Hurry Save The Murray!

First stop the Finniss Ford
We gathered at noon at the Finniss Ford: Marian Thompson, Bev and Alex Stone, Karyn Bradford, John Yelland, Carole Richardson, David Knappstein, Marie-Claire Levi, Olwyn Barwick, Sue Hogben and Diane Bell.

The rain was soft. Marie-Claire demonstrated how umbrellas can hold water as well as keep a person dry. Spare gum-boots were shared. Alex, Bev, Olywn and Sue managed without gumboots as we walked John’s plank. Next time industrial strength gum boots for monitoring in the mud.

The Finniss Ford was a healthy pH 7.4 (pH 7 is neutral).

Next stop Wally’s Landing

The Waterwatch team has records that stretch back many years for the catchment and more recently our local monitors have been testing the water at the various sites on the Finniss River and Currency Creek, in particular at the Ford on the Finniss, Wally’s Landing and random locations. The readings have always indicated alkaline rather than acid flows but a recent Press Release of Minister Maywald (12/05/09) stated “Recent rainfall has mobilised this acid in a creek bed that feeds into the Finniss River catchment near Wally’s Landing.”

The banks of the river at Wally’s Landing were acid but as we tested at regular intervals between the bank and the running water, the pH increased and the Finniss River was pH 7.4.

Carole Richardson showed us how to test in zones one (pH 6.5) two (pH 6.5) and three (pH 6.6).

The Creek and Wetland
When we tracked further upstream into the wetland, we found the creek was acid (pH 3.9). The water in the cracks along the banks was pH 4.5. This appears to indicate that the source of the acid was in the newly rewet cracked clay in the creek bed rather than from the banks.
The rain has certainly mobilised the acid in this creek and the pools through which it is flowing are toxic. However, by the time the water had joined with the anabranch of the Finniss River (below Wally’s Landing) the acid had been neutralised.

John Yelland tested the water.

Ultra-fine grained limestone
We then visited the site, several hundred metres downstream, where lime has been mounded in the river. The turtle tracks we had seen the day before were disappearing under the mud tide on the downside of the lime embankment.

John Yelland testing the water below the lime banks

Turtle tracks in the lime

The Lime bank
Above the lime the pH was 7.5 and below was 9.

What can be done?
The immediate problem is the acid in the creek that flows into the anabranch of the Finniss River below Wally Landing and above the lime site. We suggest that be managed as a problem site.
* Don’t let it dry out in first place. That advice has not been acted upon, hence the problem.
* Lime downstream. That is being done and monitored by the EPA.
* Pond the acid water at the site, perhaps with a clay bank and allow creek to bioremediate. This could occur within a matter of weeks but may take longer because the water is cold and very acid. Nonetheless it can be done.
* Mulch: there is ample research to indicate that mulching would work in this region. link, * Revegetate. Plants are already well established on banks and plans are underway with community-based groups to plant more local species.
* We need to see the CSIRO analysis and quantification. Then it will be possible to develop a better strategy.
The oft-repeated concern we have heard from the scientists is, “It’s so variable, it is hard to get a handle on it.” And their frustration in, “This could have been avoided had the area not been allowed to dry out.”

Go to the “Community Monitoring” page for details of our monitoring