Fishfriendly Innovative Technologies for Hydropower · Assessing the impact of hydropower plants (HPP’s) on different fish species and communities is a key-component supporting

Fishfriendly Innovative Technologies for Hydropower

Funded by the Horizon 2020 Framework Programme of the European Union

D1.3 Fish Population Hazard Index

Project Acronym FIThydro Project ID 727830 Work package 1 Deliverable Coordinator Christian Wolter Authors Christian Wolter1, Richard A. Noble2, Ru-

ben van Treeck1, Johannes Radinger1

1 Leibniz-Institute of Freshwater Ecology and Inland Fisheries (FVB.IGB) 2 University of Hull (UHULL)

Reviewers Colin Bean1, Peter Rutschmann2

1 FIThydro Advisory board 2 Technical University of Munich (TUM)

Deliverable Lead Beneficiary FVB.IGB Dissemination Level Public Delivery Date 31 October 2019 Actual Delivery Date 30 October 2019 Version 1

Acknowledgement

This project has received funding from the European Union’s Horizon 2020 research and in-

novation programme under grant agreement No 727830.

Ref. Ares(2019)6741294 - 30/10/2019

727830 FIThydro - Deliverable 1.3 - Page 2 of 21

Executive Summary Aim

Assessing the impact of hydropower plants (HPP’s) on different fish species and communities

is a key-component supporting decisions during the commission process and operation of

hydropower plants. Therefore, work package 1 “Fish population development in hydropower

affected environments” aimed to develop a Fish Population Hazard Index as a decision and

management tool for environmental impact assessment of hydropower plants. The index

should allow for risk assessment while considering site-specific effects of single hydropower

plants, fish species sensitivity against mortality as well as overarching environmental and

societal development targets for the respective water body.

Methods

These different tasks have been conceptualized as three distinct components: the biological

resilience of species, the operation-related impacts and the site- or group-specific impacts of

hydropower. Here we address the site-specific impact of a HPP and combine species’ sensi-

tivity against mortality (D1.1, van Treeck et al. 2017) and species at risk (D1.2, Wolter et al.

2018) with site-specific water body, habitat and project parameters as well as mitigation

measures to the Fish Population Hazard Index as an assessment tool.

This tool serves as the first step – environmental risk assessment – in the Decision Support

System (DSS) of FIThydro (D5.4). We identified and assessed eight aspects that affect fish

health and that can be used as surrogates for relevant hazards in the context of hydropower

installations:

1. Type of the plant

2. Height of the barrier/dam

3. Installed to average discharge ratio

4. Type of the installed turbines

5. Blade strike rates of Kaplan and Francis turbines

6. Mode of operation

7. Availability of an upstream migration facility

8. Installed fish protection facilities for downstream migration

Because of the extremely high variability of construction details, spatial arrangements, modes

of operation and their various interaction effects on risks for fishes paired with rather limited

availability of empirical data, it was impossible to derive accurate quantitative models for reli-


able risk assessments. Therefore, the assessment approach suggested here uses ordinal,

categorical scores of high, moderate and low risks according to typical impact thresholds ob-

tained from the available data. We individually scored and offset the hazards with the spe-

cies-specific sensitivity (D1.1, van Treeck et al. 2017), conservation concern and guild-

specific considerations and averaged them across a representative sample of fishes that are

native to the respective river. For that, we made use of the knowledge produced for D1.2

(Wolter et al. 2018). The resulting hazard score determines an unmitigated hazard of low,

moderate and high risk, associated with decimal values of 0-0.2, >0.2-0.6 and >0.6-1, respec-

tively.

Further, a set of both technical and operational mitigation measures were identified that we

integrated into the index. These measures include design and configuration of a fine screen,

a downstream bypass and adjusting the operational regime in a more fish-friendly manner.

By implementing mitigation measures the score can be incrementally lowered by 0.1 to a

maximum of 0.3 points, which permits shifts to an overall lower hazard class.

However, the effectiveness of mitigation measures is particularly dependent on the quality of

implementation. This can cause mitigation measures to either work as advertised, work only

to some extent or not work at all. During the compilation and scoring process of the relevant

parameters we therefore always assumed the implemented measures to be fully operational

and a non-fully operational measure is to score like a non-existent one.

Results

The Fish Population Hazard Index is operational and delivers sensible results within real-

world application thresholds. The Excel-based tool “Fish Population Hazard Index” (Appendix

1) and a technical user guide (Appendix 2) are available for download at the page

https://www.fithydro.eu/fphi/.

Conclusions

The Fish Population Hazard Index allows environmental impact assessment of existing and

planned HPPs. It also serves the cumulative impact assessment (D1.4) by providing the po-

tential risk for fish for consecutive HPPs. The Index is further considered as the first step in a

Decision Support System to assess the potential mitigation needs.

https://www.fithydro.eu/fphi/


Table of contents Executive Summary ............................................................................................................... 2

Table of contents .................................................................................................................... 4

1. Background ..................................................................................................................... 5

2. Methods .......................................................................................................................... 5

2.1. Identification and scoring of impact parameters ........................................................ 5

2.2. Identification and scoring of mitigation measures ................................................... 11

2.3. Generating the Fish Population Hazard score ........................................................ 14

3. Results .......................................................................................................................... 17

4. Conclusions ................................................................................................................... 17

5. References .................................................................................................................... 18

6. Appendix ....................................................................................................................... 21

List of figures

Figure 1: Screenshot of the data input sheet of the Fish Population Hazard Index. .............. 14

Figure 2: Screenshot of the impact results sheet of the Fish Population Hazard Index. ........ 15

Figure 3: Screenshot of the final hazard scoring sheet of the Fish Population Hazard Index, combining the impacts of specific hazards with the sensitivity of up to five selected species. 16

List of tables

Table 1: Risk scoring of the barrier height .............................................................................. 6

Table 2: Risk scoring of the type and the plant and its mode of operation. ............................. 8

Table 3: Risk scoring of the probability of entrainment............................................................ 8

Table 4: Risk scoring for turbine type and blade strike rate. ................................................. 11

Table 5: Scoring of the mitigation measure complex fine screen and downstream bypass ... 13

Table 6: Contrasting the impact classes with the species-specific sensitivity score. ............. 16

List of equations

𝑢𝑚𝑖𝑑 = 𝜋 × 𝑑𝑚𝑎𝑥 + 𝑑𝑚𝑖𝑛 × 𝑛120 Equation 1 ............................................................. 10

𝑣𝑖𝑛𝑓𝑙𝑜𝑤 𝐾𝑎𝑝𝑙𝑎𝑛 = 𝑣𝑎𝑥𝑖𝑎𝑙 = 4 × 𝑄𝑡𝑢𝑟𝑏𝜋 × (𝑑𝑚𝑎𝑥2 − 𝑑𝑚𝑖𝑛2) Equation 2....................... 10

𝑣𝑖𝑛𝑓𝑙𝑜𝑤 𝐹𝑟𝑎𝑛𝑐𝑖𝑠 = 𝑣𝑟𝑎𝑑𝑖𝑎𝑙 = 2 × 𝑄𝑡𝑢𝑟𝑏𝜋 × 𝑑𝑚𝑎𝑥 + 𝑑𝑚𝑖𝑛 × 𝐻 Equation 3 ................... 10

𝛽𝐾𝑎𝑝𝑙𝑎𝑛 = −19.802 × 𝑙𝑛𝑢𝑚𝑖𝑑𝑣𝑖𝑛𝑓𝑙𝑜𝑤 + 42.507 Equation 4 ......................................... 10

𝛽𝐹𝑟𝑎𝑛𝑐𝑖𝑠 = −26.951 × 𝑙𝑛𝑢𝑚𝑖𝑑𝑣𝑖𝑛𝑓𝑙𝑜𝑤 + 88.348 Equation 5 ....................................... 10

𝑠𝑟𝑒𝑙_𝑚𝑖𝑑 = 𝑠𝑖𝑛𝛽 × 𝜋 × (𝑑𝑚𝑎𝑥 + 𝑑𝑚𝑖𝑛)2 × 𝑧 Equation 6 ............................................. 11

𝑀𝑀𝑜𝑛𝑡𝑒𝑛 = 0.5 × 𝐿 𝑠𝑟𝑒𝑙_𝑚𝑖𝑑 × 100 Equation 7 ............................................................ 11


1. Background The Fish Population Hazard Index (FPHI) is intended to reflect the threats projected by any planned or already existing hydropower installation and thus, is targeting hydropower fea-tures that directly affect fish mortality. As such, it will be an integral component of FIThydro’s Decision Support System for the design and location of new or relicensed European hydro-power plants. The hazard index presented here has 3 main goals:

1. Provide an assessment of the relative hazard any conceivable hydropower constella-

tion constitutes for fish populations and their specific autecological features, summa-

rized as species-specific sensitivity (van Treeck et al. 2017).

2. Be comprehensive and versatile enough to be used with as many projects in as many

locations, summarized as constellations, as possible.

3. Be of an intuitive and easy-to-use design that allows managers and operators to fol-

low the reasoning of the assessment algorithms in a transparent and comprehensible

manner.

2. Methods We designed the FPHI as a system classifying installations of low, moderate or high risk, re-spectively, as a function of the species-specific sensitivity and general hydropower-induced mortality rates that are documented in literature. This rather broad classification allows ac-counting for the variety of combinations of factors at the single site or installation as well as a significant shortage of empirical, comprehensive data on the effect of particular hydropower aspects on particular species. To that end, we focused on parameters that purely relate to the constructional, operational and technical aspects of a plant and discuss them on the following pages. Parameter thresholds were derived as accurately as possible using empirical data and were otherwise based on expert judgement and most-consensus schemes within the FIThydro General Assembly and associated workshops.

2.1. Identification and scoring of impact parameters

2.1.1. Height of the barrier/dam

A barrier in a river, regardless of its use for the generation of electricity or regulating the water level, poses a severe impact for many species, due to habitat fragmentation, impoundment and direct mortality during downstream passage. Most affected are diadromous species and obligatory freshwater migrants, but also all other occasionally dispersing fishes. Here we as-sess especially the mortality risk resulting from barrier height.

The hazard scoring of the barrier height is shown in Table 1.


Table 1: Risk scoring of the barrier height

Risk class Low Moderate High Barrier height (m) <2 2-10 >10

2.1.2. Upstream migration facilities

There is significant evidence for the importance of unhindered fish migration to sustain fish populations and fisheries by allowing for utilizing all ontogenetically essential habitats. Thus, connectivity is a kind of prerequisite before other measures and fish migration facilities ac-cepted standard today. Therefore, we considered the presence of a fishway as a basic ele-ment of a hydropower plant. Successful upstream migration of fishes through a barrier is mainly achieved by means of fishways. Different types of fishways exist and passage effi-ciency is highly variable and not yet conclusively understood (Roscoe and Hinch 2010). Im-portant denominators, however, seem to be species, size, configuration of their energy budg-et and individual physiological state of the fish, time of the day, temperature, the fishway type and experience of the contractor (Nyqvist et al. 2017; Forty et al. 2016; Bunt et al. 2012) as well as the admission flow of the fish pass in relation to the average river discharge (Wolter and Schomaker 2019). Due to the highly variable and hardly predictable passage efficiency, we do not score the related hazard species-specifically but only as yes, if an upstream migra-tion facility is installed and operational and no, if it is not.

2.1.3. Plant type

Type-specific impacts arise from the unique impact profiles different types of hydropower plants cause in streams. Often, the type of a plant is closely linked to its mode of operation, and many attempts were made to disentangle the various definitions, for example by McManamay et al. (2016). For the purpose of our index we therefore simply differentiate be-tween i) storage plants ii) run of the river plants without reservoir and iii) diversion plants.

2.1.3.1. Storage plants

Storage plants create particularly large impoundments that retain the water for a longer peri-od rather than release it through the turbines directly. Typically, the storage capacity exceeds the several monthly up to annual discharge of the river resulting in a high, almost stagnant water column. This changes the water’s vertical temperature and oxygen distribution and sediment load (Baxter 2003) and spawning and nursing site that are normally characterized by comparably shallow gravel sections overflown by cold, oxygen-rich and swift waters are displaced. Impoundments do not only cause habitat alteration but also disrupt the river conti-nuity (Miranda and Dembkowski 2016), act as a migration barrier (Pelicice et al. 2015) and thus, threaten populations of rheophilic guilds and may cause shifts in fish assemblages (Kruk and Penczak 2009; Penczak and Kruk 2000; Taylor et al. 2002). Due to disorientation


within the impoundment caused by the lack of navigational cues (for example attraction flows), fishes may experience migration delay, energy expenditure and increased mortality by preda-tion (D. W. Roscoe et al. 2011). In our index, a storage/reservoir-type plant is therefore scored as high-risk.

2.1.3.2. Run of the river plants without reservoir

In principle, run of the river (ROR) plants are constructions that are built right into the river and that generate electricity by using the water directly without diverting it to a more remote powerhouse. Run of the river plants can, therefore, have impoundments or reservoirs but can also operate without storing much water, depending on the intended use by the operator and topographic preconditions. In this section, we only address ROR plants without storage ca-pacity. The amount of stream discharge directly relates to the average electricity generation and extreme hydrographs are not realized. We, therefore, assign ROR plants without an im-poundment an only moderate hazard.

2.1.3.3. Diversion plants

Diversion plants typically do not store water in impoundments and thus require only a moder-ate degree of civil work. They divert a defined proportion of the river’s discharge over a pen-stock to the turbines which is then fed back into the original stream bed further downstream. The remaining water in the residual water stretch (which can be as long as tens of kilometres) has a defined minimum discharge (the so-called “environmental flow”). Due to all factors, di-version plants have, by default, the lowest impact on fishes given that environmental flows are maintained.

2.1.2. Modes of operation 2.1.2.1. Hydropeaking

Hydropeaking means the periodical release of water according to temporary electricity de-mands, which results in a distinct hydrograph of very high and very low flows that alternate on an hourly, daily or weekly basis. Hydropeaking can be achieved with various types of hydro-power plants, but are probably most pronounced in storage projects in the headwaters of streams. Generally, high up- and down ramping rates seem to constitute the primary cause for impacts like stranding and displacement of fishes, dewatering of fish habitats, hydromor-phological degradation (erosion) of the stream bed causing habitat loss, increased turbidity and severe disturbance of the macroinvertebrate community, both resulting in reduced food uptake rates and ultimately starvation of fishes (Person 2013; Holzapfel et al. 2017; Tuhtan et al. 2012; Greimel et al. 2015). Some effects are aggravated in degraded, less heterogenic downstream habitats (Boavida et al. 2015). We, therefore, consider hydropeaking as a high-risk operation mode, regardless of the type of the plant.


2.1.2.2. Regular release

Power plants that do not periodically change their electricity generation but display a rather regular flow pattern have a significantly smaller impact on fishes than peaking plants, hazards caused by technical or constructional features notwithstanding. We score this particular mode of operation as a function of the plant type as shown in Table 2.

2.1.2.3. Pump storage

Pump storage power plants can be used both to store energy in times of peak production and to use it in times of high demand. They are compensating differences in production in the power grid and can, therefore -in parts- even replace peak-load (hydropeaking) power plants. Due to their balancing effects, they allow large base-load installations like coal and nuclear power plants a constant generation of electricity, which is economically beneficial. Since their working principle is usually based on a closed-circuit system of water, they may have connec-tion with regular rivers or streams but are typically not an integrated part of them (Yang and Jackson 2011), and we, therefore, expect them to have a rather low to no impact on a natural stream fish community, regardless of the plant type.

Table 2: Risk scoring of the type and the plant and its mode of operation.

Mode of operation

Hydropeaking Regular release Pump storage

Plant type

Diversion High Low Low

ROR High Moderate Low

Storage High High Low

2.1.3. Installed discharge to mean discharge ratio

The baseline probability of a fish passing through the turbines of a hydropower plant increas-es with the amount of stream water that is guided to the turbines rather than through sluice gates, spillways, bypasses or fishways. We, therefore, consider the ratio of the installed to mean discharge an important predictor for actual turbine passage and score this “probability of entrainment” for fishes as shown in Table 3.

Table 3: Risk scoring of the probability of entrainment.

Risk class Low Moderate High

Discharge ratio (𝑄𝑖𝑛𝑠𝑡𝑎𝑙𝑙𝑒𝑑

𝑄𝑚𝑒𝑎𝑛) ≤0.5 >0.5-<1 ≥1


2.1.4. Turbine type

Various types of turbines exist that are designed for very different application scenarios. By default, they cause very different mortality rates in fishes. Generally higher survival rates are associated with Archimedes screws (Edler, Diestelhorst, and Kock 2011; Schmalz 2011) and even higher survival was reported for water wheels (Muller and Wolter 2004) although due to their low efficiency they do not contribute significantly to the electricity production anymore. By contrast, very low survival rates are observed for Ossberger (Gloss and Wahl 1983; Knapp, Kynard, and Gloss 1982), Kaplan and Francis turbines (Calles and Greenberg 2009; Winchell et al. 1992) and virtually no survival is considered for passage through for Pelton turbines. Newly developed turbine concepts like the minimum gap runner (Čada 2001), the very low head turbine (Fraser et al. 2007) or the Pentair Fairbanks turbine (Winter, Bierman, and Griffioen 2012) are associated with moderate mortality rates. We score the default mor-tality rates according to Table 4, but further differentiate the mortality rates (and associated risk class) of Kaplan and Francis turbines by means of blade strike models.

2.1.5. Turbine (blade strike) mortality

Despite various attempts to deflect fishes from entering the turbines or to increase their fish friendliness, mortality at turbine passage remains still very high and most deaths occur at the actual contact of fishes with physical objects of the turbine (Čada 2001; Turnpenny et al. 2000). Predicting when and where a fish would be hit by any physical part while passaging the turbine is difficult. However, the probability of a strike by the turbine blade can be com-puted most accurately for Kaplan and Francis turbines. Generally, models for estimating tur-bine-related mortality at turbines can be grouped into empirical/inductive models and physi-cally-based/deductive models. Following physically-based models, strike probability increases with fish length, number of blades and rotational speed of the turbine and decreases with increasing space between single blades. Rotational speed, in turn, decreases typically with turbine size. Also, the overall survival rate of fish seems to correlate with increasing hydraulic efficiency, that is the highest power output per unit water, of the turbines (Ferguson et al. 2005). For the Fish Population Hazard Index, we apply blade-strike models as provided by general physically-based models following Montén (1985) described in details in the following. This model calculates the probability of a fish striking a blade depending on the length of a fish and the relative space between blades while accounting for the angle of the blade.

In general, a prerequisite for the calculation of physically-based strike mortalities for fish pas-sage through a turbine is knowledge about the velocity vectors within a turbine. For Kaplan and Francis turbines this can be estimated from several input parameters using a two-dimensional projection of the velocity characteristics (i.e. velocity parallelogram) at the turbine entrance (Montén 1985; Ebel 2013; Bell 1990).

To construct the velocity parallelogram, it is necessary to know the following Montén (1985):


1. Blade velocity (at the runner midpoint), denoted umid [m/s] 2. The water’s inflow velocity, denote vinflow (axial in Kaplan, radial in Francis turbines)

[m/s], and 3. The blade angle denoted β

The input parameters for constructing the velocity parallelogram can be obtained and calcu-lated from following input parameters: dmax=outer diameter of the turbine, dmin=inner diameter of the turbine (i.e. hub dimensions), Qturb=water inflow of the turbine (turbine capacity), n=rotational speed (RPM, revolutions per minute), z=number of blades and H=height of guide vanes (only needed for Francis turbines).

The blade velocity u is determined primarily by the revolution rate (RPM) and the by the cir-cumference of the runner (Eq. 1). For the application of the blade velocity in the strike mortali-ty model of Montén (1985), this variable is calculated for the velocity at the midpoint of the blade between the outer and inner diameter umid.

𝑢𝑚𝑖𝑑 = 𝜋 ×(𝑑𝑚𝑎𝑥+𝑑𝑚𝑖𝑛)×𝑛

120 Equation 1

The inflow velocity vinflow is the velocity by which the prevailing amount of water flowing through the turbine is taken into the runner through its entire inflow surface. The inflow is cal-culated perpendicular to the inflow surface which is axial inflow for Kaplan (Eq. 2) and radial inflow for Francis (Eq. 3) turbines. Consequently, vinflow is calculated differently for Kaplan (=vaxial) and Francis (=vradial) turbines.

𝑣𝑖𝑛𝑓𝑙𝑜𝑤 (𝐾𝑎𝑝𝑙𝑎𝑛) = 𝑣𝑎𝑥𝑖𝑎𝑙 =4×𝑄𝑡𝑢𝑟𝑏

𝜋×(𝑑𝑚𝑎𝑥2 −𝑑𝑚𝑖𝑛

2 ) Equation 2

𝑣𝑖𝑛𝑓𝑙𝑜𝑤 (𝐹𝑟𝑎𝑛𝑐𝑖𝑠) = 𝑣𝑟𝑎𝑑𝑖𝑎𝑙 =2×𝑄𝑡𝑢𝑟𝑏

𝜋×(𝑑𝑚𝑎𝑥+ 𝑑𝑚𝑖𝑛)×𝐻 Equation 3

Using the calculated variables umid and vinflow it is then possible to estimate the blade angle β for both Kaplan (Eq. 4) and Francis (Eq. 5) turbines using an empirically estimated relation-ship following (Montén 1985; Ebel 2013).

𝛽𝐾𝑎𝑝𝑙𝑎𝑛 = −19.802 × 𝑙𝑛 (𝑢𝑚𝑖𝑑

𝑣𝑖𝑛𝑓𝑙𝑜𝑤) + 42.507 Equation 4

𝛽𝐹𝑟𝑎𝑛𝑐𝑖𝑠 = −26.951 × 𝑙𝑛 (𝑢𝑚𝑖𝑑

𝑣𝑖𝑛𝑓𝑙𝑜𝑤) + 88.348 Equation 5

For the further calculation of the strike mortality according to the general fish-species-unspecific model of Montén (1985), it is necessary to obtain the relative blade distance that considers both the absolute distance between blades of the turbine and the blade angle β (Eq. 6). This accounts for the fact, that the free space available for fish during passage (i.e. rela-tive opening srel_mid) is, because of the skewed inflow angle, narrower than the absolute dis-tance measured from edge to edge (Montén 1985).


𝑠𝑟𝑒𝑙_𝑚𝑖𝑑 = 𝑠𝑖𝑛 𝛽 ×𝜋×(𝑑𝑚𝑎𝑥+ 𝑑𝑚𝑖𝑛)

2×𝑧 Equation 6

Now, given that we know the relative opening of the turbine blades srel_mid and the fish’s length L it is possible to estimate strike mortality (in %, Eq. 7) for fish passage through a Kaplan/Francis turbine following Montén (1985):

𝑀𝑀𝑜𝑛𝑡𝑒𝑛 =0.5×𝐿

𝑠𝑟𝑒𝑙_𝑚𝑖𝑑× 100 Equation 7

For the purpose of the calculation of the Fish Population Hazard Index and to obtain an ap-propriate estimate of mortality rates for given constructional parameters of Kaplan and Fran-cis turbines we use the maximum length of fish Lmax that can pass through the installed screen at the plant. Ebel et al. (2013) provided empirically derived estimates of the relation-ship between a fish’s width and its length (ratio b) which can be used for calculating meaning-ful values for Lmax. In average over many species, this ratio b is 0.11. Thus, by dividing the bar space of the installed screen by the width ratio b=0.11 we can obtain the maximum length Lmax of most fish (except for eel and other elongated species) that can pass the screen. For example, given a standard fine screen with bar spacing of 20 mm, fish of up to Lmax=18 cm (0.02/0.11=0.18) might be able to pass that screen. Consequently, the estimation of strike mortality in Kaplan and Francis turbines is based on Lmax that is dependent on the local char-acteristics of the screen.

Subsequently, the so obtained strike mortality according to Montén (1985) is categorized into three risk classes. As strike mortality can only be calculated for standard Kaplan and Francis turbines, other turbine types are categorized into appropriate risk classes based on expert judgement as shown in Table 4.

Table 4: Risk scoring for turbine type and blade strike rate.

Risk class High Moderate Low

based on strike mortality for Kaplan and Francis tur-bines

MMonten>20% MMonten=10-20% MMonten<10%

based on other turbine types

Ossberger, Pelton, Kaplan (bulb)

Archimedes screw Kaplan (MGR) Kaplan (VLH) Pentair Fairbanks

Water wheel

2.2. Identification and scoring of mitigation measures

The FPHI aims to comprehensively assess the hazard of a given project, including existing or planned measures to reduce specific hazards to fishes. This section discusses measures that have the potential to mitigate the impacts and hazards described above. These measures do


not include general habitat improvement and comparable rehabilitation measures to improve the ecological status of a different water body assigned for compensation. Mitigation measures considered here are discussed comprehensively by Ebel (2013) and their scoring follows the recommendations based on Ebel's (2013) and others’ investigations. Mitigation measures are scored after completing a full risk evaluation and consecutive scoring of a non-mitigated project so that their effect on the hazard score can be easily explored.

2.2.1. Fish guiding structures

For this tool, we define fish guiding structure as fine screens that are located in the headrace of the power plant to prevent fishes from entering the penstock and should ideally be installed at an angle of <45° horizontally to the streamflow (Ebel 2013). Flow velocity at the screen should not exceed 0.5m/s. The distance between the bars determines the maximum width of a fish being able to pass it. To some extent, the width of the fish also approximates its length, with this relationship being species-specific. Eels and lampreys, for example, maybe of the same width as other fishes but at the same time can be considerably longer. It is, therefore, necessary to consider their particular anatomy when a fine screen is implemented. Studies investigating fish mortality at hydropower plants found a bar-spacing of <20mm associated with appropriate bypasses sufficient to prevent large proportions of migrating fishes from en-tering the turbines (Gosset et al. 2005; Aarestrup et al. 2010; Böttcher et al. 2015) and reduc-ing the bar space to ≤10mm could even lower the passage mortality to less than 10% (Økland et al. 2019, 2017). Some screens (e.g. particular trash racks) that are vertically inclined are fitted with a narrow bar space as well which prevents fishes to pass it following the reasoning described above. However, vertically inclined screens guide fishes to the surface of the water body, which is the counter-intuitive direction for many species experiencing stress. For that reason, we assign screens that are vertically inclined only a mitigation score that is half of that of horizontally inclined screens with a corresponding bar space, assuming the set-up comprises an operational bypass. Guiding structures combining elements of vertically and horizontally inclined screens like Louvers, angled- or curved bar racks are installed at a hori-zontal angle of ideally <45° and feature vertical bars at a varying angle to the incoming water. They have proven similarly efficient in deflecting fishes from the penstock and hence were treated like horizontal fine screens (Table 5). We use the bar space of a fine screen and em-pirical regressions by (Ebel 2013) to derive the maximum length of a fish that can pass through it which, in turn, feeds into the blade strike models (see section 2.1.5). Other deflec-tion devices like optical, acoustic, electric or other barriers have not proven reliable long-term (Böttcher et al. 2015) and are therefore not considered here.

2.2.2. Downstream bypasses

In absence of a dedicated bypass, fishes migrating downstream have to pass through the turbines, spill- or trash gates, and passage efficiency is consequently low (Calles and Greenberg 2009). Simple bypasses at the bottom or the surface may, in theory, improve pas-


sage but the respective passage efficiency has proven highly variable as well (Gosset et al. 2005; Økland et al. 2019). An effective passage option seems to be nature-like fishways, as studies have shown that they can, in fact, provide a passage route for both down- and up-stream migrating species (Nyqvist et al. 2017; Calles and Greenberg 2009). Also bypasses that stretch across the whole water column and are therefore comparably easily accessible when fishes end up in front of the fine screen provide an effective passage option. In absence of a bypass fishes are expected to experience serious passage delays and increased mortali-ty rates.

The efficiency of a fine screen with given constructional features (e.g. bar space, installation angle) is only provided when it is set up in combination with a dedicated downstream bypass. Following literature recommendations, we score the fine screen/downstream bypass setup according to Table 5.

Table 5: Scoring of the mitigation measure complex fine screen and downstream bypass

With bypass Without bypass

Horizontal installa-

tion angle (°) <45 45-<90 90 <45 45-<90 90

Bar

space

(mm)

<10 -0.2 -0.1 0 0 0 0

10-15 -0.1 -0.1 0 0 0 0

>15 0 0 0 0 0 0

Vertical installation

angle (°) <45 45-<90 90 <45 45-<90 90

Bar

space

(mm)

<10 -0.1 -0.0.5 0 0 0 0

10-15 -0.05 -0.0.5 0 0 0 0

>15 0 0 0 0 0 0

2.2.3. Other fish-friendly improvement

It has been demonstrated that many impacts can be considerably reduced in magnitude, sometimes even without making changes to the installed hardware, by operating the plant in a “fish-friendly” manner. Examples include hydropeaking management, turbine management for fish-friendly modes of operation and (retro)fitting of turbines and other power plant struc-tures to increase safe passage for fishes. In general, these operational patterns and technical adjustments are numerous and highly specific for individual constellations. We, therefore, do not catalogue every conceivable measure that specifically targets fish welfare here but assign a general mitigation bonus of -0.1 for a fish-friendly plant management, turbine or other phys-ical structure in place.


2.3. Generating the Fish Population Hazard score

All parameters of the plant, as well as mitigation measures, need to be specified in the corre-sponding sections of the “Input” sheet of the Fish Population Hazard Index excel file (Fig. 1).

Figure 1: Screenshot of the data input sheet of the Fish Population Hazard Index.


The user input generates the parameter-specific impact classes low, moderate or high, shown in the excel sheet “Impact results” (Fig. 2). These impact classes are then contrasted with the species-specific sensitivity score as shown in Table 6 to provide score values for the final assessment. In contrast to the other parameters, the existence of an upstream migration facility is scored differently and independent of the species-specific sensitivity scores. This parameter is scored either yes (resulting in a value of 1) or no (resulting in a value of 3).

Figure 2: Screenshot of the impact results sheet of the Fish Population Hazard Index.


Table 6: Contrasting the impact classes with the species-specific sensitivity score.

Impact class Species’ sensitivity

Highest High Average Moderate Low

High 3 3 2 2 1

Moderate 3 2 2 1 1

Low 2 2 1 1 1

Up to 5 species can be considered by the assessment tool. First, all species of conservation concern that are native to the river stretch at the project’s location are added. If slots for spe-cies remain empty, they are then filled with the most sensitive species of that river stretch. If a species is of conservation concern it is treated as a species of the highest sensitivity class and is assigned the according impact parameter-specific hazard values.

An impact parameter-specific hazard score is then calculated by transforming the hazard val-ues 1, 2 and 3 into decimal numbers of 0, 0.5 and 1 and then averaged across all 5 species of the sample. This is done for each impact. The resulting 6 average hazard values are again averaged. Non-mitigated projects can assume risk classes between “low” (cumulative score between 0 and 0.2), “moderate” (between >0.2 and 0.6) and “high” (between >0.6 and 1). This score can be lowered by a maximum of 0.3 points if all proposed mitigation measures are implemented and fully operational. The final results are displayed in the excel sheet “Hazard score”.

Figure 3: Screenshot of the final hazard scoring sheet of the Fish Population Hazard Index, combining the impacts of specific hazards with the sensitivity of up to five selected species.


3. Results The functionality of the Fish Population Hazard Index and its response towards the different types of impacts can be explored in the “Hazard Score” sheet of the Fish Population Hazard Index excel file. The principal impact classification is categorical as low, medium and high risk, while its decimal scoring between zero and one allows for more differentiated cause-effect analyses and further use of the index in cumulative impact assessments and in the FIThydro Decision Support System.

A version of the Fish Population Hazard Index as operational Excel tool is available for down-load at https://www.fithydro.eu/.

4. Conclusions The Fish Population Hazard Index allows environmental impact assessment of existing and planned HPPs. Its application and calibration still needs further testing starting with selected FIThydro case studies. The index also serves the cumulative impact assessment (D1.4) by providing the potential risk for fish for consecutive HPPs. The index is further considered as first step in a Decision Support System to assess the potential mitigation needs.


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Baxter, R M. 2003. “Environmental Effects of Dams and Impoundments.” Annual Review of Ecology and Systematics 8 (1): 255–83. https://doi.org/10.1146/annurev.es.08.110177.001351.

Bell, Milo C. 1990. “Fisheries Handbook of Engineering Requirements and Biological Criteria.” CORPS OF ENGINEERS PORTLAND OR NORTH PACIFIC DIV.

Boavida, Isabel, José Maria Santos, Teresa Ferreira, and António Pinheiro. 2015. “Barbel Habitat Alterations Due to Hydropeaking.” Journal of Hydro-Environment Research 9 (2). https://doi.org/10.1016/j.jher.2014.07.009.

Böttcher, Heidi, Günther Unfer, Bernhard Zeiringer, Stefan Schmutz, and Markus Aufleger. 2015. “Fischschutz Und Fischabstieg – Kenntnisstand Und Aktuelle Forschungspro-jekte in Österreich.” Österreichische Wasser- Und Abfallwirtschaft 67 (7–8): 299–306. https://doi.org/10.1007/s00506-015-0248-5.

Bunt, C. M., T. Castro-Santos, and A. Haro. 2012. “Performance of Fish Passage Structures at Upstream Barriers to Migration.” River Research and Applications 28 (4): 457–78. https://doi.org/10.1002/rra.1565.

Čada, Glenn F. 2001. “The Development of Advanced Hydroelectric Turbines to Improve Fish Passage Survival.” Fisheries 26 (9): 14–23. https://doi.org/10.1577/1548-8446(2001)026<0014:tdoaht>2.0.co;2.

Calles, O., and L. Greenberg. 2009. “Connectivity Is a Two-Way Street-the Need for a Holistic Approach to Fish Passage Problems in Regulated Rivers.” River Research and Appli-cations 25 (10): 1268–86. https://doi.org/10.1002/rra.1228.

Ebel, Guntram. 2013. “Fischschutz Und Fischabstieg an Wasserkraftanlagen.” Handbuch Rechen-Und Bypasssysteme. Bd 4.

Edler, C., O. Diestelhorst, and M. Kock. 2011. “Untersuchungen Zur Abwanderung Und Schädigung von Fischen an Der Wasserkraftschnecke Untersuchungszeitraum Som-mer Und Herbst 2010. Abschlussbericht Im Auftrag Des Landesfischereiverbandes Westfalen Und Lippe e.V., Münster. – Planungsgemeinschaft Terra Aqu.” Edited by Bochum Planungsgemeinschaft terra aqua. Landesfischereiverband Westfalen und Lippe e.V.

Ferguson, John W, Gene M Matthews, R Lynn McComas, Randall F Absolon, Dean A Brege, Michael H Gessel, and Lyle G Gilbreath. 2005. “Passage of Adult and Juvenile Salm-onids through Federal Columbia River Power System Dams.”

Forty, Michael, Jack Spees, and Martyn C. Lucas. 2016. “Not Just for Adults! Evaluating the Performance of Multiple Fish Passage Designs at Low-Head Barriers for the Up-stream Movement of Juvenile and Adult Trout Salmo Trutta.” Ecological Engineering 94 (September): 214–24. https://doi.org/10.1016/j.ecoleng.2016.05.048.

Fraser, Richard, Claire Deschênes, Claude O’Neil, and Marc Leclerc. 2007. “VLH: Develop-ment of a New Turbine for Very Low Head Sites.” Proceeding of the 15th Waterpower 10 (157): 23–26.


Gloss, Steven P, and James R Wahl. 1983. “Mortality of Juvenile Salmonids Passing through Ossberger Crossflow Turbines at Small-Scale Hydroelectric Sites.” Transactions of the American Fisheries Society 112 (2A): 194–200.

Gosset, C., F. Travade, C. Durif, J. Rives, and P. Elie. 2005. “Tests of Two Types of Bypass for Downstream Migration of Eels at a Small Hydroelectric Power Plant.” River Re-search and Applications 21 (10): 1095–1105. https://doi.org/10.1002/rra.871.

Greimel, Franz, Lisa Schülting, G Wolfram, Elisabeth Bondar-Kunze, Stefan Auer, Bernhard Zeiringer, and Christoph Hauer. 2015. “Hydropeaking Impacts and Mitigation.” River-ine Ecosystem Management; Schmutz, S., Sendzimir, J., Eds, 91–110.

Holzapfel, P., P. Leitner, H. Habersack, W. Graf, and C. Hauer. 2017. “Evaluation of Hy-dropeaking Impacts on the Food Web in Alpine Streams Based on Modelling of Fish- and Macroinvertebrate Habitats.” Science of the Total Environment 575: 1489–1502. https://doi.org/10.1016/j.scitotenv.2016.10.016.

Knapp, William E, Boyd Kynard, and S P Gloss. 1982. “Potential Effects of Kaplan, Ossberger, and Bulb Turbines on Anadromous Fishes of the Northeast United States.”

Kruk, A., and T. Penczak. 2009. “Impoundment Impact on Populations of Facultative Riverine Fish.” In Annales de Limnologie - International Journal of Limnology, 39:197–210. EDP Sciences. https://doi.org/10.1051/limn/2003016.

McManamay, R. A., C. O. Oigbokie, S.-C. Kao, and M. S. Bevelhimer. 2016. “Classification of US Hydropower Dams by Their Modes of Operation.” River Research and Applica-tions 32 (7): 1450–68. https://doi.org/10.1002/rra.3004.

Miranda, Leandro E, and D J Dembkowski. 2016. “Evidence for Serial Discontinuity in the Fish Community of a Heavily Impounded River.” River Research and Applications 32 (6): 1187–95. https://doi.org/10.1002/rra.2936.

Montén, Erik. 1985. Fish and Turbines: Fish Injuries During Passage Through Power Station Turbines. Reports. Stockholm, Sweden: Norstedts Tryckeri. http://scholarworks.umass.edu/fishpassage_reports/549.

Muller, Gerald, and Christian Wolter. 2004. “The Breastshot Waterwheel: Design and Model Tests.” ICE Proceedings-Engineering Sustainability, 203–11.

Nyqvist, D., P. A. Nilsson, I. Alenäs, J. Elghagen, M. Hebrand, S. Karlsson, S. Kläppe, and O. Calles. 2017. “Upstream and Downstream Passage of Migrating Adult Atlantic Salmon: Remedial Measures Improve Passage Performance at a Hydropower Dam.” Ecologi-cal Engineering 102: 331–43. https://doi.org/10.1016/j.ecoleng.2017.02.055.

Økland, Finn, Torgeir B Havn, Eva B Thorstad, Lisa Heermann, Stein Are Saether, Meelis Tambets, Maxim A K Teichert, and Jost Borcherding. 2019. “Mortality of Downstream Migrating European Eel at Power Stations Can Be Low When Turbine Mortality Is Eliminated by Protection Measures and Safe Bypass Routes Are Available.” Interna-tional Review of Hydrobiology, July. https://doi.org/10.1002/iroh.201801975.

Økland, Finn, Maxim A K Teichert, Torgeir B Havn, Eva B Thorstad, Lisa Heermann, Stein Are Sæther, Meelis Tambets, and Jost Borcherding. 2017. “Downstream Migration of European Eel at Three German Hydropower Stations.”

Pelicice, Fernando M., Paulo S. Pompeu, and Angelo A. Agostinho. 2015. “Large Reservoirs as Ecological Barriers to Downstream Movements of Neotropical Migratory Fish.” Fish and Fisheries 16 (4): 697–715. https://doi.org/10.1111/faf.12089.


Penczak, T., and A. Kruk. 2000. “Threatened Obligatory Riverine Fishes in Human-Modified Polish Rivers.” Ecology of Freshwater Fish 9 (1–2): 109–17. https://doi.org/10.1034/j.1600-0633.2000.90113.x.

Person, Emilie. 2013. “Impact of Hydropeaking on Fish and Their Habitat.” EPFL-LCH. Roscoe, D. W., S. G. Hinch, S. J. Cooke, and D. A. Patterson. 2011. “Fishway Passage and

Post-Passage Mortality of up-River Migrating Sockeye Salmon in the Seton River, British Columbia.” River Research and Applications 27 (6): 693–705. https://doi.org/10.1002/rra.1384.

Roscoe, David W, and Scott G Hinch. 2010. “Effectiveness Monitoring of Fish Passage Facili-ties: Historical Trends, Geographic Patterns and Future Directions.” Fish and Fisher-ies 11 (1): 12–33.

Schmalz, Wolfgang. 2011. “Downstream Migration through an Archimedic Hydropower Plant at a Diversion Plant.” WasserWirtschaft-Hydrologie, Wasserbau, Hydromechanik, Gewässer, Ökologie, Boden 101 (7/8): 82–87.

Taylor, Christopher A., Jason H. Knouft, and Tim M. Hiland. 2002. “Consequences of Stream Impoundment on Fish Communities in a Small North American Drainage.” Regulated Rivers: Research & Management 17 (6): 687–98. https://doi.org/10.1002/rrr.629.

Treeck, Ruben van, Jeroen Van Wichelen, Johan Coeck, Lore Vandamme, and Christian Wolter. 2017. “D1.1 Metadata Overview on Fish Response to Disturbance.”

Tuhtan, Jeff A., Markus Noack, and Silke Wieprecht. 2012. “Estimating Stranding Risk Due to Hydropeaking for Juvenile European Grayling Considering River Morphology.” KSCE Journal of Civil Engineering 16 (2): 197–206. https://doi.org/10.1007/s12205-012-0002-5.

Turnpenny, A W H, S Clough, K P Hanson, R Ramsay, and D McEwan. 2000. Risk Assess-ment for Fish Passage through Small, Low-Head Turbines. Atomic Energy Research Establishment, Energy Technology Support Unit, New ….

Winchell, F, H Downing, N Taft, A Churchill, P Martin, and EPRI (Electric Power Research Institute). 1992. “Fish Entrainment and Turbine Mortality Review and Guidelines.” Re-port TR‐101231, Project 2694‐01.

Winter, H V, S M Bierman, and A B Griffioen. 2012. “Field Test for Mortality of Eel after Pas-sage through the Newly Developed Turbine of Pentair Fairbanks Nijhuis and FishFlow Innovations.” IMARES.

Wolter, C. & Schomaker, C. (2019) Fish passes design discharge requirements for successful operation. River Research and Applications, online early. DOI: 10.1002/rra.3399

Yang, Chi-Jen, and Robert B Jackson. 2011. “Opportunities and Barriers to Pumped-Hydro Energy Storage in the United States.” Renewable and Sustainable Energy Reviews 15 (1): 839–44.


6. Appendix

Appendix 1: Fish Population Hazard Index FPHI V1/Oct 2019

Appendix 2: FPHI Technical User Guide

Project Acronym FIThydroProject ID 727830Work package 1Deliverable Coordinator Christian Wolter

AuthorsChristian Wolter1, Richard A. Noble2, Ruben van Treeck1, Johannes Radinger1

1 Leibniz-Institute of Freshwater Ecology and Inland Fisheries (FVB.IGB)2 University of Hull (UHULL)

ReviewersColin Bean1, Peter Rutschmann2

1 FIThydro advisory board2 Technical University of Munich (TUM)

Deliverable Lead Beneficiary FVB.IGB

Dissemination Level PublicDelivery Date 31-Oct-19Actual Delivery Date 30-Oct-19Version 1



AcknowledgementThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 727830.

D1.3 Fish Population Hazard Index (FPHI)

The Fish Population Hazard Index allows environmental impact assessment of existing and planned HPPs. It serves also cumulative impact assessment by providing the potential risk for fish for consecutive HPPs. The Index is further considered as first step in a Decision Support System to assess the potential mitigation needs.

What is the FPHI?The fish population hazard index (FPHI) should allow for risk assessment, while considering constellation specific effects of single hydropower plants, fish species sensitivity against mortality as well as overarching envi-ronmental and societal development targets for the respective water body.

What FPHI doesThe FPHI consists of three distinct components: the biological resilience of species, the operation-related impacts and the site- or group-specific impacts of hydropower. Here we address the site-specific impact of a HPP and combine species’ sensitivity against mortality (D1.1, van Treeck et al. 2017) and species at risk (D1.2, Wolter et al. 2018) with site-specific water body, habitat and project parameters as well as mitigation measures. The different components are offset with each other and result in an overall hazard score between 0 (low risk) to 1 (highest risk).

RESULTS of FPHI

Start using the tool

This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 727830.

www.fithydro.eu@fithydroproject

Note: This is a PDF print out of the FPHI Excel based tool. To download the tool, please go to https://www.fithydro.eu/fphi/

Appendix 1: Fish Population Hazard Index FPHI V1/Oct 2019 PDF printout

Input question Answer

What is the type of the plant? Please Select

What is the height of the barrier (m)? Please Select

What is the plant's total capacity Qinstalled (m³/s)?

What is the river's discharge Qmean (m³/s)?

What type of turbine is installed? Please Select

What is the outer diameter of the turbine (m)?

What is the inner diameter of the turbine (m)?

What is the speed of the turbine at average operation (rpm)?

What is the number of blades of the turbine?

What is the height of the guide vanes for Francis turbines (m)?

What is the mode of operation? Please Select

Is an upstream migration facility installed? Please Select

What is the bar space of the fish guiding structure (mm)?

What is the inclination angle of the fish guiding structure (°)?

What is the orientation of fish guiding structure's inclination? Please Select

Is a downstream bypass installed? Please Select

Are there any other mitigation measures installed? Please select

Notes:

Fish Population Hazard IndexInput Data

This sheet constitutes the main data input window. Here, all necessary questions about the plant's specifications are handled. Some answers can be chosen from a drop-down list while others allow entering of any number. All input cells have an orange background.

All data entered by you is your own and will not be forwarded to or collected by us.

About this sheet:

Go to Hazard Score

This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 727830.

Go to Impact Results


Impact class Answers Impact score

I.1 Height of barrier MISSING INPUTSubparameter I.1.1: Height of barrier (m) Please Select

I.2 Probability of entrainment MISSING INPUTSubparameter I.2.1: Discharge Qinstalled (m³/s) 0Subparameter I.2.2: Discharge Qmean (m³/s) 0Derived subparameter I.2.3: Discharge ratio Qinstalled/Qmean #DIV/0!

I.3 Turbine type MlSSING INPUTSubparameter I.3.1: turbine type Please Select

I.4 Strike mortality MlSSING INPUTSubparameter I.4.1: turbine type Please SelectDerived subparameter I.4.2: Mortality assessment used in the tool Type-specific riskDerived subparameter I.4.3: Max. size of fish able to enter turbines (m) NADerived subparameter I.4.4: calculated mortality rates for Francis/Kaplan (%) NA

I.5 Plant type/Operation mode MISSING INPUTSubparameter I.5.1: Type of the plant Please SelectSubparameter I.5.2: Mode of operation Please Select

I.6 Upstream migration facility MISSING INPUTInstalled or not Please Select

Mitigation class Mitigation score

M.1 Downstream guidance structures MISSING INPUTBar space (mm) 0Degree of screen inclination (°) 0Orientation of screen inclination Please SelectDownstream bypass Please Select

M.2 Other mitgation measures MISSING INPUTFishfriendly operation modes, technical improvements etc. Please select

Final mitigation bonusMISSING INPUT

Notes:

About this sheet:

Fish Population Hazard IndexImpact Results

This sheet shows the translation of the specific, numerical impacts into the impact scores "low", "moderate" and "high". It allows the user to inspect the reasoning of the tool. It does not permit any interaction at this point. When the turbine type selection in the input window is not "Francis" or "Kaplan", I.4 Strike mortality will not be calculated and the impact scores of the two derived subparameters I.4.3 and I.4.4 return an "NA". In that case, the impact score is generated according to the sheet "S2_Look-up tables". (hydropeaking management, turbine management…) for calculating strike mortality based on screen bar space. This sheet does not require any user input.

This project has received funding from the European Union’s Horizon 2020 research and in-novation program under grant agreement No 727830.

Back to Input Data Go to Hazard Score


Cons. concern? Sensitivity Cons. concern? Sensitivity Cons. concern? Sensitivity Cons. concern? Sensitivity Cons. concern? Sensitivity

Hazard Impact score Please select 3.00 Please select 4.50 Please select 4.57 no 3.14 Please select 2.71 Hazard scoreHeight of the barrier MISSING INPUT #N/A

Probability of entrainment MISSING INPUT #N/A

Turbine type MlSSING INPUT #N/A

Strike mortality MlSSING INPUT #N/A

Upstream migration facility MISSING INPUT 1.0

Plant type/operation mode MISSING INPUT #N/A

#N/A #N/A

MISSING INPUT MISSING INPUT

Fish Population Hazard IndexHazard Score

This sheet is the main result window of the Fish Population Hazard Index. It summarizes the impact scores of the impact classes and offsets them with the species-specific sensitivity. It requires the user to add up to 5 species to the tool that are living in the river stretch surrounding the project that the user wishes to assess. All input cells have an orange background and purple text, as well as an input prompt. Main output cells have a light-blue background and bold orange text.

Translation of numerical to categorical risk: 0-0.2 = low; >0.2-0.6 = moderate; >0.6-1 = high.

About this sheet

Unmitigated hazard score

Mitigated hazard score

Mitigation bonus

Notes:

Affected species

#N/A

Thymallus thymallusSpecies 4Species 1 Species 2 Species 3

#N/A#N/A

3#N/A

#N/A#N/A

#N/A#N/A#N/A#N/A

3#N/A

#N/A3

#N/A#N/A3

#N/A

Cottus gobioSpecies 5

#N/A#N/A#N/A

MISSING INPUT

Barbus barbus

#N/A#N/A#N/A#N/A

Anguilla anguillaSqualius cephalus

#N/A3

#N/A#N/A


Back to Input Data Go to Impact Results


Impact – vs Sp. Sensitivity

Species sensitivity class

Impact class 5 4 3 2 1high 3 3 2 2 1

moderate 3 2 2 1 1

low 2 2 1 1 1

Plant

Regular release Hydropeaking Pump storage

Run-of-river (no reservoir) moderate high low

Diversion low high low

Storage high high low

Yes low

No high

Turbine mortality risk High Moderate LowBased on strike mortality for Kaplan and Francis turbines M Monten >20% M Monten =10-

20%M Monten <10%

Based on other turbine types Ossberger, Pelton, Kaplan

(bulb)

Archimedes

scre, Kaplan

(MGR), Kaplan

(VLH), Pentair

Fairbanks

Water wheel

Technical mitigation measures

<45 45-<90 90 <45 45-<90 90

<10 -0.2 -0.1 0 0 0 0

10-15 -0.1 -0.1 0 0 0 0

>15 0 0 0 0 0 0

Notes and references:

Fish Population Hazard IndexLook-up tables - supporting information

About this sheetThis sheet contains the rules after which the tool is generating the impact classes and impact scores. It does not require a user input.

no bypass

Upstream migration facility

bypass

Bar space

Mode of operation

Type


Back to Input Data


Kaplan Francis Formula for Kaplan Formula for Francis

Input parameters no no

Outer diameter [m] d_max 0 0

Inner diameter [m] d_min 0 0

Turbine flow [m3/s] Q_turb 0 0

Rotational speed (RPM) n 0 0

Number of blades z 0 0

Height guide vanes (only Francis) H 0 0

Derived parameters

Inflow velocity [m/s] (axial, radial) v_inflow #DIV/0! #DIV/0! (4*Q_turb)/(pi*(d_max²-d_min²)) (2*Q_turb)/(pi*(d_max + d_min)*H)

Velocity of runner blade at midpoint u_mid 0.00 0.00 (pi*(d_max+d_min)*n)/120 (pi*(d_max+d_min)*n)/120

Blade angle beta [°] beta #DIV/0! #DIV/0! -19.802*ln(u_mid/v_inflow)+42.507 -26.951*ln(u_mid/v_inflow)+88.348

Relative velocity at midpoint v_rel_mid #DIV/0! #DIV/0! v_inflow/sin(beta*(pi/180)) v_inflow/sin(beta*(pi/180))

Absolute flow velocity [m/s] v_abs #DIV/0! #DIV/0!sqrt(u_mid^2+v_rel_mid^2-

(2*u_mid*v_rel_mid*cos(beta*(pi/180))))

sqrt(u_mid^2+v_rel_mid^2-

(2*u_mid*v_rel_mid*cos(beta*(pi/18

0))))

Tangential flow velocity component v_tang #DIV/0! #DIV/0! sqrt(v_abs^2-v_inflow^2) sqrt(v_abs^2-v_inflow^2)

Difference flow velocity component v_diff #DIV/0! #DIV/0! u_mid-v_tang u_mid-v_tang

Blade distance absolute at midpoint s_abs_mid #DIV/0! #DIV/0! (pi*(d_max+d_min))/(2*z) (pi*(d_max+d_min))/(2*z)

Blade distance relative at midpoint s_rel_mid #DIV/0! #DIV/0! s_abs_mid*sin(beta*(pi/180)) s_abs_mid*sin(beta*(pi/180))

Length parameters fish

Screen [mm] screen 0 0

relative body width fish [-]; mean cf. Ebel rel_width 0.11 0.11

relative body width fish [-]; mean cf. Ebel rel_width_eel 0.03 0.03

max. body length for mortality maxL 0.00 0.00 (screen/1000)/rel_width (screen/100)/rel_width

max. body length for mortality (Eel) maxL_eel 0.00 0.00 (screen/1000)/rel_width_eel (screen/1000)/rel_width_eel

Turbine strikeMortality cf. Monten (1985) for target fish size given the

screen M_mont #DIV/0! #DIV/0! (0.500*TL/s_rel_mid)*100 (0.500*TL/s_rel_mid)*100

Mortality cf. Monten (1985) for Eel size given the screen M_mont #DIV/0! #DIV/0! (0.460*TL/s_rel_mid)*100 (0.460*TL/s_rel_mid)*100

Notes:Equations by Ebel 2013, Montén 1985.

Fish Population Hazard IndexStrike Mortality - supporting information

This sheet is providing background information and equations for the strike mortality assessments for Kaplan and Francis turbines. Input parameters are called from the "Input" sheet and the length parameters for fishes are calculated using the bar space of the fine screen. These, in turn, are used in the strike models. Dervied parameters and strike probabilites are only displayed when either "Kaplan" or "Franics" is chosen as turbine type in the "Input" sheet. This sheet does not require any direct user input.


Back to Input Data


Recent nomenclature Family Final_score Final_rounded Migration_type FFH_II FFH_IV FFH_VPlease select Placeholder Placeholder Placeholder Placeholder Placeholder Placeholder Placeholder

Abramis brama Leuciscidae 3.36 3 potamodromous no no no

Achondrostoma arcasii Leuciscidae 2.29 2 resident no no no

Achondrostoma occidentale Leuciscidae 2.14 2 resident no no no

Achondrostoma oligolepis Leuciscidae 2.29 2 resident no no no

Achondrostoma salmantinum Leuciscidae 2.57 3 resident no no no

Acipenser baerii Acipenseridae 4.00 4 potamodromous no no no

Acipenser gueldenstaedtii Acipenseridae 4.71 5 anadromous no no no

Acipenser naccarii Acipenseridae 4.57 5 anadromous no no no

Acipenser nudiventris Acipenseridae 4.57 5 anadromous no no no

Acipenser oxyrinchus Acipenseridae 4.57 5 anadromous no no no

Acipenser ruthenus Acipenseridae 4.36 4 potamodromous no no yes

Acipenser stellatus Acipenseridae 4.57 5 anadromous yes yes no

Acipenser sturio Acipenseridae 4.57 5 anadromous yes no no

Alburnoides bipunctatus Leuciscidae 1.93 2 resident no no no

Alburnus alburnus Leuciscidae 2.14 2 resident no no no

Alburnus chalcoides Leuciscidae 3.79 4 anadromous yes no no

Alburnus mento Leuciscidae 3.50 4 potamodromous yes no no

Alosa alosa Clupeidae 3.71 4 anadromous yes no yes

Alosa fallax Clupeidae 3.71 4 anadromous yes no yes

Alosa immaculata Clupeidae 2.86 3 anadromous no no no

Alosa tanaica Clupeidae 1.86 2 anadromous no no no

Ameiurus melas Ictaluridae 2.57 3 resident no no no

Ameiurus nebulosus Ictaluridae 2.64 3 resident no no no

Anaecypris hispanica Leuciscidae 1.93 2 resident no no no

Anguilla anguilla Anguillidae 4.57 5 catadromous no yes no

Atherina boyeri Atherinidae 2.07 2 resident no no no

Babka gymnotrachelus Gobiidae 2.43 2 resident no no no

Ballerus ballerus Leuciscidae 3.36 3 potamodromous no no no

Ballerus sapa Leuciscidae 4.07 4 anadromous no no no

Barbatula barbatula Nemacheilidae 1.93 2 resident yes no no

Barbus barbus Cyprinidae 4.50 5 potamodromous no no yes

Barbus meridionalis Cyprinidae 2.36 2 resident no no no

Barbus plebejus Cyprinidae 3.50 4 potamodromous yes no yes

Barbus tauricus Cyprinidae 2.93 3 resident no no no

Blicca bjoerkna Leuciscidae 2.86 3 potamodromous no no no

Carassius carassius Cyprinidae 2.79 3 resident no no no

Carassius gibelio Cyprinidae 2.36 2 resident yes no no

Chelon aurata Mugilidae 3.43 3 catadromous yes no yes

Chelon ramada Mugilidae 3.57 4 catadromous no no no

Chondrostoma knerii Leuciscidae 2.00 2 resident no no no

Chondrostoma nasus Leuciscidae 3.79 4 potamodromous no no no

Clupeonella cultriventris Clupeidae 1.21 1 anadromous no no no

Cobitis calderoni Cobitidae 2.21 2 resident no no no

Cobitis elongata Cobitidae 2.57 3 resident no no no

Cobitis elongatoides Cobitidae 2.00 2 resident no no no

Cobitis narentana Cobitidae 2.21 2 resident yes no no

Cobitis paludica Cobitidae 2.36 2 resident no no no

Cobitis taenia Cobitidae 2.21 2 resident yes no no

Coregonus maraena Salmonidae 4.71 5 anadromous no no yes

Cottus gobio Cottidae 2.71 3 resident yes no no

Cottus poecilopus Cottidae 2.93 3 resident no no no

Ctenopharyngodon idella Xenocyprididae 3.86 4 potamodromous yes no yes

Cyprinus carpio Cyprinidae 3.57 4 potamodromous no no no

Esox lucius Esocidae 3.00 3 resident no no no

Eudontomyzon danfordi Petromyzontidae 2.64 3 resident no no no

Eudontomyzon lanceolata Petromyzontidae 2.00 2 resident no no no

Eudontomyzon mariae Petromyzontidae 2.36 2 resident yes no no

Eudontomyzon vladykovi Petromyzontidae 2.36 2 resident no no no

Gambusia holbrooki Poeciliidae 2.00 2 resident no no no

Gasterosteus aculeatus Gasterosteidae 2.00 2 resident no no no

Gobio gobio Gobionidae 2.36 2 resident yes no no

Gobio lozanoi Gobionidae 2.36 2 resident no no no

Gobio obtusirostris Gobionidae 1.71 2 resident no no no

Gymnocephalus baloni Percidae 2.00 2 resident yes no no

Gymnocephalus cernua Percidae 2.07 2 resident no no no

Gymnocephalus schraetzer Percidae 2.64 3 resident yes no yes

Hucho hucho Salmonidae 4.21 4 potamodromous yes no yes

Huso huso Acipenseridae 4.57 5 anadromous no no no

Hypophthalmichthys molitrix Xenocyprididae 3.43 3 potamodromous no no no

Hypophthalmichthys nobilis Xenocyprididae 3.57 4 potamodromous no no no

Iberochondrostoma almacai Leuciscidae 1.64 2 resident no no no

Iberochondrostoma lemmingii Leuciscidae 2.21 2 resident no no no

Iberochondrostoma lusitanicum Leuciscidae 1.36 1 resident no no no

Iberocypris alburnoides Leuciscidae 2.14 2 resident no no no

Knipowitschia caucasica Gobiidae 2.07 2 resident no no no

Knipowitschia longecaudata Gobiidae 1.79 2 resident no no no

Lampetra fluviatilis Petromyzontidae 4.07 4 anadromous yes no yes

Lampetra planeri Petromyzontidae 3.21 3 resident yes no no

Lepomis gibbosus Centrarchidae 2.79 3 resident no no no

Lethenteron zanandreai Petromyzontidae 2.79 3 resident no no no

Leucaspius delineatus Leuciscidae 1.79 2 resident no no no

Leuciscus aspius Leuciscidae 3.86 4 potamodromous yes no no

Fish Population Hazard IndexStrike Mortality - supporting information

About this sheetThis sheet contains all European, native species for which a sensitivity could be calculated (see D1.1). The list is completed with the species' biological

family membership, the sensitivity score, migration type and appearence in the appendix II, IV and V of the European Habitats Directive.

Leuciscus idus Leuciscidae 3.93 4 potamodromous no no no

Leuciscus leuciscus Leuciscidae 2.93 3 resident no no no

Lota lota Loricariidae 3.57 4 potamodromous no no no

Luciobarbus bocagei Cyprinidae 4.00 4 potamodromous no no no

Luciobarbus microcephalus Cyprinidae 3.36 3 potamodromous no no no

Luciobarbus sclateri Cyprinidae 3.71 4 potamodromous no no no

Mesogobius batrachocephalus Gobiidae 2.79 3 resident no no no

Micropterus dolomieu Centrarchidae 3.21 3 resident no no no

Micropterus salmoides Centrarchidae 3.21 3 resident no no no

Misgurnus fossilis Cobitidae 2.50 3 resident yes no no

Mugil cephalus Mugilidae 4.29 4 catadromous no no no

Mylopharyngodon piceus Xenocyprididae 3.86 4 potamodromous no no no

Neogobius fluviatilis Gobiidae 1.93 2 resident no no no

Neogobius melanostomus Gobiidae 2.57 3 resident no no no

Osmerus eperlanus Osmeridae 2.86 3 anadromous no no no

Padogobius bonelli Gobiidae 2.00 2 resident no no no

Pelecus cultratus Leuciscidae 3.43 3 potamodromous no no no

Perca fluviatilis Percidae 2.79 3 resident no no no

Perccottus glenii Odontobutidae 2.43 2 resident no no no

Petroleuciscus borysthenicus Leuciscidae 2.00 2 resident no no no

Petromyzon marinus Petromyzontidae 4.93 5 anadromous yes no no

Phoxinellus alepidotus Leuciscidae 2.71 3 resident no no no

Phoxinellus dalmaticus Leuciscidae 2.71 3 resident yes no no

Phoxinus phoxinus Leuciscidae 2.14 2 resident no no no

Planiliza haematocheila Mugilidae 3.71 4 catadromous no no no

Platichthys flesus Pleuronectidae 3.29 3 catadromous no no no

Polyodon spathula Polyodontidae 3.93 4 potamodromous no no no

Pomatoschistus microps Gobiidae 1.86 2 catadromous no no no

Ponticola kessleri Gobiidae 2.14 2 resident no no no

Ponticola syrman Gobiidae 2.21 2 resident no no no

Proterorhinus semilunaris Gobiidae 1.50 2 resident no no no

Pseudochondrostoma duriense Leuciscidae 2.79 3 potamodromous no no no

Pseudochondrostoma polylepis Leuciscidae 2.93 3 potamodromous no no no

Pseudochondrostoma willkommii Leuciscidae 2.86 3 potamodromous no no no

Pseudorasbora parva Gobionidae 1.79 2 resident no no no

Pungitius pungitius Gasterosteidae 2.57 3 resident no no no

Rhodeus amarus Acheilognathidae 2.21 2 resident yes no no

Romanichthys valsanicola Percidae 2.00 2 resident yes yes no

Romanogobio albipinnatus Gobionidae 1.50 2 resident yes no no

Romanogobio belingi Gobionidae 1.79 2 resident no no no

Romanogobio benacensis Gobionidae 1.71 2 resident no no no

Romanogobio kessleri Gobionidae 1.86 2 resident no no no

Romanogobio uranoscopus Gobionidae 1.86 2 resident no no no

Romanogobio vladykovi Gobionidae 1.79 2 resident yes no no

Rutilus frisii Leuciscidae 3.57 4 anadromous yes no no

Rutilus heckelii Leuciscidae 4.07 4 anadromous no no no

Rutilus meidingeri Leuciscidae 3.50 4 potamodromous yes no no

Rutilus pigus Leuciscidae 3.14 3 potamodromous yes no yes

Rutilus rutilus Leuciscidae 2.57 3 resident no no no

Rutilus virgo Leuciscidae 2.86 3 potamodromous yes no no

Sabanejewia balcanica Cobitidae 1.79 2 resident no no no

Sabanejewia baltica Cobitidae 1.79 2 resident no no no

Sabanejewia romanica Cobitidae 1.43 1 resident no no no

Salmo labrax Salmonidae 4.07 4 anadromous no no no

Salmo marmoratus Salmonidae 3.79 4 resident no no no

Salmo obtusirostris Salmonidae 3.43 3 resident no no no

Salmo salar Salmonidae 4.71 5 anadromous yes no yes

Salmo trutta anadromous Salmonidae 4.79 5 anadromous no no no

Salmo trutta resident Salmonidae 3.36 3 resident no no no

Sander lucioperca Percidae 3.43 3 potamodromous no no no

Sander volgensis Percidae 2.43 2 resident no no no

Scardinius erythrophthalmus Leuciscidae 2.86 3 resident yes no yes

Scardinius plotizza Leuciscidae 2.57 3 resident no no no

Silurus glanis Siluridae 3.00 3 resident no no no

Squalius aradensis Leuciscidae 2.21 2 resident no no no

Squalius carolitertii Leuciscidae 2.21 2 resident no no no

Squalius cephalus Leuciscidae 3.00 3 resident no no no

Squalius illyricus Leuciscidae 2.50 3 resident no no no

Squalius janae Leuciscidae 2.36 2 resident no no no

Squalius microlepis Leuciscidae 2.21 2 resident no no no

Squalius pyrenaicus Leuciscidae 2.57 3 resident no no no

Squalius svallize Leuciscidae 2.14 2 resident no no no

Squalius tenellus Leuciscidae 2.43 2 resident no no no

Squalius torgalensis Leuciscidae 1.43 1 resident no no no

Squalius zrmanjae Leuciscidae 2.29 2 resident no no no

Syngnathus abaster Syngnatidae 2.29 2 resident no no no

Telestes souffia Leuciscidae 3.00 3 resident yes no no

Thymallus thymallus Salmonidae 3.14 3 resident no no yes

Tinca tinca Tincidae 3.50 4 potamodromous no no no

Umbra krameri Umbridae 1.79 2 resident no no no

Vimba vimba Leuciscidae 2.50 3 resident no no no

Zingel streber Percidae 1.93 2 resident no no no

Zingel zingel Percidae 2.86 3 resident yes no no

Notes:

van Treeck et al. 2017: D1.1: Metadata overview on fish response to disturbance.


Back to Input Data


Turbine types

Turbine model

Modes of

operation

Barrier height

(m) Plant type

Turbine

mortality

Qinstalled/Qme

an

Conservation

concern?

Fish guiding

structure (mm)

Fish guiding

structure (°)

Fish guiding

structure

(orientation)

Downstream

migration

Other

mitigation

measures

Upstream

migration

Please Select Please Select Please Select Please Select Please Select Please Select Please Select Please select Please Select Please Select Please Select Please Select Please select Please Select

Archimedes screw Ebel 2013, Table 16Hydropeaking <2 Diversion 0-10 ≥1 yes ≥20 90 Horizontal yes yes yes

Francis Pump storage 2-<10 Run-of-river (no reservoir)>10-30 0.5-<1 no >10-<20 <90-45 Vertical no no no

Francis - Alden Regular release ≥10 Storage >30 <0.5 ≤10 <45

Kaplan

Kaplan - Bulb

Kaplan - MGR

Kaplan - VLH

Ossberger

Pelton

Pentair Fairbanks Nijhuis/FishFlow Innovations

Water wheel

This sheet lists the possible answers of the drop-down input cells in the "Input" and the "Hazard score" sheets. This sheet does not require any user input.

Fish Population Hazard IndexDrop down answers - supporting information

Notes:

About this sheet



Back to Input Data



D1.3 Fish Population Hazard Index – Technical User guide

Project Acronym FIThydro Project ID 727830 Work package 1 Deliverable Coordinator Christian Wolter Authors Christian Wolter1, Richard A. Noble2, Ru-

ben van Treeck1, Johannes Radinger1

1 Leibniz-Institute of Freshwater Ecology and Inland Fisheries (FVB.IGB) 2 University of Hull (UHULL)

Reviewers Deliverable Lead Beneficiary FVB.IGB Dissemination Level Public Delivery Date 31 October 2019 Actual Delivery Date 30 October 2019 Version 1

AcknowledgementThis project has received funding from the European Union’s Horizon 2020 research and inno-

vation programme under grant agreement No 727830.

Note: This is FPHI Technical user guide (Version 1). To download the latest version, please go to:https://www.fithydro.eu/fphi/

Appendix 2: FPHI Technical User Guide

https://www.fithydro.eu/fphi/

727830 FIThydro - FPHI – Technical user guide - Page 2 of 7

Introduction Please refer to Deliverable D1.3 for the introduction and the background of the fish population hazard index tool.

Required Software Full functionality was confirmed for Microsoft Excel 2016, version “professional plus”.

Pre-requisites The Fish Population Hazard Index tool does not require additional software or data but works as a standalone solution. In order to use it, knowledge about turbine types and – in case of Francis or Kaplan turbines – details about the turbine’s technical specifications and furthermore, knowledge about the fish assemblage of the respective stream and conservation concern of single species within is needed. The reasoning behind the tool and its assessment principles are comprehensively described in the Deliverable D1.3.

Scope The tool is designed to screen the potential impact of a given hydropower constellation on fishes relative to other constellations. It provides a coarse assessment ranging between high, moderate and low risk. The assessment is based on a scoring system of a few key features that were identified to have the biggest potential impact on fishes.

Syntax The tool uses a set of parameters that are directly related to the physical and operational fea-tures of a hydropower plant. These parameters are divided into “Impacts” and “Mitigation measures” and assessing these is handled in a stepwise procedure. The tool offsets the as-sessed impacts with the fish species’ intrinsic sensitivity to anthropogenic disturbance and their conservation concern as a measure of prioritizing. Mitigation measures are evaluated species-independently.

The physical and operational features and their specific impacts are labelled I.1-I.6, the mitiga-tion measures are labelled M.1 and M.2. The tool uses only common abbreviations.

Model Structure

Running the tool 1. Data input

Upon starting the tool, the user is required to answer the questions in the “Input” sheet of the file (Figure 1). Input cells always have an orange background. There is two types of input: Free


entering of numbers or choosing the appropriate option from a drop-down list, indicated by the “Please select” prompt. An overview of the drop-down lists used in the tool is given in the “An-swers list” sheet.

Figure 1: Main input window. Questions have to be answered either by entering a value or by chosing the appropriate answer from a drop-down list.

2. Impact results 2.1. Impacts

After all questions in the “Input” sheet are answered the tool generates the impact-specific risk scores of “low”, “moderate” or “high”. This can be inspected in the “Impact results” sheet (Figure 2).

Chose an option

Enter a value


Figure 2: Impact results. Here, all answers of the "Input" window are shown (green background) and translated into an impact-specific score. The entered values are examples. The turbine type “Archimedes screw” has a default type-specific risk score of “moderate” (see sheet “Look-up tables”).

The impact I.4, “Strike mortality” is assessed for Franics and Kaplan turbines using a set of equations that are computed in the “Strike mortality” sheet or by using default risk scores based on literature and most-consensus expert knowledge for all other turbine types, as shown for an Archiemdes screw in Figure 2.

For the calculation of Kaplan or Francis turbine strike mortalty rates the tool requires additional input of turbine specifics (Figure 3). It uses two different sets of information to estimate the necessary input values for the calculation: i) turbine and hydraulic parameters and ii) fish size, approximated using empirical regressions and the width of the fine screen (Figure 4). Both result in a size-and turbine specific mortality rate that is displayed in the “Impact results” sheet (Figure 5).

Figure 3: Exemplary data input for the calculation of strike mortality of a Kaplan turbine.


Figure 4: Fish size used in the strike mortality models (right column) based on screen, respectively fish width and empirical regressions by Ebel (left column), displayed in the “Strike mortality” sheet: A screen width of 17mm allows passage of “normal” fishes of up to 15cm and eels of up to 57cm.

Figure 5: Fish size and turbine-specific mortality rate for a hypothetical Kaplan turbine, displayed in the “Impact results” sheet.

2.2. Mitigation

In the tool, mitigation is treated as a “positive impact”. There are two mitigation elements that can be considered: i) a safe downstream migration guidance structure and ii) any technical or operational improvements to the plant that render it more fish-friendly. Scoring of the down-stream guidance set-up is based on the installation angle of a fine screen, its bar space and the availability of a downstream bypass. The most effective set of mitigation measures subtract 0.3 points off the final hazard score (Figure 6). Less ideal solutions only yield a fraction of it. The sheet “Look-up table” provides details on the scoring.

Figure 6: Scoring of mitigation measures. For this example, an ideal configuration was chosen, resulting in the maximum mitigation score of 0.3.

If any question is left unanswered the tool will issue a “MISSING INPUT” warning (Figure 7).


Figure 7: Error warnings in cases of missing data. Note the exception for I.4; Strike mortality. Because the turbine type is not "Kaplan" or "Francis", a turbine-specific default risk score is assigned making the derived subparameters

obsolete.

3. Hazard score

The sheet “Hazard score” displays the main output of the tool. It lists the impacts and impact scores on the left side, a species sample on top, the actual generation of the score in the middle and the results on the bottom of the window (Figure 8). The species sample requires input of up to 5 species as follows: First, all species of conservation concern are added and the box “Cons. Concern” underneath the species name needs to be set to “yes”. If slots remain open the most sensitive species of the river need to be selected. In that case, the “Cons. Concern” cell needs to be set to “no”. The tool then offsets the impact scores of “low”, “moderate” and “high” according to the species’ sensitivity as shown in the “Look-up table” sheet.

Figure 8: Hazard score sheet with exemplary data. The impact scores are called form the "Impact results" sheet. The unmitigated hazard score of 0.5 (“moderate”) could, by correct implementation of mitigation measures, be low-ered to 0.2 (“moderate”).

Impact scores

Species sample

Hazard score result


Tool Output Each hazard is individually averaged across the species sample and transformed into a score between 0 (lowest impact) to 1 (highest impact). These scores are displayed on the right side of the species-impact grid. The scores, in turn, are averaged and displayed as an “unmitigated hazard score” and the associated risk class on the left bottom part of the sheet. The score of the previously specified mitigation measures (“Mitigation bonus”) is shown in the cell under-neath and the final, “mitigated hazard score” and the associated risk class on the bottom of the box.

Use limitations The tool is not capable of accurately assessing powerplants that feature more than one turbine type, turbines of different sizes or different modes of operation.

Acknowledgement and Credits We would like to extend our gratitude to Collin Bean (University of Glasgow) and Joachim Pander (Technical University of Munich) for reviewing and improving the functionality of the tool.

Documents

Fishfriendly Innovative Technologies for Hydropower · Assessing the impact of hydropower plants (HPP’s) on different fish species and communities is a key-component supporting