The question inquires about the relationship between recent rainfall levels and historical averages in the Swan Valley, and the extent to which rainfall explains current flooding. The answer indicates a downward trend in annual rainfall since the 1970s, with recent levels being within or below historical averages, but acknowledges that increased intensity of individual rainfall events may impact inundation.

AnsweredQoN 1519Legislative Council
Asked
14 April 2026
Portfolio
Aboriginal Affairs; Water; Climate Resilience; South West

QuestionView source ↗

I refer to rainfall events contributing to flooding in the Swan Valley, and I ask:(a) how do recent rainfall levels compare to historical averages; and(b) to what extent does rainfall explain current flooding?

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)    The overall trend, since the 1970s, for the annual rainfall in the South West is downwards. Recent annual rainfall has been within or below historical averages.
(b)   The increased intensity of individual rainfall events may have an impact on inundation and stormwater management.

Explore WA Government Data

Search the full archive in the free dashboard, or query programmatically via API.

Explore more