Physical Works Terms of Reference

Transcription

1 Physical Works Terms of Reference Williston Targeted Debris Management GMSWORKS #22 Order/Clause: Schedule A 3 (c ) and 5 (a) November 26, 2008

2 1.0 Introduction Terms of Reference for the Peace Water Use Plan Williston Targeted Debris Management This Terms of Reference (ToR) describes the Williston (WLL) Targeted Debris Management project for the Williston Reservoir, previously known as the Targeted Debris Removal project. This is a primary Implementation Project identified by the Peace Water Use Plan Committee (the Committee) in the WLL Dust Control Management Plan and the WLL Access and Navigation Management Plan. The project has been renamed as the term removal does not reflect the range of options available for debris management. The water use planning process for the Peace Project was initiated in February 2001 and completed in May This ToR is submitted in response to the Order (Water Act, section 88, File No /Peace) issued by the Comptroller of Water Rights (CWR) on 9 Aug The Order states in schedule A: 3. The licensee shall submit, within 9 months of the date of this Order, for approval by the Comptroller, terms of reference to: c. conduct a debris field survey and targeted debris removal 5. The licensee shall submit, within 9 months of the date of this Order, for approval by the Comptroller, terms of reference for maintenance and enhancement of reliable and safe navigational access at sites on Williston Lake Reservoir through: a. targeted debris removal following the survey in 3(c) above. Pursuant to a letter from the CWR dated 01 May 2008, the submission date for this ToR was extended to 28 November Existing debris removal programs at Geddes Bay and Tsay Keh Beach will continue under operational and maintenance programs within BC Hydro and are not included within this Terms of Reference. 1.1 First Nations Involvement in ToR Development Pursuant to contractual commitments between BC Hydro and Tsay Keh Dene First Nation (TKD), this ToR was developed through a joint planning process between BC Hydro and TKD. The ToR underwent an initial joint review by BC Hydro and TKD. An external review process followed which provided First Nations and government agencies (i.e., Fisheries and Oceans Canada, Ministry of Forests, and Ministry of Environment) with an opportunity to comment on this document. It is anticipated that TKD will be actively involved in debris management in the Finlay Arm. Costs associated with any First Nations labour are a component of the overall project costs. 2.0 Location of Project The Williston Reservoir, a part of the Mackenzie River Basin, is located in north-eastern British Columbia (Figure 1). The reservoir has three arms, the Finlay, Parsnip, and Peace, BC Hydro 2

3 together covering approximately 1773 square kilometres (km 2 ) (684.6 square miles (miles 2 )) at full pool and has an active storage of 393 Million cubic metres (Mm 3 ) (32 Million acre feet (MAF)). The operating range of the reservoir for power generation is between m ( ft) and m ( ft); although, special circumstances are required to draw the reservoir below m ( ft.). Figure 1: Place Names in Peace Water Use Plan 3.0 Background The Committee recommended a package that included operating constraints and nonoperating programs for the Peace system. One of the non-operating programs recommended by the Committee was the Targeted Debris Removal (renamed WLL Targeted Debris Management) project for Williston Reservoir. The scope of this project is to support the implementation of other projects by removing debris at known problem locations for navigation and safety or at key locations where experimental trials are being conducted. This project will increase the level of debris management that is presently in place on Williston Reservoir. Currently, BC Hydro undertakes debris collection and removal at Geddes Bay and Tsay Keh Dene Beach from time to time. The existing debris management at these two sites will continue independent of the project described within this ToR. The standing stock of debris in the reservoir is significant. Debris accumulation in the reservoir is a result of existing timber not cleared from the area prior to flooding and woody BC Hydro 3

4 debris inputs from outside sources. New debris is believed to enter the reservoir via tributaries during spring flows, forestry barging operations, shoreline erosion, and blowdown. An estimate of the total volume of debris in the reservoir will be determined as part of the WLL Debris Field Survey project, described in the ToR relating to that project. Debris on the Williston Reservoir can be challenging to manage as it generally does not remain in a fixed location. Reservoir operations result in a cycle of deposition and floatation of debris. Annually, the reservoir reaches maximum elevation around the end of August and minimum elevation around the end of April. As water levels recede during the drawdown in the autumn, woody debris floating in the reservoir is deposited along the shoreline. Over the summer, stranded debris will become active in the lake again as the water elevation rises to or beyond the level of stranding. In some cases of unusually high pool, debris may be deposited at high elevations and remain stranded on the shoreline of the lake for years until the water reaches that elevation again. The challenges and complexity of debris management in Williston Reservoir will be addressed by the WLL Debris Field Survey project which includes a component to develop a formal debris management strategy (expected to be complete for Year 3 of WLL Targeted Debris Management). 4.0 Rationale for WLL Targeted Debris Management Williston Reservoir has a large standing stock of debris. Woody debris in an aquatic system can be beneficial for organisms such as fish; however, the significant volume of material has created a number of negative impacts on humans, fish, and wildlife. Movement of debris on and around the reservoir creates navigational hazards and large accumulations can prevent access to and from the reservoir for boats as well as wildlife. Debris scouring the banks may contribute to shoreline erosion, inhibit riparian recruitment of vegetation, and cause the loss of existing vegetation. Fish access to tributaries may also be blocked by debris clogging the mouth of streams. The WLL Targeted Debris Management project will provide debris management in the reservoir over a 10-year period. Debris will be managed in order to: (i) minimize damage to trial sites associated with WUP implementation projects (e.g., Dust Control Trials, Trial Wetlands, and Trial Tributaries), (ii) improve boat safety around boat launches, (iii) improve fish access to tributaries, and (iv) reduce shoreline erosion and destruction to riparian vegetation. Targeted debris management at trial sites will significantly improve the probability of success of the Williston Management Plans. 5.0 Work Plan The work plan for this project consists of the development and implementation of an annual project plan for debris management on the reservoir. The annual project plan will be developed based on (i) an annual reconnaissance debris survey, (ii) site selection procedures for target debris sites and debris handling sites, and (iii) management plan for collected debris. A Debris Management Supervisor will act as the project coordinator and the liaison between the BCH Project Manager and debris contractor(s). Project coordination will involve the general administrative and technical oversight of the project. This task will include but not be limited to: 1) preparation of the annual project plan, 2) budget management, 3) contractor management, 4) logistic coordination, 5) technical oversight, 6) on-site supervision of the BC Hydro 4

5 debris contractor(s), and 7) facilitation of information transfer to the BCH Project Manager and other appropriate project managers. 5.1 Annual Reconnaissance Debris Survey The initial step each year in the annual project plan is a reconnaissance survey to inventory debris fields. The reconnaissance survey will be conducted by plane and, as necessary, vehicle or boat. Debris fields will be photo-documented, georeferenced, their area estimated, and relevant environmental sensitivities documented. Similarly, sites on land where debris may be handled using heavy machinery will also be georeferenced, mapped, and have relevant environmental sensitivities documented. The Debris Management Supervisor will be responsible for determining the timing of the reconnaissance survey and if more than one survey is necessary (i.e., both a spring and autumn reconnaissance) annually. Spring reconnaissance is useful for debris management of the foreshore, around boat ramps, and physical works trial sites. Autumn reconnaissance is useful for management of floating debris. Cost efficiencies in Year 1 may be gained by combining the reconnaissance survey with a an aerial survey conducted as part of the WLL Debris Field Survey. 5.2 Site Selection for Targeted Management of Debris Using the inventory of debris fields/accumulations developed as part of the annual reconnaissance, sites will be chosen for targeted management based on the following criteria (listed in order of priority): 1) WUP project sites (e.g., erosion, dust, wetland, and tributary trial sites) being damaged by debris; 2) where debris is limiting boat access at boat launches and/or damaging boat launches; and 3) accumulation of debris over a large area or in large volumes. The selection process for these sites will also consider other factors such as ease of disposal and the potential impact of debris (e.g., erosion/scouring of shoreline) if not managed. It is expected that the location and number of sites will vary annually based on the position, size of the dynamic debris fields, and foregoing priorities. 5.3 Site Selection for Land-Based Debris Handling Sites Land-based sites for debris handling will be selected by the Debris Management Supervisor as part of the annual work plan. The Debris Management Supervisor will consult the Debris Management Strategy 1 for information or recommended strategies related to debris handling sites. At a minimum (given that a Debris Management Strategy will not be available in Years 1 and 2), the Debris Management Supervisor will consider the following when selecting sites: (i) proximity of debris field/accumulation to the handling site, (ii) accessibility 1 The Debris Management Strategy is developed as a component of the Williston Debris Field Survey project and is expected to be complete by November BC Hydro 5

6 of the handling site by heavy equipment, (iii) potential environmental impacts of debris handling to the area, and (iv) potential archaeological impacts of debris handling to the area. An archaeological specialist and environmental specialist will conduct the appropriate assessments based on the type of debris handling work expected to occur. Assessments will need to be complete prior to debris work commencing at a given site and are described in more detail in section 5.6 (environmental impact assessment) and section 5.7 (archaeological assessment). Presently, the following sites are considered potential land-based debris handling sites: Raspberry Harbour at Ospika; Finlay Bay at the Park (Mile 76); Davis Bay around Chowika; Westin Bay (Peace Arm); Ted Brown Camp log dump on the Finlay River; Billy s Bay on the Ingenika. Others potentially suitable sites may be available but have yet to be identified. Location and suitability (once known) of debris handling sites will be digitally recorded on maps. These maps will be updated annually as new information is acquired. 5.4 Management of Collected Debris The Debris Management Supervisor will use the Debris Management Strategy as a guide in developing the annual plan for managing the collected debris. Given that a Debris Management Strategy will not be available until Year 3 of this Project, pile and burn operations may be the optimal means of managing collected debris in the interim. However, it is not beyond the scope of the Debris Management Supervisor to consider and select, together with the BCH Project Manager, an alternative strategy. Annual considerations may include contacting project coordinators of other Water Use Plan projects, TKD and other First Nations, and local industry to determine if they have a use for debris. Initial contact with potentially interested parties should occur early in the year (or at the end of the previous project year), and then again to those interested during development of the annual project plan. 5.5 Finalization and Implementation of Annual Project Plan The annual project plan will include: o o an annual work scope and schedule for the project including confirming the targeted debris sites, handling sites, and the means for managing collected debris; maps marked with the recommended targeted debris sites and land-based handling sites, as well as locations of debris management from previous years; BC Hydro 6

7 o all relevant archaeological and environmental information associated with the selected targeted debris sites and handling sites as well as the outcome of the assessment of management options. The Debris Management Supervisor, working jointly with TKD with respect to the Finlay Arm, will develop the annual project plan. The Debris Management Strategy will act as a guide for developing the annual project plan when it becomes available. Appropriate government agencies or other interested parties will be sent the annual project plan. 5.6 Environmental Impact Assessment The WUP Committee stressed the importance of environmental values in the Peace River basin. The environmental coordination portion of this project will investigate whether the proposed works may conflict with environmental values at those locations. Prior to work commencing at a given site, a registered professional biologist will evaluate potential impacts that work sites will have on environmental resources, such as fish and fish habitat, wildlife and wildlife habitat, and vegetation. The biologist will be responsible for identifying sensitive areas, suggesting methods for avoiding impacts (e.g., embedded wood should not be moved, or providing mitigation plans for each location, if necessary. The biologist will produce an environmental management plan (EMP) for each site to ensure that potential environmental impacts associated with the work are avoided or minimized. The biologist will also be responsible for identifying areas that are not suitable for handling debris and for recommending alternative sites in the area where impacts could be avoided or minimized. 5.7 Archaeological Assessment The WUP Committee stressed the importance of archaeological sites in the Williston Reservoir during the Water Use Planning process. Prior to work commencing at a given site, an archaeological impact assessment will be conducted. All assessments will be conducted in accordance with the terms and conditions of a Heritage Conservation Act inspection permit. The archaeologist conducting the impact assessment will determine whether a given site can be assessed by map and document review and/or preliminary field reconnaissance, or will require intensive survey and subsurface testing. The archaeologist will be responsible for identifying potential conflicts between the debris management at a given site and any known archaeological sites in accordance with BC Hydro s Best Management Practices (BMP) for heritage resources. Additional information may be gathered through interviews with appropriate First Nations. A site alteration permit will be obtained prior to the initiation of any land altering activities within any identified site that is protected under the Heritage Conservation Act. A detailed report will be prepared by the archaeologist, documenting existing conditions, and including recommendations for mitigating works through project design or for further investigation, if required. 6.0 Design and Deliverables This project includes the following deliverables: BC Hydro 7

8 1. An annual project work plan, including appropriate environmental and archaeological work; 2. Management of debris according to annual project work plan; 3. An annual project final report detailing the following: a. debris work completed for that year including the scope, methodologies, timing, and cost of the work, as well as maps showing work sites (e.g., debris removal and handling sites); b. methodology and results of any assessments completed to address archaeological interests and environmental concerns; c. summary of comments, if any, from government agencies or other interested parties and how they were addressed; and d. recommendations, if any, for improving the project in upcoming years. 7.0 Schedule WLL Targeted Debris Management is scheduled to begin in 2009 (Year 1 of the Williston Management Plans). The following are the annual milestone dates for the work: spring reconnaissance survey April/May; annual project plan proposal April/May; annual project plan finalization April/May; implementation of project plan May-November; autumn reconnaissance survey if required; annual project final report January. 8.0 Cost Objectives The estimated total cost associated for WLL Targeted Debris Management project is $10,788,360 (Table 1). The estimated cost of debris management is $8,191,476 (Table 2). In accordance with BC Hydro s new Aviation Policy, the budget includes the additional cost ($60,000/year) of using a twin engine helicopter over a single engine helicopter. The budget assumes three days per year for flights that require operations within the height-velocity curve. Debris management costs are inflated from 2003 dollars (as budgeted within the Peace WUP Committee Report). The estimated cost for required AIAs, environmental monitoring, and archaeological monitoring is $2,596,884 (Table 3). The estimated cost of the AIAs is highly uncertain as the area of land requiring AIAs is determined annually as part of the annual debris project plan. The budget, in this case, assumes a single engine helicopter is sufficient to meet BC Hydro aviation safety standards. Note that annual costs, in this case, are inflated from 2007 dollars. BC Hydro 8