Stormwater is water orginating from rainfall. Rainfall runoff enters stormwater pipes and rivulets that drain to the estuary. Stormwater is delivered to the Derwent estuary via 13 major rivulets and over 270 pipes in the Derwent estuary catchment.
As runoff passes over the ground and along kerbs and gutters it can pick up a range of contaminants like soil, litter, heavy metals, oil and dog waste resulting in stormwater pollution. Another issue with stormwater is the increased runoff associated with urbanisation.
The State of the Derwent Report Card (2007) identified stormwater runoff as the main source of pollution to the Derwent estuary. Local councils surrounding the Derwent estuary, in cooperation with the Derwent Estuary Program, have monitored stormwater quality. The concentration of faecal bacteria, turbidity and nutrients regularly exceed national water quality guidelines.
The Derwent Estuary Program has a dedicated stormwater project aimed at improving water quality by developing and implementing resources and programs for local government, business and industry, schools and the community and has the following initiatives:
- Encouraging Water Sensitive Urban Design (WSUD)
- Soil and Water Management for building and construction sites
- Regional stormwater resources for local government
- Community and school based education on how to prevent stormwater pollution
Restoring and promoting the Derwent estuary