The region is an important part of the Murray-Darling Basin. It has a significant role in protecting downstream communities along the Murray River by managing salt loads, nutrients, floods and water diversions. The Murray River is important enough to warrant being treated as an asset in its own right. However, it is included with other water resources in this section, because of its services, and the threats to those services require the same management actions as those needed to manage the other water resources.
Water resources within the region occur as groundwater and surface water systems. Rivers include the Avon-Richardson, Avoca, Campaspe and Loddon. The Campaspe and Loddon flow into the River Murray, while the Avon-Richardson terminates at Lake Buloke and the Avoca discharges into the Avoca Marshes and Lake Boga near Swan Hill. Lakes include Lake Buloke and Lake Batyo Catyo, near Donald in the region's far west, Lake Boort, Lake Meran, Kangaroo Lake, Lake Charm, Lake Lalbert and Lake Boga - all in the north. Reservoirs in the region include Lake Eppalock between Bendigo and Heathcote, the Upper Coliban, Lauriston, Malmsbury, Hepburn Lagoon, Newlyn, Cairn Curran, Tullaroop and Laanecoorie, all of which are situated in the upper catchment area.
Groundwater occurs within shallow shoestring sands (Shepparton Formation) of the Riverine plain to the north. In the north west Mallee area the shallow aquifer is the saline Parilla Sands aquifer. The quality of groundwater improves further south. Deep leads in the Loddon and Campaspe basins (Calivil/Renmark aquifer) provide medium to good quality water. Within upper catchment areas, water resource aquifers may occur in the new Volcanics, Quaternary alluvial deposits and the aquifers of the Palaeozoic basement rocks. Groundwater of suitable quality is used extensively for stock, irrigation and for town water supplies.
Regional consumptive use of water greatly exceeds the volume harvested. More than 75% of consumptive use comes from water imported from the Goulburn and upper Murray catchments. Some water used in the west of the region is imported from the Wimmera system. Consumptive use includes mineral water, domestic and stock, town water supplies, fire fighting and irrigation. By far the biggest use is irrigation, which accounts for more than 95% of the water consumed in the region and 85% of that harvested. Most imported water is drawn from the Murray and Goulburn catchments and most locally harvested water is taken from the Loddon and Campaspe catchments.
Waste water from urban sewerage and industry is increasingly being seen as a community resource to be used for irrigation rather than to be disposed. The volume of wastewater produced in the region is estimated to be approximately 15,000 ML/year, of which less than half is recycled by irrigation. Treated wastewater can have high nutrient loadings, which can benefit agriculture but are a detriment if released into waterways.
The goal for North Central Catchment Management Authority Water Resources as outlined in the Regional Catchment Strategy is:
Water will be shared equitably between environmental and consumptive uses, water quality will match users' requirements and water will be used efficiently.