Developing risk-based solutions to hydropower ... - IFM · Developing risk-based solutions to...
Transcript of Developing risk-based solutions to hydropower ... - IFM · Developing risk-based solutions to...
Developing risk-based solutions to
hydropower development:
lessons from different continents
Ian G. Cowx
Hull International Fisheries Institute
UNIVERSITY OF
Hull International
Fisheries Institute HIFI
Itezhi tezhi –
Zambia
700 MW
Nam Ngum 1
Dam, Lao PDR
Pitlochry, Scotland
Outline
• Hydropower development
globally
• Messages from the Mekong
and Zambia
• Developing risk-based
assessment protocols
Global dam development for: • Hydropower• Supply• Agriculture• Flood mitigation
Global dam development
83%
17%
4
Hydropower
Installation
Structural barrier
to the movement
of aquatic fauna
Risk of fish entrainment
in turbine intakes and
turbine mortality
Altered physico-chemical
conditions in reservoirs
and downstreamHydrogeomorphological
changes in river
functioning
Altered flow regime
in depleted reach
Altered sediment
dynamics above
and below dam
Flow requirements
for fish passage
facilities
Environmental impacts of hydropower
Governance of
resources, social
disruption food security,
livelihoods
Xayaburi
(2012)
Don Sahong
(2014)
8 planned dams on LMB (mainstream) – three under construction.
23 existed dams (> 20 MW) on tributaries
Many more tributary dams are projected or under construction
Mekong Hydropower dams
Pak Beng(2017)
Dams located in the middle and lower part of the basin• Estimated 75% loss of sediment
delivery to lower Mekong• Little change in flow –RoR schemes• Estimated reduction in fish yield by
60+%• loss of ecosystem services in lower
Mekong
Xayaburi
Fish production from Mekong
Yield = 2.5 million tonnes
Value = $17 billion
Protein for 60 million people
Mekong River dam proposals
Pak Beng
Don Sahong
MRC Prior Consultation Process
Alignment against Mekong River Commission Preliminary Design Guidance:• Hydrology and Hydraulics• Sediment and
Geomorphology• Water Quality and Aquatic
Ecology• Fish Passage and Fish Ecology• Socio‐Economic• Dam Safety• Navigation
MRC Prior Consultation Process
OutcomesRedesigning of operational procedures, sediment flushing, navigation channel, fish passage facilities, screening ……Do not address livelihood issues
Xayaburi
Kafue
Flats
Proposed hydropower at
Itezhi-tezhi with daily
hydropeaking 29 – 327
m3 s-1 (= 700 MW)
Kafue Gorge and
proposed lower Kafue
Gorge (900 MW)
Depleted reach – 14 km
Itezhi tezhi
completed 1978:
Regulating reservoir
for Kafue Gorge
Kafue Gorge and Itezhi-tezhi, Zambia
- catch including IUU – 30,000 t /yr
-value US$40 million
-Dependence – 150,000 people
Fisheries as a service
Other livelihoods
Fish farming
Production expanding –
Kafue fisheries 10,000 t -
Sugar, mining,
agriculture
Zambia Sugar Co.
27,000 ha
Kafue lechwe
Tourism and nature conservation
Water
supply
Hydropower Floodplain Agriculture Floodplain Aquaculture Biodiversity
products (RICE) grazing
Fisheries
Water remaining in
reservoirFlow regulation
Duration Timing Frequency Extent
Flow dependant livelihoodsReservoir dependant
livelihoods
Ecosystem services evaluation
Optimise overall benefits
Flow release
optionsLegislation
Water
availabilitySocioeconomic
conditions
Political
imperative
Itezhi-tezhi review outcomes
Water for fish
passage
Fisheries
Optimize for full range of ecosystem services
• Variable evidence of empirical research into hydropower schemes, especially: • Robust pre- and post- impact monitoring• Impacts of turbine mortality of populations• Impacts on other biota and ecosystem services• Assessment of cumulative impacts• Effectiveness of mitigation measures• Impact of climate change on flows
• Science supporting some decisions not defensible• Investment in and design of mitigation measures often
inadequate• Guidance documents incorporate risk-based strategies
Key messages from overseas
Risk based criteria built into design of
measures
• Mitigation – fish passes and turbine
design, screening, allocation of flows…
• Enhancement – aquaculture and stocking
• Offsetting – rarely considered
• Avoidance and optimization – rarely
considered
Environmental Impact design
Recognise dams will be built and water resources development will
occur to meet society demands for energy, food security and
improved livelihoods
But how to minimise impact?
Potential for hydropower in the UK
Barriers in
E&W
Actual hydropower
opportunities
1692 sites
146,280-248,400 kw
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Design - low-head versus high-head schemes
Scheme designed criteriaRiver topographyFlow availabilityTurbine typesAccess to infrastructure
Potential for hydropower in the UK
• Little evidence of research into small-scale schemes. NEEDS: • Robust pre- and post- impact monitoring – linked to
sensitivity and risk analysis• Impacts of turbine mortality on populations• Impacts on other biota• Assessment of cumulative impacts – FISHPIE-GIS & APEM• Effectiveness of mitigation measures
• Allocation of flows• Effectiveness of fish passage and screening options
• Impact of climate change on flows• Design guidance provides generic assessment but would
benefit from risk-based strategies being embedded into guidance –FIThydro: Fishfriendly Innovative Technologies for Hydropower <http://www.fithydro.eu/>
Key issues
Risk-based guidance
for hydropower
development -
proposed steps
(SNIFFER WFD 114
and FIThydro project)1. design criteria,
including hydrological
modelling of potential
impact of scheme in
affected reach of river
–scoping study;
Risk-based assessment of hydropower
Evaluate implementation constraints on likelihood of scheme being economically viable and environmentally acceptable
LOOKUP BOX 1: REVIEW OF FEASIBILITY – PRE-SCREENING
Assess likelihood of meeting the following conditions:
• Technically feasible • Compliance with environmental regulations • Economically viable without feed-in tariff • No significant impact on fisheries and
biodiversity ? [refer to LOOKUP BOX 2] • No significant impact of ecosystem
services
DECISION BOX 1
Is the fisheries assessment based on valid, up-to-date data?
Are the mitigation measures proposed to overcome potential risks to fisheries and biodiversity acceptable? [refer to LOOKUP
BOX 3]
Is there likely to be NO net deterioration in ecological status and ecosystem services?
Is appropriate financial support available?
DECISION BOX 2
Can ecological impact uncertainty be managed?
Are the fisheries risks acceptable?
Is the socio-economic uncertainty acceptable?
Develop proposal for full
assessment and licence
application
Are there mechanisms for
overcoming constraints?
Develop alternative strategies
No
No
Yes
Yes
Yes
Risk-based guidance for hydropower development
- proposed steps (SNIFFER and FIThydro project)1. design criteria, including hydrological modelling of potential
impact of scheme in affected reach of river –scoping study;
2. information on the status and potential impact on fisheries
and biodiversity in the affected reach of river, with emphasis
on potential depleted reach(es) (and other pressures) –
include habitat sensitivity assessment linked to catchment
modelling;
Risk-based assessment of hydropower
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Location of obstructions as
potential candidates for
hydropower development in
England and Wales (EA 2010).
Sensitivity of fish
community types to
abstraction
Initial screening of schemes to habitat sensitivity
Risk-based guidance for hydropower development
- proposed steps (SNIFFER and FIThydro project)1. design criteria, including hydrological modelling of potential
impact of scheme in affected reach of river –scoping study;
2. information on the status and potential impact on fisheries
and biodiversity in the affected reach of river, with emphasis
on potential depleted reach(es) (and other pressures) –
include habitat sensitivity assessment linked to catchment
modelling;
3. review of type of scheme and previous impacts encountered
– risk analysis;
4. specific designs for impoundment, fish passage facilities
(where needed), screening for intake and outfalls; turbine
design and operational protocols – risk analysis;
Risk-based assessment of hydropower
WATER AS A RESOURCE
WATER for LIVELIHOODS
Politics
Food and nutritional security
Employment
Profit
Socio-cultural well-being and values
Biodiversity
Hydropower
Agricultural and industrial usage
Environmental protection –flood mitigation
Water resources development (e.g. hydropower)
derives huge economic and social benefits but
needs to be balanced against other ecosystem
services including fisheries
Natural resource use
The delicate balance!
Potable supply