Commentary “Large raised reservoir”
272.Paragraph 2 amends the definition of “large raised reservoir” for the purposes of the Reservoirs Act 1975. The new definition of large raised reservoir replaces the existing definitions of “reservoir”, “raised reservoir” and “large raised reservoir” in section 1(1) to (3) of the Reservoirs Act 1975.
273.New section A1(1) provides that a large raised reservoir is (a) a large, raised structure designed or used for collecting and storing water; and (b) a large, raised lake or other area capable of storing water which was created or enlarged by artificial means. New section A1(1)(a) includes non-impounding, bunded reservoirs (reservoirs with a continuous embankment around their perimeter which are filled with water from, for example, river or groundwater sources and rain). New section A1(1)(b) includes impounding reservoirs (formed by the construction of an embankment across a watercourse or lake).
274.The terms “raised” and “large” are further defined in subsection (2) and (3) of new section A1. A “raised” structure or area will be “large” if it is capable of holding 10,000 cubic metres of water or more above the natural level of any part of the surrounding land. The volume specified in subsection (3) may be amended by order by the Minister under subsection (7) of new section A1.
275.Subsection (4) of new section A1 allows the Minister to make regulations specifying in more detail how the capacity of a large raised reservoir is to be calculated for the purposes of the Reservoirs Act 1975. This power enables the Minister to provide clarification to engineers and reservoir undertakers on how the volume capacity of a reservoir must be calculated for the purposes of determining whether a structure or area falls within the new definition of large raised reservoir.
276.Subsection (5) of new section A1 enables the Minister to provide in regulations for a structure which is designed or used for collecting and storing water, or a lake or other area capable of storing water which was created or enlarged by artificial means, to be treated as “large” by reason of its proximity to, or actual, or potential communication with another such structure or area. Where two or more reservoirs lie on the same watercourse, the uncontrolled release of water from an upstream reservoir may cause a reservoir downstream to also fail. The power will enable the Minister to extend the definition of large raised reservoir to include, for example an area or structure which is not capable of holding 10,000 cubic metres of water, but which, if it failed, could cause a connected reservoir which is also not capable of holding 10,000 cubic metres of water to release 10,000 cubic metres of water or more downstream.
277.Subsection (6) of new section A1 requires the Minister to aim to ensure, when making these regulations, that such a structure or area is treated as “large” only if 10,000 cubic metres of water or more might be released as a result of this proximity or communication.
278.Subsection (8) allows the Minister to make regulations providing for specified things not to be treated as large raised reservoirs for the purposes of the Reservoirs Act 1975.
279.Subsection (9) of new section A1 defines a large raised reservoir further to include anything used or designed to contain the water or its flow.
280.Orders made under subsection (7) and regulations made under subsection (8) of new section A1 are subject to the affirmative resolution procedure. Regulations made under subsections (4) and (5) are subject to the negative resolution procedure. See further paragraph 38 of Schedule 4.
281.Paragraph 3 makes consequential amendments to the Reservoirs Act 1975.