Environment Australia, the Department of Natural Resources and Environment and Melbourne Water,
18 January 2002
About this report
Assessment of the Impact of Private Dams on Stream Flow is a collaborative project funded by Environment Australia, the Department of Natural Resources and Environment and Melbourne Water. Goulburn Murray Water, Southern Rural Water, Wimmera Mallee Water, the Wimmera and North East CMAs and Environment Victoria also participated in the project.
The objectives of this project are to -
- Quantify the impact of private dams on stream flow on a seasonal basis.
- Trial development models which assist water authorities in assessing applications for new private dams and in determining impacts of new and existing dams on water resources and environmental flows.
The project was carried out in 3 stages -
- Stage 1 - Preliminary demonstration modelling of 5 catchments using the TEDI (Tool for Estimating Dam Impacts) model.
- Stage 2 - Workshop to present the results of Stage 1 modelling and to plan the best approach for the next stage.
- Stage 3 - Preparation of tools for assessment of the impact of farm dams.
The scope of the project allowed for a high level of involvement early in the project by the water and catchment authorities who would be the main users of the tools. This involvement ensured that development of the tools was informed by the preferences of the end-users and incorporated the practical constraints and needs of agencies.
The outcomes of this project are a set of tools which can be used to assist in the estimation of the impact of farm dams. These tools include -
- an enhanced TEDI model which can be applied to specific catchments to determine the impacts of farm dams on a time series of stream flows;
- a set of prediction equations which can be applied to any unregulated catchment in Victoria to provide a quick first order estimate of the impacts on selected stream flow statistics; and
- a quick method for making a preliminary estimate of the number and volume of farm dams in a catchment using 1:25,000 topographic maps.
Documentation of the project outcomes is summarised in this Final Report, with more detail provided in -
- Tool for Estimating Dam Impacts (TEDI) - User Manual - May 2000
- Farm Dam Impacts Study - TEDI Modelling - Impact of Farm Dams in Five Catchments, May 2000
- The Development of Regional Tools for the Prediction of Farm Dam Impacts in Victorian Catchments, October 2001.
- Paper accepted for publication in the Australian Journal of Water Resources - Identifying the Separate Impact of Farm Dams and Land Use Changes on Catchment Yield, by B Neal, RJ Nathan, S Schreider, and T Jakeman, 2002.
- Paper presented to Victorian Branch of Australian Water Association, 2001 Regional Conference Moama. Sustainable Water Management for Victoria's Unregulated Streams by Bernard J O'Kane and William R Hansen, October 2001.
The TEDI model has already been accepted as an important tool in Victoria's management of its water resources in unregulated streams. The regional prediction equations will also have a major role by linking up with the Sustainable Diversion Limit project to provide a first order estimate of the amount of sustainable diversion limit already taken up by existing farm dams and the potential for further farm dam development.