Stlixwim Hydro Corporation Proposed Right-of-Way Debris Management Plan

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2 Stlixwim Hydro Corporation Proposed Right-of-Way Debris Management Plan Submitted by Bruce A. Blackwell B.A. Blackwell & Associates Ltd Hoskins Rd. North Vancouver, BC Ph: GST No.: Submitted to Warren Hansen RPF Chartwell Consultants Ltd. # Fell Avenue North Vancouver, BC Canada, V7P 3R5

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4 Table of Contents 1 PURPOSE BACKGROUND PROCEDURES CONTRACTOR GUIDELINES TREATMENT OPTIONS BY DMZ DMZ LOW DMZ MODERATE AND HIGH Mowing Chip and Blow Pile and Burning Mulch Onsite Fuel Free Zone DMZ HIGH ONLY Full Clean-up SUMMARY OF TREATMENT OPTIONS BY DMZ PERFORMANCE MEASURES RESOURCES B.A. Blackwell & Associates Ltd. ii

5 List of Figures Figure 1. Unacceptable levels of debris left on ROWs following tree removal/slashing/brushing.5 Figure 2. Acceptable levels of debris left on ROWs following tree removal/slashing/brushing and/or chipping Figure 3. Acceptable chipping debris placement and depth for Chip and Blow Figure 4. Acceptable piles for Pile and Burning Figure 5. Acceptable fuel free zone placement and debris levels for fuel free zone Map Frames Map 1. Fire risk map Map 2. Debris management zones B.A. Blackwell & Associates Ltd. iii

6 1 Purpose This document outlines the debris management standards required to mitigate potential fire risks and to minimize the likelihood of forest health incidences or invasive alien plant species impacts due to clearing activities for Stlixwim Hydro Corporation s right-of-way (ROW) for the Tyson Creek Hydro Project and the Stl ixwim Renewable Energy Initiative Project (described as the Sechelt and Narrows Inlet Project in this report). This plan covers clearing and construction of the Sechelt and Narrows Inlet transmission line ROW and associated infrastructure, including transmission ROW, penstock ROW, powerhouse areas, and laydown areas. This plan does not apply to operations given that additional standards may be required for vegetation management once ROW infrastructure is in place and operational. However, the content of this plan would be relevant for inclusion in an operations vegetation management plan. The scope of the risk assessment aspect of the plan was limited to the assessment of wildfire risk, specifically the probability and consequence of its occurrence, within the study area. While the probability and consequence of forest health incidence or invasive alien plant spread were not modeled, the potential for their occurrence and negative impact are assumed given that construction will create debris and, in some areas, expose mineral soil. Therefore it is relevant to incorporate best management practices for integrated pest management, as well as wildfire risk mitigation, within the debris management plan for construction of the ROW to ensure that forest health is maintained adjacent to the planned ROW. The wildfire risk assessment (see the Stlixwim Hydro Corporation s Proposed Right-of-Way Wildfire Risk Management System Report) completed for the project identified areas of low, moderate and high wildfire risk (Map 1). This assessment has been used to delineate the Debris Management Zones (DMZs) (Map 2) that will dictate the appropriate response in terms of debris clean-up during clearing and construction activities. The intent of management within these DMZs is to maintain woody debris at levels below 5 kg/m 2 in contiguous areas (>100 ha) of moderate wildfire risk and in all areas of high to extreme wildfire risk. Maintaining debris at levels below this threshold will ensure that fire behaviour within the right-of-way is maintained at Rank 2 1 or lower, defined as a low vigour surface fire with little or no rate of spread that can be directly attacked by fire fighters with hand tools or water, and that will be held by a fire guard. Debris management standards for wildfire risk mitigation vary according to DMZ whereas standards for integrated pest management apply across all DMZs. Debris management standards are detailed in Section 3 of this document. 2 Background Much of the Sechelt and Narrows Inlet Project ROW is, or was, forested. During clearing and construction of the transmission line, some of the merchantable timber will be removed. However, merchantable and non-merchantable woody debris that remains on the site can pose a fire or forest health hazard. Some areas are at greater risk from wildfire than others based on the probability of wildfire and values identified during the risk assessment. The method and extent 1 B.A. Blackwell & Associates Ltd. 1

7 of debris clean-up required for fire risk mitigation is dependent on the probability and consequence of wildfire in a particular spatial location. Best management practices for integrated pest management, plus the goal to limit the use of herbicide, will apply across the right-of-way during construction. Debris generated during ROW clearing and construction has the potential to increase the habitat available for certain forest pests. Douglas-fir debris is of primary concern as it can provide habitat for Douglas-fir beetle and ambrosia beetles (also called pinworms). These species can have significant economic impacts on timber value. Ambrosia beetles may also infest debris from other species of conifer. Best management practices for forest pest management will apply to clearing and debris disposal in order to minimize the likelihood of these pests propagating in debris created during ROW clearing. A goal is to limit the use of insecticides for pest management on the ROW. Invasive alien plant species (invasives) can be spread during clearing and construction by vehicle and machine traffic carrying seeds onto ROW areas and by exposing mineral soil on which invasives can establish without competition from established native species. Invasives are able to establish rapidly on disturbed sites and can result in a loss of biodiversity through the exclusion of native species. Best management practices for weed management will apply to clearing and debris disposal in order to minimize the likelihood of invasives being introduced and propagating on the ROW. Herbicide treatment is generally not an option for pest management on the ROW. Invasives of concern that are known to occur in the study area include: Bull thistle (Cirsium vulgare) Burdock (Arctium spp.) English holly (Ilex aquifolium) Himalayan blackberry (Rubus discolor) Orange hawkweed (Hieracium aurantiacum) Common tansy (Tanacetum vulgare) Meadow hawkweed (Hieracium caespitosum) Scotch broom (Cytisus scoparius) Oxeye daisy (Leucanthemum vulgare) While there are financial costs associated with debris clean-up, proper disposal of debris, careful equipment use, minimizing damage to retained trees and cleaning equipment between sites, there are many beneficial effects, including: reducing fuel loading and fire risk; ensuring clear access to roads and trails; protecting worker and public safety; preventing damage to forest products due to outbreaks of forest pests; preventing damage to ecosystems due to the spread of invasive alien plants; preventing desirable understory species from being crushed or buried; protecting riparian habitat; and providing new habitat for small mammals when strategically placed. B.A. Blackwell & Associates Ltd. 2

8 3 Procedures The following points outline the general approach to determining where and how fuel mitigation treatments (debris clean-up) should be applied on the ROW: Use the DMZ map (Map 2) to determine the debris clean-up response. Areas designated as DMZ low require the minimum debris clean-up response. The minimum standard requires that individual trees, except Douglas-fir, are bucked to a 2 m length, laid flat on the ground surface, and limbs are bucked from the main stem and laid flat on the ground surface. Where Douglas-fir is present, it is preferable that debris >12 cm in diameter be piled and burned, chipped, or disposed of offsite. If disposal is not possible, debris should be cut into 30 cm lengths and laid flat on the ground in full sunlight, and monitored for infestation of Douglas-fir beetle or ambrosia beetles until the end of the summer, following clearing (one full year if clearing occurs in summer). Acceptable and unacceptable levels of debris are depicted in Figure 1 and Figure 2. Where debris clean-up is required (contiguous areas of moderate risk and all high or extreme risk areas), all areas with road access should be mowed, chipped, piled, or reoriented on the site (i.e., to create fuel free zones). o In areas of non-merchantable standing trees that are within the height and size limits of a mower, and where a mower can gain access, the terrain is suitable and the transport and operation costs are economically viable, mowing is the preferred treatment option. o In areas where mowing is not feasible, and clearing will involve slashing, brushing or tree removal and there is road access for a chipper, debris should be chipped. o In areas where mowing is not feasible and there is road access but it is not suitable for a chipper, then piling and burning should be considered. o In areas with no access (i.e., helicopter only), piling and burning should be considered. o In areas with no access where piling and burning is not feasible due to cost constraints or safety concerns, fuel free zones (5 m minimum) should be created. Fuel free zones should not be homogeneously applied at all sites. Sites should be assessed for terrain and natural fuel breaks before determining where, if at all, fuel free zones should be placed. Each area of clearing must result in site specific debris clean-up plans. Particularly in the case of fuel free zones, site maps showing the specific location of the treatments should be provided to the contractor to ensure that treatments are applied where they will be most effective. Contractors should be supervised on site at the beginning of their contract so that they understand the level of work required to achieve the objectives of the prescription. B.A. Blackwell & Associates Ltd. 3

9 All prescribed debris clean-up plans must be approved by Stlixwim Hydro Corp. prior to the commencement of work. As a standard, all clearing/construction contracts should have statements in the prescription to prevent contractors from: o Leaving debris (excluding chips) within a 2 m radius of planned right-of-way structures, 5 m of public roads, and within 2 m of ROW edges. Chipped material must not be piled and should be spread over the site to a maximum of 10 cm in depth. This statement should not use the term fuel free zone because it only refers to the placement of fresh debris, not the removal of all debris (fresh or historical) to create a fuel free zone. o Leaving damaged trees at the ROW edges. The removal of damaged trees will reduce the potential for infestation and spread of forest pests and disease organisms. o Leaving mineral soil exposed without a prescribed planting plan that utilizes locally successful native plant species, other species that are locally successful, or a high grade seed mix (i.e., Canada No. 1 or Common # 1). An invasive species survey should be conducted while clearing and construction occurs, and for a period of one year post clearing, particularly on sites where piling and burning has occurred and left exposed mineral soil. Aside from the removal of merchantable timber, in a few cases, physical removal of debris from the ROW to another location may be required. This would only occur when: o The vegetation to be cleared on the ROW will create more debris than can be adequately cleaned up on site. o The ROW is in a densely populated urban interface area and fuel hazard concerns have been identified as high risk and or as an issue by stakeholders (i.e., this applies to the high risk zone at the northern end of Narrows Inlet, on a portion of Skookumchuck Narrows, and on the east end of the ROW near Ruby Lake). If the DMZ or the judgement of a qualified professional (RPF) indicates that fuel mitigation is not required, then debris management will default to the minimum standard to fully limb and buck to no more than 2 m lengths and lay flat on the ground. Ensure that the contractor disposes of debris properly, in an environmentally sound manner, and as per the procedures and guidelines in this standard. Burning of heavy slash is not normally recommended for ROWs because of the danger posed to electrical lines and structures. However, if the burning occurs under an approved prescription before the ROW infrastructure is in place and operational, then this may be an appropriate and preferred method of reducing heavy accumulations, particularly where Douglas-fir is the debris species. In cases where burning is appropriate, burning must be done by qualified individuals and under a contract and approved standard set out by Stlixwim Hydro Corporation. Special consideration must be given to fire control B.A. Blackwell & Associates Ltd. 4

10 measures as required by legislation. Any burning requires a burning reference number from the Ministry of Forests and Range and must following burning regulations as specified in the Wildfire Act Regulation. Figure 1. Unacceptable levels of debris left on ROWs following tree removal/slashing/brushing. B.A. Blackwell & Associates Ltd. 5

11 Figure 2. Acceptable levels of debris left on ROWs following tree removal/slashing/brushing and/or chipping. B.A. Blackwell & Associates Ltd. 6

12 3.1 Contractor Guidelines In all DMZ types: Disposal of vegetative debris within private land must be carried out to the satisfaction of the landowner and/or occupant. Remove all debris (excluding chips) within a 2 m radius of planned structures, 5 m of public roads, and within 2 m of Stlixwim Hydro Corp. road/trail edges. Chipped material must not be piled, but is to be spread over the site to a maximum of 20 cm in depth. Fully limb and buck stems (other than Douglas-fir) into 2 m lengths. Lay main stems parallel to each other, but scatter them across the ROW. Limb branches to allow full contact with the ground. No accumulation of slash can exceed 1 m in depth. Where Douglas-fir is present, it is preferable that debris >12 cm in diameter be piled and burned, chipped, or disposed of offsite. If disposal is not possible, debris should be cut into 30 cm lengths and laid flat on the ground in full sunlight, and monitored for infestation of Douglas-fir beetle or ambrosia beetles until the end of the following summer (one full year if clearing occurs in summer). If insect larvae or branch/stem cankers are evident, prune and destroy affected branches and bolewood to reduce the spread of forest insect and disease organisms. In or near all riparian areas, fell trees away from waterways so that stems can be skidded or yarded by machines located well back from the stream. Leave no debris below the high water mark of a water body, or into a water body, without specific regulatory agency approval (i.e., Fisheries and Oceans Canada). Do not leave debris in and around drainage ditches and culvert openings so that it will impede the desired flow of water. Any heavy equipment used for disposal must disturb the ground surface as little as possible. Avoid compaction of soil around retained trees. Avoid direct damage to retained trees and their roots. If trees planned for retention are damaged, they should be removed. Where substantial area (>0.2 ha) of mineral soil is exposed, the area should be replanted with locally successful native plant species, other species that are locally successful, or a high grade seed mix (i.e., Canada No. 1 or Common # 1). Contractors should be familiar with the following invasive species of concern and take the following actions if they are encountered: o Bull thistle: Mow or hand-cut shortly before the plant flowers. If cut too early in the season, plants will re-sprout and flower before the first frost. The uneven flowering times of the species may make it necessary for more than one treatment. B.A. Blackwell & Associates Ltd. 7

13 o Burdock: Mowing or cutting can be used to eliminate seed production. Mow after the plant has bolted but before it has flowered. o English holly: Holly should be removed while it is still young and not producing berries. Young plants should be pulled from moist soil, or cut during dry soil conditions. Mature trees and saplings should be cut below the root crown and berries should be collected for disposal. Cut holly should be stockpiled on a tarp and removed from the site. o Himalayan blackberry: Blackberry should be removed before it becomes established in an area. The canes must be pulled from the ground before they produce berries and canes that are cut as the plant is producing flowers are least likely to re-sprout. Roots should be removed to reduce the opportunity of resprouting. o Orange or meadow hawkweed: Dig out rosettes and their shallow roots in new, small infestations. Stockpile plants on a tarp for removal from the site. Take care not to spread any of the vegetative parts of the plant as re-growth from roots, stolons and rhizomes can occur. Although mowing removes flower stems and may prevent seed set, it should be used with caution as it encourages vegetative spread. o Common tansy: Common tansy cannot be controlled with single mowing events (i.e., once a year), as the plants will respond with an increase in vegetative growth. Mowing very low to the ground before July can prevent seed production but mowing may not be effective without an accompanying herbicide treatment, which is not encouraged on the ROW. The treatment would also have to be repeated over several years. Therefore, hand pulling may be more effective. Gloves and other protective clothing should be worn to prevent skin irritation. o Scotch broom: Cut larger plants below ground level before flowering and seed set. Plants with stems less than 1.5 cm in diameter may be hand pulled, preferably in late spring when the plant is directing its energy to flower and seed production. Due to enormous seed banking and re-sprouting capability (stumps and roots), mechanical treatment may need to be repeated over a 3 to 5 year period. Mechanical control is most effective if all of the plant is removed, seeds are not dropped, and soil disturbance is minimized. Hand pulling can encourage the growth of broom due to the high level of soil disturbance. If pulling will result in significant soil disturbance, plants can be cut as close to the ground as possible. Burning is not an effective control method as broom seeds germinate following a burn. o Oxeye daisy: Mowing may effectively reduce seed production, but should be repeated as it may stimulate vegetative growth. Pulling or digging up plants, ensuring that roots are completely removed, may reduce oxeye daisy numbers and distribution. New shoots may emerge from remaining roots. Follow-up treatments are required as seeds can remain viable in the soil for many years. In DMZ moderate and high areas: Residential areas, groomed areas, specific grazing areas, major roads and recreational trails require either mowing, chipping, piling and burning, or hauling (to a specified B.A. Blackwell & Associates Ltd. 8

14 distance) away of all felled slash. If clearing costs are unacceptable and/or other operational constraints prohibit debris removal, then debris >12 cm in diameter may be left on the ROW at the discretion of a trained professional. Remove fine woody debris unless cost and/or other operational constraints prohibit it. In DMZ high areas, remove the majority of fine and coarse woody debris to the satisfaction of a qualified professional. Create fuel free zones where cost and/or other operational constraints prohibit debris removal or other disposal methods. This will require the input of a qualified professional and it is recommended that site specific prescriptions be developed for sites where debris removal is costly and/or operationally constrained. Where Douglas-fir is present, debris should be cut into 30 cm lengths and laid flat on the ground in full sunlight, and monitored for infestation of Douglas-fir beetle or ambrosia beetles until the end of the following summer (one full year if clearing occurs in summer). 4 Treatment Options by DMZ 4.1 DMZ Low The minimum standard applies: fully limb and buck stems, other than Douglas-fir, into 2 m lengths. Lay main stems parallel to each other, but scatter them across the ROW. Limb branches to allow full contact with the ground. No accumulation of slash can exceed 1 m in depth. Where Douglas-fir is present, it is preferred that debris >12 cm in diameter be piled and burned, chipped, or disposed of offsite. If disposal is not possible, debris should be cut into 30 cm lengths and laid flat on the ground in full sunlight and monitored for infestation of Douglas-fir beetle or ambrosia beetles until the end of the following summer (one full year if clearing occurs in summer). 4.2 DMZ Moderate and High Mowing Where terrain is suitable, use a mower to mulch standing trees and scatter debris. Do not create mulch piles that exceed a depth of 20 cm. Do not allow mulch to be scattered into a water body, watercourse, wetland ditch, road or trail. Mowing is the preferred method where access and machine transportation costs allow Chip and Blow Using a mechanical brush disposal machine, chip the debris into pieces that are 10 cm or less in diameter. For trunks too large to be handled by the chipper, fully limb the stems and chip the debris. Place trunks in rows along the edge of the ROW or scatter, as appropriate. Drag debris to the road from within a zone of 5 m into the ROW, depending on the terrain steepness and size of material (i.e., where terrain enables easier access and/or material is smaller, drag debris from further away). Chip the fuels along the roadside and blow/disperse the chips towards the right-of-way centre. Minimize chips falling within 3 m of the road edge. Do not create chip piles that exceed a depth of 20 cm. Locate the operation where chips cannot be blown B.A. Blackwell & Associates Ltd. 9

15 into a water body, watercourse, wetland ditch, road or trail. Acceptable chipping and dispersal of debris is depicted in Figure 3. Figure 3. Acceptable chipping debris placement and depth for Chip and Blow Pile and Burning Fully limb and buck each stem into 2 m lengths. Drag debris into piles of approximately 4 m radius and not exceeding 3 m in height (assuming that there are no conductors overhead). Ensure that piles are at least 5 m apart. Pile the cut vegetation with stems parallel to each other. Do not place piles within 10 m of the base of a planned structure. Do not place piles within 10 m of the forest edge. Each pile must be partially covered with a sheet of plastic such that a portion of the pile can be easily ignited under winter weather conditions. Acceptable piles are depicted in Figure 4. Figure 4. Acceptable piles for Pile and Burning. B.A. Blackwell & Associates Ltd. 10

16 4.2.4 Mulch Onsite Using a chainsaw, fully limb and buck cut stems into 2 m lengths, mulch all branches and debris, and scatter in the ROW. Mulching is intermediate between chipping and pile and burn. With pile and burn, debris is cut into cm lengths. Use this method when terrain and conditions do not allow the use of a mower, mechanical chipping equipment or piling for burning Fuel Free Zone All new and old dead woody material within the fuel free zone (including stems and small branches) is to be manually moved out of the area, or onto the ROW. Very small material (< 3 cm) can be left if it is scattered and covers less than 50% of the treatment area. Similarly, large material (>12 cm diameter) can be left if it is scattered and covers less than 30% of the treatment area. In both cases, scattered means that there are no accumulations of debris in patches and that there is space between each piece or few pieces of material. Where Douglas-fir is present, debris >12 cm in diameter should be cut into 30 cm lengths and laid flat on the ground in full sunlight, and monitored for infestation of Douglas-fir beetle or ambrosia beetles until the end of the following summer (one full year if clearing occurs in summer). Around planned ROW structures, fuel free zones should be maintained as a 2 m radius area around the base of each ROW tower structure. Fuel free zones in additional strategic locations should be a minimum of 5 m in width. It is not acceptable to locate a fuel free zone beneath an overstory canopy (i.e., within the forest drip zone). The forest edge is defined as the edge of the drip zone (i.e., where the overstory canopy ends) (Figure 5). The fuel free zone method would only be used in areas where mowing, chipping, or piling and burning are not treatment options. B.A. Blackwell & Associates Ltd. 11

17 Unacceptable amount of fine fuel for a fuel free zone Forest edge begins at drip zone (fuel free zone must be located to the right of this arrow) Acceptable debris level for fuel free zone Acceptable debris level for fuel free zone Figure 5. Acceptable fuel free zone placement and debris levels for fuel free zone. 4.3 DMZ High Only Full Clean-up This is only an option for accessible DMZ high areas due to the costs associated with the removal of debris off site. Chip all branches and debris and haul off site. Debris removed from work locations must be disposed of in a manner acceptable to Provincial and local authorities, the owner/agent, and Stlixwim Hydro Corporation. All associated dumping fees are the sole responsibility of the contractor and should be a part of the original bid price. Leave large wood in manageable pieces for firewood or, where agreements are in place with the local Ministry of Forests, Lands and Natural Resource Operations, cut merchantable timber into log lengths and leave the logs in an accessible area. This method would only be used in cases where: B.A. Blackwell & Associates Ltd. 12

18 The ROW is in a densely populated urban interface area and fuel hazard concerns have been identified as an issue by stakeholders (i.e., residents, the Regional District). The vegetation to be cleared on the ROW will create more debris than can be adequately cleaned up on site by mowing, chipping, or piling and burning. 4.4 Summary of Treatment Options by DMZ These recommended treatment options apply by DMZ unless modified based on the judgement of a Qualified Professional (RPF) at the prescription level. Debris Management Zone Treatment Options Low Moderate High Minimum Standard Mowing Chip and Blow Pile and Burning Mulch Onsite Fuel Free Zone Full Clean-up Red = Not a recommended option Green = Recommended option 5 Performance Measures Stlixwim Hydro Corp. will use the following measures to audit the work of the clearing and construction contractor: All vegetation debris disposed of properly, leaving planned ROW structures, drainage ditches, culverts, designated trails, water bodies, and access roads undamaged and free of debris. Slash left on ROWs or along the edges of ROWs, with slash piles no more than 1 m in depth, and no pieces larger than 2 m long. Douglas-fir debris >12 cm diameter should be cut into 30 cm lengths and laid flat on the ground in full sunlight, and free of Douglas-fir beetle and ambrosia beetle infestations. Felled slash chipped or hauled away from residential areas, groomed areas, grazing areas, major roads, and recreational trails. Disposal within private land carried out to the satisfaction of the landowner and/or occupant. No new infestations of invasive species detected. Wood waste disposed of in a preferred, environmentally appropriate manner (i.e., for a compatible use). 6 Resources BC Forest Act. Wildfire Act and Regulation. B.A. Blackwell & Associates Ltd. 13

19 Stlixwim Hydro Corporation Proposed Right-of-Way Debris Management Plan Map 1. Fire risk map. B.A. Blackwell & Associates Ltd. 14

20 Stlixwim Hydro Corporation Proposed Right-of-Way Debris Management Plan Map 2. Debris management zones. B.A. Blackwell & Associates Ltd. 15