2012 – Decommissioning of Water Supply Dams – Worldwide State of Knowledge

Stephen Newman

In recent years the option to decommission water supply dams has had renewed focus due to a number of drivers. These include the increased costs of upgrading aging infrastructure against their provided value, climate change reducing the effectiveness of some dams as a reliable water source, greater value placed on environmental outcomes and changing demands for the water including power in case of Hydropower dams. In addition the recent construction of large coastal desalination plants as an alternate water source for large urban areas, particularly in Australia, has reduced the need for some dam assets.

In response to this changing dynamic in the Industry, ICOLD formed a technical committee in 2007 to prepare a bulletin on dam decommissioning for use by those considering the option of decommissioning a dam. The purpose of the bulletin or guideline was not as a design manual but to provide industry with information and guidance to better understand the key drivers of decommissioning and the issues around decommissioning. It is probably a fair summation of the practice to date, that issues associated with decommissioning of major dams have not always been well understood prior to this option being selected. This has on occasion resulted in dramatic increases in the cost of decommissioning, extended timelines and not least, strong community and other stakeholder resistance. Hence the ICOLD decision to prepare a bulletin. The Author of this paper was a part of this committee and has also been involved with a number of dam decommissionings and assisting regulators in developing their own guidelines.

In this paper the key findings from development of the ICOLD bulletin will be presented including illustration of various key issues via case studies from this region and internationally. In particular, the true cost of decommissioning. The final draft of bulletin is currently under review.
Keywords: Decommissioning, ICOLD, community, stakeholder, water supply, hydropower, cost.