Greens (WA) Water Spokesperson Alison Xamon MLC today released an action plan for reversing the decline of the Swan and Canning rivers due to excessive build-up of nutrients.
"Perth's urban drain network is a major source of the excessive loads of nitrogen and phosphorous entering the Swan-Canning rivers," Ms Xamon said.
"For too long, responsibility for the drains has been a grey area with the main arterial network owned by Water Corporation, and the much larger local drain network managed by local governments.