By Sokhem Pech, Hatfield Consultant and M-Power
Presented at the Mekong Forum on Water, Food and Energy
Phnom Penh, Cambodia
December 7-9, 2011
Session 1: Managing water resources development within a water-food-energy nexus
BC Hydro is a commercial crown corporation owned by the Province of British Columbia. It operates 30 hydroelectric facilities and three natural gas-fueledthermal power plants. It supplies approximately 95% of the population of British Columbia, generating between 43,000 and 54,000 GWh of electricity annually. Two of the major hydroelectric generating stations on the Columbia and Peace rivers supplying about 80% of the province's electricity.
All BC Hydro activities are guided by the Canadian Regulatory Environment.New, replacement or rehabilitation as well as abandoning and decommissioning of hydropower projects in Canada all require Fisheries Act Authorization, which in turn would trigger an Environmental Assessment under the Canadian Environmental Assessment Act.BC hydro and the province recognize that within a hydroelectric system a number of factors can affect fish and their natural habitats. Under the BC Water Act, in order for BC Hydro to be issued a water license they must complete a water use plan for each facility.
BC Hydro protects fish and fish habitat through initiatives that limit the impact of theiroperations near reservoirs, rivers and streams.Their ISO 14001-consistent Environmental Management System (EMS)provides a framework for their staff to plan, operate, check, review and continually improve their environmental management and performance.This system includes best work practices and protocol agreements such as:Protocol agreement: Maintenance Work In and Around Water; and Approved Work Practices: Managing Riparian VegetationTwo other components of this system are:BC Hydro’s water use planning process; and their fish and wildlife compensation program
Water Use Plans are technical documents defining the proposed operating parameters to be applied in the day to day operations of all BC Hydro hydroelectric facilities. Theyrecognize multiple water use objectives by better balancing the social, economic, environmental and recreational uses of water to benefit the public and province. WUPs are based on the outcomes of advisory consultative processes and are designed to:- support BC Hydro's corporate purpose to provide reliable power, at low cost, for generations; and - help meet BC Hydro's objective to build and maintain public support by engaging external constituents—the public, First Nations, our regulators and our shareholder—in a dialogue about options, tradeoffs and priorities in operating our hydroelectric facilities. The Key components of the process are the consultative committee, the recognition of multiple water uses, tradeoff analyses, and monitoring, compliance and review. Some of the groups involved in public participation are:First Nations Environmental organizations Fisheries and Oceans Canada The B.C. Government Communities surrounding our hydroelectric facilities These groups contribute by consulting with BC Hydro about options, tradeoffs and priorities in operating our hydroelectric facilities. Consultation involving these interested parties occurs in the watersheds where BC Hydro operates a hydroelectric facility. The WUP process strives for consensus among these interested parties and uses tradeoff analyses to demonstrate in concrete terms how different allocations of water affect different interestsMonitoring programs completed by environmental consulting firms, RBO etc ensure that operations remain compliant and that operating procedures are achieving desired results. Monitoring and review policies are based on adaptive management principles.
BC Hydro’s Fish and Wildlife Compensation Program (FWCP) has delivered more than 700 projects that conserve and enhance fish, wildlife and their supporting habitats affected by the creation of BC hydro owned and operate generation facilities in the Coastal, Columbia and Peace regions of British Columbia. More than $100 million has been invested in projects since 1988. The FWCP is delivered through joint partnership including BC Hydro, the province of BC, fisheries and oceans Canada and in collaboration with First Nations, local government and community and environmental groups. The funding is awarded through a competitive grant-awarding process to local communities, First Nations, and environmental groups (RBOs)Two examples include:Neilson Lake Wetland Enhancement Project - Enhancement was divided into three stages. A dam or weir structure was built to maintain the integrity of the wetland and to provide a means of manipulating the water level to optimize the vegetation conditions for the wildlife. Level ditching was undertaken to provide travel corridors and potential feeding and nesting sites. And finally, nest boxes and floating islands supplemented the available nesting and resting habitat.
BC Hydro is committed to protecting fish and their habitat from the impact of their operations.They recognize that within a hydroelectric-based system, a number of factors can affect fish in their natural habitats that BC Hydro mitigates through various programs.At reservoirs – changes in water levels affect spawning cycles, change plant life and nutrient levelsAt dams – migration is prevented, downstream movements through water intakes affects survival.Clearing for power lines can reduce stream shade and cover affecting water temperature.
BC Hydro works to minimize impacts in a number of ways:Through adaptive operating strategies, restoration projects, nutrient restoration, and different fish friendly technologies.
BC Hydro implementsand provides financial resources to ensure that the environment is considered during all aspects of hydropower activities, this includes environmental monitoring during the construction and operation phases.All projects (expansions, replacements, new projects) have environmental management and monitoring plans. For example, Hatfield Consultants is contracted to complete the environmental management and monitoring for the Waneta Dam Expansion project in Castlegar, BC (top photo). This includes completing the Environmental Impact Assessment, Monitoring Activities, writing the Environmental Management Plan and consulting with key stakeholders on impacts and impact mitigation.Stakeholder in British Columbia and BC Hydro through the WUP process have created adaptive operation strategies. These allow different options to be evaluated to ensure that desired values for the system are being met. An example, is trying to determine the best operating strategy for flow to sustain and improve current level of salmonid smolt production. This involves smolt enumeration programs and experimenting with different flushing flows.Bottom left – rotary screw trap used to catch smolts for enumeration (used to evaluated the number of smolts that outmigrated from reservoir and evaluate number produced in system)Bottom right – inclined plan traps also used for smolt enumeration.
Changes to flow regimes and blocking of longitudinal connectivity can change downstream habitat, such as the loss of off channel nursery habitat, gravel recruitment, loss of wood debris etc. Restoration projects funded through the Fish and Wildlife compensation program allow habitat to be restored. Rehabilitation of sockeye spawning gravel in the gates creek spawning channel – This project focused on replacing spawning habitat with a new gravel source. The intention was to increase sockeye egg to fry survival, stimulate adult sockeye production, and mitigate some of the footprint impacts of the Seton Dam e.g. smolt entrainment mortality and adult migration difficulties
Changes in water levels and blocking of upstream migration affects the nutrient cycles and levels of the system. To mitigate this, BC Hydro uses fertilization programs to help maintain the production of fish food and sustain fish populations.Within this program, liquid nitrogen and phosphorus are added to reservoirs on a weekly/monthly basis depending on size and requirements of the system. To ensure the right amount is added, the reservoirs are monitored on a weekly basis.
The construction of several of BC Hydro hydro-electric facilities resulted in a blockage to fish that previously used the portion of the watershed above the dam. Fish passage is required to re-establish selected species of fish to portions of the watershed that they historically utilized. Various fishways and ladders have been constructed for BC Hydro dams.Fish moving downstream can be drawn through water intakes that also put their survival at risk. BC Hydro uses different methods to help fish safely bypass our installations such as physical and behavioural barriers.
On the Alouette River and Reservoir, several species of Salmon and Sockeye in particular have been block from reaching areas upstream of the dam. Currently, this is overcome using a trap and transport system funding through BC Hydro and in partnership with BC Ministry of Public Safety and Solicitor General, the Alouette River Management Society and Katzie First Nations.Sockeye are trapped at fence and transported over the dam using tanks specially made to fit the back of a truck and the trailer (right photo)
An example of a pool-type fish pass called the vertical slot fishway established on the Seton river in British Columbia (top right photo). Among the pool type, the vertical slot fish pass type is the most appropriate for large rivers provided that (1) the dimensions of pools are suited to the size of the largest fish and the migration intensity to be accommodated; (2) the turbulence, velocities and flow pattern in pools are acceptable to the smaller fish to be passed. Another pool-type fish pass was used along the salmon river in BC (bottom right photo). The general principle behind the pool pass is that the division of the height to be passed into several small drops forming a series of pools. The passage of water from onepool to another is either by surface overflow, through one or more submerged orifices situated in the dividing wall separating two pools, or through one or more notches or slots.
Along the Quinsam River in British Columbia a combination of a pool-type fish way and a natural bypass channel is used to help fish migrate over the dam.Natural bypass channels are characterized by very low gradient and energy is dissipated through a series of riffles or cascades.
BC Hydro has been proactive in its attempts to mitigate long-standing fish impacts when new technologies or opportunities arise. In terms of downstream passage, they have used physical barriers i.e. stopping the fish physically from passing through turbines using screens.These screens guide fish towards a bypassBC hydro at the Puntledge Diversion Dam uses two Eicher screens in the intake penstocks to divert and return juvenile fish to the Puntledge River via fish bypass pipes. Eicher screens consists of a wedge-wire screen installed in a steel penstock at a shallow angle to the flow, and passes fish through a bypass pipe branching from the top of the penstock.
Behaviour barriers such as visual, auditory, electrical or hydrodynamic stimuli are another way of preventing fish from passing through turbines. BC Hydro uses the Louver screen at the Seton Dam. The louvers are a removable line of parallel vertical slats supported by metal guides and floats at an angleto the flow. The louvers partially block the flow from the water surface to a depth of 2.4 m, where the majority of the juvenile fish migrate. The fish are diverted away from the canal intake by both the sweep velocity, which carries them along the louvers and by being discouraged from swimming through the louvers.