Roodeplaat wind energy facility

Aquatic assessment- ADDEDNDUM

Prepared for:

SRK Consulting

Prepared by:

Scherman Colloty & Associates

1 Rossini Rd

Pari Park

Port Elizabeth

6070

October 2016

SPECIALIST REPORT DETAILS

This report has been prepared as per the requirements of the Environmental Impact Assessment Regulations and the National Environmental Management Act (Act 107 of 1998), any subsequent amendments and any relevant National and / or Provincial Policies related to biodiversity assessments.

Report prepared by: Dr.Brian Colloty Pr.Sci.Nat. (Ecology) / Certified EAP / Member SAIEES and SASAqS.

Expertise / Field of Study: BSc (Hons) Zoology, MSc Botany (Rivers), Ph.D Botany Conservation Importance rating (Estuaries) and interior wetland / riverine assessment consultant from 1996 to present.

I, Dr. Brian Michael Colloty declare that this report has been prepared independently ofany influence or prejudice as may be specified by the National Department of Environmental Affairs.

Signed:………………… Date:…28 October 2016…………

This document contains intellectual property and proprietary information that is protected by copyright in favour of Scherman Colloty & Associates cc. The document may therefore not be reproduced, or used without the prior written consent of Scherman Colloty & Associates cc. This document is prepared exclusively for SRK Consultingand is subject to all confidentiality, copyright, trade secrets, and intellectual property law and practices of SOUTH AFRICA.

Aquatic assessment – October 2016

Table of Contents

1Introduction

1.1Study terms of reference

1.2Limitations

2Impact Assessment

2.1Impact 1: Changes to the hydrological regime

2.2Impact 2: Impact of changes to water quality

2.3Impact 3: Loss of riparian vegetation, aquatic habitat and stream continuity (migration corridors)

2.4Impact 4: Loss of species of special concern

3Conclusion and Recommendations

4References

5Appendix 1: DWS Risk Assessment Matrix as per Notice 509 of 2016

List of Tables

Table 1: A summary of the potential impacts for the respective water course crossings

List of Figures

Figure 1: The 19 road crossings (green dots) and the observed watercourses and or drainage lines

Scherman Colloty & Associates1 Roodeplaat WEF - Addendum

Aquatic assessment – October 2016

ACRONYMS

CARA / Conservation of Agricultural Resources Act
CBA / Critical Biodiversity Area
CSIR / Council for Scientific and Industrial Research
DWS / Department of Water and Sanitation formerly the Department of Water Affairs
EIS / Ecological Importance and Sensitivity
ESA / Ecological Support Area
GIS / Geographic Information System
PES / Present Ecological State
WUL / Water Use License
WULA / Water Use License Application

1Introduction

Scherman Colloty & Associates (SC&A) was appointed by SRK ConsultingSouth Africa (Pty) Ltd (SRK) as an independent specialist to evaluate the aquatic ecological aspects ofthe proposed Roodeplaat Wind Energy Facility and associated infrastructure. A survey was conducted in January and March 2016, and a report was submitted as part of the EIA in March 2016. After comments received from the authorities and due to changes in the National Water Act (Department of Water and Sanitation Notice, 509 of 2016), SRK proposed that SC&A provide an addendum report to the aquatic assessment submitted with the EIA.

This allowed for an opportunity to reassess the impacts based on the updated engineering detail provided by Africoast Engineers in August 2016, which included the following:

  1. Details on proposed crossing design for each road crossing upgrade
  2. Method statement
  3. Rationale statement
  4. Photo record

Thus, the focus of this report is on the potential impacts of the 19 proposed crossings (Figure 1) based on the design detail supplied and in line with the required Risk Assessment Matrix as detailed in Appendices of DWS Notice 509 of 2016. However, the March 2016 aquatic assessment must be referred to for:

  • The remainder of the project components,
  • Regional or catchment descriptions,
  • Review of the bioregional conservation planning systems,
  • Provincial policies
  • Legal requirements
  • Study methods
  • Results of the Present Ecological State and Ecological Importance and Sensitivity Assessment

It must also be reiterated that all new roads have be placed in a manner to avoid the creation of any new watercourse / drainage line crossings (Figure 1). Figure 1 also indicates three crossings (B, P & O), but these had not direct connection with any watercourses (streams) and are associated with surface water runoff and thus these crossings are a result of dealing with stormwater runoff within these drainage lines.

Figure 1: The 19 road crossings (green dots) and the observed watercourses and or drainage lines

1.1Study terms of reference

  • A map demarcating the relevant local drainage area of the respective waterbodies, and the respective catchments within a 500m radius of the study area. This will demonstrate, from a holistic point of view the connectivity between the site and the surrounding regions, i.e. the zone of influence. Maps depicting demarcated waterbodies will be delineated to a scale of 1:10 000.
  • Assess the potential impacts, based on the supplied methodology for each crossing with regard the FEIR, and produced a Risk Assessment Matrix in line with DWS Notice 509 of 2016 to determine if a WUL or GA will be required for each crossing.
  • Provide mitigations regarding project related impacts, including engineering services that could negatively affect demarcated aquatic areas.
  • Provide the relevant aspects with regard updating the Environmental Management / Monitoring Plans.
  • Supply the client with geo-referenced GIS shape files of the aquatic areas.
  • Provide one draft report for comment, with a maximum of two rounds of comments addressed as required.

1.2Limitations

To obtain a comprehensive understanding of the dynamics of both the flora and fauna of both the terrestrial and aquatic communities within a study site, as well as the status of endemic, rare or threatened species in any area, assessments should always consider investigations at different time scales (across seasons/years) and through replication. However, due to time constraints these long-term studies are not feasible and are mostly based on instantaneous sampling.

Therefore, due to the scope of the work presented in this report, a detailed investigation of all, or part of, the proposed site was not possible and are not perceived as part of the Terms of Reference. It should be emphasised that information, as presented in this document, only has reference to the study area as indicated on the accompanying maps. Therefore, this information cannot be applied to any other area without detailed investigation.

Scherman Colloty & Associates1 Roodeplaat WEF - Addendum

Aquatic assessment – October 2016

2Impact Assessment

Several impacts have been highlighted and have been rated based on the project actions / impacts, as well as any potential cumulative impacts during the construction and operational phases of the project. These were also assessed with and without mitigation. To reiterate the assumptions, the proposed transmission line towers will span any of the shown rivers and streams (incl 32m buffer), while the proposed existing access roads will be upgraded with regard the present low level crossings. The designs and methods statements for each of the 19 crossings have been assessed on an individual basis in this addendum.

Furthermore, no new structures including laydown / temporary works areas are located outside any of the watercourse and their buffers (32m).

Two types of impact rating summary tables are provided in this report, the first related to the FEIR, i.e. for the purposes of comparison with the March 2016 aquatic report and the second (Appendix 1) the Risk Assessment Matrix as required by DWS. The Risk Assessment Matrix outcomes will determine if a General Authorisation of Water Use License is required for any Section 21 c and i activities.

2.1Impact 1: Changes to the hydrological regime

Nature of the impact

Due to the nature of the proposed project this would be an operational phase impact, once the crossing upgrades are in place. These structures create impacts such as the upstream impedance of flows, that the released on the downstream side in concentrated flows with high velocity. The downstream areas are thus susceptible to scour and erosion during wet cycles or drying out during drought periods (i.e. upstream flows are impeded)

Significance of impacts without mitigation

The soils within the study area are susceptible to erosion when subjected to high flows (high volumes and velocities), with head-cuts readily forming within the water courses. This creates bed and bank instability in the aquatic ecosystems and consequent sedimentation of downstream areas. Due to the nature of the study area hydrology, its present state and the surrounding impacts this would be negative impact, if severe erosion occurred, thus the overall significance of the impact would be rated as Low for all crossings except for Crossing N= High (Table 1). This is due to the potential sedimentation of downstream pools that contain rare and protected fish species.

Proposed mitigation

  • Where water course crossings need to be upgraded, the engineering team must provide an effective means to minimise the potential upstream and downstream effects of sedimentation and erosion (erosion protection) as well minimise the loss of riparian vegetation (small footprint).
  • No vehicles to refuel within drainage lines/ riparian vegetation.
  • During the operational phase, monitor culverts and stormwater management features to see if erosion issues arise and if any additional erosion control is required.
  • Where possible culvert bases must be placed as close as possible with natural levels in mind so that these don’t form additional steps / barriers.
  • No flows within any of the water courses should be altered by any of the proposed access roads.

Significance of impact with mitigation

Although permanent changes to the local hydrological regime is likely, the intensity of impact in the operational and closure phases would be low, thus the overall significance of this impact would be Very Low for all crossings, and Low for Crossing N (Negative) (Table 1).

Cumulative impacts

The increase in surface run-off velocities is likely to occur considering that the site is located within very steep catchments, however with appropriate mitigation and the fact that no other projects of a similar nature in the region the cumulative impacts are low

Residual impacts

Possible impact on the remaining catchment due to changes in run-off characteristics in the development site.

2.2Impact 2: Impact of changes to water quality

Nature of the impact

Presently little is known about the water quality of the water courses directly in the study area, but it is assumed due to the activities in the study area, that the aquatic systems contain very little in the form of pollutants, other than elevated sediment loads during floods.

During construction, various materials, such as sediments, diesel, oils and cement, could pose a threat to the continued functioning downstream areas, if by chance it is dispersed via surface run-off, or could permeate into the groundwater. The possible negative changes to water quality during the operational phase would be limited to sedimentation and erosion related issues assessed in See Section 4.1 of the March 2016 Aquatic assessment. These negative impacts would persist into the medium term.

Significance of impacts without mitigation

Changes to water quality impact on the functioning of plants and instream biota. This impact without mitigation would have a Medium intensity (High for Crossing N due to the present of SSC fishes), as excessive pollution will also impact on instream conditions due the introduction of toxins. Potential toxins include the following:

  • Grout and concrete – these products contain cement which increases the pH (basic) of surfaces waters impairs the metabolism and breathing physiology of aquatic organisms.
  • Hydrocarbons (shutter oil, other lubricants, grease and fuels) – The persistent impact of these pollutants is varied, but can enact negatively on metabolic pathways, cellular structures (plant and animal), respiration and gene stability (heavy metals).

This would be similar for all crossings, without mitigation

Proposed mitigation

  • Chemicals used for construction must be stored safely on site and surrounded by bunds. Chemical storage containers must be regularly inspected so that any leaks are detected early.
  • Littering and contamination of water sources during construction must be prevented by effective construction camp management.
  • Emergency plans must be in place in case of spillages onto road surfaces and water courses.
  • No stockpiling should take place within a water course.
  • All stockpiles must be protected from erosion, stored on flat areas where run-off will be minimised, and be surrounded by bunds.
  • Stockpiles must be located away from river channels.
  • Erosion and sedimentation into channels must be minimised through the effective stabilisation (gabions and Reno mattresses) and the re-vegetation of any disturbed riverbanks.
  • The construction camp and necessary ablution facilities meant for construction workers must be beyond the 32m buffer described previously.

Significance of impact with mitigation

Should the construction site and the works be managed properly, the negative impacts would remain localised and in the short-term. This would result in an overall low intensity as the introduction of any pollutants would be probably be limited with mitigation for all crossings.

Cumulative impacts

The potential cumulative impact is unlikely with appropriate mitigation and the fact that no other projects of a similar nature in the region the cumulative impacts are low

Residual impacts

Possible impact on the remaining catchment due to changes in run-off characteristics in the development site.

2.3Impact 3: Loss of riparian vegetation, aquatic habitat and stream continuity (migration corridors)

Nature of the impact

Riparian and aquatic corridors create longitudinal links between a variety of habitats and refugia. The refugia are particularly important in times when surface flows are low, i.e. fish populations can survive in deeper pools during droughts as was observed in this assessment at Crossing N. These populations are then able to recolonise the remaining river reaches, when reconnected by increased river flows. This function of a catchment and its ability to act as refugia is highlighted by the conservation plans that have earmarked the study area as such.

Road crossings, and culvert crossings disrupt both the instream and riparian continuity, both in terms of flows and physical habitat availability. It is thus important for road designs, especially any proposed upgrades to incorporate these aspects with the aim of retaining instream and riparian continuity. Any lack in continuity in the present crossings (elevated and small pipe culverts) are not recommended and for this reason only culverts with suitable bases level with natural ground have been specified.

Significance of impacts without mitigation

This impact without mitigation i.e. culverts with large embankments or similar in structure to the present-day crossings would have a Mediumsignificancefor Crossing N and Low for the remaining crossings.

Proposed mitigation

  • Any road crossing embankments are outside of the floodline areas or the 32m buffer
  • Only box culverts should be used in the crossing upgrades, with their bases level with the natural riverbed height.
  • Old structures with elevated / sing pipe culverts should be removed.

Significance of impact with mitigation

With the mitigations,the negative impacts would remain localised and be permanent. This would result in an overall significance of be LOW (negative) as the overall continuity of the instream areas, could remain (Table 1) for all sites. This is also if the alien vegetation is removed from the catchment and the natural vegetation can recover, and that no new water course crossings will be required.

Cumulative impacts

The potential cumulative impact is unlikely with appropriate mitigation and the fact that no other projects of a similar nature in the region the cumulative impacts are low

Residual impacts

Possible impact on the remaining catchment due to changes in run-off characteristics in the development site.

2.4Impact 4: Loss of species of special concern

Nature of the impact

Loss of riparian and instream habitat and or water quality changes could possibly result in the loss of species of special concern due to the destruction of habitat during the construction phase or increased sediment levels in the operational phase. Changes in the hydrological region in the operational phase, could also impact on the presence of other species, should surface water flows be increased or refugia are disconnected from available habitat (fish & invertebrates). This is also of importance with regard the presence of the Eastern Cape Redfin (Pseudobarbusafer) observed in pools above Crossing N. No standing water or pools were observed at any of the other crossings during the survey.

Significance of impacts without mitigation

This impact without mitigation i.e. culverts with large embankments and now connects would have a High significance (Table 1) if limited stormwater management is provided for Crossing N, while the remaining crossings due to the lack of pools, i.e. dry would be Low

Proposed mitigation

  • Where water course crossings need to be upgraded, the engineering team must provide an effective means to minimise the potential upstream and downstream effects of sedimentation and erosion (erosion protection) as well minimise the loss of riparian vegetation (small footprint).
  • No vehicles to refuel within drainage lines/ riparian vegetation.
  • During the operational phase, monitor culverts and stormwater management features to see if erosion issues arise and if any additional erosion control is required.
  • Where possible culvert bases must be placed as close as possible with natural levels in mind so that these don’t form additional steps / barriers.
  • No flows within any of the water courses should be altered by any of the proposed access roads.

Significance of impact with mitigation

This impact with mitigation i.e. culverts with large embankments allowing proper upstream/downstream connections and suitable erosion / sedimentation protection measures would reduce significance to Lowfor Crossing N and Very Low for the remaining sites (Table 1)