❓ I refer to stormwater discharge from new developments into the Swan Valley catchment, and I ask: (a) what standards apply to stormwater management in these developments; (b) how is compliance monitore
AnsweredQoN 1508Legislative Council
Asked
14 April 2026
Member
Portfolio
Aboriginal Affairs; Water; Climate Resilience; South West
QuestionView source ↗
I refer to stormwater discharge from new developments into the Swan Valley catchment, and I ask: (a) what standards apply to stormwater management in these developments; (b) how is compliance monitored; (c) what role does the State Government have in ensuring the appropriate outcomes are achieved for local land owners; and (d) what roles does the City of Swan have in ensuring the appropriate outcomes are achieved for local land owners?
AnswerView source ↗
Answered
14 May 2026
Responded by
Leader of the House representing the Minister for Aboriginal Affairs; Water; Climate Resilience; South West
Response time
6 days
a) Design criteria are typically applied in stormwater and drainage design, aligned with the national guideline Australian Rainfall and Runoff (Commonwealth of Australia 2019), factoring in rainfall event management for small to major rainfall events.
The State Government’s recommended design criteria are included in the guidelines Decision process for stormwater management in WA (DWER 2017) and Stormwater management manual for WA (DWER 2022).
There are also various publications such as codes of practice, specifications, guidelines and manuals published by local governments including the City of Swan, Institute of Public Works Engineering Australasia (WA), and Engineers Australia. Publications may also contain site specific stormwater and drainage management design criteria.
(b) Local governments assess and approve water management reports associated with subdivision and development applications, including stormwater and groundwater drainage systems, consistent with State planning policies, approved planning frameworks, stormwater management manual for WA (DWER 2022) and engineering standards.
(c) The State Government is responsible for the framework that guides land development and water management through the implementation of legislation, policies, and publications such as guidelines, manuals, codes of practice and specifications.
(d) Local governments are responsible for the planning and management of drainage systems, including subsoil drainage systems. This includes reviewing the capacity of existing drainage infrastructure, upgrading systems where capacity constraints are identified, and undertaking the operation, repair and maintenance of drainage assets to ensure they perform as intended.
The State Government’s recommended design criteria are included in the guidelines Decision process for stormwater management in WA (DWER 2017) and Stormwater management manual for WA (DWER 2022).
There are also various publications such as codes of practice, specifications, guidelines and manuals published by local governments including the City of Swan, Institute of Public Works Engineering Australasia (WA), and Engineers Australia. Publications may also contain site specific stormwater and drainage management design criteria.
(b) Local governments assess and approve water management reports associated with subdivision and development applications, including stormwater and groundwater drainage systems, consistent with State planning policies, approved planning frameworks, stormwater management manual for WA (DWER 2022) and engineering standards.
(c) The State Government is responsible for the framework that guides land development and water management through the implementation of legislation, policies, and publications such as guidelines, manuals, codes of practice and specifications.
(d) Local governments are responsible for the planning and management of drainage systems, including subsoil drainage systems. This includes reviewing the capacity of existing drainage infrastructure, upgrading systems where capacity constraints are identified, and undertaking the operation, repair and maintenance of drainage assets to ensure they perform as intended.
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