Protecting our Dams and Communities

Sydney Water manages 16 declared dams within our area of operations, whilst many of these are called reservoirs, they are still classified as dams.

We work in partnership with Water NSW, which supplies much of the untreated raw water from rivers and dams. Water NSW manages 11 major dams and reservoirs that provide raw water to Sydney Water to enable us to treat and supply drinking water to Greater Sydney, the Blue Mountains and the Illawarra.

Part of managing our water, is managing our dams. Dams Safety NSW declares dams that can potentially endanger life downstream, cause major damage or loss to infrastructure or the environment, or have major health and social impacts. Each declared dam has a consequence category that reflects its potential. Any risks concerning our dams must follow safety requirements from the Dams Safety Act 2015 and the Dams Safety Regulation 2019. These provide the framework and activities that ensure dams don't put the safety of persons, property or the environment at risk.

In accordance with the Dam Safety Act 2015, and associated regulations and guidelines, we will be doing dam maintenance work at some of our dams. This work will include the removal of vegetation, predominantly trees and shrubs from dam embankments and where required from within five metres of the embankment base. This will allow Sydney Water to effectively assess ground, below ground and the structural condition of our dam and minimise safety and operational risk.

Why this work is essential:

Regular maintenance of dam embankments is required to ensure slope stability and to permit observation of any cracking, sliding or seepage, for example:

• The roots can dislodge joint fillings and penetrate cracks in concrete walls or foundation rock possibly leading to crack widening and concrete or rock deterioration resulting in increased leakage.
• Vegetation roots can disguise, absorb and transpire substantial amounts of water and, therefore, could prevent early detection of water leaking through cracks and joints in the wall or foundation.
• Toppling of trees during windstorms can cause damage to the embankment, wall or foundation if substantial material is dislodged with the root system.
• Trees and large shrubs limit access and visibility and prevent effective inspection for early identification of structural issues.
• Vegetation can also provide habitat and cover for ground burrowing or digging animals (eg. foxes, rabbits) that may also impact and threaten the safety of the embankment

For details on the work at a specific site please scroll below.