Managing the Managing the Environmental Impacts of Environmental Impacts of

HydropowerHydropowerScottish R&D ProgrammeScottish R&D Programme

IWRMIWRMStockholmStockholm

November 2008November 2008

Overview of theOverview of thePresentationPresentation

BackgroundBackground

R&D Needs and ScopeR&D Needs and Scope

Methods & TechniquesMethods & Techniques

ConclusionsConclusions

Limited hydro development late 19th Limited hydro development late 19th early 20th Centuryearly 20th Century

NOSHEB formed in 1943 to provide NOSHEB formed in 1943 to provide electricity to highland communitieselectricity to highland communities

NOSHEB were privatised in 1989 and NOSHEB were privatised in 1989 and became part of SSE in 1998became part of SSE in 1998

SSE operate 72 hydropower stations SSE operate 72 hydropower stations (incl. 84 major dams & hundreds of (incl. 84 major dams & hundreds of intakes)intakes)

We generate around 3,200 GWhrs/yr We generate around 3,200 GWhrs/yr (( 40% of current UK renewables) 40% of current UK renewables)

SSE Hydropower SSE Hydropower GenerationGeneration

Mitigation was highly developed for the timeMitigation was highly developed for the time These measures focussed largely on salmonThese measures focussed largely on salmon A new large storage scheme currently being commissioned A new large storage scheme currently being commissioned

Examples of Examples of Existing Mitigation Existing Mitigation

There is already significant There is already significant mitigation on our schemesmitigation on our schemes

These include:These include: compensation flowscompensation flows ‘‘hands off’ flowshands off’ flows freshetsfreshets fish passesfish passes fish countersfish counters smolt screenssmolt screens smolt trapssmolt traps tailrace screenstailrace screens adult fish trapsadult fish traps a hatcherya hatchery

Why does Hydropower matter?Why does Hydropower matter?

Plays an important role in combating climate change:Plays an important role in combating climate change: very low COvery low CO22 lifetime emissions lifetime emissions storage schemes help manage intermittent supplies (e.g. wind)storage schemes help manage intermittent supplies (e.g. wind)

European targets have been set for renewable energy European targets have been set for renewable energy

UK & Scottish Governments have set ambitious targets UK & Scottish Governments have set ambitious targets for renewable electricity and renewable energyfor renewable electricity and renewable energy

Any reduction in output from existing sites will inevitably Any reduction in output from existing sites will inevitably be made up by fossil fuel fired generationbe made up by fossil fuel fired generation

A recent Scottish Govt. sponsored study identified >650 A recent Scottish Govt. sponsored study identified >650 MW of financially & environmentally viable new schemesMW of financially & environmentally viable new schemes

Balance of global environmental benefits vs. local Balance of global environmental benefits vs. local environmental impactsenvironmental impacts

WFD and HydropowerWFD and Hydropower For waterbodies affected by large scale hydropower For waterbodies affected by large scale hydropower

WFD has an objective of Good Ecological Potential (GEP)WFD has an objective of Good Ecological Potential (GEP)

GEP is the best ecological outcome that can reasonably GEP is the best ecological outcome that can reasonably be achieved given the existing type and scale of usebe achieved given the existing type and scale of use

UK environment agencies are defining GEP in terms of UK environment agencies are defining GEP in terms of the ‘alternative approach’ the ‘alternative approach’ (see next slide)(see next slide)

This means considering if ‘missing’ measures are This means considering if ‘missing’ measures are consistent with the existing scale of useconsistent with the existing scale of use

This approach is an admission that the basic science is This approach is an admission that the basic science is not sufficiently well developednot sufficiently well developed

Even using this approach we are not able to fully define Even using this approach we are not able to fully define measures for some problems measures for some problems (e.g. sediment management)(e.g. sediment management)

Definition Definition of GEPof GEP

R&D Needs and ScopeR&D Needs and Scope¹¹ There is a general recognition that hydro-morphology There is a general recognition that hydro-morphology

is linked to ecologyis linked to ecology But a lack of empirical data means we are not able to But a lack of empirical data means we are not able to

predict the ecological effects of changes in hydro-predict the ecological effects of changes in hydro-morphology with any confidence morphology with any confidence

We want to be sure that any measures we implement We want to be sure that any measures we implement really do workreally do work

This will require:This will require: baseline hydro-morphology and ecological surveysbaseline hydro-morphology and ecological surveys long term monitoring following any changeslong term monitoring following any changes

SSE has initiated a number of projects to begin SSE has initiated a number of projects to begin collecting this datacollecting this data

Collaborative R&DCollaborative R&D

We are in the process of setting up a We are in the process of setting up a collaborative research programmecollaborative research programme

We hope that collaboration will:We hope that collaboration will: pool expertise and resourcespool expertise and resources build confidence with regulators and stakeholdersbuild confidence with regulators and stakeholders deliver a better research programmedeliver a better research programme

Partners include the Scottish EPA and other Partners include the Scottish EPA and other research and academic organisationsresearch and academic organisations

The initial aim is to fund a long term (5yr+) The initial aim is to fund a long term (5yr+) post to co-ordinate the research and support post to co-ordinate the research and support publication of peer reviewed paperspublication of peer reviewed papers

Site Based MethodsSite Based Methods¹¹ Geomorphic conditions:Geomorphic conditions:

Grain Size DistributionGrain Size Distribution ArmouringArmouring Sediment DeficitsSediment Deficits

Material finer than 64 mm Material finer than 64 mm (gravel) missing from many (gravel) missing from many areasareas

Clearly some very degraded Clearly some very degraded rivers but tributary inputs rivers but tributary inputs rapidly improve conditionsrapidly improve conditions

Natural rivers are also Natural rivers are also armoured – need for reference armoured – need for reference conditionsconditions

Site Based MethodsSite Based Methods²²

Input data to hydraulic models Input data to hydraulic models and equations to calculate and equations to calculate critical dischargescritical discharges

This can identify This can identify geomorphically effective flowsgeomorphically effective flows

Discharges needed to mobilise current Discharges needed to mobilise current beds (coarse, stable and armoured) can beds (coarse, stable and armoured) can be extremely large (<700 mbe extremely large (<700 m33ss-1-1))

Clear need to look at parallel flow Clear need to look at parallel flow restoration and sediment augmentationrestoration and sediment augmentation

Links to aerial sediment size mappingLinks to aerial sediment size mapping

Aerial Photography Aerial Photography TechniquesTechniques

1. Aerial grain size maps

2. Aerial bathymetry (depth) maps

Sediment Grain Size MapsSediment Grain Size Maps

High resolution digital aerial photography

(e.g. 3cm resolution)

Ground truth data(grain size samples)

Aerial photo-sievingCan be performed post-survey. Ground samples / geo-referencing not strictly necessary.Can be performed on back-dated imagery.

Ground data Requires images and ground samples to be geo-referenced with differential GPS. Cannot be performed on back-dated imagery.Calibrated aerial

grain size maps

OR

Bathymetry (Depth) MapsBathymetry (Depth) Maps

High resolution digital aerial photography

(e.g. 3cm resolution)

Ground truth data(river depth profiles)

Ground DataRequires images to be geo-referenced with differential GPS.

Depth profiles of river must be taken at site of geo-referencing. Profiles must be taken on day of aerial survey to ensure that river level is same as imagery.

Bathymetry maps cannot be produced without accurate ground control or river level data.

Calibrated aerial bathymetry maps

Habitat MapsHabitat MapsAerial grain size maps

Aerial bathymetry maps

Salmonid habitat map

Salmonid habitat requirements

(e.g. optimal spawning = grain size of 25-60mm and depth of 250-500mm)

Other Species?Requires habitat requirements to be defined

Example: Salmon Habitat Example: Salmon Habitat MapMap

Optimal spawning habitat

Sub-optimal spawning

Mixed juvenile (fry, parr)

Passageway (torrent, glide, pool)

Not useable (eg. too shallow)

Traditional walkover survey (Cragg-Hine & Hendry, 1997)

Computer-generated habitat map

DetailedDetailedHabitat Habitat MapMap

Optimal spawning habitat

Sub-optimal spawning

Mixed juvenile (fry, parr)

Passageway (torrent, glide, pool)

Not useable (e.g. too shallow)

Salmon Smolt ProductivitySalmon Smolt Productivity

Eggs: c. 5000 eggs per female 100,000

Fry 0+: 10% survival egg to fry 10,000

Parr 1+: 33% survival fry to parr 3,300

Smolt 2+: 50% survival parr to smolt

1,650Smolt trap

data

(Figures used are for illustrative purposes only)

ConclusionsConclusions There is a clear need to improve our understanding of There is a clear need to improve our understanding of

the links between hydro–morphology and ecologythe links between hydro–morphology and ecology

We are attempting to combine traditional ground We are attempting to combine traditional ground based methods with aerial survey / remote sensing based methods with aerial survey / remote sensing techniquestechniques

The initial results look very positiveThe initial results look very positive

The next steps will be to:The next steps will be to: compare habitat map based predictions with field data compare habitat map based predictions with field data

(e.g. smolt numbers)(e.g. smolt numbers) try to develop habitat maps for other flora / faunatry to develop habitat maps for other flora / fauna try to develop the aerial techniques further try to develop the aerial techniques further (e.g. flow (e.g. flow

velocity)velocity)

If the method works we will apply it at more sites and If the method works we will apply it at more sites and revise our operational practice where we canrevise our operational practice where we can