Appendix X Fish passage technical report SunWater and Gladstone Area Water Board Lower Fitzroy River Infrastructure Project Eden Bann Weir and Rookwood Weir - assessment and planned provisions for fish passage June 2015 Executive summary The Lower Fitzroy River Infrastructure Project (Project) is the construction and operation of a raised Eden Bann Weir and a new weir at Rookwood on the Fitzroy River, Central Queensland. Key Project components include the following: Eden Bann Weir (EB1) (an existing structure): – Eden Bann Weir Stage 2 (EB2) – a raise of the existing EB1 to a full supply level (FSL) 18.2 m Australian Height Datum (AHD) and associated impoundment of the Fitzroy River – Eden Bann Weir Stage 3 (EB3) – raising EB1 to EB2 and include the addition of 2 m high flap gates to achieve FSL 20.2 m AHD and associated impoundment of the Fitzroy River The proposed Rookwood Weir: – Rookwood Weir Stage 1 (RW1) – a new build to FSL 45.5 m AHD, saddle dams and associated impoundment of the Fitzroy, Mackenzie and Dawson rivers – Rookwood Weir Stage 2 (RW2) – a new build to RW1 and including the addition of 3.5 m high flap gates to achieve FSL 49.0 m AHD and associated impoundment of the Fitzroy, Mackenzie and Dawson rivers Any combination of the above (development scenarios) Fish passage infrastructure and turtle passage infrastructure, namely fish locks and a turtle bypass, respectively, at each weir. Other infrastructure components associated with the Project include: Augmentation to and construction of access roads. Construction of low level bridges in areas upstream of weir infrastructure. Installation of culverts at Hanrahan Crossing downstream of Rookwood Weir. Aquatic ecology assessments undertaken for the Project conclude that no Environment Protection and Biodiversity Conservation Act 1999 (Cth) listed-threatened fish species have been previously recorded or are predicted to occur in the Project area. Further no Nature Conservation Act 1992 (Qld) listed-threatened fish species have been previously recorded or are predicted to occur in the study area. Endemic species are present. The raising of an existing weir and the development of a new weir is however a waterway barrier works, and is assessable development under the Sustainable Planning Act 2009 (SP Act). Development approval is required to raise Eden Bann Weir and construct Rookwood Weir. The purpose of this report is to provide a summary document that consolidates material in support of the required waterway barrier works development application for weir construction and operation and in particular the fish passage design process and outcomes such that stated conditions can be achieved through the environmental impact statement (EIS). It is recognise that one of the key potential risks requiring consideration and management during the design, construction and operation of the Project is the maintenance of upstream and downstream passage of fish species. To address this, a fishway design process was undertaken in accordance with Queensland Fisheries (then as the Department of Employment, Economic Development and Innovation (DEEDI)) Design Process criteria). This process involved the selection of fishway design ii |GHD | Report for SunWater and Gladstone Area Water Board - Lower Fitzroy River Infrastructure Project, 41/20736 specifications and success criteria and the development of preliminary fishway designs for both Eden Bann Weir and Rookwood Weir. Members of the fishway design team were selected such that a range of engineering and scientific disciplines necessary for fish passage design were present and that representation from the range of key stakeholders, including DEEDI fish biologists, an independent freshwater fish biologist and an independent fishway engineering specialist, were involved in the design process. Fish passage infrastructure has been designed to preliminary level as follows: Eden Bann Weir fish passage infrastructure: – An upgraded fish lock on the left bank – A new fish lock located on the right bank for high and low reservoir levels to cater for flows from about 500 m3/s to 2700 m3/s. This provides for normal operating conditions as well as low spillway flow conditions at the weir. Rookwood Weir fish passage infrastructure: – A right bank fish lock to cover low and high reservoir levels to cater for flows from a minimum operating level up to 500 m3/s. The lock arrangements proposed are considered suitable for the purpose of fish passage as: The lock is in a configuration known to work (although physical model studies are required to assist with refinement of entry / exit conditions and sedimentation management). The addition of a right bank fish lock will improve on current passage efficiency above spilling flows (Table 8-1). Currently fish are attracted to the right bank spillway section of the weir, and as there is no passage become stranded as tailwater levels drop. The lock would provide passage for 87 out of 123 flood events as well as ongoing ‘normal flows’ at Eden Bann Weir and it provides for between 89.4 per cent and 99.8 per cent of flows across the seasons at Rookwood Weir. It reduces average wait days per occurrence from 11 to seven at Eden Bann Weir. At Rookwood Weir the average number of waiting days per event is estimated at ten. The lock arrangement is capable of providing continuous attraction flows when the fishway is operating and allows for variable attraction flows between phases of the cycle. Attraction flow velocities can be varied between: 0.15 m/s and 1.8 m/s. It caters for small and large-bodied fish. It provides upstream and downstream passage. It can be shut down in large floods to maximize operation following flood A Fish Monitoring Program will be designed and implemented to monitor the effectiveness of fish passage infrastructure during both the construction and operation phases. A detailed construction plan will be developed during detailed design for a determined build scenario. Fish passage will not be inhibited during construction as flow is maintained instream and the existing fish lock at Eden Bann Weir would remain operational. Further, downstream works will only occur during the dry season when flows have ceased. Detailed design will include the provision for CFD and physical model studies. It is considered that assessment, analysis, mitigation, management and monitoring proposed in relation to fish passage infrastructure at a raised Eden Bann Weir and a new weir at Rookwood satisfies performance objectives as defined in the State Development Assessment Provisions Module 5 Fisheries resources (V1.5) 5.2: Constructing or raising waterway barrier works in fish habitats state code. GHD | Report for SunWater and Gladstone Area Water Board - Lower Fitzroy River Infrastructure Project, 41/20736 | iii Table of contents 1. Introduction .................................................................................................................. 1 1.1 Project overview .................................................................................................. 1 1.2 Purpose of this report ........................................................................................... 8 2. Regulatory framework .................................................................................................... 9 2.1 Commonwealth.................................................................................................... 9 2.2 Queensland......................................................................................................... 9 3. Fish passage design process ........................................................................................ 14 3.1 Approach .......................................................................................................... 14 3.2 Roles and responsibilities .................................................................................... 14 3.3 Methodology ..................................................................................................... 15 4. Ecological understanding for the provision of fish passage ................................................ 23 4.1 Movement, dispersal and migration....................................................................... 23 4.2 Impact of barriers to movement ............................................................................ 23 5. Existing environment and ecological values of the Fitzroy River.......................................... 25 5.1 Aquatic habitat values ......................................................................................... 25 5.2 Water quality ..................................................................................................... 28 5.3 Fish habitat areas............................................................................................... 30 5.4 Fish species ...................................................................................................... 30 5.5 Existing barriers to movement .............................................................................. 42 6. Weir design and construction ........................................................................................ 46 6.1 Preliminary design.............................................................................................. 46 6.2 Construction methodology and work sequence ....................................................... 61 6.3 Diversion strategy .............................................................................................