of the first two components, it now becomes possible to establish prioritization criteria that direct the implementation phase of the rehab plan. The prioritization  76  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  criteria not only reflect the overall plan objectives, but must also address such factors as the immediacy and magnitude of potential impact. These latter concerns can be inferred from the inventory data. The soil erosion and sediment control specialist (CPESC) has the primary responsibility in developing this component. Although an experienced specialist may intuitively assign priorities, this decision is usually based on a self-developed expert system. The three-step expert system that formed the basis for the decisions made in the Shomar Creek study is presented in Figure 3. This format, which is customized to meet the conditions encountered in a specific project watershed, serves as a guide in a decision making process that ultimately relies upon the experience and capability of the specialist. The initial step in this expert system (Step 1) addresses the stage of the erosion process. In general, control of early stage erosion (or prevention) is immediately classified as a very high priority. Such sites commonly require action to direct or control surface water flow to preclude conditions for accelerated soil erosion. Prevention and the control of early stage erosion is by far the most cost-effective approach to watershed protection. Those sites that are in an advanced stage of erosion, having begun natural recovery through vegetation recolonization, are considered very low priority. Such sites have very limited potential for continued sediment delivery and usually require no treatment. It is the actively eroding areas that present the most difficult problem in assigning priorities, thus the need for step 2 .  Figure 1  System for assigning priority classes in the Shomar Creek study area  Step 1: Determine the stage of erosion Stage  Priority  Early/Prevention Very High Active  see Step 2  Advanced/Stable Very Low Step 2: Determine active erosion priority (AEP) 2a. Assess potential erosion magnitude (PEM) PEM = f(erosion hazard, size of area) Erosion hazard (VH,H,M) based on Figure 5 Size: Large (L) - >0.2 ha Small (S) - <0.2 ha  77  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Erosion Hazard and Size yield PEM RatingVH L 6 VH L 5 H L 4 H S 3 M L 2 M S 1  2b. Assess sediment delivery potential (SDP) SDP = f(sediment entry route, distance) Route: direct (D), indirect (I), nil (N) Distance: Long (L) ->100m Short (S) - <100m Route and Distance yield SDP Rating: D S 3 D L 2 I S or L 1 N S or L 0 2c. PEM+ SDP = AEP Total 7-9 High 4-6 Medium 1-3 Low  Step 3: Conditional modifiers 3a. Inaccessible - reduce class 3b. Potential trigger mechanism - raise class 3c. Sensitive watershed resource - raise class In determining the priority assignment for actively eroding areas (AEP or active erosion priority), both the magnitude of the erosion/sediment problem and the immediacy of the impact must be considered. The potential erosion magnitude (PEM) is a function of erosion hazard and size (Step 2a). Surface erosion hazard may be determined using one of many standard keys. In this case study, the model currently recommended by the British Columbia Ministry of Forests was used (Carr et al. 1989). For the Shomar study area, the erosion hazard ranged from medium to very high. This basic hazard is then combined with a size classification to yield a  78  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  PEM. In the Shomar study, 0.2 ha was chosen as the boundary for large versus small sites. The resulting PEM rating ranges from 1 to 6. The second part of Step 2 (2b) develops a rating for sediment delivery potential (SDP) to gauge the immediacy of potential impact on watershed resources. The SDP is a function of sediment entry route (direct, indirect, or nil) and the distance to a particular resource of concern. For the Shomar study, a SDP rating from O to 3 was created. The summation of the potential erosion magnitude (PEM) and the sediment delivery potential (SDP) in Step 2c yields the active erosion priority (AEP), which for this study area ranged from low to high. There is an important final step in assigning priorities to problems sites (Step 3) which provides scope for professional judgement. Specific conditional modifiers can be superimposed on the priority process. These modifiers are specifically developed for each area, and may either raise or lower a previous priority level. Access (3a) is often an overriding factor to operational rehabilitation, and as such may limit treatment options to less effective methods or total deferment. Risk factors (3b & 3c) can also be included. Areas that appear relatively stable but have the potential to trigger other erosion problems (3b), e.g. small sidecast slopes with tension cracks, may be raised in treatment priority to that of prevention. It is also possible to include factors that further address specific plan objectives (3c). A site with a medium AEP may be moved into a higher category if a very high value resource, e.g. fish habitat or water quality, is at jeopardy. As stated in the beginning of this section, the type of decision model used in the prioritization process is usually a self-developed expert system that can be modified for a range of conditions. The system presented in this report is based on over twenty years of soil erosion and sediment control experience in the forest environment by the authors, and as such it may not be suitable for use by other practitioners. However, it does present a general format that one should follow in assigning priorities for soil erosion and sediment control activities. Priority criteria for the Shomar Creek study area The assignment of priorities to identified problem sites in the Shomar watershed was based on the magnitude and immediacy of potential impact on the road network, slope stability, and/or water quality. The qualifications for the priority classes are: Very High - designated for those sites that are associated with road maintenance or repair; primarily concerned with surface water management, High - designated for those sites that currently affect water quality, slope stability, or transportation network, Medium - designated for those sites that have a moderate impact on water quality, slope stability, or transportation network; sites that have potential for expansion or reactivation Low - designated for those sites where impact is minimal  79  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Very Low - designated for those sites that are no longer eroding; sites that have been recolonized with natural vegetation. The priority assignment is usually presented in a rehab treatment and priority table (Table 2 - a sample portion from the Shomar plan). A substantial amount of very high priority road rehabilitation (maintenance and repair) is required in the Shomar area. These activities, being very site specific, are presented on the rehab mylar, not in the tables. These locations were also flagged in the field during the watershed inspection.  Table 2 Shomar Creek rehab and priority summary  (Note: Example from the Shomar plan. Rehab options are defined later in this section.)  Erosion and sediment control treatment options The sediment and erosion control specialist has a wide range of methods or techniques available from which to develop a rehab plan. These methods are usually divided into the following four general categories: 1. prevention 2. temporary sediment and erosion control 3. permanent sediment and erosion control 4. biotechnical slope stabilization. Each method has certain soil, climate, and seasonal requirements; response time and effectiveness; and associated cost. These factors must be evaluated in relation to the management objectives and priority assignment before a rehab treatment or combination of treatments is selected for a specific problem site. The goal of prevention is to preclude the conditions for accelerated soil erosion and mass wasting from occurring. Deferring timber harvesting or employing special development  80  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  techniques are forest management options for erosion prevention. However, within the operational context of this planning system, the goal is management of water flow patterns to prevent undesirable diversions or blockages. Included among the preventative treatments are enhancement of road drainage through increased culvert capacity (size and/or number), improved ditch maintenance and construction, proper long-term road maintenance using waterbars and cross-drains, and the removal of slash/debris deposits from natural drainage courses. Many of these prevention treatments are recommended standard procedures in road building and timber harvesting. However, potential problem areas that may have been overlooked or not anticipated should be identified during the inventory process. The goal of temporary sediment and erosion control techniques is to control surface erosion and sediment production until permanent erosion control systems are in place. These measures are often used immediately following soil disturbance when the erosion and sediment potential are greatest. Sediment trapping systems such as silt fences, straw bale barriers, and settling ponds are often employed to protect water quality. Rapid ground cover establishment using short-lived cover crops or biodegradable mulches is also an option. These temporary measures are usually assigned to active, high priority sites. The more permanent rehab treatments are to provide for long-term sediment and erosion control by creating a low maintenance system that: - dissipates excessive erosive energies - increases resistance to particle detachment - controls sediment transport. The establishment of a vigorous, self-sustaining grass/legume ground cover is the primary objective of these techniques. Aside from providing highly effective and cost-efficient surface erosion control, grass-legume establishment has a secondary benefit of accelerating the recolonization of native vegetation (the "natural" healing process). The method of cover establishment, either dry seeding or hydroseeding, is dependent on slope steepness, erosion potential, and site priority. Access is often the determining factor between ground or helicopter application. Erosion control revegetation mats (ECRM) can be used to either augment or replace vegetation establishment should the priority assignment warrant the extra cost. Permanent and temporary sediment and erosion control methods are discussed in detail in Carr (1980) and Carr (1985). The fourth category of rehabilitation methods, biotechnical slope stabilization, refers to the use of woody vegetation to increase slope stability against shallow mass wasting events such as soil flow or rotational slumps. Often combined with engineering structures, biotechnical slope stabilization encourages the establishment of a dense root network to enhance soil shear strength. The variety of techniques available are discussed at length in Gray and Leiser (1982) and Schiechtl (1980). These systems may be very simple to extremely complex in design depending upon specific site requirements. Experienced personnel are necessary to plan and implement the more complex systems.  81  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Recommended treatments for Shomar Creek The rehabilitation methods recommended for use in the Shomar Creek study are: D.S.  dry seeding by hand  D.S.(Heli)  dry seeding using helicopter bucket  H. S.  hydroseeding by truck  H.S.(Heli)  hydroseeding using helicopter bucket  B.S.S.  biotechnical slope stabilization using Sitka spruce and shrubs  D.C.C.  drainage course clearing.  The recommended treatment option for each problem site is presented in the rehab and priority table (Table 2 - a sample portion of the Shomar plan). The treatment may consist of a single operation or a combination of techniques. The combination treatment, generally including hydroseeding (H.S.) and biotechnicaJ slope stabilization (B.S.S.), is designed to control surface erosion and to enhance slope stability. This treatment, usually assigned to areas that have been subjected to major site disturbance, has been successfully used for landslide rehabilitation in other areas of the Queen Charlotte Islands. The sequence of implementation in the combination treatments is implied by the order in which they are listed. Detailed descriptions and specifications for each rehabilitation option are presented in the operational plan. In addition to the treatments presented in the rehab and priority table, a number of site specific road rehabilitation activities are noted directly on the master rehab mylar. These activities include such activities as waterbar installations , cross-drains (or impassable waterbars), fords (wide, shallow waterbars), ditch establishment, and general ditch/culvert maintenance. Costs and Scheduling The last component, cost and scheduling, goes through an evolutionary process as the implementation of the plan approaches. In the initial planning stages, such as the Shomar Creek study, this section is more of an approach toward eventual operational rehabilitation with limited costing data. The development of a budget is difficult in the initial phase of a rehab project because there are a number of complicating factors. Some treatment options, especially those deemed as preventative, are often operations routinely undertaken by the forest licensee or management agency. In such cases, "in-house" costs can be applied once minor adjustments have been made to include extra mobilization to the treatment area. For those options requiring special contractor services, particularly the revegetation options, direct negotiations are necessary. Such factors as the scale of operation, logistical considerations addressing mobilization and site access, and the availability of support services can dramatically influence "outside" contractor costs. Because of all the operational variables that enter the costing process,  82  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  the initial plan should treat costs in a general way. The budget will become more definitive as the planning for field operations is finalized. The scheduling aspect of this component is not only dependent upon access and equipment/contractor availability, but also anticipated environmental conditions. Many of the revegetation treatment options have specific moisture and temperature requirements which cannot be ignored. As such, some flexibility in scheduling must be maintained to insure optimum conditions at the time of operation. An additional consideration in scheduling is the sequence of treatment installation where multiple treatments are prescribed, and whether there are any downslope implications. The proper order of installation is mandatory to prevent detrimental impacts of one treatment upon another. Scheduling and costing for Shomar Creek At the present time, access is the overriding factor in the implementation of this soil erosion and sediment control plan. Much of the watershed is inaccessible due to two bridge washouts and numerous instances of road failure . All rehab activity in such areas must be deferred until these problems are corrected. The accessible area includes the most recently logged portion of the watershed and a majority of the actively eroding sites. The road network has extensive cut banks, considerable grade, and numerous drainage problems. All very high priority road rehabilitation activities, primarily directed at prevention, should be undertaken immediately. Failure to do so will result in new road initiated mass wasting. The rehabilitation of all other very high, high, and medium priority sites in this accessible area should also be initiated as soon as possible. Fletcher Challenge has the capability to perform much of this work. The road maintenance/rehabilitation treatments are an extension of standard programs. Their current revegetation program can easily undertake the dry seeding operations and the shrub/tree planting component of biotechnical slope stabilization. However some operations, particularly the hydroseeding treatments, will require the services of an erosion control contractor. Summary The implementation of soil erosion and sediment control procedures in managed forest watersheds can alleviate, if not prevent, the potential negative impact of harvesting development on watershed values. This implementation should be an integral part of forest land management. Proper planning of sediment and erosion control operations, often referred to as watershed rehabilitation or rehab, is paramount to the initiation of a cost-efficient soil conservation program. The planning system presented in this report incorporates both timber and non-timber management objectives. It is based on a fundamental understanding of erosion and sedimentation processes, including the potential for resource damage, and extensive experience with sediment and erosion control systems. Although the planning process should follow the basic structure discussed in this report, flexibility must be maintained to address specific watershed concerns.  83  th  Proceedings of the 15 Annual British Columbia Mine Reclamation Symposium in Kamloops, BC, 1991. The Technical and Research Committee on Reclamation  Literature Cited Belous, R. 1984. Restoration among the redwoods. Restoration and Management Notes 2(2): 57-64. British Columbia. 1987. Coastal fishery forestry guidelines. Min. of Forests, Min. of Env., Fed. D.F.O., and C.O.F.I. 11 pp. + appendices. Carr, W.W. 1980. Handbook for forest roadside erosion control in B.C. Land Management Report Number 4. B.C. Min. of Forests, Victoria. 43 pp. Carr, W.W. 1985. Watershed rehabilitation options for disturbed slopes on the Queen Charlotte Islands. Land Management Report Number 36. B.C. Min. of Forests, Victoria. 35 pp. Carr,W.W., W.R. Mitchell, and W. Watt. 1989. Basic soil interpretations for forest development planning: Surface soil erosion and soil compaction hazard indices. Land Management Report 63. Research Branch, Ministry of Forests, Victoria. Gray, D.H. and A. Leiser. Biotechnical slope protection and erosion control. Van Nostrand Reinhold Co., New York. 271 pp. Schiechtl, H. 1980. Bioengineering for land reclamation and conservation. (Trans, by N. K. Horstmann). Univ. of Alberta Press, Edmonton. 404 pp.  84  


Citation Scheme:


Usage Statistics

Country Views Downloads
Australia 11 0
United States 5 0
Canada 5 1
Germany 2 6
France 1 0
South Africa 1 0
Japan 1 0
City Views Downloads
Brisbane 11 0
Unknown 5 7
Ottawa 3 0
Ashburn 3 0
Wilmington 2 0
Thohoyandou 1 0
Tokyo 1 0

{[{ mDataHeader[type] }]} {[{ month[type] }]} {[{ tData[type] }]}
Download Stats



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items