Background and Policy Objectives
3.Reservoirs are structures and areas that have been artificially created to hold and store water above the natural level of the surrounding land. They have been created for a variety of purposes including public water supply, transportation, energy production, flood risk management and recreation. The majority of impounding structures are considered to be in excess of 100 years old.
4.The safety of reservoirs in Great Britain (GB) has been regulated since 1930. In the South of Ireland there is no legislative provision for reservoir safety and, as in Northern Ireland currently, common law applies. Under common law the owner or the reservoir manager is responsible for reservoir safety.
5.No fatalities have been reported due to dam failure in Northern Ireland unlike in England, Scotland and Wales. The Department is aware of the following flooding incidents due to dam failure. In December 1876 a newspaper reported that Wilson’s Dam in Carrickfergus “as usual after heavy rain overflowed its banks” flooding many houses and injuring property. In 1902 it was reported that a dam burst on the Springfield Road, Belfast and discharged into the Blackstaff River causing the river to burst its banks. In the 1980s Church Dam in Hillsborough failed and it was reported that the flood water caused erosion. A breach in the bank of Wolfhill Millrace, North Belfast in 1995 resulted in a number of dwellings being flooded. Flooding in the Doagh area in 1998 was attributed to the collapse of a spill weir at Tildarg Dam and a number of houses were flooded.
6.The European Community Floods Directive(1) requires member states to identify, assess, and manage potential significant flood risks. The preliminary flood risk assessment(2) to comply with the Floods Directive identified a potential risk from total dam failure of 156 impounding reservoirs having a capacity of greater than 10,000 cubic metres of water above the natural level of any part of the surrounding land to 66,000 people. The 10,000 cubic metre capacity threshold was used in the preliminary flood risk assessment as it is generally agreed by reservoir engineers that an uncontrolled release of that amount or more of water due to dam failure has the potential to result in loss of life and significant damage to property.
7.The Floods and Water Management Act 2010 which applies to England and Wales and the Reservoirs (Scotland) Act 2011 have made provision for the threshold at which reservoirs are regulated to be reduced from 25,000 cubic metres to 10,000 cubic metres.
8.The findings from the preliminary flood risk assessment were presented to the Executive which at its meeting on the 11 December 2011 agreed that the Minister for Agriculture and Rural Development should bring forward primary legislation to regulate reservoirs in Northern Ireland.
9.The policy objective of the Act is to introduce a regime for the management and regulation of reservoirs to protect the public from the risk of flooding. It is proposed that reservoirs should be managed and operated to minimise the risk of flooding due to an uncontrolled release of water resulting from dam failure thereby protecting people, the environment, cultural heritage and economic activity. The Department would be responsible for administrating and enforcing the legislation.
10.The policy has been developed to comply with industry best practice for the management of reservoirs.
11.Key stakeholders, including known reservoir owners, were contacted directly by the Department and invited to stakeholder events(3) during the policy development process.