Water Journal : Current August 2017
T he Goulburn Broken Water Quality Strategy (WQS) was originally developed in the mid-1990s. Strategy implementation was expected to occur over 20 years, finishing in 2016. The 1996 version of the WQS was reviewed in 2002 and 2008. The original strategy focused on reducing the risk and impacts of blue green algal blooms by reducing the inputs of nutrients, especially phosphorus, to waterways and water bodies. Many of the actions in the WQS were incorporated in the Goulburn Broken CMA Regional River Health Strategy 2005-2015 (now updated as the Goulburn Broken Waterway Strategy 2014-2022). The Goulburn Broken Catchment Management Authority (GBCMA) undertook a review to assess WQS progress in 2016. Changes in catchment conditions suggest that modifications in the approach to water quality management might be warranted. CAUSE AND EFFECT A substantial program of works has been implemented. In dry-land areas, 818km of stream buffers have been established; in irrigation areas, 3475 water reuse systems and 34 high flow storages have been installed, and a number of wastewater management facilities have been upgraded. Over the 20-year period of WQS implementation, numerous changes have affected nutrient delivery to waterways. These changes affect planning and implementation and include: • drier climate; • wastewater treatment plants discharging to land rather than to a stream; • very large reduction in irrigation water availability and subsequent focus on water use efficiency; • steady increase in urbanised areas, and a large increase in urban area in the south due to Melbourne expansion; • 20 years of catchment and waterway management activities; and • education and best-practice development and adoption. WATER QUALITY CHANGES Current and past estimates of nutrient loads discharged to waterways shows that since WQS implementation began: • wastewater treatment plants are no longer a major nutrient source in the catchment; • irrigation drainage contribution has reduced substantially; • the ratio of irrigation drain to dry land source has changed, such that dry land is now the major nutrient source (in 1996 the ratio of irrigation to dry land was 1:5 and in 2016 it was 0:5); and • loads from intensive animal industries and urban stormwater are unlikely to have changed much over time. Assessment of water quality against objectives in the State Environment Protection Policy (Waters of Victoria) shows a slight improvement in the number of sites that do not meet water quality objectives. Total nitrogen, total phosphorus and turbidity are the parameters most frequently in excess of desired objectives. Decommissioning of Lake Mokoan in 2009 has led to a major improvement in water quality in the Broken River, Broken Creek and the Goulburn River at Shepparton. THE NEXT 20 YEARS Water quality will continue to be one of many issues to be considered when managing catchment land and water resources. Activities that focus on the things that make a difference, no-regrets approaches and implementing resilience and adaptive pathways approaches should result in water quality improvements. Maintaining and extending partnerships to ensure a strong caretaker ethic for the quality of the region’s water will be critical to achieving this. Pat Feehan is an independent consultant, a Director of Water Stewardship Australia and co-Chair of the Australian Water Association Catchment Management Specialist Network. Mark Turner is the River and Wetland Health Program Manager and the Goulburn Broken Catchment Management Authority. To read the full article, visit the Water e-Journal at bit.ly/water_ejournal The Goulburn Broken Water Quality Strategy: 20 years on PRESENTING OUTCOMES OF LONG-TERM NUTRIENT MANAGEMENT IN A LARGE VICTORIAN CATCHMENT. P Feehan, M Turner executive summary catchment water quality www.awa.asn.au 70 Over the 20-year period of WQS implementation, numerous changes have affected nutrient delivery to waterways.
Current May 2017