Southern Rural Water (SRW) says recent rainfall has tested the integrity of some farm dams, serving as a timely reminder for landowners to carry out routine maintenance.
Manager Groundwater and Rivers, Hugh Christie, said that the Bureau of Meteorology (BoM) has also forecast higher chances of a La Nina over coming months, at three times more likely than normal, which could bring higher than average rainfall across Eastern Australia.
The last significant La Nina event was in 2010-11, which was Australia’s wettest two-year period on record.
“The BoM La Nina forecast makes it more important than ever to ensure farm dams are safe and operating properly,” Mr Christie said.
“A dam is a valuable asset on any farm, providing essential stock or irrigation water supplies and should be regularly inspected during the year as part of preventative maintenance. Dam failure not only leads to expensive repair bills; it also means lost production while the dam is repaired,” Mr Christie said.
“The owner is also liable for any damage a failed dam causes to people, property or the environment.”
Southern Rural Water encourages all dam owners to follow good practice guidelines to help achieve a long operating life from your dam:
- Spillway – the spillway must be designed to cope with large storms and rainfall runoff. The spillway must never be reduced in size without the approval of your rural water authority.
- Compensation pipe and valve – the valve must be operated regularly to avoid seizure due to rust and other build up. Operating regularly will also reduce the amount of silt and other debris that can build up in the compensation pipe. Safe and simple access to the valve must be maintained at all times.
- Dam wall – the downstream wall should be kept clear of trees, shrubs and weeds. The slope should have an even cover of deep-rooted grass, regularly maintained to allow visual assessment of the wall.
- Dam crest – the crest may be used to allow stock or vehicles to cross the dam wall. However, it should be kept level to avoid potholes and uneven areas forming. The crest should also be fenced to exclude stock from both the upstream and downstream walls. Allowing stock access to the walls will cause damaging erosion.
- General surveillance – You should regularly check for leaks, wet spots, slumping or any signs that the dam may be at risk. Regular inspections and prompt maintenance should ensure you get the maximum life span from your dam. Any movement should immediately be reported to your local rural water authority (eg. Southern Rural Water) and your farm dam engineer.
“This advice is general – we encourage all dam owners to seek expert advice about the best way to keep their dam safe and operating properly,” Mr Christie said. “A qualified and experienced farm dam consulting engineer is a great place to start.”
For more information, please contact Southern Rural Water on 1300 139 510.