For many in the Tamar Valley, the Tamar River Estuary is a growing concern, and topic of discussion in our households and communities.
While many focus on the very obvious mud problem that plagues the estuary, there is a second major problem facing the Tamar.
Rice grass was planted on the banks of the Tamar Estuary in the 1920’s, and it has taken hold of the area since then, leading to one of the world’s largest rice grass infestations – not a record we should be aiming to set.
Rice grass can transform open intertidal mudflats into tall, dense vegetation, and although this can provide some habitat value, it destroys valuable environmental assets such as sandy beaches.
This can be seen in the example of Gravelly Beach, what was once a popular spot for swimming and gathering is now overrun with rice grass, blocking access to the water. The invasive weed also causes build ups of large quantities of silt and debris along the edges of the estuary, which may exclude all native flora and fauna.
In addition, rice grass creates monocultures that can exclude all other native plants.
Provoked by the lack of action on these issues, a local group was formed called the Tamar Action Group, with the aim to advocate for action to be taken – first with temporary measures, to be then followed through with permanent solutions.
But what are the solutions to the Rice Grass problem?
Chair of the Tamar Action Group, Andrew Lovitt, said there are a number of possible solutions.
“Rice Grass can be removed 1 of 3 ways.”
“The ‘approved for the purpose’ poison called fusillade. But though it’s approved, using any type of poison is widely unpopular – especially on the scale that would be needed on the Tamar.”
“It can also be dug or dredged by hand, or machine, but it’s both very difficult and expensive.”
“The 3rd way is elegant, and economical. Rice Grass drowns in fresh water. It can then be scooped up and used for fertiliser.”
The use of fresh water is an obvious choice for removing the Rice Grass, but how can this be achieved?
Luckily, the Tamar Action Group have an idea for this too.
“Most folk have heard of the concept called Tamar Lake.” Said Mr Lovitt
“A barrage on the river, as has been done on many other rivers and estuaries around the world, creates a freshwater lake above the barrage with locks for vessels, ladders for eels etc.”
“This would be best based at Point Rapid near Rowella.”
The idea of a barrage would be expensive, a fact that the Tamar Action Group do not deny, however they say that according to a feasibility study by an international consultant, there was no doubt the project would pay for itself.
“The economic benefits would be enormous.”
“Houseboats would be able to use the lake and be popular all year round. They cannot currently because of the dangerous speeds of the tides.”
“Thanks to the natural beauty of the valley, it would be hailed as Australia’s version of Lake Como.”
“This would also make it more attractive for cruise ships to visit Beauty Point and do local tours including the vineyards.”
“Fresh water for the proposed irrigation and hydrogen projects would be more economically available.”
“Both these projects would provide employment along with ancillary industries and services.”
“Real Estate values would rise dramatically all along the valley – Not just for those with river frontage.”
“Think of the Gold Coast and other resort areas around the world. If you are only 1-2 km from beach or the river your property value would still rise significantly.”
“The eradication of the rice grass would free up access to the river for other forms of boating and the lake would be a mecca for freshwater fishing as it would be stocked in much the same way as the highland lakes.”
Although the idea of a barrage is well-supported, it is not without its critics.
“There are, of course, doubts and misinformation about a project to this size and scope.”
“For example, the fear that a barrage would push the silt and sediment problem further up the river on the sea side of the barrage.”
“Such a conclusion is not supported by the scientific analysis of the 3D hydrodynamic modelling done by a specialist consulting firm, BMT – which is why the Tamar Action Group is calling of an Independent Authority to evaluate this, and other projects – to select the best and then implement it.”
The Tamar Action Group, as part of their campaign for action on the Tamar Estuary, have produced signs and bumper stickers calling for action to fix the rice grass and fix the mud.
For those wanting to get a sign or bumper sticker (Pictured above), you can contact the Tamar Action Group via email at Info@tamaractiongroup.org.au