Policy CC/WE: Water efficiency in new developments

DRAFT version for various committee meetings.

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What will this policy do?

This policy will set the standards of water efficiency that new developments must comply with.

Proposed policy direction

Developments will be required to meet high standards of high water efficiency: 

  • Residential developments should be designed to achieve a standard of 80 litres/person/day unless demonstrated impracticable. 

  • Non-residential development will be required to achieve full credits for category Wat 01 of BREEAM unless demonstrated impracticable.  

Why is this policy needed?

The Greater Cambridge Integrated Water Management Study (2021) has shown that the current level of water abstraction from the chalk aquifer is widely believed to be unsustainable, with potential to cause environmental damage, unless abstraction rates are reduced significantly to safeguard natural river flow.  Whilst water company plans have taken account of planned growth in the existing local plans, there is no environmental capacity for additional development in the new Local Plan to be supplied by water by increased abstraction from the chalk aquifer.  Future water demand and supply will need to be balanced in other ways, such as through reduced usage, reduced leakage, import of water /licence trading between water companies and the development of new reservoirs at the regional scale. Water Resources East is coordinating these regional efforts and producing a regional plan for water. 

Many of these solutions are outside the control of the Local Plan, but one way in which the Local Plan can reduce the demand for water is by requiring high levels of water efficiency in all new developments.  The current Local Plan policies require 110 litres/person/day, which is the lower optional requirement allowed by Building Regulations.  It is proposed to go further than that and include a policy requiring 80 litres/person/day in all new housing development. This is the equivalent of the Code for Sustainable Homes Level 5/6 (now withdrawn) and which was the design standard for the University’s development at Eddington in North West Cambridge.  An equally water efficient level is proposed for non-residential developments of full credits for category Wat 01 of BREEAM (the current level in Cambridge Local Plan policy). 

The Integrated Water Management Study (IWMS) has shown that 80 litres/person/day is achievable by making full use of water efficient fixtures and fittings, and also water re-use measures on site including surface water and rainwater harvesting, and grey water recycling.  It also shows that the cost effectiveness improves with the scale of the project, and that a site-wide system is preferable to smaller installations. 

A standard of 80 l/p/d goes beyond what Local Authorities are currently able to require (as set out in the Deregulation Act 2015), but the Councils consider that there is a strong case for greater water efficiency in Greater Cambridge based on the strong evidence provided by the Integrated Water Management Study.  Increased standards of water efficiency for Greater Cambridge are also supported in principle by Cambridge Water, Water Resources East, and the Environment Agency.   

The Shared regional principles for protecting, restoring and enhancing the environment in the Oxford-Cambridge Arc are clear that they will encourage local partners to exceed minimum standards required by building regulations on issues such as water consumption, and that they will be working with Government on this issue. 

What consultation have we done on this issue?

Feedback received during the First Conversation consultation expressed concern about the level for water abstraction from the chalk aquifer south of Cambridge, and that water should be sourced more sustainably. We should use water resources efficiently and include more ambitious water consumption targets.  There were suggestions of 75 and 80 litres per person per day. There was support for rainwater harvesting and grey water use in new development, and some suggestions that this should be mandatory.

What alternatives did we consider?

For residential: 

  • No policy – rely on standard Building Regulations (125 litres per person per day) - Not considered a reasonable alternative as it would not respond to the level of water stress in the area. 

  • Implement the Building Regulations alternative standard (the current policy of 110 litres/person/day) - This is not the preferred approach as whilst this does seek to reduce water use, the level of reduction is not sufficient to respond to the pressure on water resources in the area. 

For non-residential: 

  • No policy – there is currently no standard in Building Regulations for water efficiency in non-residential developments - Not considered a reasonable alternative as it would not respond to the level of water stress in the area. 

  • Require a minimum water efficiency standard of 2 credits for category Wat 01 of BREEAM unless demonstrated not practicable (current policy in the adopted South Cambridgeshire Local Plan, 2018) -  This is not the preferred approach as whilst this does seek to reduce water use, the level of reduction is not sufficient to respond to the pressure on water resources in the area. 

Supporting evidence studies and topic papers

  • Greater Cambridge Local Plan: Topic paper 2: Climate Change 

  • Greater Cambridge Integrated Water Management Study (2021) 

Existing policies in adopted 2018 Local Plans

South Cambridgeshire Local Plan 2018 

  • Policy CC/4: Water Efficiency 

Cambridge Local Plan 2018 

  • Policy 28: Carbon reduction, community energy networks, sustainable design and construction, and water use 

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