Responding to the impacts of recent storms on bushfire affected catchments

Photo of a boat ramp and the Clyde River after heavy rainfall. There is a lot of ash and sediment on the boatramp and in the water.

Debris, sediment and highly turbid water in the Clyde River following heavy rains on the NSW South Coast. Photo: Jamie Maclean, EES.

While the recent heavy rains were very welcome, the effects are being closely studied in bushfire ravaged areas.

DPIE-EES has teamed up with the NSW Environmental Protection Authority (EPA) and DPI Fisheries to understand what’s in the rainfall runoff from bushfire affected areas following the east coast low pressure system in July.

This research aims to increase knowledge about the impact of bushfires on water quality, waterway health and surrounding catchments.

Freshwater overland flows from heavy rain increase in bushfire affected areas as tree and ground cover are not there to slow flows and encourage infiltration into the ground. These increased overland flows wash debris, ash, sediment and burnt material into creeks, streams and rivers that lead to the marine estate.

Computer drawn image showing that heavy rain falling on bushfire affected areas creates a large amount of run off into waterways.Image showing that heavy rainfall after a bushfire will result in a lot of sediment and ash running into waterways which creates poor water quality.

Water quality is being tested in affected areas of the south coast, including Lake Conjola, Durras Lake, Lake Tabourie and the Clyde, Moruya, Tomaga and Tuross rivers.

Samples are collected to measure nutrients, sediment and organic matter. The data will help determine how much material is being absorbed into the system or washed out to sea.

This information will improve knowledge of how bushfires impact aquatic ecosystem health and the values the community derives from the NSW marine estate. It will also help to understand how burnt material moves from catchments affected by bushfires.

The research will guide management and mitigation responses by regulators, local government and land managers to help protect the marine estate and improve water quality longer term.

The work is funded by the Marine Estate Management Strategy (MEMS), with support from partners.

Read more marine estate news.

Page last updated/reviewed: 23 Sep 2020