# Reservoirs Act 1975, Section 6: Construction or enlargement of reservoirs.

Extent: E+W+S

(1) No large raised reservoir shall be constructed (whether as a new reservoir or by the alteration of an existing structure or area that is not a large raised reservoir) or shall be altered so as to increase or decrease its capacity, unless a qualified civil engineer (“the construction engineer”) is employed to design and supervise the construction or alteration; and where the use of a reservoir as a reservoir has been abandoned, and the reservoir is to be brought back into use after being altered so as to increase or decrease its capacity, that shall be treated for purposes of this Act as the construction of a new reservoir.
(2) Where a large raised reservoir is constructed as a new reservoir, it shall not be used for the storage of water, or be filled wholly or partially with water, otherwise than in accordance with the certificate of the construction engineer responsible for its construction (or, in the event of any alteration to it, in accordance with subsection (4) below).
(3) Where a large raised reservoir is constructed by the alteration of an existing structure or area that is not a large raised reservoir, the ... reservoir shall not be used for the storage of water, or be filled wholly or partially with water, otherwise than in accordance with the certificate of the construction engineer responsible for the construction of the reservoir (or, in the event of any alteration to it, in accordance with subsection (4) below).
(4) Where a large raised reservoir is altered so as to increase or decrease its capacity, then from the time when the construction engineer responsible for the alteration gives any certificate for the reservoir, the reservoir shall not be used for the storage of water, or be filled wholly or partially with water, otherwise than in accordance with the certificate of that construction engineer (or, in the event of any further alteration to it, in accordance with this subsection as it applies on that alteration).
(5) Where the construction or alteration of a reservoir is by this section required to be supervised by a construction engineer, the reservoir shall be under the supervision of the construction engineer until he gives his final certificate for the reservoir.
(6) ...
(6A) This section and sections 7 and 8 do not apply in relation to alterations, or proposed alterations, to decrease the capacity of a large raised reservoir so that it is incapable of holding 10,000 cubic metres of water above the natural level of any part of the surrounding land (in which case section 13 applies instead).
(6B) The Minister may by order substitute a different volume of water for the volume specified in subsection (6A).

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Source: https://www.legislation.gov.uk/ukpga/1975/23/section/6 (the official version)
Page: https://openlegislation.uk/reservoirs-act-1975/section-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.