Ecologists from Charles Sturt University (CSU) in collaboration with the NSW Department of Land and Water Conservation (DLWC) have developed a set of tools to help measure the benefits of environmental flows to plants and animals in the Murrumbidgee River, one of the most regulated rivers in NSW.

They are the first in Australia to develop biological indicators for the assessment of environmental flows, implemented by the NSW State Government in 1998 to partly restore natural water flows to inland waterways.

“To assess whether environmental flows are effective, we need biological indicators to measure their impact,” said project leader Dr Robyn Watts.

“Although there are several indicators currently used to assess river health, our project differs in that we have developed indicators that respond specifically to flow regime. We need these indicators to make a good assessment of how successful the flows are in improving the ecological health of the river system.”

Dr Watts and Dr Darren Ryder together with researcher Laurie Chisholm and postgraduate student Bronwyn Lowe, sampled 18 locations along the Murrumbidgee from the South-West Slopes to its junction with the Murray River. 

The researchers studied a wide range of biological “indicators” including algae, aquatic insects, riverbank vegetation and River Red Gums.

“We identified which biological indicators have the most predictable and reliable response to flow regimes,” Dr Watts said.

The results of the three-year study have been given to the DLWC to assist the development of a biological monitoring program and to the Murrumbidgee River Management Committee to help determine environmental flow rules. The CSU research will continue over the next three years with a new $520 000 Australian Research Council grant.

Drs Watts and Ryder are members of the River and Floodplain Ecology Research Group within CSU’s Johnstone Centre. The Group’s contribution to the region was recognised late last year when it was awarded the 2001 Vice-Chancellor’s Research Excellence Team prize.