During a three-year monitoring program, Caulfield Grammar year8 geography students have found the creek to be in a "stressed" state at Jells Park, Blind Creek and Wellington Road. The team will make a presentation on the creek's water quality and macroinvertebrates at a Melbourne Water river health youth conference in June.

Humanities teacher Greg Yarnton initiated the monthly monitoring program to keep sustainability at the forefront of students' minds.

"They've learnt not only about the pollutants entering our stormwater system but the maximum level of pollutants to sustain a local, natural system. It's a pretty stressed environment down there, which is no surprise, and it's not improving."

He said the creek's low number of macroinvertebrates or bugs was an indication of the waterway's poor health. "It's a beautiful area of Waverley, but what runs through it is a dirty creek."

The class also found levels of dissolved oxygen too low to support fish and moderately high levels of phosphates caused by fertilisers and detergents, enough to lead to algal blooms and further loss of species.