Trip to the Lower Lakes

On 20 October 2016, fifteen water industry professionals travelled to Goolwa, Hindmarsh Island and Point Sturt to investigate the ecological health of the Lower Lakes, engineering structures used in the management of the Lakes and the cultural significance of the area to the Ngarrindjeri people. Jason Higham from the Department of Environment, Water and Natural Resources was our tour guide. He did an outstanding job, sharing his vast knowledge of the Lower Lakes and Coorong. Darrell Sumner, a Ngarrindjeri elder, joined the tour in Goolwa, sharing with the group his local cultural knowledge and family stories.

Standing on the Goolwa Barrage on a beautiful sunny day, the group inspected the barrage and heard about how the system of barrages regulates the flow through the Lakes and prevents saltwater intrusion into the main body of Lake Alexandrina and Lake Albert. We saw how barrage structures are moved and maintained to regulate water flow, the operation of locks that allow vessels to pass through, and fishways that assist fish movement through the barrage system. Our inspection revealed a vast array of wildlife taking advantage of the current high flows, including pelicans and other sea birds and plenty of seals making use of the structures.

Goolwa Barrage

High Flows through the Goolwa Barrage

Seal at the Goolwa Barrage

Seal at the Goolwa Barrage

Darrel Sumner spoke about how changes to the system impacted on Ngarrindjeri culture and connectedness in particular the impact of the barrages on water depth, water quality and fish resources overtime.

The tour then headed out to Hindmarsh Island where we stopped at Sugars Beach. This position offers an excellent view of the Murray Mouth. There we learned about the history of the Murray Mouth and how it has moved over the centuries. We observed and discussed the operation of sand dredging barges to ensure the Murray Mouth remains open. During the millennium drought, low flows and the closure of the river mouth resulted in significant environmental issues associated with water availability, water quality and acid sulphate soils. Sand dredging of the river mouth was implemented to reduce the impact of these disastrous outcomes. Dredging continues to be undertaken as required.

Darrell reflected on the significant number of Aboriginal burial sites that exist in the vicinity of Sugars Beach and that because of this it is an especially important place.

Sand dredging at the Murray Mouth

Sand dredging at the Murray Mouth

Sugars Beach

Coastal Vegetation at Sugars Beach

The tour then headed to Wyndgate. This rural property was purchased by the South Australian Government in 2001 with the aim of protecting wetlands and rehabilitating terrestrial habitat on Hindmarsh Island. We had lunch at Wyndgate House where Jason gave us a comprehensive overview of drought recovery projects for the Lower Lakes and Coorong. We learned of the significant environmental impacts, social dislocation and economic hardship caused by the drought. Detailed information and some excellent videos can be found here.

Wyndgate House

Wyndgate House

After lunch the tour headed to Point Sturt, just outside of Clayton, where we got an excellent view of Lake Alexandrina and an appreciation of the scale of the lakes. We also got to view up close some important wetland habitat. We learned of the hydrology and limnology of the lakes prior to barrage construction in particular the zone where the lakes transition from a marine dominated environment to a freshwater dominated system.

View from Point Sturt including wetland

View from Point Sturt including wetland

Group Enjoying the view at Point Sturt

Group Enjoying the view at Point Sturt

From Point Sturt the tour then headed back to Adelaide. Everyone exhausted but much wiser for the experience.

Special thanks to our sponsor, Ecological Associates, and all of the presenters and participants in the tour.