44.The Flood and Water Management Act 2010 amended the Reservoirs Act 1975, the statutory framework governing the way in which reservoirs are controlled and managed in England and Wales. The measures apply a risk-based regime to assessing above-ground reservoirs’ safety: before the changes took effect, the owner of such a reservoir was bound to comply with the 1975 Act irrespective of whether or not it posed a threat to surrounding land. Under a new section inserted into the Reservoirs Act by Schedule 4 of the 2010 Act, the Environment Agency is now directed to take a more risk-focused approach to reservoir safety. However, Schedule 4 was commenced with a transitional provision so that the measures apply to reservoirs with a capacity of 25,000 cubic metres or more, rather than the lower threshold of 10,000 cubic metres specified in new section. Reservoirs with a capacity of below 25,000 cubic meters therefore remain outside the scope of Reservoirs Act provisions. The Government stated that:
smaller reservoirs generally pose les of a risk than larger reservoirs because they hold less water, although there is evidence that a minority of smaller reservoirs could pose a risk in certain circumstances. The Department has commissioned further research to inform a future decision on whether to regulate smaller reservoirs.59
45.Witnesses were split over whether or not there was a need to apply the measures to the smaller-sized reservoirs. Some were concerned that lowering the threshold would add costs without concomitant risk-reduction benefits. For example, the National Farmers’ Union was concerned a lower threshold could deter farmers from developing water storage on farms, to the detriment of effective water management. It considered that the case had not been made that the change would improve safety but was “certain” that it would lead to extra costs and increase the regulatory burden on the farming community. The costs of engineers’ risk assessments and management as well as the need to undertake flood modelling would be “prohibitively expensive” for small reservoirs.60 Conversely, others, such as Wessex Water, considered that applying the lower threshold would “provide a more comprehensive approach to the management of risk from reservoirs”.61
46.The Government’s Memorandum states that it has paused its intention to reduce the threshold to 10,000 cubic metres since the evidence base “does not currently support such a change”.62 The Government does not make it clear however how the research it has commissioned will be used to ensure decisions on reducing the threshold will balance safety, economic and water management issues.
47.Taking into account the balance of evidence to this inquiry, we support the Government’s current decision to retain the threshold for the application of the Reservoirs Act 1975 to raised reservoirs with a capacity of 25,000 cubic metres or more. However, the Government has said that it is keeping its decision under review and has commissioned further research on regulating smaller reservoirs. The next Government must update our successor Committee on the findings of this research. It is vital that, should the Government propose reducing the threshold to apply provisions to reservoirs with a capacity of 10,000 cubic metres or more, that it sets out a full evidence base to justify how its decision balances safety, economic and water management issues.
25 April 2017