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

Media responses

Addressing development issues

Experiences from Asia and Africa

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

19

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

23

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