Flood studies
Riverine
Riverine and creek flooding is caused when the runoff from major storms exceeds the channel capacity of a river or creek and overflows onto the surrounding floodplain. With adequate rainfall monitoring and flood warning systems: riverine and creek flooding can be predicted in terms of extents and timing. It can generally be known in advance when and where a river or creek is likely to overflow its banks, so advance warnings and preparations can be made accordingly. The City of Mackay is built on the banks of the Pioneer River, as are the satellite townships of Finch Hatton, Mirani, Marian and Walkerston. Levee systems have been implemented to provide a level of flood protection from the Pioneer River in some locations.
Pioneer River and Goosepond Creek Flood Studies
The Goosepond Creek Flood Study commenced in May 2007 and included the Janes Creek, Goosepond Creek and Vines Creek waterways with a combined catchment of 35km2. The Goosepond Creek catchment experienced an extreme flood event on 15 February 2008 and the study was expanded to assess the impact of this extreme flooding event. A draft Goosepond Creek Flood Study report was produced in September 2009.
The Goosepond/Vines Creek Flood Study, 2012 updates the data and flood modelling methodology and found that the Goosepond Creek flood (Feb 2008) was a 1-in-500 year event.
The Goosepond/Vines Creek Flood Study, 2012 provides clarity on the potential impact of climate change (sea level rise, increased rainfall intensity), and the effect of mitigating actions on flood levels in this catchment.
Fact sheet
- Goosepond Creek Flood Study Fact Sheet - March 2010 (PDF 3.0 MB)
Summary report
- Goosepond Creek/Vines Creek Flood Study - February 2012 (PDF 5.6 MB)
GOOSEPOND CREEK (INCLUDING PIONEER RIVER FLOOD STUDY)
The Goosepond Creek (including Pioneer River) Flood Study (WRM, October 2012) assessed the interaction of flood flows between Goosepond Creek and the Pioneer River. This study should be viewed as an addendum report to the Pioneer River Flood Study, 2011 and the Gooseponds/Vines Creek Flood Study, 2012 and be read in conjunction with them.
The Goosepond Creek (including Pioneer River) Flood Study (2012) reviewed findings from the earlier separate Goosepond River and Gooseponds/Vines Creek studies. The study used recently updated Light Detection and Ranging (LiDAR) technology the measure ground levels and determine flood flows. The flood level modelling considered the impact of stormtide events, historical river flood events, the impact of climate change to the year 2100 in estimating flood levels for events between 5 and 500 years.
The flood levels in the combined Goosepond Creek (including Pioneer River) Flood Study, 2012 now override the flood levels of the previous individual reports.
These assist in informing planning controls and consideration of flood risk within the Pioneer and Gooseponds catchments.
- Goosepond Creek (Including Pioneer River Flood Study) - October 2012 (3.27 MB)
PIONEER RIVER FLOOD STUDY
The Pioneer River is a major natural feature with a catchment of 1.560 km2 which impacts on planning and development along its waterways.
Since the 1970s, numerous hydrologic and hydraulic studies have been undertaken to assess flood behaviour along the river.
In 2008, Council commissioned the Pioneer River Flood Study to determine flood risk from Mirani to its discharge into the South Pacific Ocean at Mackay City.
The Pioneer River Flood Study, 2011 includeds an assessment of the impact of climate change, and provideds detail on flood events for a range design flood events between 5 and 500 years. The study provideds more accurate estimates of flood events and risk that the previous Pioneer River Flood Study, 2004 by Chaseling McGiffin Pty Ltd.
The Flood Study was updated in 2021 as part of the Mackay Floodplain Risk Management Study and Plan. This study was adopted by Council on 24 November 2021.
- Pioneer River Flood Study (PDF 11.1MB)
Finch Hatton Flood Study
The Finch Hatton catchment of Cattle Creek is approximately 205 km2 in size (including Finch Hatton Creek catchment). Cattle Creek is a major tributary of the Pioneer River and the Finch Hatton township on the southern banks of Cattle Creek is located approximately 70km west of Mackay. The catchment is characterised by very steep, densely vegetated headwaters that forms part of the Clarke Range whilst the lower floodplain is mainly agricultural farming lands.
The Finch Hatton Flood Study was prepared for Council by Water Technology and the study commenced in the second half of 2023 following the collection of survey and lidar to provide an accurate representation of the ground surface elevation. Community consultation about the preparation of the flood study occurred in mid and late 2023 when the community was invited to provide information on past flood events. Finch Hatton has been impacted by flooding in the past and a levee wall to protect the township was completed in 2006. The flood study updates previous studies prepared for Mirani Shire Council in 2003 and the Queensland Reconstruction Authority in 2013.
The flood study, adopted by Council in October 2024, utilised best practice flood study guidelines and defines the flood hazard over the catchment. The detailed study will be used to inform a flood risk assessment and management plan and be used to update council’s flood information and disaster management systems.
Bakers Creek through Walkerston (Adopted)
The Bakers Creek through Walkerston catchment covers the area from Marian in the west, to the east of Walkerston and includes the tributaries of Rocky Creek and MacLennan Creek. The study area mainly consists of agricultural land and the township of Walkerston.
The Bakers Creek Through Walkerston Flood Study was updated in 2021 as part of the TC Debbie Flood Studies and the Mackay Floodplain Risk Management Study and Plan. The study was adopted on November 24, 2021.
- Bakers Creek Walkerston Flood Study (PDF 7.1MB)
The Bakers Creek Through Walkerston flood study commenced in 2012. The final report was produced in May 2013. The reports focuses on modelling the existing flood impacts in the catchment for numerous events in order to better understand the flood risk posed to the community and allow it to be effectively managed in the future. The investigation does not propose any new infrastructure.
The final report was adopted by council on January 27, 2016. This study has been superseded by the October 2021 flood study.
- Bakers Creek Walkerston Flood Study (PDF 19.1MB)
Bakers One (Ongoing)
The Bakers One catchment covers an area of approximately 1,500 hectares from the east of Walkerston through to Ooralea and Bakers Creek in the east. The study area mainly consists of agricultural land and urban developments in the south Mackay suburb of Ooralea.
The Bakers One Catchment Stormwater Trunk Drainage Study study commenced in 2012. The objective of the study is to identify future stormwater trunk infrastructure required to cater for existing and potential ultimate development in the catchment, focusing on Ooralea and north of Bakers Creek. The report is still a work in progress, however the existing hydraulic assessment is complete and provides the community with knowledge of the existing flood extents, levels and risks. The remainder of the report, including investigating trunk drainage infrastructure, is not yet finalised or adopted.
An extract of the report, including only the Existing Scenario Hydraulic Assessment, was adopted by council on February 3, 2016.
McCreadys Creek
McCreadys Creek Baseline Flood and Stormwater Assessment
The McCreadys Creek Catchment is approximately 34km2 in size and discharges into the Coral Sea about 7.5km north of the Mackay City Centre. The main waterways draining the catchment are McCreadys Creek and its tributaries are Little McCreadys Creek coming from the west and McCreadys Creek South.
The main uses in the upper catchment are grazing and sugar cane with the middle catchment dominated by urban uses including key growth areas zoned ‘Emerging Community’ in the Mackay Region Planning Scheme 2017. Key community and commercial uses in the catchment include Beaconsfield State School, Eimeo State School, Northern Beaches High School, Northern Beaches District Centre, Specialised Centre (Richmond) and the future Northern Beaches Community Hub.
The Baseline study commenced in 2021 with survey and commissioning of aerial LIDAR to provide an accurate representation of ground surface elevations. The community was consulted in 2021/2022 via a letterbox drop and Connecting Mackay/Facebook campaign.
The baseline report, adopted by Council in August 2024, utilised best practice flood study guidelines and defines the flood hazard over the catchment.
- Volume 1 - Report (SMEC, 2023)
- McCreadys Creek - Volume 1 - Appendix A - J (technical parameters)
- McCreadys Creek - Volume 1 - Appendix K (critical duration maps)
- McCreadys Creek - Volume 1 - Appendix L (flood maps - depths)
- McCreadys Creek - Volume 1 - Appendix L (flood maps - velocity)
- McCreadys Creek - Volume 1 - Appendix L (flood maps - hazard)
- McCreadys Creek - Volume 1 - Appendix M (sensitivity maps)
McCreadys Creek South
The McCreadys Creek South catchment covers the area from Glenella and Mt Pleasant in the south, through to the south of Beaconsfield and Richmond in the north. The study area is approximately 1,040 hectares, and forms the upper part (non-tidal sections) of the catchment.
The McCreadys Creek South Stormwater Trunk Infrastructure Study commenced in 2010. The objective of the study is to identify future trunk infrastructure required to cater for existing and potential future development in the catchment, focussing on the Richmond Development Area. The report is still a work in progress, however the existing hydraulic assessment is complete and provides the community with knowledge of the existing flood extents, levels and risks. The remainder of the report, including investigating trunk drainage infrastructure, is not yet finalised or adopted.
An extract of the report, including only the Existing Scenario Hydraulic Assessment, was adopted by council on February 3, 2016.
Sandy Creek Catchment Flood Study (Adopted)
The Sandy Creek Catchment Flood Study was undertaken with funding assistance provided from the Australian and Queensland governments through the 2017- 2018 Natural Disaster Resilience Program (NDRP).
The local community played a key role in the completion of the flood study providing firsthand accounts, photographs and records of flooding behaviour during Tropical Cyclone Debbie. This information was critical in the development of flood models over the catchment
The study focuses on understanding existing flood hazards across the catchment under existing and projected climate conditions for numerous events to better understand the flood risk posed to the community and allow it to be effectively managed in the future. The study provides recommendations on improving the floodplain management into the future.
The final report was produced in January 2020 and was adopted by council on February 12, 2020
Rocky Dam Creek Catchment Flood Study (Adopted)
The Rocky Dam Creek Catchment Flood Study was undertaken with funding assistance provided from the Australian and Queensland governments through the 2017- 2018 Natural Disaster Resilience Program (NDRP).
The local community played a key role in the completion of the flood study providing firsthand accounts, photographs and records of flooding behaviour during Tropical Cyclone Debbie. For large parts of the catchment, flooding that occurred during Tropical Cyclone Debbie was the worst recorded.
The study focuses on understanding existing flood hazards across the catchment under existing and projected climate conditions for numerous events to better understand the flood risk posed to the community and allow it to be effectively managed in the future.
The final report was produced in January 2020 and was adopted by council on February 12, 2020
Overland Flooding
Overland floods, or flash floods, occur when runoff from storms exceeds the capacity of the underground and overland drainage systems. When this occurs, water begins to flow over the surface of the land along natural flow paths or valleys towards the nearest creek or river. Overland flows usually occur with little or no warning following intense rainfall, often associated with short duration thunderstorm activity. They can be localised or widespread depending on the path or extent of storm activity.
Mackay City Flood Study (Adopted)
The Mackay City Flood Study is an update to the Mackay CBD Drainage Study (AECOM 2015) and the Shellgrit Creek Flood Study (Cardno 2014)
The study was undertaken by consultants WRM as part of the Mackay Floodplain Risk Management Study and Plan and adopted on November 24 2021.
Sarina Drainage Study (Adopted)
The Sarina township catchment is approximately 13,000ha bounded by Plane Creek to the south, Bells Creek to the north and east and topographic ridges within agricultural lands to the north and west. The broader catchment extends north and south to the peak of Bells and Plane Creeks. Bells Creek catchment extends approximately 9 km north of the Sarina Township which comprises of gentle sloping land with hills on the edge of the catchment. Planes Creek catchment, significantly larger than Bells Creek extends approximately 14 km south-west of the Sarina Township which comprises of hilly areas with peak elevations exceeding 560m AHD. Plane creek passes through the southern area of Sarina south of Range Road. Both areas consist of open spaces consisting of farmland for crops or cattle.
The Sarina Drainage Study commenced in 2018. The final report was produced in September 2018. The reports focuses on modelling the existing flood impacts in the catchment for numerous events in order to better understand the flood risk posed to the community and allow it to be effectively managed in the future. The study identifies a number of options for mitigating potential drainage issues which will considered in accordance with the Mackay Flood and Stormwater Management Strategy.
The final report was adopted by council on November 14, 2018
- Sarina Drainage Study Volume 1 (PDF 11.6MB)
- Sarina Drainage Study Volume 2 - A (PDF 14.4MB)
- Sarina Drainage Study Volume 2 - B (PDF 15.7MB)
- Sarina Drainage Study Volume 2 - C (PDF 12.1MB)
Bakers Creek South Mackay Stormwater Trunk Infrastructure Study
The Bakers Creek South Mackay Stormwater Trunk Infrastructure Study commenced in 2018. The final report was produced in December 2018. The reports focuses on modelling the existing flood impacts in the catchment under existing and projected climate conditions for numerous events in order to better understand the flood risk posed to the community and allow it to be effectively managed in the future. The study identifies a number of options for mitigating potential drainage issues which will be considered in accordance with the Mackay Flood and Stormwater Management Strategy.
The final report was adopted by council on March 13, 2019
Andergrove Beaconsfield (Adopted)
The Andergrove Beaconsfield Drainage Study (AECOM 2020) was undertaken using the direct rainfall method which involves the application of rainfall directly to the two-dimensional model domain. The study was adopted by council in January 2021.
West Mackay (Adopted)
The West Mackay Drainage Study (AECOM 2019) was undertaken using the direct rainfall method which involves the application of rainfall directly to the two-dimensional model domain. The catchment was divided into two parts: Study Area 1 and Study Area 2. Proposed mitigation and flood damages assessment were only undertaken in Study Area 1 (refer Figure 1). The study was adopted by council in January 2021.
North Mackay (Adopted)
The North Mackay Drainage Study (WRM 2019) was undertaken using the direct rainfall method which involves the application of rainfall directly to the two-dimensional model domain. The North Mackay model extends to the levees bounding the study area adjacent to Goosepond Creek to the west, Vines Creek to the north and east, and the Pioneer River and Barnes Creek to the south. The study was adopted by council in January 2021.
Coastal inundation
Ocean tides can affect normal sea levels and cause flooding along the coastline and lower reaches of the Pioneer River and other creek systems, especially when combined with high rainfall. However, the tidal effects along an estuary or river diminish with distance inland. Storm surge is another mechanism that can affect water levels along coastal areas. Storm surge occurs through a combination of low barometric pressure, strong winds and large waves. It is generally uncommon for extreme rainfall events and extreme storm surges to occur simultaneously, albeit the 1918 event in Mackay is an example of this occurring.
Mackay Region Storm Tide Study
The Mackay Region Storm Tidy Study commenced in 2011 and the final report was produced in June 2013. The study covers the mainland coastal areas within the Mackay Regional Council jurisdiction and includes almost 550km of mainland coastline (including estuaries and inlets).
The study was completed to provide an indication of the risk to the community from potential storm surge events. The final report was adopted by council on April 26, 2017.
In progress and future studies
It is not feasible for council to complete flood studies over the entire region at one time. Instead, council has an ongoing program of works to map coastal and flood hazards across the region. Flood studies, particularly in urban environments require details of the stormwater network. Collection of this data can be time consuming and is reliant on weather conditions. For this reason, the general process for completing flood studies is for data collection to occur during the financial year before the flood study commences.
The section below provides a summary of the flood studies that are currently being completed and future planned studies. It is important to note that the timing and order of future flood studies are subject to change.
Studies currently in progress
Council are working on the Finch Hatton Flood Study and this study is expected to be completed in the second half of 2024.
Planned flood studies
Council are planning to do future flood studies in:
- Reliance Creek
- Goosepond Creek & Glenella