Flooding and stormwater impacts

Intent statement

Your proposed development must not result in adverse impacts from flooding or overland flow of stormwater. Hydrologic and hydraulic investigations must be carried out to demonstrate that the proposed development will not adversely impact on flooding to upstream, downstream or adjacent properties, or create nuisance ponding on other properties. Where necessary, suitable impact mitigation measures must be implemented. A professional engineer (RPEQ certified) with the relevant expertise and experience in hydrological and hydraulic assessments needs to undertake the work.


This document is a guide to help external consultants and applicants to address flooding and overland stormwater flow impacts of their development, and prepare investigations and reports for review by Council.


Where a site is affected by flooding or overland stormwater flow, the investigation, reporting and proposed mitigation measures accompanying the application will demonstrate clearly and conclusively that if the development is carried out in accordance with the proposed mitigation measures then there will be no adverse impacts from flooding and overland stormwater flow on the development and up, down stream or adjacent properties.

The reliability of the assessment approach and methodology and inputs together with the accuracy of the base data used will be proven.

Last updated:7 May 2019