Willochra Creek Catchment
The Willochra Creek Catchment is located in the Southern Flinders Ranges approximately 250 kilometres north of Adelaide. The catchment area of around 6425 square kilometres is bound to the west by the Flinders Ranges, including Mt Remarkable; to the east by the Pekina Ranges; to the north east by the Druid Range; and to the north by the Yappala Range and Mt Eyre.
Around five per cent of the catchment is conservation parks including Mt Remarkable National Park and Mt Brown and The Dutchman’s Stern Conservation Parks.
The major land use in the southern area of the catchment is cropping and grazing of sheep and cattle. Irrigation is mainly used for viticulture but also for olives and intensive animal production.
Former Northern and Yorke Water Officer Jennifer Munro said the catchment’s renowned landmarks make it one of the State’s prime tourist areas.
In conjunction with agriculture, tourism brings significant economic and social benefits to the district.
“We all need to be mindful of the pressure being put on the limited ground and surface water resources of the catchment as well as the future effects on resource condition and availability,” Ms Munro said.
Located in a semi-arid to arid region with overall low annual rainfall and highly variable runoff, the Willochra river system is ephemeral. The catchment’s main watercourse is the Willochra Creek, which originates at the eastern base of Mt Remarkable.
Willochra Creek is approximately 205 kilometres long and flows north from the town of Melrose through the Willochra Plain then north westerly until it discharges into the saline Lake Torrens. Major tributaries of the Willochra Creek include Yellowman Creek, Wild Dog Creek to the south; Booleroo Creek, Old Booleroo Creek, Coonatto Creek, Boolcunda Creek and Kanyaka Creek to the east; and Spring Creek, Stony Creek, Beautiful Valley
Creek and Mt Arden Creek to the west.
Threats to the sustainability of the catchments water resources include reduced surface water run-off, shorter seasonal flows, lack of flow during drought periods, and increased irregularity in the frequency and volume of flow events.
Historically connectivity between the upper and lower reaches of the catchment has also reduced. Factors which can impede catchment connection include altered runoff due to diversions, and increased numbers and high evaporation of dams.
Vegetation clearing, channel modification and point source and diffuse pollution also have an adverse effect on water resource sustainability.
“Any major alteration to the system’s flow can negatively impact on native flora and fauna in the water and on land,” Ms Munro said.
“Without permanent pools and periodic flow, populations are unable to disperse, recruit, rebuild and survive the next drying phase – this could lead to localised species loss.”
The prolonged drought of the 2000s contributed to the declining and drying of wells, springs and soaks that are sustained by groundwater discharge. This was further compounded by expansions in groundwater use.
“When a spring or soak dries up, the major cause is a drop in water table levels underground. These episodes can have serious implications on species that use springs and soaks as refuges or breeding areas.’’
“Surface water and groundwater resources need to be managed holistically and preserving permanent pools and maintaining flows should be a priority,” Ms Munro said.
The current Hydrological and Ecological Assessment report for the Willochra Catchment identifies the assets and threats and provides a holistic understanding of water resource use and sustainability at a catchment scale.
“This report is now under review and it’s a great chance to put in place strategies to protect the long term future of the catchment,” Ms Munro said. “Consultation with the community, landholders and volunteers is a critical part of this review process. One of the easiest ways for people to have their say is by getting involved in our Four Catchments project.”
The Four Catchments project was launched in 2012 and encourages landholders, community groups and volunteers to take an active role in looking after their catchment. The project includes a range of on-ground work including revegetation, weed management and fencing. This year the target section is in the Melrose area and future activities will build on that foundation. The second part of the project involves seeking community input into future action planning for the catchment. An initial workshop was held in Melrose in April 2014 to discuss river assets and management issues, and identify the future priority actions of concern to the catchment community.