STATEMENT OF EVIDENCE OF PHILLIP GRAEME JELLYMAN

Transcription

1 Before the Hearings Commissioners At Christchurch UNDER the Resource Management Act 1991 AND IN THE MATTER OF Applications by MainPower New Zealand Limited, Rooney Group Limited, Rooney Farms Limited and Kakapo Joint Venture Limited to Canterbury Regional Council for resources consents for the Kakapo Brook Hydro-Irrigation Project at Glynn Wye Station, North Canterbury STATEMENT OF EVIDENCE OF PHILLIP GRAEME JELLYMAN Dated 7 October 2015

2 2 STATEMENT OF EVIDENCE OF PHILLIP GRAEME JELLYMAN Introduction 1. My name is Phillip Graeme Jellyman. 2. I am a freshwater fisheries ecologist employed with the National Institute of Water and Atmospheric Research Limited (NIWA). 3. I am a freshwater ecologist with over 10 years of experience. I was first employed with NIWA in 2005 and I have held my current position as a freshwater fisheries ecologist since January My involvement and knowledge of the instream values of the Hurunui-Waiau zone commenced in 2007 with fish surveys in both river catchments. I led a research project in the Hurunui catchment in 2011 aimed at predicting the effects of river regulation on freshwater communities (i.e., periphyton, stream macroinvertebrates and fish) which involved sampling over 40 sites from the headwaters through to the river mouth. I have conducted additional work in the Waiau catchment on various smaller projects (e.g., periphyton monitoring). In my present position, I lead NIWA s research on freshwater fisheries in our government-funded programme addressing sustainable water allocation. 5. I hold the following qualifications: a. B.Sc in Biology, B.Sc (Hons 1 st Class) in Ecology and a Ph.D in Ecology all from the University of Canterbury; b. I am an executive committee member of the New Zealand Freshwater Sciences Society, a member of Society of Freshwater Science (USA) and the American Fisheries Society. 6. Although this is a Council hearing, I note that I have read the Expert Witness Code of Conduct set out in the Environment Court's Practice Note I have complied with the Code of Conduct in preparing this evidence and I agree to comply with it while giving oral evidence before the hearing committee. Except where I state that I am relying on the evidence of another person, this written evidence is within my area of expertise. I have not omitted to consider material facts known to me that might alter or detract from the opinions expressed in this evidence. 7. I provide the following statement of evidence for the resource consent application lodged by MainPower New Zealand Ltd (MainPower), Rooney Holdings Ltd and Rooney Farms Ltd (Rooney) for the proposed Kakapo Brook hydro-generation and irrigation scheme ( the Project ). Scope of Evidence 8. As part of my involvement with the Project, I have prepared the following reports:

3 3 a. Jellyman PG (2014a) Fish survey of the Kakapo Brook headwaters and Lake Lorraine. Prepared for MainPower NZ Limited and Rooney Group Limited. 14p. April b. Jellyman PG & Booker DJ (2014) Instream habitat and flow regime requirements in Kakapo Brook. Prepared for MainPower NZ Limited and Rooney Group Limited. 47p. June CHC 2014_058. Updated January c. Jellyman PG (2014b) Response to aquatic ecology issues for the proposed Kakapo Brook scheme. Prepared for MainPower NZ Limited and Rooney Group Limited. 26p. June CHC 2014_081. Updated January In my evidence I have been asked to discuss the following: a. Freshwater taxa present in the Kakapo Brook catchment (and Lake Lorraine); b. The habitat requirements of instream biota in Kakapo Brook and the effects of the proposed take on riverbed habitat; c. Habitat and longitudinal connectivity for fish and macroinvertebrates; d. Flat-lining of the flow regime for instream biota; e. Mitigation measures for altering the flow regime; f. Submissions related to aquatic ecology; g. Issues identified in the Section 42A Officer s Report. 10. In preparing my evidence, I have reviewed the following documents: a. The Application; b. The Applicants response to the further information requests from the Canterbury Regional Council; c. Consent submissions; d. Section 42A Officer s Report; e. The Applicants proposed consent conditions. 11. In preparing my evidence, I have reviewed the evidence of: a. Mr. Bas Veendrick; b. Mr. Patrick Lees; c. Dr. Mark Sanders; d. Mr. Martin Bonnett;

4 4 e. Mr. Gary Rooney; and f. Mr. John De Ruyter. 12. I note that in prior evidence presented to the commissioners, Mr. Veendrick has outlined details of the proposed scheme, a description of the general environment and the proposed flow and allocation regime. Mr. Lees has presented water quality data, periphyton monitoring data and recent stream macroinvertebrate data for Kakapo Brook. Mr. Bonnett has discussed the effectiveness of the proposed fish screen at the intake location. 13. I have read the planning report prepared by the Reporting Officers for the Canterbury Regional Council under section 42A of the Resource Management Act 1991 (RMA) and where appropriate, I have commented on it below. Where appropriate I have also commented on submissions and any other relevant reports. Freshwater taxa present in the Kakapo Brook catchment (and Lake Lorraine) 14. Surveys of freshwater taxa were initially conducted in Kakapo Brook by NZ Environmental Ltd in 2012 and 2013 as part of the Assessment of Environmental Effects (AEE). It was identified in the Section 92 report that further fish sampling was required in the upper catchment and NIWA conducted a third fish survey in More rigorous algal and stream macroinvertebrate monitoring work was initiated at this time undertaken by Pattle Delamore Partners (PDP) and sampling has been conducted from 2014 to present as outlined in Mr. Lees evidence. For freshwater fish analyses, I have drawn on data collected across all three fish surveys and examined the New Zealand Freshwater Fish Database (NZFFD). Stream macroinvertebrate taxa 15. Initial stream macroinvertebrate surveys were carried out by NZ Environmental on 30 October 2012 as part of the AEE. These samples identified 24 taxa across 12 sampling sites located in the mid-reaches of Kakapo Brook from below the water recorder site to just above the proposed intake 1. This macroinvertebrate sampling was undertaken approximately three weeks after a large rainfall/flood event. For the 12 sites sampled by NZ Environmental, richness varied between 2 and 13 taxa. In comparison, PDP have taken invertebrate samples at 3 sampling sites on 4 occasions between February 2014 and March 2015 and have recorded a total of 46 taxa with richness varying between 18 to 27 taxa across all samples (note both NZ Environmental and PDP were processed to the same taxonomic resolution). My interpretation of this marked contrast is that the samples taken by NZ Environmental in 2012 were influenced by the preceding flow conditions, therefore in my macroinvertebrate analyses I have only used data collected by PDP. 1 Samples were processed to the same taxonomic level as regional council macroinvertebrate monitoring data [i.e., taxa were identified to the level required to calculate the Macroinvertebrate Community Index (MCI); generally genus level)].

5 5 16. To examine whether Kakapo Brook had macroinvertebrate communities that varied substantially from those of nearby waterways I have compared data from Kakapo Brook with survey data from six sites sampled in 2011 in tributaries of the upper Hurunui River catchment (Jellyman & Harding 2011). I am not aware of another data set that has macroinvertebrate data from waterways of comparable size in the Waiau catchment that could be used for a comparative analysis. As the six Hurunui tributary sites were sampled in February and March 2011 I have compared these data to the PDP samples collected at their 3 monitoring sites in February 2014 and March The mean richness per site in Kakapo Brook was 23.0 taxa compared to 21.0 taxa per site in tributary sites in the upper Hurunui catchment; this difference in taxa richness was not statistically significant (Figure 1a). The percentage of pollutantsensitive mayfly (Ephemeroptera), stonefly (Plecoptera) and caddisfly (Trichoptera) (EPT) taxa in samples and the MCI score 2 were higher on average for upper Hurunui tributary sites compared to Kakapo Brook sites, although the differences were not statistically significant (Figure 1b,c). On average, 63% of the taxa in samples from Kakapo Brook sites were composed of EPT and the mean MCI for a site was 119 (scores 120 indicate clean water of excellent quality and scores between are interpreted as doubtful quality or possible mild pollution). It is important to recognise that these MCI scores are an average of three sites located longitudinally down the river and there is a general trend of slightly higher MCI values ( 120) above the proposed intake site and slightly lower values (<120) at the monitoring site in the lower reaches, as stated in the evidence of Mr. Lees. 18. Taxa from Kakapo Brook were compared to samples from the six upper Hurunui tributary sites to determine whether there were many unique taxa in Kakapo Brook. A total of 53 taxa where recorded across samples from both catchments. There were 37 taxa present in both catchments and both the upper Hurunui and Kakapo Brook had 8 species that were not recorded in the other catchment (Figure 1d). Of the 8 taxa recorded in Kakapo Brook, 1 was a caddisfly, 2 were snail species and 5 were dipteran (true flies) taxa. In comparison, 6 of the 8 taxa only recorded in the upper Hurunui tributaries were EPT taxa. None of the freshwater macroinvertebrate species recorded from Kakapo Brook are listed as threatened by the Department of Conservation (DOC) (Grainger et al. 2014). 2 The MCI is a bioassessment tool used in New Zealand to report on stream health.

6 6 Figure 1: Variation in stream macroinvertebrate metrics (a-c) and species assemblages (d) in upper Hurunui tributaries compared to the Kakapo Brook catchment. The results of single-factor ANOVA tests examining whether or not there were significant differences between catchments for graphs a-c are shown. P < 0.05 indicates a statistically significant difference. Stream fish species 19. Fish surveys by NZ Environmental on 30 October 2012 and 29 October 2013 recorded four native species from the catchment (see Appendix A). A survey of the Kakapo Brook headwaters by NIWA on 3 April 2014 found that as well as these four species, introduced brown trout were also present (Jellyman 2014a). When data were combined across all three surveys, these five species had the following size ranges: upland bully (range: mm), Canterbury galaxias (range: mm), alpine galaxias (range: mm), longfin eel (range: mm) and brown trout (range: mm). Of the four native species, upland bully and the two galaxiid species are non-diadromous (i.e., non-migratory) species and can complete their life-cycle solely within the Kakapo Brook catchment. Longfin eel is a diadromous species and requires access to and from the ocean to complete its lifecycle. For longfin eel to be present above the Kakapo Brook gorge 3, these fish will 3 The section of river I was termed the Kakapo Brook gorge extends from 1.2 km upstream of the State Highway Bridge to a point in the river where it stops being highly confined (approx. 1 km east of Dismal Valley).

7 7 have entered the Waiau River mouth as a glass eel, become pigmented and then migrated up the mainstem river as an elver/juvenile eel before entering the lower reaches of Kakapo Brook and moving upstream. The only other diadromous fish species that could be present above the Kakapo Brook gorge is koaro. If present, this diadromous species would have entered the Waiau River mouth as whitebait before moving upstream. Juvenile longfin eel and koaro are excellent climbing species capable of penetrating long distances inland. Because it is over 100 km to the sea from the confluence of the Kakapo Brook and Hope River, non-diadromous species are far more abundant than diadromous species in the Kakapo Brook catchment. None of the freshwater fish species recorded from Kakapo Brook are listed as threatened by the Department of Conservation (DOC) (Goodman et al. 2014). However alpine galaxias, Canterbury galaxias and longfin eel are all taxa classified as At Risk either because their populations are declining or because they are naturally uncommon. 20. A fish survey of Lake Lorraine by NIWA on 3 4 April 2014 recorded three species: upland bully, longfin eel and shortfin eel (DOC threat status: not threatened). Lake Lorraine is located in the headwaters of Glynn Wye Stream which is not hydrologically connected to Kakapo Brook. A total of eight eels were caught in the four fyke nets that were set. Six of the eels caught were longfin (mean length 627 mm, range mm) and two were shortfin (mean length 799 mm, range mm). Shortfin eel are not commonly recorded this far inland (>100 km from the coast) but they have a preference for lake habitat over alpine rivers and tributaries which explains their presence in the lake and their absence from waterways in Kakapo Brook. Although the stream flowing out of Lake Lorraine was dry at the time of sampling (April 2014), and appeared to have been dry for some time, I consider it likely that the stream connects to the Hope River during some months or years and that the eels in the lake have probably recruited naturally. Dr. Meredith suggests in his evidence contained in the Section 42A Officer s Report that there is also the potential that fish may have been deliberately stocked in the lake and I agree that this possibility cannot be discounted. 21. To examine whether the fish species recorded in Kakapo Brook were typical of those in the upper Waiau catchment, the NZFFD was interrogated. For streams and rivers located more than 100 km from the coast, seven species have been recorded: upland bully, Canterbury galaxias, alpine galaxias, koaro, longfin eel, brown trout and Chinook salmon. Of these fish species, five are known to be present above the Kakapo Brook gorge and it is assumed that koaro could reach the Kakapo Brook headwaters although they have not been caught during electrofishing surveys. Chinook salmon are not considered to be present above the Kakapo Brook gorge and they have not been caught electrofishing. The major salmon spawning sites in the Waiau catchment are located in the headwaters of the upper Waiau and Henry Rivers (Figure 2, Unwin 2006). Therefore, the majority of Chinook salmon returning to fresh water to spawn should head up the Waiau River rather than head past the Waiau River and up the Hope River (thus potentially encountering Kakapo Brook).

8 8 Figure 2: Significant Chinook salmon spawning sites (red sections) in the upper Waiau catchment. Data are redrawn from Unwin (2006). The habitat requirements of instream biota in Kakapo Brook and the effects of the proposed take on riverbed habitat 22. As outlined above, Kakapo Brook has a range of aquatic biota present and these taxa can have vastly different instream habitat requirements and preferences. To assess the effect of changes in flows on instream physical habitat and aquatic biota, surveys of physical habitat at different flows were undertaken and physical habitat modelling was conducted (see Jellyman & Booker 2014). These models predict how physical habitat availability is likely to vary in response to flow changes for a particular species by calculating the change in weighted useable area (WUA). WUA is the wetted area of a stream weighted by its suitability for use by an aquatic species. Eleven aquatic species, known to present in the catchment, were examined in this study, they were: diatoms, short filamentous algae, long filamentous algae, food producing habitat, Deleatidium mayfly nymphs, upland bully, alpine galaxias, Canterbury galaxias, longfin eel, brown trout (< 100 mm) and black-fronted tern. Jellyman & Booker (2014) noted that the habitat suitability curves available for black-fronted tern were made for specific rivers (i.e.,

9 9 Waimakariri and Rangitata Rivers) - rather than produced from survey data pooled across many rivers as for most modelled species - and stated that the transferability of this data from a braided river to a single thread river could be questioned. Dr. Sanders shares this concern and as he has addressed black-fronted tern (and other bird species present in the catchment) in his evidence, modelling data are no longer presented for this species. 23. Instream habitat was surveyed, modelled and predicted at different discharges for the Kakapo Brook study reach. The study reach was located next to the proposed intake for the Project. The study reach consisted of 15 cross-sections and the instream hydraulic model was calibrated using measurements taken at three different flows (i.e., on three separate occasions). The River Hydraulics and Habitat Simulation (RHYHABSIM) software was used to model physical habitat changes at different flows in Kakapo Brook (Jellyman & Booker 2014). These data were used to determine how physical habitat conditions (i.e., depth, velocity and substrate) varied with flow for the 11 target species. 24. In the Kakapo Brook study reach, the substrate consisted mainly of cobble, gravel and fine gravel in varying proportions. The site contained no instream macrophytes and none of the 15 cross-sections had any overhead vegetation in the form of trees, although at a couple of cross-sections there was some overhanging matagouri in places. For this study reach, hydraulic modelling predicted that as discharge increases, width increases rapidly at low flows and then remains relatively constant with changing flow due to the vertical bank profiles present at this site (Figure 3a). Steady increases in both depth and velocity are also predicted as flow increases (Figure 3b).

10 10 Figure 3: Mean width and wetted perimeter (a) and mean velocity and depth (b) against discharge for the Kakapo Brook survey reach. Data are redrawn from Unwin (2006). 25. WUA increased for all biota until a flow of 0.15 m³/s when useable habitat for long filamentous algae started to decline (Figure 4a). The WUA for Deleatidium mayfly nymphs and food producing habitat increased across the modelled flow range (0 1 m³/s) whereas the WUA for native fish species peaked between m³/s (Figure 4b,c). Very little useable habitat was available for adult brown trout although high WUA was predicted for juvenile brown trout (<100 mm) across the range of modelled flows (see Jellyman & Booker 2014).

11 11 Figure 4: Variation in weighted useable area (WUA m 2 /m) with flow for periphyton, macroinvertebrates and native fish species. Note, two different curves for longfin eel are plotted based on body length. 26. Jellyman & Booker (2014) recommended that the minimum flow was set between m 3 /s, however, the minimum flow that is set in Kakapo Brook will depend on what level of protection is chosen for instream species versus the amount of water to be taken for the Project. A minimum flow of at least 0.35 m 3 /s would mean that 90% (or more) of the useable stream habitat for all native fish species is provided for by the proposed Project (Jellyman & Booker 2014). A minimum flow of more than 0.4 m 3 /s would mean that in addition to native fish values being maintained, at least 60% of the useable stream habitat would be available for short filamentous algae, Deleatidium mayfly nymphs and food producing habitat. A summary table (Figure 5) was produced by Jellyman & Booker (2014) which outlines how different instream ecological values (averaged across various values groups) will be affected for a range of minimum flow options. 27. Based on this work, MainPower and Rooney have proposed a minimum flow for the Project of 0.32 m 3 /s (320 L/s). At this proposed flow, all four native species present have at least 90% of their maximum WUA available (upland bully 98.2%, alpine galaxias 94.0%, Canterbury galaxias 90.8% and longfin eel 90.8%). Habitat

12 12 availability for nuisance periphyton is very high (94.7%) at this proposed flow but it is high across a wide range of flows (e.g., it does not decrease below 90% until 0.43 m³/s, see Figure 5). Figure 5: Relative level of maintenance of instream ecological values for a range of minimum flow options. The table is coloured using a rainbow spectrum with the most change relative to maximum WUA for each group in red and the least change in dark blue. The colour spectrum is reversed for nuisance periphyton because high WUA numbers are considered undesirable. The figure is modified from Jellyman & Booker (2014) as birds have been removed.

13 13 Habitat and longitudinal connectivity for fish and macroinvertebrates 28. The middle reaches of Kakapo Brook were surveyed by Jellyman & Booker (2014) at a flow of 0.28 m³/s and the main channel had continuous flow from the proposed intake site downstream to the flow recorder site (see Figure 6). A natural low flow of 0.28 m³/s is less than the proposed minimum flow of 0.32 m³/s for the Project so longitudinal connectivity should not be impeded for aquatic species at this minimum flow. At a flow of 0.28 m³/s there was still sufficient water depth and velocity for invertebrates to drift downstream and adequate water for all fish species to move in both directions in the main channel (Figure 7). As no adult brown trout have been found in any survey above the gorge to date, the species requiring the most water for habitat connectivity is likely to be longfin eel. The largest longfin eel recorded from electrofishing surveys above the gorge has been 415 mm and there will be no impact to the movement of eels of this size. Adult longfin eels have not been recorded above the gorge and habitat modelling data suggests there is almost no adult longfin eel habitat available. However, if adult longfin eels were present, they would tend to migrate downstream during a high flow event (on their way out to sea to complete their life-cycle at sea) rather than move downstream at low flows. Adult female longfin eels (the much larger of the sexes) commonly grow to over 1 m in length before migrating; at this size they generally have a body height of 8 9 cm (NIWA unpubl. data). At this size there would be sufficient water depth for them to be fully submerged as they moved downstream through run and pool habitat at low flow (noting they may not be fully submerged in all riffle zones). These findings confirm that the Project is consistent with the Te Poha o Tohu Raumati (2007) (Iwi Management Plan) for the Waiau River (Section , Policy 9) identified in the Cultural Impact Assessment, which states mahinga kai species have uninhibited access to and from the river, its tributaries, associated lakes and the sea. Figure 6: Kakapo Brook (below intake site) flowing at 0.28 m³/s on 31 March Note, Kakapo Brook is flowing at 40 L/s below the proposed minimum flow for hydro-generation.

14 Measured value 14 Depth Velocity Distance from TR bank (m) Figure 7: Cross-sectional profile of depth (m) and velocity (m/s) in Kakapo Brook at a flow of 0.28 m³/s. This cross-section was located approximately 30 m upstream of the photo on the left of Figure The width of the river that provides suitable depth and velocity for fish passage was also calculated using the Passage width function in the RHYHABSIM software. Passage width was calculated after specifying that water depth had to be at least 5 cm and water velocity less than 0.6 m/s. Modelling results indicated that fish passage is available as long as flows are greater than 0.2 m³/s (Figure 8). 2.0 Passage width(m) Contiguous Total Flow (m 3 /s) Figure 8: Variation in predicted passage width (m) for flow changes in Kakapo Brook. This model was produced for the physical habitat survey reach downstream of the proposed Project intake. Results are presented as the contiguous width where this is the maximum width in a cross-section with the required minimum depth and velocity. The total width is the sum of all the elements of the cross-section that meet the specified criteria.

15 15 Flat-lining of the flow regime for instream biota 30. The quantity and timing of flow in a stream are critical components of water supply, water quality and ecological integrity (Poff et al. 1997). Historically, the protection of stream ecosystems has been limited to one aspect of water quantity - minimum flow - but there is now a better understanding about the importance of flow timing and flow variability in maintaining functional stream ecosystems (i.e., streams that support critical physical, chemical and biological processes). The ecological processes in a stream are regulated by five critical components of the flow regime: the magnitude, frequency, duration, timing, and rate of change of hydrologic conditions (Poff & Ward 1989). These five components, defined for completeness in Appendix B, can be used to characterize the entire range of flows or specific hydrological events (e.g., floods or low flows) that are critical to stream ecosystem integrity. 31. The proposed Kakapo Brook Project would primarily alter the magnitude of flows, frequency of flood flows and duration of low flows (changes to the rate of flow change below the intake during high flow events is not a major consideration). MainPower and Rooney have proposed a change in flow magnitude up to 1,600 L/s and Jellyman & Booker (2014) have advised on how different minimum flows may alter instream ecological values. 32. Based on RHYHABSIM modelling work, MainPower and Rooney have proposed a minimum flow of 0.32 m³/s. The proposed minimum flow equates to 88.6% of the 7D MALF (361 L/s) (Table 1). This proposed flow regime also involves flat-lining the hydrograph for 85% of the year so 0.32 m³/s also represents the lower quartile, median and upper quartile flow (Table 1). The extent of this flat-lining is shown in Appendices C and D. Biggs et al. (2008) state A long period (e.g., 2 3 months) of constant minimum flow in summer will usually reduce invertebrate production and diversity through accumulation of periphyton and silts. The distance between the intake site and the next major tributary is 750 m so this is the length of river that will experience the least flow variability and be most affected by the minimum flow that is set. From this tributary onwards, mean flow and flow variability in the mainstem would increase compared to the upstream reach. 33. A lack of flow variability as a result of prolonged flat lining of flows may lead to excessive periphyton growth, primarily in the 750 m reach below the intake before the next major tributary inflow. The ecological consequences of excessive periphyton growth tends to be a reduction in invertebrate community diversity as well as a decline in diversity of the surrounding periphyton community. Invertebrate communities generally tend to become dominated by smaller invertebrates and taxa (e.g., Chironomid midges) that are less available (i.e., harder to access), or of lower food quality for the fish communities present.

16 16 Table 1: Flow summary statistics (L/s) for natural and proposed flows at the Kakapo Brook intake site. Data are from Veendrick (2015). Flow type Mean Median 7D MALF Upper Quartile Lower Quartile Natural flow 1, , Proposed flow The importance of flow variability is often debated (e.g., how much or how little variability is required to maintain instream values) because of, in my opinion, a lack of published research in New Zealand on this topic. This opinion is supported by Jowett et al. (2008) in their guide to New Zealand instream habitat survey methods: Although flow variability is often thought an essential element of the flow regime that should be maintained, there is little published biological evidence that flow variability is essential. One of the issues with examining flow variability impacts in New Zealand streams is that similar biological communities are often found in streams with very different patterns of flow variability (Jowett et al. 2008). The importance of flow variability is context-dependent, for example, natural lake outlets and springs generally have low flow variability and are highly productive systems whereas a large, braided river (e.g., Rakaia River) has very high flow variability and much lower productivity. It is not however a simple case of low flow variability being good and high flow variability being bad because there are numerous examples around New Zealand where catchments with naturally variable flow regimes have been modified to a state with very low flow variability resulting in significant adverse effects on instream values (see Jowett & Biggs 2006 for examples and how IFIM has been applied to mitigate these effects). Avoiding such scenarios requires an understanding of both minimum flow and variability requirements of biota as well as knowledge of the timing of different lifecycle stages for key species (Biggs et al. 2008). 35. Biggs et al. (2008) identified the three components of a flow regimes in New Zealand that they considered to be ecologically important. These are: 1) low flows which set a limit to habitat quantity; 2) small floods which occur moderately frequently and contribute to maintaining habitat quality through flushing away accumulated silt and periphyton from coarse river substrate such flows are usually about 3 to 6 times the median flow; and 3) large floods, usually termed channel forming or channel maintenance flows, which fill the whole channel and occur about once a year. These floods are large disturbances to the river ecosystem and wash away most periphyton, many stream invertebrates and a large proportion of introduced fish species (e.g., trout). Many native fish species have developed some strategies to cope with floods, provided they are larger than about 25 mm (Jellyman & McIntosh 2010). 36. These key flow components form the basis of most flow assessments and flow regime design around New Zealand. All flow assessments will vary to some extent because there are different values to consider in each assessment which is likely why, in my opinion, the HWRRP specifies values that need to be considered but does not specify the method by which a flow assessment should be made. For

17 17 example, in Kakapo Brook values that do not require major consideration would be kayaking and boating, commercial fishing and river mouth openings for diadromous fish requirements whereas ecological and water quality values as well as the natural character of the river do require extensive consideration. The key flow components outlined above, as well as the requirements of the HWRRP, have formed the basis of my assessment of the flow regime components that need to be retained in Kakapo Brook to ensure the life-supporting capacity of the waterway is not significantly compromised by the Project. Mitigation measures in response to the modified flow regime 37. The extent of flat-lining of the hydrograph by the Project could have negative effects on aquatic ecology unless adequate mitigation measures are applied; this issue was identified in a number of submissions. As the Project is proposing a runof-river take then the primary mitigation measure available is a cessation of the take. Below I have used the term flushing flow to describe flows of different magnitudes that need to be maintained through the implementation of different take cessation rules; the purpose of these flows is analogous to that of a true flushing flow although technically a flushing flow is associated with an artificial flow release from a reservoir. 38. Flushing flows are generally defined as flows with the purpose of maintaining or improving the downstream channel and habitat (e.g., a flow removes the fine sediments and periphyton accumulations from stream substrate). Flushing flows are necessary in most streams to remove accumulated fine sediments and to restore interstitial space in gravel substrates. In the short-term, flushing flows can have a detrimental effect on streams because they result in a loss of productivity but in the longer term they benefit aquatic species through improved habitat quality (Jowett 2009). There are various guidelines that specify limits for periphyton cover or biomass below which a range of instream ecological values are likely to be maintained (Biggs 2000, Wood et al. 2009, Matheson et al. 2012). For example, cover of less than 30% by filamentous green algae, or biomass of less than 35 g/m 2 periphyton ash-free dry mass (a measure of organic content), is considered necessary to maintain values for aesthetics and recreation (Biggs 2000). However, determining how long it will take for periphyton to reach nuisance levels depends on a number of factors such as: water temperature, dissolved nutrient concentrations, velocity, substrate size, depth, turbidity, shade, and initial periphyton biomass. 39. Whilst the time it will take for periphyton to accumulate to nuisance levels is highly river (or even reach) specific, it is possible to make a general prediction about the magnitude that a flushing flow might need to be. The relationship between bedmoving flows and flow statistics may not always be clear, but flow statistics are often used to estimate how large a flushing flow needs to be and how often these events should occur. Flow events that exceed three times the median flow (3x MEDIAN) (i.e., freshes or floods) are most commonly used as they have previously

18 18 been found to substantially decrease periphyton biomass (Clausen & Biggs 1997) because a flow of this magnitude is generally of sufficient size to disturb the river bed to such an extent that a significant proportion of the periphyton is lost from the reach. 40. At the intake site, a flow event of 3x MEDIAN would require the flow to exceed 2.63 m³/s and Table 2 indicates that this currently occurs 3.5 times during the low flow period from 1 November to 30 April. Water temperature data from Kakapo Brook collected by continuous data loggers indicates that mean water temperature exceeds 10 C at the start of November and drops below this temperature at the start of May; this temperature threshold was used for defining warmer months in the Kakapo Brook catchment when there is the potential for nuisance periphyton growth to be most rapid. Under the flow regime proposed at the time the consent application was submitted, flow events of 3x MEDIAN would only occur 2.5 times during that period. In conjunction with increased time between flow events of 3x MEDIAN, this had the potential to result in excess periphyton accumulation which could have detrimental effects to instream ecological values. These longer accrual times could allow periphyton to grow to nuisance levels; this generally takes between 21 and 50 days during periods of low flow (Biggs 2000). Because of the potential for adverse effects to instream ecological values, the Project is proposing new consent conditions that will not result in a reduction in the number of flow events of 3x MEDIAN. Therefore, the values for modified flow are no longer relevant although are useful for observing the change that this proposed condition will have on the flow regime (Table 2). An additional consent condition that is now proposed will also ensure that there is no reduction in the number of events of one and a half times the median (1.5x MEDIAN; 1.31 m 3 /s) for the duration of the low period outlined in Table 2. Table 2: Flushing flow and periphyton accrual time for natural and modified (in consent application) flows at the Kakapo Brook intake site and downstream of tributaries. Flow statistics are for the low flow period between 1 November and 30 April. Data are from Veendrick (2015). FRE Flow type Mean number of events per annum Mean number of days absent (accrual time) Maximum number of days absent (accrual time) 1.5x median Natural flow Intake Modified flow x median Natural flow Modified flow x median Natural flow Downstream of tributaries Modified flow x median Natural flow Modified flow Note, with a new proposed consent condition that provides for flows 1.5x MEDIAN, the mean number of events per annum with be as per the natural flow and accrual times will be similar to those of the natural flow. Accrual times will not be identical because the proposed take cessation rules means that the duration of some freshes would be reduced.

19 As this project also had modelling data available from Jellyman & Booker (2014), these data were used to examine what magnitude flushing flow might be required in Kakapo Brook rather than solely using a flow-statistic based approach. These data were used in combination with the RHYHABSIM software to assess the magnitude of surface and deep flushing flows. These different types of flushing flows are defined by Jowett (2009): Surface flushing flows remove the fine sediments from the surface layer, leaving the armour layer largely intact. Periphyton will also be removed by the abrasive action of fine sediments moving over the surface. Deep flushing flows (also termed channel maintenance flows) disturb the armour layer, removing the sediments that have deposited within the gravel matrix. Therefore, deep flushing flows are larger than surface flushing flows. Flushing flows only cause movement over part of the stream bed because in the middle reaches of Kakapo Brook for example, the stream width increases as flow increases. The flushing flow will only be mobilising sediment in the main flow channel rather than the newly inundated habitat along the stream margins. Jowett (2009) states that a suitable flushing flow might be the flow that flushes 80% of the river bed that is submerged at base flow. To assess what magnitude a flushing flow should be, the RHYHABSIM model requires baseflow to be specified (for the proposed Project I have assumed the proposed minimum flow is baseflow). The magnitude of a surface flushing flow that flushes 80% of the river bed that is submerged at base flow is calculated to be 2.7 m³/s. The magnitude of a deep flushing flow that flushes 80% of the river bed that is submerged at base flow is calculated to be 7.0 m³/s. 42. The concurrence in the magnitude of a flushing flow from the flow statistics (3x MEDIAN: 2.63 m³/s) and the modelling data (surface flushing flow: 2.7 m³/s) provides a robust rationale for guiding flow cessation rules. As baseline monitoring data shows that periphyton accrual exceeds the guidelines in the Land and Water Regional Plan (LWRP), Mr. Lees states in his evidence that a reduction in flow and an increase in flat-lining could see further proliferation of nuisance periphyton growths. To mitigate nuisance periphyton accrual and maintain stream health, Jellyman (2014b) suggested that the Project should provide for deep flushing flows larger than 7.0 m³/s (i.e., 8x MEDIAN), regardless of when during the year they occur, and that they should remain untapped for a period not less than 6 hours. Jellyman (2014b) also suggested that the Project should provide for surface flushing flows exceeding 3x MEDIAN and that they should be untapped for 6 hours from 1 November and 1 May. 43. The Project had included both of these suggested flow cessation rules in their proposed consent conditions but based on further flow analyses, and feedback from Environment Canterbury (ECan), now propose to let flows exceeding 3x MEDIAN to pass untapped for 6 hours year-round. This will increase flow variability downstream of the intake. 44. The six hour duration for these flushing flows is based on analyses of a relationship between mean channel velocity at different flows which indicates that it takes just under 5 hours for a flow of 3x MEDIAN (2.63 m³/s) to pass from the intake site to the confluence with the Hope River. Therefore, there is more than sufficient time

20 20 to ensure that a flushing flow (greater than 3x MEDIAN) is allowed to pass unmodified from the intake site through to the confluence. 45. The provision of flows between 1.5x and 3x MEDIAN is a policy in the Hurunui and Waiau River Regional Plan (HWRRP) aimed at increasing flow variability in waterways with takes, dams or diversions. In the HWRRP, Policy 2.5 states that any take must provide for flow variability above the minimum flow, including flows between 1.5x and 3x MEDIAN to scour and flush periphyton and cyanobacteria accumulations, mobilise and transport bed material, trigger flow dependent aquatic life-cycle processes such as fish migration, and provide for recreational values. Because the HWRRP states that In the mainstem of the Hurunui and Waiau River flows of around 1.5x to 3x MEDIAN are important, the scientific defensibility for applying the policy to tributaries in the catchment could be questioned. 46. However, if the Project was operating, then an ecologically relevant flushing flow could be less than 3x MEDIAN because the reduced flow (due to abstraction) would likely result in periphyton colonising lower down in the channel profile since the hydraulic conditions that previously precluded colonisation by certain nuisance periphyton species had become suitable under the modified flow regime. Therefore, the magnitude of a fresh required to exert sufficient shear stress on the periphyton species in their newly colonised locations would be less so nuisance periphyton accumulations could be sloughed off/flushed away at flows lower than previously required when nuisance periphyton was distributed further up the channel cross-section. 47. The ecological role of flows between 1.5x to 3x MEDIAN in a tributary such as Kakapo Brook would be to reduce excess periphyton accumulation to improve stream health for macroinvertebrates and fish (flows of this magnitude would not be expected to turn over and mobilise gravel). Although periphyton could potentially accumulate to a level exceeding the HWRRP guidelines at any time of the year, it is most likely to occur during summer and early autumn when longer daylight hours, warmer temperatures and lower rainfall produce conditions favourable for rapid periphyton growth. Rapid periphyton growth at this time of year has the potential to impact the growth and survival of invertebrates and fish more so than during colder months when aquatic biota have lower metabolic requirements. Therefore, Jellyman (2014b) suggested that flows between 1.5x and 3x MEDIAN should remain untapped for 12 hours from 1 November to 1 May each year. The Project has included this suggested flow cessation rule in their proposed consent conditions to ensure that flow variability is maintained during the time of year when rapid algal growth could be most detrimental to invertebrates and fish. 48. The extent of flat-lining during cooler months, primarily July to September during Average and Dry years (see Appendix C), could result in the Project having adverse effects on aquatic biota. To examine monthly trends in periphyton cover I have analysed data for 22 years of monthly monitoring from the Hurunui Mandamus (from the National River Water Quality Network, NRWQN, run by NIWA); this is the nearest site to Kakapo Brook with long-term water quality data available. These data show that relative to other months of the year, August tends

21 21 to be an above average month for the coverage of algal mats (Figure 9a) and that July and August are months of above average filamentous algal coverage (Figure 9b). It should be noted that there is a tendency for periphyton coverage in winter months to be more variable than during other months (Figure 9). The monthly differences during winter relative to summer are likely to be slightly larger in the Hurunui River because of nutrient dynamics associated with upstream lakes. However, in my opinion, the same general pattern of above average periphyton coverage during winter months has the potential to occur in Kakapo Brook during average and dry years. Therefore, flat-lining during winter months has the potential to exacerbate the accrual of periphyton. Whether periphyton would accrue to a level exceeding the HWRRP guidelines is unknown although I consider it a strong possibility. This above average accrual would be most evident in the 750 m reach below the intake because for an average year, there were be a several events exceeding 1.5x MEDIAN after the addition of the next significant downstream tributary which should remove filamentous algae from parts of the channel section where they would not usually have occurred prior to the Project. To mitigate potential adverse effects associated with increased periphyton during cooler winter and early spring months, a consent condition has been proposed that would allow ECan to require the applicant to undertake periphyton monitoring if a flow event exceeding 1.5x MEDIAN had not occurred for 40 days. If the periphyton trigger level had been reached, as outlined in the consent conditions, then the take would cease when the next flow event exceeding 1.5x MEDIAN occurred. Figure 9: Variation between months in the % cover (+SE) of algal mats (a) and filamentous algae in the Hurunui Mandamus. Data are averages from 1989 to 2010 at the NRWQN monitoring site administered by NIWA. 49. The take cessation rules outlined above will mean that components of the flow regime that are critical for maintaining ecological values and instream health are provided. Presently, periphyton and stream macroinvertebrates are being monitored to establish a baseline data set to determine the potential effects that the Project might have on these freshwater values. Whilst modelling data indicate that a high proportion of suitable fish habitat will be available at the proposed minimum flow, the effect of the Project on fish communities cannot be fully

22 22 predicted from modelling. Therefore, I have recommended as part of the Environmental Management Plan that monitoring of the fish community is conducted annually for five years in the reach below the intake (as well as in a nearby mainstem reach above the intake) to determine whether the Project is adversely affecting fish communities. This monitoring would be conducted between mid-january and March each year, no sooner than two weeks after any take cessation rule had been exercised, to ensure that fish communities were being sampled at a time when the potential impact of the Project on stream fishes was likely to be highest. Response to aquatic ecology submissions Trout and salmon habitat 50. A number of the submissions from members of the public have expressed concern about the effect on trout and salmon habitat. Three fish surveys have now been undertaken in the Kakapo Brook catchment and no Chinook salmon parr (i.e., juvenile salmon) were found during any survey. In addition, they have not been recorded in the Kakapo Brook catchment on the New Zealand Freshwater Fisheries Database (NZFFD). It is concluded Chinook salmon are not present above the gorge. The lower reach of Kakapo Brook is not a noted salmon spawning location, and North Canterbury Fish & Game note in their submission that it is not classified as an outstanding salmon fishery, but insufficient data is available to conclude whether they are present or absent. As detailed in Paragraph 21, the vast majority of Chinook salmon returning to fresh water to spawn should head up the Waiau River rather than bypass the Waiau River and potentially encounter the mouth of Kakapo Brook. 51. Two brown trout, 89 and 96 mm, were recorded above the gorge during the electrofishing survey by NIWA in Across all surveys, approximately 2.5 km of waterways in the middle and upper catchment were electrofished at over 15 sites; I also walked an additional 1.1 km looking for brown trout whilst conducting habitat mapping for the physical modelling work. The two brown trout mentioned above were recorded from a single site located 2.1 km above the proposed intake. The flow regime at the site where they were recorded would not be directly affected by the Project. 52. The lower reaches of Kakapo Brook contain potential adult brown trout habitat. Whilst none were observed during surveys, they are known to be present in the section between the confluence of the Hope River and the bottom of the gorge. No surveys have been conducted in the gorge itself although in Mr. Rooney s evidence he has stated that he has walked from the mid-reaches of the gorge up to the intake site each year for the last four years and has never caught or observed a brown trout of angling size. This anecdotally confirms a lack of brown trout in the midand upper sections of the gorge. I would be surprised if juvenile brown trout were not present in the lower reaches between the Hope River and the gorge. However, the instream habitat below the gorge is in contrast to that of the middle and upper

23 23 reaches which are generally shallower, narrower and has smaller substrate. A number of submissions contend that the Kakapo Brook is an important spawning tributary for brown trout. This cannot be confirmed nor denied for the lower reaches based on available data but I have observed suitable spawning habitat in places below the gorge and consider it sensible to assume that brown trout spawning could occur in this section of the river. 53. Brown trout tend to spawn later in autumn or early winter (McDowall 2000). They generally excavate spawning redds when flows are not elevated and they prefer to spawn at depths between cm (Shirvell & Dungey 1983). Therefore, the spawning gravels used by trout would not be exposed by the variation in flow associated with the Project. The Project may reduce the magnitude of high flow events during spawning and during the time when eggs are developing but this would not be expected to have a significantly adverse effect on trout spawning success. 54. The lower reach of Kakapo Brook, where I assume adult brown trout to be present, will not experience flat-lining of the hydrograph but there would be a reduction in mean flow of 33% and a reduction in MALF of 9%. As stated above, I would not expect this to have a significantly adverse effect on trout spawning success but there could be a change in the abundance of adult brown trout. 55. Although habitat modelling has not been conducted in the lower reaches of Kakapo Brook, based on the habitat suitability curves of adult brown trout I expect a RHYHABSIM model would likely show that there would be a decline in the quantity of adult brown trout habitat available under the modified flow regime compared to the natural flow regime. To what extent cannot be predicted without additional work. The number of adult brown trout in the lower reach is not known and if numbers are currently low then that could suggest that the population is not limited by habitat availability. Under a scenario where the availability of adult brown trout habitat was a factor limiting for the population, the proposed change in flow regime could result in fewer adult trout being supported; if this occurred it could result in higher numbers of juvenile trout being present in the reach (Jellyman et al. 2014). Higher numbers of juvenile trout moving downstream out of Kakapo Brook would probably not be of benefit to the Hope-Waiau trout fishery during years of high juvenile trout survival in this system. During years of low trout recruitment the export of juvenile trout from Kakapo Brook may be beneficial to the Hope-Waiau trout fishery. However, given the size of the Waiau catchment and the number of trout supported in many of its well-known angling reaches and rivers, I doubt that a modest decrease in the number of adult trout or a moderate increase in the number of juvenile trout would have any detectable effect on the wider fishery. 56. The submission from North Canterbury Fish & Game states that While not classified as an outstanding trout or salmon fishery, these backcountry fisheries are often sought after by experienced fisher men and women. Based on electrofishing survey data from the middle and upper parts of the catchment and Mr. Rooney s anecdotal angling attempts from Iron Bridge to the proposed intake site, the only potential angling section of Kakapo Brook is the 4 km stretch of river between the

24 24 Hope River confluence and Iron Bridge. However, it is noted by the applicant that this reach of Kakapo Brook is located on private property and there is no practicable public access. Therefore any potential loss to recreation is a private recreational loss. 57. The submission from North Canterbury Fish & Game also states that We disagree strongly with the applicant that reduced water flows will increase the abundance and access for trout higher up the river system. This appears to be a misinterpretation of a statement in the AEE (at a time when no brown trout had been recorded from above Kakapo Brook gorge) that was cautioning that a change in the flow regime could result in hydrological conditions that allowed brown trout to move into habitat in which they were thought (at the time) to be absent from. Since Jellyman (2014a) recorded brown trout above the gorge this issue of trout expansion due to flow alteration is no longer relevant. The report of Jellyman & Booker (2014) supports the statement by Fish & Game but it should be noted that it has never been suggested by the applicant that the proposed flow regime will increase the abundance of brown trout. 58. Submissions from the public and North Canterbury Fish & Game raise concerns about trout movement being affected by the Project. As outlined above, the extent of hydrological alteration to the flow regime is far less in the lower reaches where adult trout are likely to be present and the water depth in this part of the river will be sufficient for the movement of adult trout (the decrease in the 7D MALF at SH7 is 9%). The proposed minimum flow may not be sufficient for adult brown trout to move upstream and downstream at certain times of the year above the gorge. However, no adult brown trout have been recorded above the Kakapo Brook gorge and given low flows below the proposed minimum flow naturally occur, even if adult trout were present, their movement would have been impeded in this section of the river prior to the proposed Project. Moreover, the presence of adult brown trout is highly unlikely based on the near-absence of suitable habitat for such fish in the middle reaches of the catchment (Jellyman & Booker 2014). In addition, under the Canterbury Water Management Strategy, one of the targets for Ecosystem health/biodiversity is to see An upward trend in diversity and abundance of native fish populations. Thus, in an alpine catchment with moderate native fish abundance and very low abundance of brown trout - well below angling size - providing for brown trout movement through the mid-reaches of the catchment is undesirable. Eel habitat 59. A submission from the South Island Eel Industry Association contends that the adverse effects of the Project on eel fishing are high. It is stated that Effects on eel habitats downstream of intake structure has not been adequately considered, particularly the adverse effects of truncated flood flows on eel feeding behaviour. I will address this submission in three parts, first the eel species present, second examining eel abundance in Kakapo Brook and third the issue of eel feeding at flood flows: (1) In the mainstem of Kakapo Brook, only longfin eel have been recorded.

25 25 Shortfin eel have been caught from Lake Lorraine. Shortfin eel are very rarely caught in alpine rivers and tributaries as they tend to dominate eel catches closer to the coast. When caught over 100 km inland, they are almost exclusively caught from lakes rather than riverine habitats; (2) Electrofishing data showed that longfin eels were at very low abundance in the mainstem of the Kakapo Brook in the reach downstream of the intake site. Longfin eel abundance in the Kakapo Brook catchment is highest below the gorge which terminates approximately 13.5 km downstream of the intake site. Only one eel has been recorded in the reach downstream of the intake site whereas Canterbury galaxias are abundant and alpine galaxias are relatively common. The electrofishing data are consistent with the results from the physical habitat modelling which indicate that there is very limited habitat available for longfin eel (>300 mm) (Figure 4). At the proposed minimum flow of 320 L/s, the weighted usable area for Canterbury galaxias is 5.21 m²/m compared to only 0.21 m²/m for longfin eel (>300 mm). Maximum WUA for longfin eel (>300 mm) is only m²/m; (3) Truncation of flood flows which I take to mean a shortening of the duration of a flood event would often occur as a result of the proposed Project and would reduce the extent of time that riverine habitat (above the depth of the minimum flow) is inundated. The inundation of previously dry habitat has the potential to make terrestrial insects available to fish in the inundated habitat. Shortfin eels in some South Island lakes (e.g., Lake Brunner) are thought to feed extensively in recently inundated habitat to take advantage of a new, previously terrestrial, food source. However, this behaviour has not been documented for longfin eels in lakes nor has it been documented to occur in rivers (although given the opportunistic scavenging behaviour of eels it cannot be discounted). Given the lack of longfin eels in the catchment, the size of the longfin eels caught (i.e., well below the minimal commercial size limit) and the comparatively low productivity of the potentially inundated habitat (i.e., when dry stony river banks are compared to the shoreline of Lake Brunner where such behaviour has been observed), there does not seem sufficient evidence to support the contention that truncated flood flows will have highly adverse effects on commercial eel fishing as suggested by the submitter. Section 42A Officer s report Ms. Natalie van Looy 60. I have read Ms. van Looy s report and whilst I agree with some of the concerns raised, there are also a number of points in which I disagree with her conclusions. In addition, there are issues of factual inaccuracies where she has misinterpreted or incorrectly summarized the work I have undertaken for the Project. I outline these below so that there is no confusion relating to the work I have been involved with. There are instances where I do not think her summation correctly represents the statements from the expert evidence of Mrs. Jen Dodson and Dr. Adrian Meredith so for clarity, I have responded directly to the expert comments contained in the appendices of the Section 42A Officer s Report. As a number of the issues raised have already been addressed in my main evidence, I have responded to

26 26 paragraphs that raise new issues relevant to aquatic ecology or that I consider to be of significant importance so as to require further comment from that already provided. 61. In Paragraph 116, it is stated There is currently insufficient information available to determine the full effects of flat lining Kakapo Brook on instream water quality and ecological values, particularly megafauna including birds and fish. I consider that there is now sufficient information for the catchment to determine the potential effect of the Project on stream macroinvertebrates. I think there is sufficient freshwater fisheries information to determine the potential effect of the Project on the most affected reaches (i.e., in the middle and upper catchment) and although the data for the lower reaches is not as complete as for the middle and upper catchment, sufficient data are available to make a judgement on the likely effects of the scheme for this part of Kakapo Brook also. The only reach that would be flatlined is the 750 m reach below the intake and there has been information collected during various surveys on periphyton, stream invertebrates and fish and habitat modelling has been conducted. Therefore, I disagree with Ms. van Looy and consider that there is sufficient information available to determine the effects on megafauna such as fish. 62. In Paragraph 134, Ms. van Looy states that Policy 1.4 of the HWRRP which states that the frequency of flow events between 1.5 and 3 times the median flow will not be compromised for tributaries of the Waiau River. This is what the policy states for Community and/or Stock Drinking Water (Part 2.1), not Environmental Flows (Part 2.2). With regards to Environmental Flows, it states in Section that In the mainstem of the Hurunui and Waiau River flows of around 1.5 to 3 times the median flow are important for flushing accumulations of fine sediment, periphyton and cyanobacteria, and to trigger flow dependent aquatic life-cycle processes such as fish migration. The relationship between flow statistics and ecological processes in the mainstem cannot automatically be applied to tributaries within the Waiau catchment because at the local catchment scale, there may be differences in climate conditions, topography, geology, land cover, source-of-flow or channel morphology which may mean that changes in flow have a greater or lesser effect on instream processes in the tributaries compared to the mainstem. 63. It is stated in Paragraph 155 that The applicant concludes that flow variability will only be affected for a 750 metre stretch of the river, at which point a tributary provides the flow variability seen during freshes and floods. That summation by Ms van Looy is not an accurate representation of what has been stated. Jellyman (2014b) clearly states The distance between the intake site and the next major tributary is 750 m so this is the length of river that will experience the least flow variability and be most affected by the minimum flow that is set. From this tributary onwards, flow variability in the mainstem would increase compared to the upstream reach. Therefore, it has not been concluded that flow variability will only be affected for a 750 m reach of Kakapo Brook. What is stated is that the tributary 750 m downstream of the intake will provide flow variability downstream of this point, so the flow regime no longer flat-lines, because the flow from this tributary is not modified by the Project. This is accurately summarised by Mrs. Dodson in

27 27 Paragraph 156 when talking about the flow regime below the 750 m reach, the remaining stretch of the river will experience modified flows albeit at lower levels relative to distance increases from the point of abstraction. 64. Ms. van Looy has commented in Paragraph 157 on the analysis of Mrs. Dodson which showed that the Project would cause a large reduction in the frequency of flood flows in Kakapo Brook and therefore an increase in periphyton accrual times. I agree with these points and the Project has now proposed conditions that will mean there is not a reduction in the frequency of flows 3x MEDIAN and that there is not a reduction in the frequency of flows 1.5x MEDIAN between 1 November and 1 May (see Paragraphs 42 and 47 in my evidence for further detail). 65. The summation by Ms. van Looy in Paragraph 159 is incorrect as she states the applicant citing that flows of this size [1.5x MEDIAN] are insufficient for mobilising bed material and scouring out algal growths. In Jellyman (2014b) it is stated Based on observations when gauging at approximately 1.5 times the median flow, a flow of this magnitude should not be expected to cause meaningful bed movement (as no filamentous algae was present at the time it is not known whether such a flow would be sufficient to reduce excess accrual of nuisance periphyton). The applicant has not stated that flows 1.5x MEDIAN are insufficient to scour out algal growth as I have clearly stated in the above report I could not observe whether or not a flow of this magnitude was sufficient to scour algae. As stated in Paragraph 46 of my evidence, I think flows of at least 1.5x MEDIAN will be an important tool for mitigating the potential effects of the Project during warmer months. 66. In Paragraph 192, Ms. van Looy appears to have extrapolated a comment in her summation of Dr. Meredith s opinion expressed in Paragraph 37 of his evidence. I agree, in part, with the view expressed by Dr. Meredith that having a proliferation of nuisance algae upstream has the potential to increase the speed at which a proliferation could return in the downstream reaches. However, I strongly disagree with the extrapolation made by Ms. van Looy that this will affect water quality in the mainstem of the Hope and Waiau Rivers. Nuisance algae may proliferate in different parts of a river (which could affect water quality) that has suitable hydraulic conditions. Whilst some reaches of Kakapo Brook could be modified at certain times of the year to have hydraulic conditions that are more suitable for the proliferation of nuisance algae than at present, this cannot be extrapolated beyond the confluence with the Hope River to simply assume that if a larger number of nuisance algal cells/material were present in the water column that it would result in nuisance proliferations in a much larger waterway with different hydraulic conditions. 67. In Paragraph 215, Ms. van Looy states Ecological assessments carried out by Jellyman and Booker (2014) on the behalf of the applicant recommended that a minimum flow between 0.3 and 0.6 m 3 /s was set. Later in the paragraph she concludes The applicant has chosen a minimum flow of 320 L/s which is below the ranges discussed in the report. This conclusion is incorrect because the minimum flow selected by the applicant of 320 L/s (0.32 m 3 /s) is within the range of 0.3 and 0.6 m 3 /s as recommended by Jellyman and Booker (2014).

28 Ms. van Looy has concluded that the minimum flow requirements report of Jellyman and Booker (2014) indicates that a flow of 0.32 m 3 /s may affect the movement of eels. This conclusion is not supported by the analyses in the technical reports. Jellyman (2014b) concludes Modelling results indicated that fish passage is available as long as flows are greater than 0.2 m³/s. Longfin eels are specifically mentioned in the report and it is stated that they migrate downstream on high flows. For the sake of completeness the report comments on the highly unlikely scenario of a 1 m longfin eel migrating at minimum flow (even though eels have only been caught up to 415 mm and they migrate on elevated flows). Even under this scenario it concludes there would still be sufficient water depth to be fully submerged through run and pool habitat but that they may not be fully submerged in all riffles zones when moving downstream. 69. I think there are some inconsistencies for some of the summary statements Ms. van Looy concludes from the expert evidence contained in the later Appendices. Therefore, to avoid any confusion I have addressed the expert comments directly. Mrs Jen Dodson Appendix In response to Paragraph 23, in the latest proposed consent conditions the Project has re-worked them so that all flows of 3 times the median will be untapped for a minimum of 6 hours year-round (this also addresses Mrs. Dodson s comment in Paragraph 25). Therefore, this issue has been dealt with although I will clarify a further point. 71. Mrs. Dodson has referenced my comment (Appendix B, Report 1, page 20) that a flow of this magnitude should not be expected to cause meaningful bed movement based on a gauging I conducted at 1.5 times the median flow. Mrs. Dodson then cites examples of flow gaugings at sites when the mean water velocity exceeds the highest RHYHABSIM model threshold for long filamentous algae suitability (i.e., that at a flow of 1.5 times the median flow the water velocity should not be particularly suitable for long filamentous algae to exist). In this instance I think Mrs. Dodson has confused the statement that I have about bed movement because she has taken it to be a statement about the water velocity required to remove long filamentous algae. I agree with Mrs. Dodson that a flow of 1.5 times the median has the potential to remove long filamentous algae from the reach that will experience the most flat-lining (although the precise flow is not known). To be clear, I was making a statement about the flow magnitude required to physically move bed substrate which would definitively result in the loss of long filamentous algae through physical abrasion and scour, and such a flow, as the modelling data in Jellyman & Booker (2014) indicates, is higher than 1.5 times the median flow. 72. In response to Paragraph 24, I agree with expert caucusing for the HWRRP and have made comments in Paragraph 46 of my evidence that are very similar to the rationale for why flows of 1.5 to 3 times the median should be provided for during the time of year when algal growth is fastest.

29 In response to Paragraph 26, the proposed conditions have been altered to ensure flushing flows (of three times the median) are now provided year-round. Dr Adrian Meredith Ecological communities in Kakapo Brook that should be considered in assessing the use and abstraction of water 74. In response to Paragraph 23, Dr. Meredith has misinterpreted the AEE text in his comment the deepest and swiftest sections of several sites could not be sampled because it applied to the October 2013 survey as stated, and did not apply to the October 2012 survey. I was the electrofishing operator (sub-contracted to NZ Environmental) during the October 2013 survey and requested that the comment electrofishing may have underestimated the presence and abundance of any large salmonid fishes (>30 cm) 4 be included in the AEE. However, the deeper, swifter sites in question were all in the lower reaches of Kakapo Brook, below the gorge. The location where sampling may have been sub-optimal was not made clear in the AEE so I can understand why Dr. Meredith has misinterpreted this and made a comment about underestimating salmonid fishes (>30 cm) in the middle reaches of Kakapo Brook. 75. To clarify, salmonid sampling effectiveness was not markedly impacted in the middle reaches during the October 2013 survey; it appeared that the majority of the sediment causing the discolouration of the river water in the lower reaches was originating from either the gorge or tributaries flowing into the gorge because water clarity was significantly better in the middle reaches of Kakapo Brook. As previously stated in Paragraph 51, across all electrofishing surveys approximately 2.5 km of waterways in the middle and upper catchment were sampled and an additional 1.1 km was walked looking for trout. Only two brown trout were recorded above the intake and they were <100 mm. Based on electrofishing data and the very limited habitat available for brown trout based on the modelling work of Jellyman & Booker (2014), I do not consider that adult brown trout are an instream value that should be considered for flow setting in the middle and upper reaches of Kakapo Brook. 76. There is a suggestion in Paragraph 24 that the sampling of fish communities in April 2014 was limited by low flow conditions. The implication from Dr. Meredith is that this may have impacted sampling but the sampling time was actually quite intentional. There had been a lack of freshes through mid-january and February and then in early March there was a fresh around 2.5 times the median. Thus, sampling fish communities approximately 3 weeks after a fresh between 1.5 and 3 times the median allowed me to observe whether waterways in the middle and upper catchments had: (1) perennial flow, (2) significant algal accrual at this time of 4 Salmonid fishes is a term used to cover fish species from the family Salmonidae. In the context of Kakapo Brook, the salmonid fish species are brown trout and Chinook salmon.

30 30 year, and if so, (3) whether there were markedly affecting fish numbers compared to previous surveys. 77. I had also expected that if brown trout were present in the middle and upper reaches (as they have not previously been recorded), then sampling at this time may increase the likelihood of capture, because if present, they may have moved upstream as I expected the water flowing from the upper catchment to be cooler given that the headwaters are more shaded from forest. It seems somewhat unjustified to criticise the design of a survey that did manage to locate brown trout in the upper catchment for the first time for having not potentially optimised the timing of the survey for larger-sized brown trout that were not known to be present prior to the survey and for which modelling predicts there is almost no habitat available for. 78. The response above in part also answers Paragraph 25 with regards to brown trout. For large longfin eels, modelling also shows that there is almost no habitat available. Although in my opinion, modelling may not always predict adult longfin eel habitat well in systems where ample daytime cover is present even if stream habitat conditions may be sub-optimal. For that situation to be applicable, Kakapo Brook requires daytime cover to be present and I observed a surprising lack of any potential cover at the sites surveyed in Kakapo Brook. The waterways, both mainstem and tributaries, are generally shallow, undercut banks are extremely rare and significant debris clusters (often the preferred daytime cover for longfin eels) are essentially absent from all but the smallest of headwater tributaries (which generally had no fish present). Therefore I do not consider the absence of adult longfin eel to be a flow issue related to wetter or drier years but in my opinion there absence from electrofishing surveys is due to a lack of daytime cover. As such I disagree with the view of Dr. Meredith expressed in Paragraph 26 that abstraction will render Kakapo Brook unsuitable for fisheries such as eels and trout because the middle and upper reaches of Kakapo Brook, where the impacts of abstraction will be most pronounced, does not contain fish of a size relevant for anglers or commercial eel fishers thus it is already unsuitable habitat for these fisheries. 79. Numbers of both juvenile longfin eel and brown trout are very low in the middle and upper reaches of the catchment, and what fish there are appear to be more abundant in the upper catchment. Therefore, as long as adequate fish passage is maintained which modelling data suggests it will be at the proposed minimum flow then I do not think a valid argument can be made that the trout and eel fishery values in this section of the Kakapo Brook catchment will be adversely affected by the Project. Ecological effects of abstraction for hydro-electric and irrigation storage resulting in flat-lining in Kakapo Brook 80. Dr. Meredith considers in Paragraph 31 that the work undertaken by NIWA for proposing a minimum flow has been professionally carried out but disagrees that it should be the only flow assessment criteria used. The flow assessment I have made draws extensively on my own analyses but it is not the only data used in my

31 31 assessment. I have also incorporated the findings from the work of others when making the assessment. For example, the potential effects of the scheme on sediment transport (Veendrick 2015) as well as how water quality parameters such as temperature and dissolved oxygen will be influenced (Mr. Lees evidence, Paragraph 11.7). I think it is clear from the analyses in my evidence that the flow assessment for this project has gone beyond purely setting a minimum flow in assessing what components of the flow regime need to be retained to ensure values such as biodiversity, ecosystem function and natural character are maintained. 81. The HWRRP does not state a method (or even a suite of methods) that should be used for flow setting but it does state the values that should be considered and states aspects of the flow regime that need to be retained so that those values are not compromised. The Biggs et al. (2008) paper outlines the ecologically important flow components that need to be retained in a flow regime in New Zealand. I have included all of these components when recommending take cessation rules that should maintain instream values. Moreover, provisions have been made so these rules also align with those of the HWRRP (e.g., for example flows of 1.5x the median will be retained during at risk periods). 82. In Paragraph 36 Dr. Meredith has noted the applicant states that these potential effects are only likely to be seen for a 750 m reach of river downstream of the abstraction point because an inflowing tributary provides increased and unaffected flow variability. This does not seem to be an accurate summation of what is stated in the application (Effects on Kakapo Brook, Page 50) which is The hydrographs and flow duration curves indicate that the proposed take results in stable flows immediately downstream of the take but that this effect is much less pronounced at the recorder site and even more so at SH 7. This is due to tributary inflows downstream of the proposed take. The relative reduction in flow is much larger immediately downstream of the proposed intake (mean flow reduces by 52%) compared to further downstream at the recorder site (mean flow reduces by 38 %) and SH7 (mean flow reduces by 28%). 83. I agree with Dr. Meredith that the flat-lining effect could have a significant adverse effect on instream ecology in Kakapo Brook (Dr. Meredith s evidence, Paragraph 36) if no mitigation measures were in place. However, with the proposed mitigation measures there may still be some adverse effects as a result of the take, particularly in the 750 m reach downstream of the intake, but I would still expect this section of Kakapo Brook to retain many of its current instream values. For example, there could be a decline in the total number of fish supported in the reach but I would not expect species to be lost from even the most affected reach below the intake. As my B.Sc (Hons) research was focussed on Canterbury and alpine galaxias and my Ph.D research had a strong focus on fish communities in Canterbury headwater streams I am very familiar with the habitat conditions, temperature ranges and water chemistry requirements of the fish species found in the Kakapo Brook catchment. 84. Of the fish species present, juvenile brown trout would likely be the species most adversely affected by the modified habitat conditions in the reach below the intake

32 32 because of their lower temperature tolerance (compared to native species) and higher food requirements; although I note they have not been recorded between the intake and the flow recorder site. However, even juvenile brown trout populations can be highly tolerant of low flow conditions. In a recent study, Hayes et al. (2010) found that during a low flow event in a tributary of the Motueka River (Tasman) from February to April (return period >8.4 years), no adverse effect on the juvenile brown trout population was observed despite the flow dropping below the 7D MALF for 46 days (flows fell to 56% of the 7D MALF). The study went as far as to state The study identified ecological redundancy, which could be exploited for flow allocation. Significantly, it has shown that minimum flows equivalent to the MALF (often advocated by New Zealand conservation and fisheries management organisations) are not always necessary for sustaining juvenile trout populations. As outlined by myself and Dr. Meredith, there are other components of the flow regime that are important to consider for ecology beyond just the minimum flow (e.g., flow variability) but this study does show that fish species are capable of surviving extended periods of low flow without adverse effects on the population. 85. In Paragraph 37, Dr. Meredith suggests that excessive nuisance algal proliferation can have both localised effects at the point they first occur, and an effect based on seeding of downstream reaches with the nuisance proliferation. Dr. Meredith goes on to make the point that with an upstream source of nuisance algal material, nuisance proliferations can occur more quickly. I agree in part because having a nearby inoculum of algal material could clearly increase the potential for proliferations to occur. However, it has been my experience that algal proliferations only occur when suitable hydraulic conditions are present. For example, on large braided rivers (e.g., Waimakariri and Rakaia Rivers) I have observed side braids with algal proliferations when the main channel has had no such proliferations. In such examples, water chemistry, antecedent flow conditions, temperature regime, etc. are almost identical and the difference in whether or not algae proliferates must be because of hydraulic conditions. In this example, the inoculum of algal material may even be higher in the mainstem compared to the side braid but because the hydraulic conditions are not suitable in the side braid, the nuisance algae does not proliferate. 86. In Paragraph 41, Dr. Meredith raises the concern that algal blooms have the potential to naturally occur at any time of the year in the Hurunui catchment, and that because of the potential for abstraction to occur at any time of the year by the Project, that flow mitigation measures should not be limited to the proposed period of November 1 to May 1. I am in agreement with Dr. Meredith that there is the potential for algal blooms to potentially occur during any month of the year and that additional mitigation measures are likely to be required to maintain the ecological values in Kakapo Brook. In the proposed consent conditions seen by Dr. Meredith it was proposed that year-round deep surface flushing flows (>7 m 3 /s) would flow unmodified for a minimum of six hours and that flows more than 3 times the median would flow unmodified for a minimum of six hours between November 1 to May 1. This has now been further addressed by the changes to the proposed conditions stated in Paragraph 42 and 47 of this evidence.

33 The rationale for a 6 hour take cessation is outlined in Paragraph 44 of this evidence. No supporting rationale was supplied with the application which is undoubtedly why Dr. Meredith, in Paragraph 43 of his evidence, suggested the duration of the take cessation was ad hoc. 88. To clarify, the rationale for the 6 hour take cessation duration was based on the time taken for a flow of three times the median to pass from the intake to the confluence which was calculated to be 5 hours (with an additional hour added to ensure flows are sustained for an hour). 89. For flows of 1.5 to 3 times the median the 6 hour calculation was simply doubled. I considered this to be an ecologically conservative approach, since even a flow of 1.5 times the median could reach the confluence in under 6 hours. However, the frequency of freshes in this flow range varies between wet, average and dry years and because they are being proposed as a mitigation tool during warmer months from November 1 to May 1 I considered it important that they be allowed to flow for an extended period of time to ensure adequate time for periphyton removal. I was of the opinion that for a small fresh around 1.5 times the median, a 6 hour flow may shift nuisance periphyton biomass but it may not be long enough for much of it to be removed from the catchment. Hence I considered that a longer duration was required for flows of this magnitude to serve their intended function. 90. In Paragraph 47 from Dr. Meredith s evidence he states It would be more appropriate that monitoring results led to triggering of conditions. The Project has taken an alternate approach during the warmer months where instead of conducting monitoring to initiate a take cessation rule, the Project has instead opted to have mandatory take cessation rules when flows exceed 1.5x, 3x and 7x MEDIAN. Under this approach, all available flows that may potentially remove nuisance periphyton proliferations are being allowed to flow down Kakapo Brook for a specified duration (see proposed consent conditions). Therefore, the applicant has not proposed a specific consent condition to undertake summer periphyton monitoring as all practicable mitigation measures to minimise periphyton accrual have been specified as consent conditions. However, I note that as part of the EMP (Condition 53), the applicant is still proposing monthly periphyton monitoring, between 1 November and 1 May, for three years. 91. Dr. Meredith is correct in his analysis (Paragraph 49) that the original take cessation rules proposed may not have been effective in controlling nuisance algal proliferations during particularly dry years. Thus, the Project has modified the proposed rules to increase flow variability throughout the year with a take cessation rule associated with flows of 3x MEDIAN and during warmer months (from November 1 to May 1) with a take cessation rule for flows of 1.5x MEDIAN when lower flows are more likely in this catchment. Effects of fish screening proposed 92. In Paragraph 61, Dr. Meredith states that the bypass diversion will functionally reduce the flow of the remaining section of Kakapo Brook to a lesser flow that may be as low as 140 L/s. In the evidence of Mr. De Ruyter it is stated that the flow of

34 34 water in the bypass channel will be approximately 30 L/s (although the final design for the fish bypass will be confirmed during Stage 2 design) so the minimum flow in Kakapo Brook should be approximately 290 L/s for the 50 m distance that it takes for this water to be returned. Therefore, Dr. Meredith has overstated the extent of the change in minimum flow in this 50 m reach of Kakapo Brook. The change in habitat availability for this 50 m reach can be quantified by examining Figure 5. For example, at a flow of 0.29 m³/s, average habitat availability for fish species has decreased from 90% to 87.9%. Given the point of having a fish screen is to stop fish leaving the river and entering the race, it is my opinion that the benefit of having the fish returned back at river outweighs the negative effects of a flow reduction of 30 L/s for this 50 m reach. Effects on ecological values of the downstream environments in Hope River and Waiau River 93. Dr. Meredith states in Paragraph 78 that The effects of reduced flows in Kakapo Brook will have a lesser effect on flow reductions in the downstream receiving rivers, but will still be measurable and an incremental change in the quality of habitats, and functions such as migration potential, fishery quality etc.. Downstream of the confluence of the Kakapo Brook and Hope River, the mean flow will be reduced by 0.68 m³/s as a result of the take and will be increased by up to 0.92 m³/s during hydropower generation. Given that the mean flow of the Hope River at Glynn Wye is 44.9 m³/s I am not convinced that minor flow fluctuations (1.51% decrease up to a 2.1% increase) would result in a detectable change given the total quantity of water flowing down the Hope River each day remains unchanged. 94. Under MALF conditions (7D MALF in Hope River 14.0 m³/s), the decrease in flow would be 2.2%. At the point of discharge of the tailrace, an increase in flow of 1.6 m³/s (11.4% of Hope River MALF) might act as a very small flush for a short distance with a measurable effect, probably positive, on aquatic ecology, although any such effects would probably be limited to no more than a few hundred metres. Given the minor changes in flow at both MALF and mean flow I disagree with Dr. Meredith s opinion that there will be a detectable impact on migration potential in the mainstem of either the Hope or Waiau Rivers. 95. In Paragraph 79 Dr. Meredith states The potential abstractive use proposed for Kakapo Brook may be functionally removing this brook from the resilience and potential of headwater fisheries of this river system. The fisheries information presented does not support this statement in my opinion. 96. The middle and upper reaches of Kakapo Brook are dominated by two nondiadromous native fish, Canterbury galaxias and alpine galaxias, and these fish species do not move significantly during their lifecycle. For example, in a project examining Canterbury galaxias movement in a Canterbury stream, 97% of the 384 fish monitored had moved less than 250 m in almost a year (Cadwallader 1976). It is highly likely that any excess larvae or juvenile fish would drift (or swim) downstream towards the lower reaches of Kakapo Brook although the probability of survival would be very low if moderate numbers of trout were present (Jellyman

35 35 & McIntosh 2008; 2010). Therefore, I would consider these fish more in the context of an isolated self-sustaining population that is unlikely to make a significant contribution to the headwater fisheries of the Hope or Waiau Rivers. 97. In addition, given that a number of longfin eels have been caught across several surveys, but none larger than 415 mm, this would tend to suggest that although the middle and upper catchment may be suitable for the growth of smaller eels, it is not capable of supporting large eels. I do not think longfin eels are being functionally removed from the river system but rather that the middle and upper reach of Kakapo Brook is likely to be supplying the Hope/Waiau Rivers with a small number of sub-adult longfin eels. I would not expect this to change as a result of the Project. Effects on ecological values resulting from the discharge of hydro-electric flows to a braid of the Hope River 98. I agree with the point made by Dr. Meredith that there is a risk of fish stranding if the water discharged from the tailrace is not discharged into an active braid of the Hope River. There is a proposed consent condition that states this will be done. Recommendations/Consent conditions 99. Proposed consent conditions associated with my evidence have been tabled. Conclusions 100. There are a number of indigenous aquatic species present in the Kakapo Brook catchment but I am in agreement with Dr. Meredith that the AEE listed communities that would be expected from a small alpine braided river. None of the fish or invertebrates recorded during faunal surveys are consider by DOC to be threatened although three of the species recorded have populations classified as At Risk either because they are considered to be in gradual decline or because they are naturally uncommon. In my opinion the mitigation measures proposed by the Project will be sufficient to ensure there is no loss of species from the catchment and that there is not a significant adverse effect on the abundance of any particular species The applicant has selected a minimum flow for the Project of 320 L/s based on habitat modelling data. At this proposed flow, all four native species present have at least 90% (range: %) of their maximum WUA available. At this proposed minimum flow, modelling data suggests there should be no impact to the upstream and downstream movement for the size and species of fish recorded in the middle and upper catchment; this result is supported by observational data during a survey undertaken at a flow less than the proposed minimum flow.

36 The Project will result in a 750 m reach of Kakapo Brook being flat-lined for around 85% of the year. A tributary draining a 5.6 km² catchment (i.e., 11.4% of the total catchment size) joins the Kakapo Brook mainstem at this point and downstream of this confluence, flow variability increases. The Project has the potential to cause adverse effects to aquatic biota, particularly in but not limited to, the 750 m reach below the intake. I have outlined a number potential effects to ecological values, as have the experts in the Section 42A Officer s Report. The applicant has proposed a number of additional consent conditions to address these effects and I am satisfied that with the implementation of these conditions, particularly the take cessation rules for flows of 1.5x, 3x and 7x the median flow, the ecological values present in Kakapo Brook will be maintained It should be noted that not all effects from abstraction on aquatic ecology can be predicted prior to any project being implemented so it will be important that the applicant has a robust Environmental Management Plan that sits alongside their proposed monitoring to ensure they can adequately respond to/mitigate unforeseen effects of the Project. I am satisfied that the Environmental Management Plan, and specifically Condition 53, will mean that the Project will address unforeseen effects on aquatic ecology.. Phillip Graeme Jellyman Date: 5 October 2015

37 37 References Biggs, B.J.F. (1982) The effects of flow regulation on river ecology: a case study. In: River low flows Conflicts of water use. (ed. McColl RHS). Water and Soil Miscellaneous Publication 47: Biggs, B.J.F. (2000) New Zealand Periphyton Guideline: detecting, monitoring and managing enrichment of streams. Ministry for the Environment, Wellington. Biggs, B.J.F., Ibbitt, R.P., Jowett, I.G. (2008) Determination of flow regimes for protection of in-river values in New Zealand: an overview. Ecohydrology and Hydrobiology 8: Bonnett, M. L. (2014a) Review of Kakapo Brook fish screen design. Prepared for MainPower New Zealand Limited and Rooney Group Limited. NIWA Christchurch letter 6 p. Bonnett, M.L. (2014b) Review of updated design of fish screen for the proposed Glynn Wye/Kakapo Brook scheme. Prepared for MainPower New Zealand Limited and Rooney Group Limited. NIWA Christchurch memo 2 p. Cadwallader, P.L. (1976) Home range and movements of the common river galaxias, Galaxias vulgaris Stokell (Pisces: Salmoniformes), in the Glentui River, New Zealand. Australian Journal of Marine and Freshwater Research 27: Clausen, B., Biggs, B.J.F. (1997) Relationships between benthic biota and hydrological indices in New Zealand streams. Freshwater Biology 38: Clausen, B., Plew, D. (2004) How high are bed-moving flows in New Zealand rivers? Journal of Hydrology (NZ) 43: DeRuyter, J. (2014) Glynn Wye Preliminary Design Report. Prepared for MainPower New Zealand Limited and Rooney Group Limited. Rooney Earthmoving Limited. 8 p. Goodman, J.M., Dunn, N.R., Ravenscroft, P.J., Allibone, R.M., Boubee, J.A.T., David, B.O., Griffiths, M., Ling, N., Hitchmough, R.A., Rolfe, J.R. (2014) New Zealand Threat Classification Series 7. Department of Conservation, Wellington. 12 p. Grainger, N., Collier, K., Hitchmough, R., Harding, J.S., Smith, B., Sutherland, D. (2014) Conservation status of New Zealand freshwater invertebrates, New Zealand Threat Classification Series 8. Department of Conservation, Wellington. 28 p. Hayes J.W., Olsen D.A., Hay J. (2010) The influence of natural variation in discharge on juvenile brown trout population dynamics in a nursery tributary of the Motueka River, New Zealand. New Zealand Journal of Marine and Freshwater Research 44: Jellyman, P.G. (2014a) Fish survey of the Kakapo Brook headwaters and Lake Lorraine. Prepared for MainPower New Zealand Limited and Rooney Group Limited. NIWA Christchurch memo 14 p. Jellyman PG (2014b) Response to aquatic ecology issues for the proposed Kakapo Brook scheme. Prepared for MainPower NZ Limited and Rooney Group Limited. 26p. June CHC 2014_081. Jellyman, P.G., Booker, D.J. (2014) Instream habitat and flow regime requirements in Kakapo Brook. Prepared for MainPower New Zealand Limited and Rooney Group Limited. NIWA Christchurch report 43 p.

38 Jellyman, P.G., Harding, J.S. (2011) Aquatic ecosystem survey of the Hurunui River catchment. Prepared for the Hurunui Water Project. 52 p. Jellyman, P.G., McHugh, P.A., McIntosh, A.R. (2014) Increases in disturbance and reductions in habitat size interact to suppress predator body size. Global Change Biology 20: Jellyman, P.G., McIntosh, A.R. (2008) The influence of habitat availability and adult density on non-diadromous galaxiid fry settlement in New Zealand. Journal of Fish Biology 72: Jellyman, P.G., McIntosh, A.R. (2010) Recruitment variation in a stream galaxiid fish: multiple influences on fry dynamics in a heterogeneous environment. Freshwater Biology, 55, Jowett, I.G. (2009) RHYHABSIM software manual. Version 5.0. Jowett, I.G., Biggs, B.J.F. (2006) Flow regime requirements and the biological effectiveness of habitat-based minimum flow assessments for six rivers. Journal of River Basin Management 4: Matheson, F., Quinn, J., Hickey, C. (2012) Review of the New Zealand instream plant and nutrient guidelines and development of an extended decision making framework: Phases 1 and 2 final report. NIWA Client Report, HAM Poff, N.L., Allan, J.D., Karr, J.R. (1997) The Natural Flow Regime: A paradigm for river conservation and restoration. Bioscience 47: Poff, N.L., Ward, J.V. (1989) Implications of streamflow variability and predictability for lotic community structure: a regional analysis of streamflow patterns. Canadian Journal of Fisheries and Aquatic Sciences 46: Scott, T.S., Butt, J., O Brien L (2013) Kakapo Brook hydro-scheme: Assessment of Ecological Effects. Prepared for MainPower Ltd. 54 p. Shiwell C.S., Dungey, R.G. (1983) Microhabitats chosen by brown trout for feeding and spawning in rivers. Transactions of the American Fisheries Society 112: Snelder, T., Booker, D., Jellyman, D.J, Bonnett, M.L., Duncan, M. (2011) Waiau River midrange flows evaluation. Prepared for Environment Canterbury. NIWA Client Report No: CHC p. Te Poha o Tohu Raumati (2007) Te Rūnanga o Kaikōura Environmental Management Plan. 324 p. Unwin, M.J. (2006) Assessment of significant salmon spawning sites in the Canterbury region. NIWA Client Report CHC p. Veendrick, B. (2015) Glynn Wye Hydro and Irrigation Scheme Hydrology Assessment. Prepared for MainPower New Zealand Limited and Rooney s Holding Limited. 22 p. Wood, S.A., Hamilton, D.P., Paul, W.J., Safi, K.A., Williamson, W.M. (2008) New Zealand guidelines for Cyanobacteria in recreational fresh waters: interim guidelines. Publication, 981. Ministry for the Environment, Wellington. 38

39 39 Appendices Appendix A native fish species caught in Kakapo Brook The four native fish species shown are: a) Canterbury galaxias, b) upland bully, c) alpine galaxias, and d) longfin eel. Photo credit: Angus McIntosh (a-c) and Anon (d).

40 40 Appendix B definitions of components of the flow regime The following definitions are taken from Poff et al. (1997): The magnitude of discharge at any given time interval is simply the amount of water moving past a fixed location per unit time. Magnitude can refer either to absolute or to relative discharge (e.g., the amount of water that inundates a floodplain). Maximum and minimum magnitudes of flow vary with climate and watershed (i.e., catchment) size both within and among river systems. The frequency of occurrence refers to how often a flow above a given magnitude recurs over some specified time interval. Frequency of occurrence is inversely related to flow magnitude. For example, a 100- year flood is equalled or exceeded on average once every 100 years (i.e., a chance of 0.01 of occurring in any given year). The average (median) flow is determined from a data series of discharges defined over a specific time interval, and it has a frequency of occurrence of 0.5 (a 50% probability). The duration is the period of time associated with a specific flow condition. Duration can be defined relative to a particular flow event (e.g., a floodplain may be inundated for a specific number of days by a ten-year flood), or it can be a defined as a composite expressed over a specified time period (e.g., the number of days in a year when flow exceeds some value). The timing, or predictability, of flows of defined magnitude refers to the regularity with which they occur. This regularity can be defined formally or informally and with reference to different time scales. For example, annual peak flows may occur with low seasonal predictability or with high seasonal predictability. The rate of change, or flashiness, refers to how quickly flow changes from one magnitude to another. At the extremes, "flashy" streams have rapid rates of change (i.e., high flashiness), whereas "stable" streams have slow rates of change (i.e., low flashiness).

41 Appendix C hydrographs showing the natural and modified flow regime in different parts of the Kakapo Brook catchment for average, wet and dry years 5. 5 During the period 1 May to 31 October, there is a condition that provides for flows 1.5x MEDIAN to be passed if periphyton trigger levels are exceeded. As an example, I have shown using red arrows - on the above graph only - which flows would also be passed under this condition if trigger levels were exceeded. 41

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