Urban Stormwater Quality Management Plan for Mackay (USQMP), March 2017
Waterways within the Mackay Regional Council Local Government Area provide many benefits including recreation, aesthetics, habitat and environmental values that are important to the community.
Studies have found that there is a direct link between urban development expansion and the degradation of waterway health. Increased impervious area brought about by urbanisation, significantly alters the quality and quantity/volume of stormwater runoff and by doing so, interferes with the natural hydrologic cycle. Increased levels of toxicants (oil, sediment, nutrients and litter), erosion risk and a decrease in the natural functioning of waterways are negative environmental side effects associated with urban development.
This Urban Stormwater Quality Management Plan (USQMP) has been prepared to “establish a framework to manage stormwater quality in urban waterways that maintains or enhances a state of balance among environmental, social and economic interests within our community". It supersedes the Stormwater Quality Management Plan (SWQMP) for Mackay City prepared by consultants GHD and adopted by MRC in 2006.
The document provides MRC, the industry and community with certainty that MRC is striving to improve policy and processes that dictate stormwater quality management in the Mackay region. This document addresses current legislative requirements, highlights past and present stormwater quality related challenges and aims to guide the future planning and design of stormwater quality systems in the MRC region. It sets a clear way forward for achieving sustainable outcomes that are supported and minimises the impact of urban stormwater quality on the receiving environment. The purpose of the document is to:
- Provide a concise history of stormwater quality management in the Mackay region
- Provide clear direction on MRC’s vision, preferred approach and expectations for stormwater quality management in the Mackay region
- Summarise the current frameworks for improving stormwater quality management in the Mackay region
- Identify the issues currently facing MRC and stormwater quality management in the Mackay region
- Outline future implementation actions and funding requirements for planning, implementation, communication and education.
Stormwater Quality Objectives
To support the delivery of the stormwater quality objectives through the development approval process, council developed guidelines for the use of the industry standard predictive modelling software: Model for Urban Stormwater Conceptualisation (MUSIC).
A series of development scenarios in accordance with Mackay MUSIC Guidelines were tested and treatment performance curves were developed. These curves were used as a basis for assessment of stormwater quality objectives. Proposed stormwater quality objectives for the Mackay Region are as follows:
- 75% reduction in Total Suspended Solids (TSS)
- 60% reduction in Total Phosphorous (TP)
- 35% reduction in Total Nitrogen (TN)
- 90% reduction in Gross Pollutants
Full report Stormwater Quality Performance Curves and Stormwater Quality Objectives for Mackay (April 2009) (PDF 3.14 MB)