River Diversion Hydropower in BC: Impacts, Assessment, and Planning

Transcription

1 River Diversion Hydropower in BC: Impacts, Assessment, and Planning Aaron Hill Adding It All Up Smithers,, BC November 14,

2 All energy development has impacts Credit: Garth Lenz Credit: Damien Gillis

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4 Proposed hydropower development in Northwest BC

5 What is river diversion hydropower (a.k.a. run of river )? Credit: Soren Henrich for Watershed Watch Salmon Society

6 Dam/weir and intake

7 Ashlu River intake construction

8 Reservoir/headpond

9 Penstock and/or tunnel

10 Diversion reach

11 Powerhouse

12 Substation

13 Transmission lines

14 Access roads

15 Aquatic impacts of river diversions Dramatically reduced flows in the diversion reach (often <5% of former flows): Reduces habitat quantity and quality Alters ecosystem processes Altered flow patterns within and below the diversion reach Direct habitat loss and habitat degradation due to project infrastructure

16 McLymont Creek diversion

17 What about fish? Of 42 existing and proposed river diversions that have public information on fish presence: 72% confirmed or suspected fish presence 21% unknown status of fish presence 7% confirmed no fish present Usually resident (non-sea sea-going) fish, but projects have been approved with salmon present through all or most of the diversion reach.

18 Terrestrial impacts of river diversions Permanent industrial infrastructure, remote areas Removal of some wildlife habitats, diminished quality of others Long roads and transmissions lines = habitat fragmentation, loss, degradation Construction disturbances and increased human presence degrade wildlife habitats and lead to human-wildlife conflicts

19 Riparian Loss, East Toba

20 Loss of spray zones

21 Climate change considerations Rising air and water temperatures Longer summer droughts and lower flows Melting glaciers Climate change will exacerbate local impacts of river diversions River diversions may also be negatively affected by climate change (efficiency)

22 Cumulative impacts of river diversions and other land uses

23 Environmental Assessments? Environmental assessment process doesn t t adequately address cumulative impacts: Scope of assessments is too narrow Cumulative impacts almost never deemed problematic Mitigation and adaptive management are the default prescriptions Projects under 50MW are exempt from the BC Environmental Assessment Act

24 Project splitting

25 A path forward A serious look at what s s on the table Determine what impacts are acceptable Ensure that ecosystems & species are not pushed past tipping points Ensure that we get the highest quantity and quality of electricity for the least amount of social and environmental impact.

26 A proposed strategic planning framework for BC Only way to deal with cumulative effects is a strategic assessment at a regional scale This assessment then used for land use planning First Nations, public, stakeholders, involved Many precedents in other jurisdictions

27 Thank you Acknowledgements: Tanis Gower, Andrew Rosenberger, Alison Peatt, Craig Orr

28 Fluctuating flows: ramping Fluctuating flows through the powerhouse and in the diversion reach are caused by operational decisions based on: Reducing diverted flows to meet the IFR Increasing diverted flows to maximize short- term profit opportunity and/or to maximize power generated during high stream flow events Operational shut down or start up for maintenance or due to plant malfunction or transmission line issues

29 Fluctuating flows: ramping Ramping rates must be slow to allow stream life to adapt especially to avoid stranding fish Overly fast ramping rates an issue (diversion reach and downstream of the diversion) Problems with ramping may be one of the most serious aquatic impacts of river diversions Two projects investigated due to fish kills caused by inappropriate ramping rates

30 Operational mishaps Mishaps and emergency shutdowns always possible, particularly in rugged, remote locations Rigour of government/proponent oversight is another issue Known mishaps to date: Miller Creek, Rutherford Creek and Alkolkolex diversion reaches have run dry Tyson Creek released a large sediment plume from excessive drawdown of an alpine lake, that reached the Tzoonie River estuary and Narrows Inlet A TransAlta facility near Canmore,, Alberta (storage hydropower) had a devastating release of flows,, exterminating west-slope slope cutthroat trout in the Spray River

31 Direct habitat loss and degradation In addition to habitat problems caused by low and fluctuating flows, diversions cause habitat loss and degradation through: Habitat conversion (loss of riparian and aquatic habitats) Migration barriers that can affect the viability of fish populations

32 Habitat removal/degradation Permanent vegetation clearing can: affect species at risk remove important riparian vegetation that supports many species and provides ecological linkages in the forest landscape legally remove old growth management areas previously protected from logging remove wildlife trees fragment habitat

33 Roads Roads - serious and well-documented impacts: habitat fragmentation habitat loss barriers to movement and migration wildlife-vehicle collisions changes to habitat use and predator/prey interaction increased hunting pressure and wildlife-human conflicts drainage problems, erosion, sedimentation and landslides

34 Transmission lines Transmission lines come with most of the same impacts as roads, as vegetation is managed differently, creating a new habitat type Electrocution and collisions of bats and birds are additional problems, particularly for the at- risk marbled murrelet.

35 Terrestrial impacts: unaddressed risks Huge species diversity, lack of inventories, mean that proponents can t t be expected to find every species at risk in a project area Lack of data makes it difficult to understand the likely impacts to wildlife populations; adaptive management needed. Even so, some problems can be addressed only by removing development.

36 Cumulative Effects?

37 Conservation Planning

38 A proposed planning process Gather information, examine land use options Model scenarios in public land use planning Monitor land use outcomes and use adaptive management to ensure cumulative impacts are acceptable

39 Public input Land use planning as much about social values as it is about scientific data Tradeoffs between different values are inherent in any land use choice The public and First Nations require meaningful input into development scenarios and final land use plans

40 Getting it right with renewable energy development in BC Give energy conservation high priority Strategic plan or a series of regional strategic plans that include all renewable energy options Develop most energy for the least amount of environmental damage Be global leader in sustainable energy development