Improving water security for farms and lakes in the northern Lake Corangamite area

Research is being undertaken to improve farm water security and farm resilience in response to climate change in the Lake Corangamite area.

A website has been established as a resource for the landholders to use as a planning tool for the future https://nrmp.ccmaknowledgebase.vic.gov.au/nrmpp_map.php?view=26452_f407abe&map=59

Background

In recent decades, the geographical region for this project has experienced declining surface water runoff and water table levels. While various causes have been attributed to these trends, reduced rainfall is considered the major contributing factor. Since climate change models predict further declines in rainfall, managing water resources and balancing competing needs for farm water supplies and the water requirements of the lakes, which has high environmental value, is a priority.

CeRDI partnered with the Cundare-Duverney Landcare and Leslie Manor Landcare groups on this project with the aim of increasing knowledge of water resources and to improve farm water security for landholders and farmers in the northern Lake Corangamite area of the Victorian Western Plains.

Outcomes

The project established a data and information base to inform the following project objectives: 

1. Determine current farm water requirements for stock water supply, cropping activities, house and garden, and other uses;
2. Identify and evaluate sources of farm water supply, regarding quantity, quality, and reliability;
3. Determine interactions between groundwater systems and surface water and lakes using information from water quality analysis;
4. Develop farm water plans to improve security of supply and demonstrate best farm water management practices.

Technical Features

A high-resolution terrain model has been constructed for the region, and from this, drainage lines, sub catchments and surface water flow directions have been modelled. These were used to estimate the rainfall runoff into farm dams, using modelling. The volume calculations for the farm dams identified in aerial imagery has been undertaken as part of this work.

Access to data about groundwater systems for the district has been sourced from existing work complemented by groundwater information collected from the landholders’ bores. This provides valuable information about how the groundwater flows and water levels contribute to the lakes at different periods of the year, enabling changes in climate to be mapped across years.

Climate surfaces for precipitation, evaporation and temperatures have been sourced for the project from the latest CSIRO modelling. Season predictions are available for a 30-year period through to 2104.

Approach

Ten landholders in the Cundare-Duverney and Leslie Manor Landcare areas are participating in the project. Each landholder completes an inventory of water use for their property. This data provides a benchmark of current water requirements in the district and will be used to generate an approximate water balance.
 

Peter Dahlhaus presenting at a project workshop