Shoalhaven City Council Northern Floodplain Risk Management Committee Meeting Date: Wednesday, 25 November 2020 Location: Teams Time: 4.00pm Please note: Council’s Code of Meeting Practice permits the electronic recording and broadcast of the proceedings of meetings of the Council which are open to the public. Your attendance at this meeting is taken as consent to the possibility that your image and/or voice may be recorded and broadcast to the public. Agenda 1. Apologies 2. Confirmation of Minutes Nil 3. Declarations of Interest 4. Presentations NFM20.1 Terms of Reference NFM20.2 Overview of NSW Floodplain Development Manual and Purpose of Floodplain Risk Management Committees John Murtagh, Senior Natural Resource Officer, Biodiversity and Conservation, Department of Planning, Industry and Environment 5. Reports NFM20.3 Floodplain Management Program and Projects Update .............................. 1 NFM20.4 Lower Shoalhaven River Floodplain Risk Management Study and Plan Update ................................................................................................ 6 NFM20.5 St Georges Basin Floodplain Risk Management Study and Plan Update ........................................................................................................ 9 NFM20.6 Currarong Creek Flood Study Update ....................................................... 12 NFM20.7 Millards Creek Flood Study Update ........................................................... 14 6. General Business Northern Floodplain Risk Management Committee – Wednesday 25 November 2020 Page ii Membership Clr Wells (Chairperson) All Councillors CEO or nominee Community representatives:- John Gould David Brawn Mark Kielly Plaxy Rowe Leonard White Phil Guy Government Agency representatives:- Local Aboriginal Land Council NSW State Emergency Services Department of Planning, Environment and Industry (DPIE) Other relevant Government Agency representatives Quorum – Three (3) provided that a minimum of the Chairperson and two community representatives are present. Purpose: The principal objective of the North Floodplain Risk Management Committee is to assist Shoalhaven City Council in the development and implementation of one or more floodplain risk management plans for the north area of the Council. This will need to be in accordance with the NSW Floodplain Development Manual. The north area applies to the following catchments: • Lower Shoalhaven River; • Crookhaven River; • Kangaroo River; • Broughton Creek; • Bomaderry Creek; • Nowra and Browns Creek; and • Lake Wollumboola. Role: 1. To assist the Council in the development and implementation of the floodplain management plan for the areas listed under ‘Purpose’ (see above); 2. To assist the Council monitoring and assessing the effectiveness of the management plans during and after its implementation; and 3. To assist the Council providing input into known flood behaviour as part of the flood study. Northern Floodplain Risk Management Committee – Wednesday 25 November 2020 Page 1 NFM20.3 Floodplain Management Program and Projects Update HPERM Ref: D20/505916 Section: Environmental Services Approver: Phil Costello, Director - City Development Reason for Report To inform the Committee of the current Floodplain Management Program and other projects undertaken by Council’s flood unit. Recommendation (Item to be determined under delegated authority) That the Committee receive the Floodplain Management Program and Projects report for information. Options 1. The Committee receive the report for information. Implications: Nil NFM20.3 2. The Committee could choose an alternate recommendation. Implications: Nil Background Floodplain Management Program Council receives grant funding from Department of Planning, Industry and Environment (DPIE) to undertake projects under their Floodplain Management Program. Grant funding is provided to Council on a 2:1 basis, with grant applications sought each financial year. The Floodplain Management Program provides grant funding to: • Develop flood studies; • Develop floodplain risk management studies and plans (FRMSP); and • Implement flood mitigation options identified in floodplain risk management plans. Council is currently undertaking the following projects from the program: • Review of the Lower Shoalhaven River Floodplain Risk Management Study and Plan; • Review of the St Georges Basin Floodplain Risk Management Study and Plan; • Millards Creek Flood Study; • Currarong Creek Flood Study. Please refer separate business papers for more detail in relation to the above projects. Northern Floodplain Risk Management Committee – Wednesday 25 November 2020 Page 2 Council is seeking grant funding for the review of the Broughton Creek Flood Study. Council is currently awaiting advice from DPIE in relation to whether Council has been successful or not. Furthermore, a capital budget bid has been submitted for 2021/22 financial year to fund this project if Council were not successful with grant funding. Shoalhaven Flood Alert Network Council maintains a network of water level and rain gauges that are part owned by Council and the Bureau of Meteorology (BoM). There are 21 water level gauges and 46 rain gauges throughout the LGA. In the Shoalhaven River catchment alone, there are 12 water level gauges and 17 rain gauges. The gauges feed into BoM’s flood alert network, providing Council access to live data recordings through the Enviromon software. The benefit of having this secondary Enviromon software and data recording is that it provides back up to BoM’s system, allows information to be interrogated, and allows email alerts which are triggered by certain water levels or rainfall amounts to be set. The service level agreement between the Natural Resources and Floodplain Unit and the Communications Section of Shoalhaven Water is currently being updated to ensure the system continues to be maintained and function at its highest level. In addition to gauges, water level boards are present at gauge sites so that visual checks of the water level can occur. This is most beneficial during a flood event, when the gauges are most likely to fail due to debris, dynamic changes in rainfall and water level, gauges being damaged due to extreme weather. NFM20.3 In many locations Manly Hydraulics Laboratory (MHL) has gauges alongside or joining Council’s gauges. The benefit of having two gauges in the one location is that information can be validated should one system fail. It also allows cost savings and knowledge sharing for sites with joint infrastructure. In the coming year Council will be implementing recommendations of adopted FRMSP and working with local State Emergency Service (SES) Units to identify locations for the installation of additional gauges and water level boards. A water level gauge is being procured for a site in Woollamia, and Council is further investigating an additional rainfall gauge upstream of Fisherman’s Paradise. Tomerong water level gauge was destroyed in the August 2015 flood. This gauge provides vital information to the SES, aiding them in their flood planning and response during a flood event. Council has received funding from the Natural Disaster Relief and Recovery Arrangements (NDRRA) and the gauge has been replaced. A capital budget bid has been submitted for 2021/22 financial year to fund a rainfall gauge to be installed in the upper reaches of the Lake Conjola catchment. SMART Management Water Project The Illawarra Shoalhaven Joint Organisation (ISJO) Councils have formed an unprecedented partnership with the University of Wollongong (UOW) and corporate property group Lend Lease, to break new ground in the field of innovative water management. Water management is an area of key community concern and is identified in the Smart Region Strategy as an area warranting early investment in smart technologies. The SMART Management Water project will use new smart technologies and develop data analytics to help improve water quality, flood mitigation and ensure community safety in flash flood events. The project will be delivered through five components: Northern Floodplain Risk Management Committee – Wednesday 25 November 2020 Page 3 1. Stop Block: Improved stormwater culvert blockage management and analytics including new rugged sensors 2. Flood Aware: A new information platform for the public to provide warnings and other information to reduce risk to life and property 3. Go Flow: New estuary management solutions including sensors and cameras to reduce flooding 4. Quality Watch: New water quality monitoring stations including custom technology, sensors and a regional Internet of Things network at Lend Lease’s Calderwood development 5. Pollution Stop: Improved water quality with new sensing devices and analytics in monitoring stations including changes to management of gross pollution traps Shoalhaven City Council Natural Resources and Floodplain Unit have been working with project partners in the “Go Flow” component of this project. The aim is to: 1. Improve transparency regarding Councils’ decisions to mechanically open an estuary (using Council plant to breach the existing sand berm) prior to a significant rainfall event. 2. Reduce flood-risk for residents and businesses upstream of the ICOLLS entrance. 3. Reduced costs to Councils – the smart technology solutions will automatically advise Councils if ambient conditions are conducive to mechanically breaching the sand berm. This replaces the periodic site observations that currently need to be made by Council officers