Works to the existing reservoir including the following: 1. Raising of the existing dam. 2. Construction of an auxiliary spillway 3. Construction of a new outlet chamber with low-level side weirs and low-level penstock 4. Extension of the existing discharge point to move further downstream away from the toe of the embankment and the construction of a new headwall. 5. Removal of high-level overflow pipe. 6. Minor improvements to the existing spillway entrance to realign the inlet wingwall. 7. Lowering of the intermediate weir on the main spillway.

Variation of conditions 9 (off-site highway improvement works to junction 39 of the M1 motorway) and 10 (off site improvement works design trigger point) of permission 13/01161/RPP (Renewal of outline planning permission previously approved under application 05/99/56189/AU on the 4 November 2005 (for the variation of conditions 1,3,4,20 to 24 & 32 of permission 04/99/56189/AK dated 27.10.04 to extend time limit for reserved matters & permit phased discharge of conditions) and originally approved under application 98/99/56189/E on the 24 May 2000 for a High Technology/Business Park (B1) & associated open space & leisure facilities) dated 19th August 2013 to exclude a number of ancillary uses within Calder Park before an improvement scheme is required to be delivered.