Swansea Dam

TasWater is aiming to have the Swansea Dam fully repaired by Spring 2018, but the timeline depends on many things, including having normal rainfall patterns on the east coast over the next two years.

History

The Swansea Dam was designed as a back-up water supply that would be the envy of many towns throughout Tasmania and Australia, and when it's fixed it will be.

The dam and water treatment plant were built in 2009 by Southern Water to improve water quality and secure Swansea's supply. In 2010, shortly after dam filling commenced, seepage was noted downstream of the dam wall. Since TasWater was formed in 2013, our focus has been on ensuring the safety of the dam by reducing the operating level to lower the pressure on the surrounding structure and continuously monitoring the site.

Swansea continues to be supplied with drinking water from the Swan River, but without the back up of the Swansea Dam. In January 2016, water restrictions were imposed due to drought.

The plan

Fixing a dam is a complicated process and there are no quick solutions. This project is made up of many smaller steps with multiple agencies, contractors for design and construction, and we expect some of these steps may even create further delays. Our plan accounts for this by taking a flexible approach where different solutions may be needed.

Ultimately, TasWater must empty the Swansea Dam for repairs, which we are aiming to do in late 2017-early 2018, which means we need to find a temporary alternative water supply for Swansea.

TasWater has an agreement with Tasmanian Irrigation to connect to the Melrose Dam, part of the Swan Valley Irrigation Scheme, currently under construction. When required, local irrigators will allow TasWater to temporarily purchase water for our water treatment plant to supply Swansea during the dam repairs.

In early 2017, TasWater will work with Tasmanian Irrigation to assess their progress on the construction of the Melrose Dam. If the Melrose Dam will not be ready in time, then TasWater will instead build its own temporary storage.

Either way, it is TasWater's goal to have an alternative water supply for Swansea available by late 2017, to empty the dam in early 2018 and to then have the Swansea Dam fixed by Spring 2018, at the earliest.

Why has TasWater chosen this process?

Though this approach does involve a delay and is dependent on weather, it is the most sensible approach to take for the following reasons:

  1. A permanent connection to the Swan Valley Irrigation Scheme provides an emergency back-up for Swansea if it is ever needed in future.
  2. Building temporary storage presents its own risk of delays, as with any construction project
  3. Once the Swansea Dam is drained, the dam then has to dry out before we can work on it and it is not clear how long that will take
  4. The repairs to the Swansea Dam itself are also weather dependent, hence could take longer than anticipated
  5. Finally, building temporary storage is very expensive and working with Tasmanian Irrigation instead will provide a significant saving.
TasWater has carefully analysed Swansea's requirements, the annual rainfall data and the amount of water already allocated for irrigation. We are confident that if the Melrose Dam goes according to plan and the east coast receives the normal amount of rainfall, there will be enough water for Swansea during repairs.

TasWater is aiming to have the Swansea Dam fully repaired by Spring 2018, but the timeline depends on many things, including having normal rainfall patterns on the east coast over the next two years.

History

The Swansea Dam was designed as a back-up water supply that would be the envy of many towns throughout Tasmania and Australia, and when it's fixed it will be.

The dam and water treatment plant were built in 2009 by Southern Water to improve water quality and secure Swansea's supply. In 2010, shortly after dam filling commenced, seepage was noted downstream of the dam wall. Since TasWater was formed in 2013, our focus has been on ensuring the safety of the dam by reducing the operating level to lower the pressure on the surrounding structure and continuously monitoring the site.

Swansea continues to be supplied with drinking water from the Swan River, but without the back up of the Swansea Dam. In January 2016, water restrictions were imposed due to drought.

The plan

Fixing a dam is a complicated process and there are no quick solutions. This project is made up of many smaller steps with multiple agencies, contractors for design and construction, and we expect some of these steps may even create further delays. Our plan accounts for this by taking a flexible approach where different solutions may be needed.

Ultimately, TasWater must empty the Swansea Dam for repairs, which we are aiming to do in late 2017-early 2018, which means we need to find a temporary alternative water supply for Swansea.

TasWater has an agreement with Tasmanian Irrigation to connect to the Melrose Dam, part of the Swan Valley Irrigation Scheme, currently under construction. When required, local irrigators will allow TasWater to temporarily purchase water for our water treatment plant to supply Swansea during the dam repairs.

In early 2017, TasWater will work with Tasmanian Irrigation to assess their progress on the construction of the Melrose Dam. If the Melrose Dam will not be ready in time, then TasWater will instead build its own temporary storage.

Either way, it is TasWater's goal to have an alternative water supply for Swansea available by late 2017, to empty the dam in early 2018 and to then have the Swansea Dam fixed by Spring 2018, at the earliest.

Why has TasWater chosen this process?

Though this approach does involve a delay and is dependent on weather, it is the most sensible approach to take for the following reasons:

  1. A permanent connection to the Swan Valley Irrigation Scheme provides an emergency back-up for Swansea if it is ever needed in future.
  2. Building temporary storage presents its own risk of delays, as with any construction project
  3. Once the Swansea Dam is drained, the dam then has to dry out before we can work on it and it is not clear how long that will take
  4. The repairs to the Swansea Dam itself are also weather dependent, hence could take longer than anticipated
  5. Finally, building temporary storage is very expensive and working with Tasmanian Irrigation instead will provide a significant saving.
TasWater has carefully analysed Swansea's requirements, the annual rainfall data and the amount of water already allocated for irrigation. We are confident that if the Melrose Dam goes according to plan and the east coast receives the normal amount of rainfall, there will be enough water for Swansea during repairs.