Urban sprawl from Perth is now being allowed by commercially driven Planning approvals to spread south with no obvious restriction. Unless Government Planning authorities reconsider the negative environmental consequences that will surely follow, urban development; predominantly low density housing, will shortly spread around the Peel-Harvey Estuary that is a massive body of deceptively shallow water that is already at serious risk of decline.
The Dawesville Cut intervention in 1994 was initially conceived as a response to blocking of large areas in the southern part of the estuary by algal growth. This was due to the trapping of water entering the estuary polluted principally by chemical fertilisers from a vast area of surrounding land developed for agriculture over the two centuries since ‘Settlement. The downstream ‘eutrophication’ (the undesirable effect of algal growth and nutrients) in this polluted water en route to the ocean was exacerbated, especially at the Harvey end of the Peel-Harvey Estuary, which is overall an extremely large but shallow and slow-moving waterway formed by natural processes. The ‘Dawesville Cut’ linking the Harvey end of the Estuary to the ocean deliberately introduced seawater at a new point. That resulted in some increase in circulation and promoted the exit and dilution of some of the nutrients forming algal mass through creating a more saline regime.