Twitter LinkedIn

Water neutral development - passing fad or here to stay?

Unless we act there simply isn't going to be enough water available for the environment and for growth. One potential solution, discussed recently at the Waterwise 2022 conference, is to try to make new development in water-stressed areas water neutral. Nathan Richardson and Laura White from Waterwise explain.

May 2022

What does it mean to be ‘water neutral’?

Water neutrality is defined as “For every new development, water demand should first be minimised then any remaining water demand offset, so that the total demand on the public water supply in a defined region is the same after development as it was before.”

This means that the additional water demand from a new development is zero. It therefore doesn't add to an existing or future water scarcity challenge.

Why is it important?

Most of England is classified as seriously water stressed. We need to address a potential 4 billion litres a day deficit by 2050 if we want secure water supplies, a healthy environment and to enable future growth.

So, it is important that new development minimises the additional pressure it places on water supplies and the water environment, especially where they are already under stress. To do this, all new development needs to be far more water efficient than current Building Standards require. The cross sector Future Homes Delivery Plan sets out many of the things that are needed together with a recommended timeline. One of the key things that the plan includes is water neutrality for new developments.

Is it possible for new development to be water neutral?

Yes it is….as set out by Waterwise in 2021, to achieve water neutrality water demand is first minimised through efficient fittings, rainwater harvesting and water reuse with any remaining additional demand offset locally through water saving interventions in the local community. Collaboration between relevant stakeholders and useful, timely water consumption data is key, particularly for offsetting. We already take a similar approach with new development and flooding so why not for water demand?

An Innovation Fund project was started in 2021 to dig into how to achieve water neutrality in new developments. Three large new housing developments are being looked at and the project will assess a mix of water saving technology and behavioural nudges to see what works best.

The practicalities of achieving water neutral development are currently very real for developers in parts of Sussex, where new development is on hold unless it can be shown to be water neutral. This requirement stems from concerns highlighted by Natural England that the additional water demand and associated extra abstraction might impact a nearby internationally important wildlife site. Developers in the affected areas have to provide a Water Neutrality Statement setting out how they will achieve water neutrality and their approach must be approved before planning permission can be granted.

Also helping make water neutrality real are Thames Water who recently launched an incentive scheme to encourage developers to go further on water efficiency and ultimately to try to to achieve water neutrality with a three tier financial payment per property. 

How might this play out in the future?

If we are to meet water deficits, so that we facilitate sustainable growth and have a healthy environment, then water neutral development needs to be part of the toolkit. The more water efficient we can make all new development, the less likely it is that realising future growth or a healthy environment will be limited by water availability.

It is heartening to see a mix of research, practical examples and incentives emerging over the last year and to see that many big corporates are also committing to water neutrality - for example, Sainsbury’s has three water neutral stores . Water neutrality will definitely feature in the new UK Water Efficiency Strategy currently being developed by Waterwise.

The current situation in Sussex is a golden opportunity to learn through experience and take these learnings forward to other areas. We really do need water neutrality to be on the table and actively being explored by planning authorities, developers and water companies when any large water hungry development is coming forward, particularly in places we know are seriously water stressed - the red areas on this 2021 Environment Agency map.

To make this happen needs encouragement from policy makers and so we will be pushing for water neutrality to be included in Defra’s proposed roadmap for more water efficient buildings to be published later this year . We also need the planned Defra and DLUHC letter to local planning authorities to send a clear signal to them that they can be more ambitious than just requiring developers to meet current Building Standards water use thresholds (125 or 110 lppd).

In conclusion, we can’t afford for water neutrality to be just a passing fad given the water scarcity challenges we face. It makes sense to minimise the additional water demand footprint of new development in seriously water stressed areas….in much the same way as we already do with flood risk. Waterwise will be pushing for it to be a key part of Defra’s promised 2022 roadmap towards more water efficient new development and retrofit .

Nathan Richardson is Head of Strategy and Policy at Waterwise. Laura White is Projects and Research Ma
nager at Waterwise.

Follow: @Waterwise

The opinions expressed in this blog are the author's and not necessarily those of the wider Link membership.