8.2.3.Keeping it clean
Most negative impacts on water ecosystem can be attributed to human intervention, including reduced water flows, increased erosion in and around the waterway and infestations of exotic species such as willows trees and carp.
Vegetation loss can have a serious impact on water quality, with bushfires being a major risk to water supply catchments. Bushfires denude much of the landscape of trees, which hold fragile soils in place and slow the flow of water across the landscape during rain events. Both of these functions significantly reduce erosion and limit turbidity (suspended solids) in waterways.
Water quality will gradually improve with regrowth and strategic vegetation planting, but progress can be stilted by drought and outdated land management techniques.
Local water quality concerns can often be ameliorated by increasing riparian vegetation and removing direct access to the waterway by stock. These two actions are effective in promoting and sustaining good water quality.
By fencing out riparian areas, and planting deep rooted trees, salinity is reduced, nutrient run-off from fertilisers and stock is controlled, and stream bank stability is maintained.
Waterwatch, a community water quality monitoring program in the region offers free training, equipment and facilitation of water quality monitoring and improvement on both small and large scale projects. For more information about Waterwatch in the Murrumbidgee region go to Waterwatch or contact Sue Buik from the Murrumbidgee CMA on (02) 6940 2942 or sue.buik@cma.nsw.gov.au
Photo of fenced off dam or well-vegetated dam (Alison Elvin)
Box section:
Causes of riparian zone degradation
• Recreational activities
• Invasion and competition by pest species
• Land management practices such as grazing and cropping
• Erosion
• Channel realignment
Effects of riparian zone degradation
• Flow regulation
• Weed invasion
• Loss of topsoil and livestock trampling
• Reduced water quality
• Reduced biodiversity
• Reduced aesthetic value
• Loss of windbreak and shelter
• Reduced aquatic flora and fauna
• Unstable stream banks
END Boxed section
