Recovery of montane rivers in the Snowy mountains following environmental flows

In April 2021, the Water Science team collected data on how environmental flows may overcome the impacts of Snowy Hydro Scheme weirs and dams on aquatic ecosystems within the Snowy mountains.

Since 2011, environmental water has been released from weirs into the regulated montane rivers of the region. Ecohydrologists Andrew Brooks, Dan Coleman and Tim Haeusler have monitored how these releases restore creeks and rivers by studying freshwater invertebrates. Invertebrates are an important part of food webs. They provide food for birds, fish and platypuses.

The study found that these water releases allow invertebrates to disperse from undisturbed locations above weirs. They disperse and colonise downstream tributary riverbeds that have been dry for 50 years. These newly formed communities quickly resemble free flowing rivers. This demonstrates that water releases can restore degraded river ecosystems. However, larger flow releases may be needed to improve regulated main-stem rivers.