The optional water efficiency standard of 110 units is strongly supported given that
Rother is identified as an area of 'serious water stress'. However, it could go further by incorporating grey water and / or rainwater harvesting, including appropriate placement of downpipes to facilitate rainwater harvesting where practical, within all new buildings (including commercial and industrial buildings) to further reduce demand from the mains and help to manage flows to surface water and sewerage systems. This would tie in with the policy DEN5 on SUDs.

Additionally paragraph 6.10 & the proposed implementation, as described in the
Suggested Notes on page 14 of the Water Efficiency background paper, is too weak. The Validation checklist should include for a mandatory requirement to include the proposed 'letter of intent', rather than a mere 'expectation', otherwise it is too easy for the applicant to either ignore or even be unaware of the requirement. As it is applicant's responsibility to inform the BCB (Building Control Body) about the reduced standard, and there is no process for the BCB to check back with the planning authority, the requirement is difficult to enforce as it relies on the goodwill of the applicant to inform the BCB.
Reference: Water Efficiency Background Paper RDC June 2016

The policy should be expanded to include a standard for commercial and industrial
buildings. The BREEAM standard linked to the efficient use of water is appropriate.
We would refer you to the following that provide more guidance on this subject:
https://www.selfbuild-central.co.uk/green-design-overview/water-conservation
plus paper published by the Environmental Agency

'Evidence Energy and carbon implications of rainwater harvesting and greywater
recycling Report SC090018 August 2010