FARM WATER STORAGE

The Hon. A. BRESSINGTON (14:46): My questions are to the Minister for Sustainability, Environment and Conservation. What environmental impact studies or feasibility studies have been done to show that dams are interfering with environmental flows in the Hills, and were hydrology studies done as well? Can the minister state exactly how much—from these studies—water is actually captured in dams from rainfall that falls on properties in the Adelaide Hills? Of the 2,000 dams over five megalitres that have been identified in the Hills, how many dam estimates have been disputed and what dispute resolution process is in place for farmers for inaccurate estimates of dam capacity?

The Hon. I.K. HUNTER (Minister for Sustainability, Environment and Conservation, Minister for Water and the River Murray, Minister for Aboriginal Affairs and Reconciliation) (14:47): I thank the honourable member for her most interesting and important question. The Department of Environment, Water and Natural Resources uses a number of scientifically validated methods to estimate farm dam capacities. Methodology and formulas, or formulae, were developed by the former engineering and water supply department.

A cross-section of dams in the Mount Lofty Ranges were bathymetrically surveyed to determine actual storage capacities for each dam, and this work was subsequently used to develop a best-fit formula for estimating dam capacities. These formulae take into account surface area measurements, depth or dam wall measurements and dam construction engineering principles and have been used to estimate the capacity of licensed dams in the Mount Lofty Ranges.

Ninety-three per cent of all the dams in the Mount Lofty Ranges that are the subject of a licence application have been field verified, and data has been collected on site by departmental staff utilising survey equipment. The only dams not verified are small dams under one megalitre, I am advised. I am also advised that the formulae for estimating dam capacities have been adopted by interstate natural resources management agencies as well.

My department recognises that any dam measurement is an estimate and will consider additional evidence from a landowner if they question this estimate. If the landholder still disagrees, the bathymetric survey of the dam undertaken by a licensed surveyor will also be accepted by the department. I can confirm that, prior to the issue of water licences, the department will engage with landholders regarding their proposed licence, including dam capacity estimates, to use the most accurate data available.