What to look for?
To ensure dams remain in a safe and working condition, regular dam monitoring is recommended.
For some dams this monitoring will be done regularly through dam surveillance reports. However it is still important for all dams, regardless of size to be observed on a regular basis for any changes to its structure.
The NRE Tas Dam Safety Program recommends dam owners look for the following issues, particularly after any heavy rainfall events:
- Erosion of spillways, particularly if continued erosion could endanger the dam wall;
- Unusually high flows, or pooling of water, downstream of the dam wall;
- High levels of turbidity in water downstream of the dam, which could be an indication of internal erosion within the dam;
- Debris deposited in the spillway that may reduce its capacity; and
- Any slumping, cracking or obvious changes to the crest or downstream wall of the dam.
Dam spillway erosion following a heavy rain event
Cracking in dam wall
Downstream turbidity can indicate internal dam erosion
An example of slumping following a heavy rain event.
With regular use and exposure to a variety of weather conditions, dams can need a bit of repair and maintenance to ensure they remain in working order for the longer term.
Monitoring and assessing dams now will help ensure they continue to provide a valuable resource into the future and do not present any danger to third parties.
Maintenance and repairs after high rainfall
During periods of high or sustained rainfall, it is important for dam owners to actively monitor their dams to make sure they are in safe condition.
If you identify any issues that you are concerned about, or there is damage to your dam wall and you would like advice on requirements for repair works, please contact NRE Tas at firstname.lastname@example.org or on 1300 368 550.
Dam safety monitoring after a flood event (379Kb)
How do I repair my dam?
In the majority of cases, maintenance and repairs on a dam do not require any formal approval, as this type of dam works are exempt under the Water Management (Dam Works Exemption) Order 2005. The following provides some examples of dam works that can be undertaken on an existing dam without a dam works permit.
- Remove vegetation from the spillway, dam wall or within the dam storage area. Note: Before removing stumps, especially on the embankment itself, please seek professional advice;
- To place any protective topsoil, gravel, rock or other natural material to prevent erosion or other damage to –
- a dam embankment; or
- a spillway, as long as the designed flood capacity is not reduced (i.e. the same volume of water can still be passed through the spillway channel);
- Minor repairs to spillway as long as the designed flood capacity is not reduced (i.e. the same volume of water can still be passed through the spillway channel);
For further examples of dam works that can be undertaken on an existing dam without a dam works permit, please read the dam maintenance and repairs factsheet.
Dam maintenance and repairs (306Kb)
Please note that in some cases, the level of repair will not fit with the exemption examples shown above and therefore a new dam works permit is required. This will include cases where a dam has been breached completely or where the previous permitted requirements no longer meet current standards (for example spillway and outlet pipe capacities).
Where repairs are likely to be outside of the exemption, a dam works permit will be required.
Contact your local dam consultant for further advice on how to apply for a dam permit.
More information on the Dam Construction approval and permitting processes, including relevant codes and forms is available on our Dam information page
If you would like advice on maintenance or repair works, please contact NRE Tas at email@example.com or on 1300 368 550.