CHAPTER 1 Introduction Chapter 1 - Introduction Table of Contents 1 INTRODUCTION ....................................................................................................................................................... 3 1.1 Project Overview .......................................................................................................................................... 3 1.2 Project Proponent ........................................................................................................................................ 6 1.3 Impact Assessment Requirements ............................................................................................................... 6 List of Tables Table 1-1: IAR Structure .................................................................................................................................................... 10 List of Figures Figure 1-1: Regional Project area ........................................................................................................................................ 4 Figure 1-2: Project Area ...................................................................................................................................................... 5 Figure 1-3: Impact assessment report and EPBC referral process ...................................................................................... 8 CHAPTER 1 – INTRODUCTION Seqwater Six Mile Creek Dam Safety Upgrade Project 25 January 2019 1-ii Introduction 1 Introduction 1.1 Project Overview Six Mile Creek Dam (Lake Macdonald) Safety Upgrade Project, commonly referred to as Lake Macdonald, is located on the Sunshine Coast in Noosa Shire. It is one of two principal raw water sources that supply potable drinking water to the Sunshine Coast. Ownership of the dam was transferred from Noosa Council to Queensland Bulk Water Supply Authority (trading as Seqwater) on 1 July 2008. The dam requires an upgrade to meet modern safety standards and the performance requirements of the Queensland dam safety regulations into the future (the Project). The upgrade will allow the dam to better manage severe weather and any possible earthquake events. This includes improving the spillway discharge capacity and earthquake stability while maintaining water supply security. Studies have considered a range of options including decommissioning of the dam, retrofitting of strengthening works and new build options. The proposed upgrade of Six Mile Creek Dam does not change the footprint of the existing water impoundment. The dam’s full supply level (FSL) will remain the same post-upgrade and the proposed dam infrastructure will largely occupy the existing footprint. The operation of the upgraded dam will effectively reinstate the existing situation, with improvements to the spillway and its ability to effectively pass large flood events. The regional Project area and Project area are shown in Figure 1-1 and Figure 1-2. The final detailed design of the dam is currently being progressed and is not expected to differ significantly from that described in the Initial Advice Statement (2017). However, design updates in response to recent geotechnical findings, water security considerations, and construction methodology have led to two notable departures in design since the Initial Advice Statement was submitted to the Coordinator General for consideration in September 2017. In particular, the concept for a temporary construction coffer dam was reviewed and altered, and the design for the left embankment was updated. Minor design changes may be required as the Project progresses in the future, but will not alter the Project footprint. Construction for the Project was previously scheduled to occur from August 2019 to December 2021 (which is reflected in the technical reports provided in the appendices), but will now commence in August 2020. CHAPTER 1 – INTRODUCTION Seqwater Six Mile Creek Dam Safety Upgrade Project 25 January 2019 1-3 FIGURE 1-1: REGIONAL PROJECT AREA LOCATION Six Mile Creek Dam Safety Upgrade Project OVERVIEW QUEENSLAND T a Mcquade g kmig 0 250 500 Gully ! a Ë WEIPA n ek C e Wilsons r N r Y C o e ar d s Pocket ek o sa R ! i CAIRNS v e r Coe ! TOWNSVILLE s ek C Cre oo NO nd OSA ! MACKAY oo SHIR C E T re in Wolvi ek a ! n ROCKHAMPTON a C re Project NT QLD e k Location SA ! BRISBANE Beenaam NSW Valley Coondoo Neusa Vale Cedar Pocket Lake Lake Cooloola Como Deep C r Mothar e e Mountain k Kin Kin Creek Yellow Creek Cootharaba Como e k K r e i n nC k Ki Lake ree d C Cootharaba Noosa oondum C Kin Kin on W reek m North n i K Shore Tandur Creek Boreen Point Sandy Coral Sea Traveston k e e Pinbarren r C Cooroibah Cooran en Ringtail arr Pinb Creek Six Mile Creek Lake Cooroibah ree Coles C k Pomona Project Area Sky Tewantin rin g Cr eek Federal Doonella Lake M C Tuchekoi id Tinbeerwah dle C oo re ro ek y Black C r e Lake Macdonald Mountain e k Doonan Cooroy (Noosa Mountain Shire) H ap py J a Lake c Cooroy Doonan (Sunshine k Weyba Creek Coast Regional) ek Weyba Downs Cre Carters Ridge ch an r chy B ro o R Eumundi rth North Ma i low No ve ckfel r la Ridgewood B r e Eerwah Vale v Eerwah Vale i (Noosa Shire) R y (Sunshine Coast Verrierdale r B a e l l Regional) M i Cr Magpie e e k Creek North Arm PROJECT NO: 30041832 CREATED BY / DATE: BM14706, 30/11/2018 LEGEND VERSION: DRAFT A 0 2 4 PAGE SIZE: A4 Kilometres Bruce Highway Project Area DISCLAIMER: K Sunshine Motorway Local Governmental Area © SMEC Australia Pty Ltd 2017. All Rights SOURCES: Reserved. While all reasonable care has been 1. Localities, Roads, LGA, Waterways, Waterbody © Secondary Road taken to ensure the information contained on this QLD Spatial Catalogue, State of Queensland map is up to date and accurate, this map contains (Department of Natural Resources, Mines and Energy) Watercourse data from a number of sources - no warranty is 2018 given that the information contained on this is free 2. Basemap © Esri, HERE, Garmin, © OpenStreetMap Six Mile Creek and Upper Tributary from error or omission. Any reliance placed on contributors, and the GIS user community such information shall be at the sole risk of the Lake Macdonald user. Please verify the accuracy of all information prior to using it. This map is not a design document. Path: R:\PROJECTS\30031970\MXD\IAS_ReportMaps\P30031970_Figure1_1_RegionalProjectAreaLocation.mxd FIGURE 1-2: PROJECT AREA Six Mile Creek Dam Safety Upgrade Project Path S i F x o e C r M e v r i i e l s r e e t sDrive d e D k Acr a o a l R a a ad r o r R m Tewantin Yurol n a a a l K w a National Park State a d l l Forest n i a K w G e ke Macdonald Dri v La Old Tew antin Road D view r C lear i v e Tewantin National Tewantin oad ood R National Park Collw Park K e n n e d y s R o a d G u m b o i l R o a d S i vy LA e KE M rs AC R DO Coo o k a NA s Road LD d H ne oy La R e o rs a o d e h Rac Road s y e v C o Ha yward R oa d Gran ge Ro a d a Road Drive oos ee N r roy T k o e W e o orba L e a n C n i r e P C e il M x e Si n T a U L OVERVIEW NOOSA SHIRE Kau r S e i w e S if r t t T r D r Fig 0 4 E 8 km e i Ë ve c e h t i e d Gumtree Driv n d d a a o M a R c o n p L ti a R n u a ! a l s n Kin Kin w e Te ! Cootharaba t e Project e F D r r Location t a S o t g h a Ringtail m ! e H v i ! Creek n o Pomona e M a u n d L Lake t ! e i h ! Black r r Macdonald son u L Mountain Road a a K n e ! Ridgewood yMountain Road ro o o C PROJECT NO: 30041832 CREATED BY / DATE: BM14706, 30/11/2018 LEGEND VERSION: DRAFT A 0 300 600 PAGE SIZE: A4 Metres Bruce Highway Project Area DISCLAIMER: K Secondary Road Local Governmental Area © SMEC Australia Pty Ltd 2017. All Rights SOURCES: Reserved. While all reasonable care has been 1. Localities, Roads, LGA, Waterways, Protected Areas Local Roads Protected Areas taken to ensure the information contained on this © State of QLD (DNRME) 2018 map is up to date and accurate, this map contains 2. Sources: Esri, HERE, Garmin, Intermap, increment P Watercourse National Parks data from a number of sources - no warranty is Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, given that the information contained on this is free IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Six Mile Creek and Upper Tributary State Forest from error or omission. Any reliance placed on Esri China (Hong Kong), swisstopo, © OpenStreetMap such information shall be at the sole risk of the contributors, and the GIS User Community Lake Macdonald user. Please verify the accuracy of all information prior to using it. This map is not a design document. Path: R:\PROJECTS\30031970\MXD\IAS_ReportMaps\P30031970_Figure1_2_ProjectArea.mxd Introduction 1.2 Project Proponent Seqwater is the proponent for the Six Mile Creek Dam (Lake Macdonald) Safety Upgrade Project. Seqwater is a statutory authority established under the South East Queensland Water (Restructuring) Act 2007. Seqwater is one of Australia’s largest water businesses, with the most geographically spread and diverse asset base of any Australian capital city water authority. Seqwater manages up to $11 billion of water supply assets and the natural catchments of the South East Queensland’s major water supply sources, including dams, weirs, conventional water treatment plants, and climate resilient sources of water through the Gold Coast Desalination Plant and the Western Corridor Recycled Water Scheme. A 600 km reverse flow pipeline network allows drinking water to be transported to where it is needed most, from the Sunshine Coast to Greater Brisbane, to Redlands, and south to the Gold Coast.