Keeping watch on water quality

WATER quality in the River Derwent and its tributaries above New Norfolk will be closely monitored over the next year to keep tabs on changes in southern Tasmania’s major drinking water supply.

The 12-month monitoring trial is an initiative of the Derwent Estuary Program in co-operation with TasWater, Hydro Tasmania and NRM South. The focus area will be the Derwent River above New Norfolk and in its tributaries including the Plenty, Styx, Tyenna, Clyde, Broad, Dee, Ouse and Florentine Rivers.

Water samples from 14 sites are being taken monthly and they align with a monitoring program last conducted in 1998.

Derwent Estuary Program director Christine Coughanowr said a review of the state of the catchment in 2011 identified land use changes and water-quality issues that may affect drinking and ambient water quality.

“The water quality of the Derwent in 1998 was excellent however an observed increase in nutrients in the Derwent estuary near New Norfolk, plus the findings of the 2011 catchment review, has prompted the DEP and other organisations to revisit the monitoring program” Ms Coughanowr said.

“The security of fresh water from the Derwent River for drinking, farming, industry and the natural environment is essential and this trial will help inform best practice management to mitigate pollution” she said.

“The monitoring of the Derwent and its tributaries will provide baseline information for managing water quality now and in the future, and may also help explain why we have seen an increase in nutrients in the upper estuary. A co-operative monitoring program such as this one will see a whole of catchment picture emerge which will improve opportunities for managing often complex issues that affect river water quality."

Results of the water quality trial will be made publicly available. More information about the Derwent Catchment and the State of the Derwent Estuary is available at the Derwent Estuary Program website. 

Established in 1999, the Derwent Estuary Program is a regional partnership between local governments, the Tasmanian Government, industries, scientists and community-based groups to restore and promote the estuary. Major sponsors include the Brighton, Clarence, Derwent Valley, Glenorchy, Hobart and Kingborough councils, the Tasmanian Government, Nyrstar Hobart, Norske Skog Boyer, TasWater, TasPorts and Hydro Tasmania.