Edward River Council is responding to a significant outbreak of the invasive aquatic weed Sagittaria in Deniliquin's town lagoon system, with plans underway to remove the infestation and restore the lagoons to a healthy state.
Mayor Cr Ashley Hall said Council recognises community concern about the current appearance and condition of the lagoon.
"The Waring Gardens lagoon has a pretty thick cover of weed at the moment, and we know it can detract from the appearance of our beautiful park," Cr Hall said.
"However, this isn't just a visual issue. The weed can restrict water flow, block drainage and irrigation systems, and contribute to stagnant water, which affects the habitat of our lagoons."
Council has applied for NSW Government funding to support efforts to remove the weed, and is working closely with community partners on lagoon health, including the Deniliquin Kolety Lagoons Landcare Group, drawing on local knowledge and technical expertise to coordinate ongoing management activities.
Roseanne Farrant, Chairperson of Deniliquin Kolety Lagoons Landcare Group, said the group was supportive of Council's efforts to control the weed and stop it invading the broader lagoon system.
"Sagittaria platyphylla (commonly known as Sagittaria) is an introduced invasive species which has flourished in the Waring Gardens because of the shallow depth of water.
"A de-silting programme in the winter will remove the plant's large rhizomes and the resulting increase in the depth of water will make it unsuitable for the Sagittaria to return.
"The Catfish in the lagoon are currently breeding and we need to ensure that we manage the lagoons to support our native fish and plant species," said Ms Farrant.
Under the proposed project, removal would be undertaken through contained, sectioned excavation of affected lagoon pockets to reduce disturbance to aquatic habitat. Mechanical removal would be supported by manual follow-up to ensure plant fragments, rhizomes and corms are fully extracted. Herbicide was not put forward as a solution due to lagoon wildlife and the sensitivity of the ecosystem.
If funded, Council will implement an ongoing monitoring program, including permanent photo points across Waring Gardens and regular data capture aligned with Crown Lands reporting requirements. Council will also monitor for regrowth every four weeks during the growth period and carry out maintenance removal as required.
Cr Hall said Council expects to receive notification on the funding application outcome within the next few months, so works could be undertaken over winter when impacts on wildlife and aquatic habitat can be minimised.
"We've put forward a strong case for funding because the removal of this invasive weed is critical to maintaining the ecological health of the lagoons, improving water quality, and protecting our much-loved public spaces," Cr Hall said.
"We value the time, knowledge and on-ground support provided by Deniliquin Kolety Lagoons Landcare Group and other community members.
"With the right funding and the right plan, together with knowledgeable and committed people in our community, we can work together on practical solutions that will protect our lagoons into the future."
