Hydropower Planning Assessment Methodology and Fish Passage Improvement A workshop for Local Authority Planners, Environment Agency Staff and Catchment Stakeholders 30 th September 2011 Trentside, Nottingham 2 2 Hydropower Planning Assessment Methodology and Fish Passage Improvement Why is climate change important to us?
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Hydropower Planning Assessment Methodology and Fish Passage
Improvement
A workshop for Local Authority Planners, Environment Agency Staff and Catchment
Stakeholders
30th September 2011
Trentside, Nottingham
22Hydropower Planning Assessment Methodology and Fish Passage Improvement
Why is climate change important to us?
33Hydropower Planning Assessment Methodology and Fish Passage Improvement
Our climate risks
What are we are doing about climate change?
44Hydropower Planning Assessment Methodology and Fish Passage Improvement
What are we are doing about climate
change?
Reduce emissions: reduce demand and increase
Sustainable renewable energy
55Hydropower Planning Assessment Methodology and Fish Passage Improvement
Government drivers for mitigation
� Climate Change Act 2008 - legally commits the UK to reducing CO2 emissions.
� EU Emissions Trading System
� CRC Energy Efficiency Scheme
� The Climate Change Levy
� Climate Change Agreements
� Renewables Obligation
� Feed in tariffs
� Renewable heat incentive
� Renewables 2020 target
66Hydropower Planning Assessment Methodology and Fish Passage Improvement
Hydropower’s role:
� Small but significant contribution – up to 1% energy in 2020 (over 800,000 homes)
� But environmental & physical constraints
� Huge increase in the number of applications
77Hydropower Planning Assessment Methodology and Fish Passage Improvement
The Big Question
�We want more ‘good’ green energy- including
hydropower
�We want more
fish - eels, salmon & the rest
88Hydropower Planning Assessment Methodology and Fish Passage Improvement
The Big Question
Can we have both
?
99Hydropower Planning Assessment Methodology and Fish Passage Improvement
- and emerge alive?
Some other questions
� How can we strike the right balance in the right places?
� Could the planning & environmental impact assessment process be streamlined together to make this easier?
� Cumulative impacts of barriers & HEP schemes ‘in combination’ matter to fish access & health - would a a catchment model + ‘policy/plan/strategy’ help?
� Can we bring all stakeholders together around ‘their common ground’ – i.e. anglers, hydropower developers, conservationists, planners & all functions within the Environment Agency
generate ‘less heat, more light’, better information and an agreed way forward?
1010Hydropower Planning Assessment Methodology and Fish Passage Improvement
(we know its not just fish…)
� A variety of locally specific planning and environmental issues may often dominate a hydropower application
� Flooding
� Bryophytes
� Depleted reach impacts
� Heritage value
� Visual impact
� Hydropeaking, levels
� Screening, Operation etc
1111Hydropower Planning Assessment Methodology and Fish Passage Improvement
So what will we do today?
1212Hydropower Planning Assessment Methodology and Fish Passage Improvement
So what will we do today?
1313Hydropower Planning Assessment Methodology and Fish Passage Improvement
So what will we do today?
1414Hydropower Planning Assessment Methodology and Fish Passage Improvement
Some background…
� Previous phases of national barrier mapping and modelling work
� Water Framework Directive requirement for good ecological status
– weir removal
– depleted reach
– water quality
– habitat change e.g.
– weir pools affected by local changes in hydrodynamics
– shallow areas affected by drying due to water level fluctuations
� flood management responsibilities on main river
� navigation (recreation duties under XXX)
� IDB
� may occasionally be relevant
4242Hydropower Planning Assessment Methodology and Fish Passage Improvement
Case study – Sawley Weir (Trent)
� Overview
� 0.8MWe scheme using two Kaplan turbines
� EIA required
� Cross boundary scheme
(North West Leicestershire and Erewash LPAs)
� Consented
� Key Issues
� Impact on fish populations, particularly -
– proposed fish pass design
– weir pool morphology
– proposed screening
– impact from raising the weir
– impounding effects upstream and associated habitat issues
� Potential impact on Lockington Marsh SSSI
� Hydrology and flood risk -
– impact on outfalls and discharges to the River Trent upstream
– changes to land drainage patterns
� Navigational effects
4343Hydropower Planning Assessment Methodology and Fish Passage Improvement
Case study – Sawley Weir (Trent)
� Objections also received in relation to:
– impact on anglers’ interests
– reduced natural scouring of the river bed caused by slowed river flow
– limited renewable contribution
– non-compliance with the WFD
– requirement for an eel pass
– increased use of the Sawley Flood Lock causing queuing and requiring additional local operators
4444Hydropower Planning Assessment Methodology and Fish Passage Improvement
Case study – Gunthorpe Weir (Trent)
� Overview
� 1.2 MWe scheme comprising 3 “Kaplan” turbines
� EIA required
� Cross-boundary application (Gedling and Rushcliffe)
� Consented
4545Hydropower Planning Assessment Methodology and Fish Passage Improvement
Case study – Gunthorpe Weir (Trent)
� Key Issues
� Ecology including impacts on breeding birds, otters, water voles, badgers, bats, amphibians, invertebrates and macrophytes.
� Fish (including salmon and eel) populations:
– impact of river impoundments
– proposed fish pass design
– proposed screening
– cumulative impacts (due to existing scheme further upstream)
– impact on weirpools
� Flood risk:
– previous application refused due to failure to provided an adequate Flood Risk Assessment
– additional flood risk modelling undertaken
– potential impact of increased flood risk on footpaths
� River geomorphology:
– impact on silt movement and affect on the geomorphology of the river
– potential impact on erosion on The Split (which provides protection to a boatyard)
4646Hydropower Planning Assessment Methodology and Fish Passage Improvement
Challenges for regulators
� External and internal coordination of regulators
� one or more LPAs plus the EA
� internal EA coordination between hydropower permitting and consultation responses on planning applications
� Simplifying application procedure for EA permits
� single point of contact (account manager)
� single application pack
� coordinated decision making
� bring abstraction and impoundment licensing into EPR
� Pre-application consultation – both EA and LPA
� guidance to applicants – specific to hydropower, without extraneous
information (Community guide, GPG – being updated – provides focus)
� pre-application screening form
� aim to ensure that only realistic schemes are submitted and take up time
� does one regulator need to take the lead?
4747Hydropower Planning Assessment Methodology and Fish Passage Improvement
Challenges for developers
� Achieving a scheme that is likely to be permitted before applying
� Understanding permit requirements
� Pre-application consultation
� balance as to when to consult
� Environment Agency
� LPA
� electricity network operator
� local community – including anglers, boat users
� statutory advisors if designated/scheduled features present
4848Hydropower Planning Assessment Methodology and Fish Passage Improvement
Challenges for developers
� Application
� LPA
– Planning application
– Design and Access Statement
� EA only
– Licence/consent applications (multiple)
– Environmental Site Audit checklist/report
� Both
– design details
– environmental statement
– flood risk assessment
– Habitats Regulations assessment – use EA format?
� Monitoring
� Who should do it?
� Who benefits?
4949Hydropower Planning Assessment Methodology and Fish Passage Improvement
Existing policy and guidance
Planning guidance
� National planning policy
� Planning and Climate Change Supplement to Planning Policy Statement (PPS) 1
� PPS 7: Sustainable Development in Rural Areas
� PPS 9: Biodiversity and Geological Conversation
� PPS 22: Renewable Energy
� PPS 25: Development and Flood Risk
� Also, PPG13 (Transport), PPG2 (Green Belt) etc
� Draft National Planning Policy Framework
� Local planning policy
� Existing Local Plans
� Local Development Framework (LDF) Development
Plan Documents
� LDF Supplementary Planning Documents
Issues:
� Does not provide
specific guidance
in relation to HEP
delivery
Issues:
� Existing Local Plan
policies outdated (no
reference to HEP)
� No specific policies
within LDF
documents related to
HEP
5050Hydropower Planning Assessment Methodology and Fish Passage Improvement
Existing policy and guidance
Environment Agency guidance
� Hydropower guidance
� Hydropower community guide
� EA Hydropower Good Practice Guidance (under
revision)
� Fish passage guidance
� Screening intakes and outfalls
� Guidance notes on forms (some not specific to HEP)
� Internal guidance/work instructions
� EA Streamlining the Permitting of Hydropower
Projects in England and Wales
� Other relevant plans
� River Basin Management Plans
� Catchment Flood Management Plans
� Catchment Abstraction Management Plans
Issues:
� Catchment Hydropower
Plans could provide a
mechanism for greater
co-ordination
� EA and LPAs could identify areas/locations
where HEP may be
acceptable (in principle)
Issues:
� Too many different documents
� Some contain
extraneous info
� Guidance on erosion
needed
5151Hydropower Planning Assessment Methodology and Fish Passage Improvement
Issues to consider
� Development of guidance
� no guidance for planners specific to HEP applications identified – is there any?
� should this be separate or incorporated into EA GPG?
� can other guidance be improved/simplified
� geographic guidance (catchment HEP strategies) to discuss this afternoon,
also potential for guidance on text to include in LDF, or SPD on HEP
� Coordination of pre-application discussions involving:
� Developer
� LPA Planning Officer(s)
� EA Staff
� Stakeholders (who? when?)
� Planning decisions by LPAs
� need to be aware of EA requirements and concerns
� cross-boundary applications need good communication from start
� how to assess and attach weight to the range of issues?
� EA staff have received considerable HEP training but more needed to
ensure LPA/EA interactions can be streamlined
� Erosion is a grey area. Who has the expertise to take a lead?
Hydropower Planning Assessment
Methodology and Fish Passage
Improvement
A workshop for Local Authority Planners,
Environment Agency Staff and Catchment
Stakeholders
30th September 2011
Trentside, Nottingham
2 Hydropower Planning Assessment Methodology and Fish Passage Improvement
2
Barriers, hydropower, fish and
risk assessment tool
IAN G. COWX
HULL INTERNATIONAL FISHERIES INSTITUTE,
UNIVERSITY OF HULL
3 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Major
obstructions in
Trent catchment
4 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Typical major obstructions
Borrowash, Derwent
Cromwell Weir
Holme Sluices -
Nottingham
Beeston Weir
5 Hydropower Planning Assessment Methodology and Fish Passage Improvement 5
Issues
Barriers disrupt migration
Restrict access of migratory salmonids,
lamprey and eel to upper catchment
Construction of fish passes has opened up
Trent catchment but connectivity remains
compromised
Recognise large numbers of weirs (LH barriers)
features of rivers since before the 19th century
6 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Distribution of eel and
migration barriers
Result of
stocking?
7 Hydropower Planning Assessment Methodology and Fish Passage Improvement 7
Hydropower development
Barriers offer opportunities for small scale run
of river hydropower development
8 Hydropower Planning Assessment Methodology and Fish Passage Improvement
8
Design - low-head versus high-head schemes
Scheme designed criteria
• River topography
• Flow availability
• Turbine types
• Access to infrastructure
Hydropower development
9 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Hydropower
Installation
design
Structural barrier
to the movement
of aquatic fauna
Risk of fish entrainment
in turbine intakes and
turbine mortality
Altered water
level in depleted
reach
Altered physico-
chemical conditions
in depleted reach Altered structure and
condition of bed,
banks and riparian
zone in depleted
reach
Altered flow
regime in
depleted reach
Altered sediment
dynamics within
depleted reach
and above weir
Flow requirements
for fish passage
facilities
Issues related to run-of-
river hydropower
10 Hydropower Planning Assessment Methodology and Fish Passage Improvement
• Salmon daily rod
catches and flow -
River Exe
• Catches relate to
upstream access that is
regulated by flow over
weirs
0
5
10
15
20
25
30
35
40
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Da
ily s
alm
on
ro
d c
atc
h
0
500
1000
1500
2000
Dis
ch
arg
e a
t T
ho
rve
rto
n (
ML
/d)
0
5
10
15
20
25
30
35
40
45
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Da
ily s
alm
on
ro
d c
atc
h
0
500
1000
1500
2000
Dis
ch
arg
e a
t T
ho
rve
rto
n (
ML
/d)
Disruption to connectivity
• Change in flow dynamics and hydraulics round
barrier or depleted reach
potentially disrupt migration
Modification of flow regime
11 Hydropower Planning Assessment Methodology and Fish Passage Improvement
0
5
10
15
20
25
30
35
Fre
qu
ency
Bellflask
n = 520
0
5
10
15
20
25
30
35
Fre
qu
ency
Westwick Weir
n = 546
0
5
10
15
20
25
30
35
0 8
16
24
32
40
48
56
64
72
80
88
96
10
4
11
2
12
0
12
8
13
6
14
4
15
2
16
0
Length class (mm)
Fre
qu
ency
Boroughbridge Weir
n = 176
0
1
2
3
4
5
Fre
qu
ency
0
1
2
3
4
5
Fre
qu
ency
0
5
10
15
20
25
Fre
qu
ency
Langton Bridge
n = 681
0
5
10
15
20
25
Fre
qu
ency
Thornton Bridge
n = 473
0
5
10
15
20
25
0 8
16
24
32
40
48
56
64
72
80
88
96
10
4
11
2
12
0
12
8
13
6
14
4
15
2
16
0
Length class (mm)
Fre
qu
ency
Myton
n = 618
•Ure •Swale •Length distribution of
Lampetra ammocetes
•in two tributaries of
the Ouse
2002 low flows and
barriers affect adult
migration
Weak recognition of importance of migration to
non-salmonid species
2003 spawning in
both rivers
Modification of flow regime
12 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Modification of flow regime
• Flow - critical component in the economic
viability of run-of-river hydropower schemes
Issues relate to design of schemes
• Minimal impact on peak flows
• Loss of flows is in the middle of the flow range
• Low flows generally protected (Hands off flows)
in Good Practice Guidelines (EA & SEPA) or
inadequate to drive turbines (not economically
viable)
Issues related to run-of-
river hydropower
13 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Modification of flow regime
• Flow - critical component in the economic
viability of run-of-river hydropower schemes
Issues relate to design of schemes
• Minimal impact on peak flows
• Loss of flows is in the middle of the flow range
• Low flows generally protected (Hands off flows)
• Hydropeaking - potential problem with LH
schemes causing water level fluctuations
upstream of impoundment
Issues related to run-of-
river hydropower
14 Hydropower Planning Assessment Methodology and Fish Passage Improvement 14
Hydropower development
Conclusion: impounding structures associated with
small-scale hydropower schemes likely to impede
upstream migration of most fish species in the UK
BUT
Hydropower schemes offer opportunity to improve
connectivity through construction of passage facilities
Note: Potential gains from improved connectivity
provided by scheme conflicts with increased
prevalence of downstream mortality
15 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Mitigation measures
Mitigation measures to ameliorate likely impacts
of various scheme types and scenarios focus on:
• in-take and outfall locations,
• fish passage facilities,
• screen designs,
• User friendly turbine design (recognition that
only effective way to improve survival is to
direct the fish away from the intakes – screens
and bypass channels)
• measures to ameliorate the potential impact of
depleted reaches – allocation of flows
16 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Gap Analysis
• Most information relates to large hydropower schemes
• Little research into small-scale schemes, especially:
• Robust pre- and post- impact monitoring
• Impacts of turbine mortality on populations
• Assessment of cumulative impacts
• Effectiveness of mitigation measures
• Impact of climate change on flows
• Rigour of science supporting some decisions not
defensible
• GPG provides generic assessment but risk-based
strategy should be embedded in guidance
17 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Risk-based guidance for run-of-river hydropower
development - proposed steps (SNIFFER project)
1. design criteria, including hydrological modelling of
potential impact of scheme in affected reach of river;
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
run-of-river hydropower
18 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Risk and uncertainty
REJECT
EVALUATE THE POTENTIAL
IMPACTS OF THE PROPOSED
SCHEME
DEVELOP ALTERNATIVE STRATEGIES
RETURN TO LOOKUP BOX 1
NO
LOOKUP BOX 4: RISK ANALYSIS FLOW CHART
ARE THERE BIOGEOGRAPHICAL OR
HISTORICAL REASONS WHY THE
SCHEME SHOULD NOT OCCUR?
NO
NO
SUMMARISE THE BIOLOGICAL
INFORMATION ON THE SPECIES IN
THE IMPACT REGION
IS THE SCHEME TECHNICALLY
FEASIBLE AND ECONOMICALLY
VIABLE IN THE LONG-TERM?
ARE THERE POTENTIAL ECOLOGICAL
IMPLICATIONS OF THE SCHEME?
GO TO LOOKUP BOX 2
ARE THE PROPOSED MITIGATION
MEASURES ACCEPTABLE?
GO TO LOOKUP BOX 3
NO
NO
NO
YES
ARE THERE MECHANISMS FOR
ELIMINATING POTENTIAL
IMPACTS?
SEE NOTES ON BOX 7
ARE THERE MECHANISMS
FOR OVERCOMING
POTENTIAL IMPACTS?
SEE NOTES ON BOX 8
NO
NO
UNDERTAKE FULL IMPACT
ASSESSMENT
YES
Likelihood
Consequence
Insignificant Minor Moderate Major Significant
Rare N L L M M
Unlikely N L M H H
Possible N L H H E
Likely N M H E E
Almost certain N M E E E
Table 7. Risk Matrix. N = negligible; L = low, M = moderate; H =
high; E = extreme
Table 9. Proposed weighting to account for uncertainty of
information about potential risks run-of-river hydropower
scheme
Degree of certainty of risk from scheme
Description Rating scale
High Well established knowledge from assessment and post-project monitoring of existing run-of-river hydropower schemes.
0.5
Medium Knowledge from limited assessment and post-project monitoring of existing run-of-river hydropower schemes, supported by documented ecological and environmental studies
1.0
Low Little or no previous knowledge from assessment and post-project monitoring of existing run-of-river hydropower schemes, and little or no supporting ecological and environmental studies
3.0
19 Hydropower Planning Assessment Methodology and Fish Passage Improvement 19
20 Hydropower Planning Assessment Methodology and Fish Passage Improvement 20
Hydropower development
What fish are where now
Fish impact evidence
How to do the barrier survey?
21 Hydropower Planning Assessment Methodology and Fish Passage Improvement 21
What fish are where now
Need to understand fish community
structure and dynamics
Meta-analysis of NFPD
■ Brown trout
□Other salmonids & grayling
Cyprinids
22 Hydropower Planning Assessment Methodology and Fish Passage Improvement 22
What fish are where now
Need to understand fish community
structure and dynamics
Meta-analysis of NFPD
FCS2 or EFI+
23 Hydropower Planning Assessment Methodology and Fish Passage Improvement 23
What fish are where now
Need to understand fish community
structure and dynamics
Meta-analysis of NFPD
FCS2 or EFI+
Interpretation of migration
pathways and barriers
24 Hydropower Planning Assessment Methodology and Fish Passage Improvement 24
Prioritisation of fish
migration barriers
Need to understand fish community
structure and dynamics
Meta-analysis of NFPD
FCS2
EFI+
Interpretation of migration
pathways and barriers
25 Hydropower Planning Assessment Methodology and Fish Passage Improvement 25
Prioritisation of fish
migration barriers
Methodology - Prioritisation matrix, based on the
National Fish Pass Prioritisation Matrix (Wilson,
2006) and Nunn et al. in press
Data Collection
Develop Prioritisation
Model
Site Visits
&
Identify Fish Passage
Solutions and hydropower development
initiatives
Apply Prioritisation
Model
Prioritisation Results
26 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Data collection - site visits
Identify barriers to migration, compare historical and current distributions by: interrogation of NFPD and consultation with EA staff;
interrogation of other historical reports and records.
Complete section 1 of barrier survey form
Prioritisation of fish
migration barriers
27 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Complete section 1 of barrier survey form - barrier ID
Prioritisation of fish
migration barriers
Voluntary Stakeholder Survey of River Barriers in the Derbyshire Derwent Catchment and Downstream Trent Corridor, October 2011
Barrier Identification
The aim is to improve understanding of existing barriers to fish in order to make better informed decisions on hydropower. NB Surveyors are
responsible for their own safety.
Barrier ID (see
map)
Add this ID to the .xls
name Photographs
Please take photos of the whole barrier and of details (fish pass, spillway, HEP
installation etc)
Barrier Name
Record the date & time of the photos below, note what they show & change the digital photo file name to the
barrier ID.Photo number
River Name Photo Date & time taken Photo shows
Please print & staple to the back or e-mail the
photos in
Barrier Owner 1 whole
Survey Date 2 detail
Surveyor's Name 3 detail
Affiliation Access
Permis
sion
needed
?
(yes/no
)
from
who?
e-mail
Access
route
notes
telephone
(to help
other
visits)
28 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Data collection - site visits
Data on brown trout, Atlantic salmon, coarse fish, grayling, bullhead, brook lamprey, river lamprey, sea lamprey, spined loach, white-clawed crayfish and non-native crayfish.
Barrier features that influence passage
Species-specific assessment of barrier passability
Engineering constraints on solutions
Hydropower development opportunities
Potential fish pass solutions at each site
Complete section 2 of barrier survey form
Prioritisation of fish
migration barriers
29 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Complete section 2 of barrier survey form - barrier details
Prioritisation of fish
migration barriers
Barrier characteristics: Size
Measured or
estimated? Barrier Type:
if other, please
describe
Approx. height metres Weir Dam Lock
Waterf
all Ford
Culver
t Bridge Other
Approx. width metres Profile vertical
steppe
d angled
Sketch plans (barrier, by-pass channels, fish passes, turbines, pools,
labels, distances)
Impounded reach, bypass channels and flow splits
Approx length of upstream impounded
reach metres
Barriers on the bypass
channels?
Are there any leats or bypass channels?
(yes/no) yes no yes no
If yes, approx length of flow depleted
reach metres
Approx flow depth over
barrier
If yes, approx % of total flow going over
the barrier % cm
Fish pass or not
Is there an existing fish pass
(yes/no) yes no
If yes, how effective do you think
it is? What is the heritage value of the weir
(judge & put 1 in box) not at all, 0%
totally
100% (judge & put 1 in box) no value
high
value
If yes, what type of fish pass is
it? Baffled ladder Lock and lift Pre-barrage
Natural
bypass
Rock channel
Existing or proposed hydropower scheme If there is a scheme, is the intake and/or tailrace screened?
Is there a hydropower scheme
NOW? yes no
Is the INTAKE screened?
(yes/no)
if yes,
mesh
size mm
Is there a hydropower scheme
PROPOSED? yes no
Is the TAILRACE screened?
(yes/no)
if yes,
mesh
size mm
if yes, turbine location (barrier or
bypass) Barrier
Bypas
s
Is there any evidence of fish death in downstream passage through
30 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Complete section 2 of barrier survey form - barrier details
Prioritisation of fish
migration barriers
Overflow depth over crest (in centimetres)
Width (in metres) Total flow
Total flow
Depleted reach
Flow % over barrier
Bypass channel or leat
Bypass
barriers?
Impounded reach
31 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Types of fish passes
31
Baffled
Pool - weir
Pool - traverse
Denil
vertical slot
32 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Types of fish passes
32
Larinier Rock chute/bypass channel
33 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Types of hydropower
schemes
33
Archimedes screw
Water wheel
Kaplan
34 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Prioritisation matrix, Complete Section 3 of
survey form.
Obstruction type and height
Existing fish pass type
Ease of rectification - expert judgement
Fish stock status - dominant species groups
Degree to which barriers are limiting – expert judgement.
Percent estimate of current passability
Fish species habitat quantity and quality upstream – estimate of
distance to next barrier and WFD risk categories
Prioritisation of fish
migration barriers
35 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Complete section 3 of barrier survey form - species details
Prioritisation of fish
migration barriers
Upstream fish stocks, habitat suitability and barrier passage assessment (upstream and downstream)
Is there stocking of trout upstream
(yes/no)
How many fish upstream of this
barrier NOW
How suitable is the upstream
habitat?
What % fish pass barrier
upstream?
What % fish pass barrier
downstream?
Salmon & trout
Eels
Coarse fish
Lamprey/grayling
(judge & put 1 in
boxes) None Lots
0% None
suitable
All very
suitable 100% 0% none
All
100% 0% none
All
100%
36 Hydropower Planning Assessment Methodology and Fish Passage Improvement
FIS
H P
AS
ES
S P
RIO
RIT
ISA
TIO
N P
RO
JEC
T
36
5 points
4 points
3 points
2 points
1 point
0 points
Impassible under any conditions
Passage likely during periods of high flow
Passable at all times
Low Priority
High Priority
Prioritisation of fish
migration barriers
Scoring system - barrier passability - species specific
37 Hydropower Planning Assessment Methodology and Fish Passage Improvement
What fish are where now
Habitat quality assessment
Dove
Derwent
38 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Prioritising migration barriers
Scored inputs for the matrices are: Fish stock status (fish biomass or density, scored from 1 to 5).
Degree to which barriers are limiting (the degree to which
barriers and other factors are limiting fish species in the
watercourse, scored from 1 to 5).
Passability (the % passability of each barrier by fish species,
scored from 1 to 5).
Fish species habitat quantity upstream (the quantity of riverine
and stillwater eel habitat upstream of each barrier, up to the next
barrier, scored from 1 to 5).
Fish species habitat quality upstream (the quality of eel habitat
upstream of each barrier, scored from 1 to 5).
39 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Prioritising migration barriers
The output of the matrices is a barrier score (S), derived as:
S = FS × B × Qnr × Qns × Ql × P
where FS is the fish stock status, B is the degree to which barriers
are limiting, Qnr is the riverine habitat quantity upstream, Qns is the
stillwater habitat quantity upstream, Ql is the habitat quality upstream,
and P is the percent passability.
• Each barrier is then ranked according to their barrier score,
identifying priority barriers for passage improvements.
• NOTE: the barriers ranked as highest priority for passage
improvements are not necessarily the most significant migration
barriers!
40 Hydropower Planning Assessment Methodology and Fish Passage Improvement
Prioritisation of eel migration barriers
First two major barriers to eel migration on each main water course flowing into the Humber Estuary identified.
Prioritisation matrix, based on the National Fish Pass Prioritisation Matrix (Wilson, 2006)
Eel score – a function of the eel stock status, the degree to which barriers are limiting, percent passability, eel habitat quantity upstream and eel habitat quality upstream.
Priority – rank of each barriers in terms of eel score.
41 Hydropower Planning Assessment Methodology and Fish Passage Improvement