Water Neutrality

The problem

We are living in the most over-stressed water supply zone in the country It’s called the Sussex North Water Resource Zone (SNWRZ) and is served by Southern Water (SW). Click here to see the Sussex North Water Resource Zone map, image also to the right.

 

The area extends from Crawley through Horsham, Pulborough, Arundel to Chichester. This serious problem is largely due to mass housebuilding across our region over recent decades, which massively increased demand on the finite water supply available to be drawn at Hardham, near Pulborough.

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The solution

The lack of water supply was recognised by the Government’s Environment Agency (EA) and Natural England (NE) and other stakeholders, including Southern Water and the affected District Councils. So, Natural England developed the policy of “water neutrality” and robustly and unambiguously defined what this means;

 

“The definition of water neutrality is the use of water in the supply area before the development is the same or lower after the development is in place”

 

To meet the water neutrality test any development on rural land, which will inevitably introduce very significant new water demand ,will need to show that it can match (or better) this new demand through offset savings on existing buildings.

 

In September 2021, NE published guidance on how this unique policy should be implemented within SNWRZ.

 

The guidance

Their guidance advises on how new building developments can demonstrate compliance with the water neutrality requirement. Developers have to show both significant water efficiency in new-build properties through a combination of water flow restriction, use of grey water and/or rainwater harvesting, and offsetting by reducing water use in already built properties through retro-fitting of water flow restriction devices.

 

The fiction

The Natural England guidance sets a target for water use ‘per person per day’ (pppd) of 85 litres for new builds. This target figure is not based on any actual use data from properties fitted with flow restriction devices, but rather on aspirational and theoretical calculations prepared mainly by water consultants and suppliers in the water industry who have financial motivations in promoting their goods and services.

 

The reality

A target consumption of 85 litres pppd is:

1. far below Southern Water’s actual average daily water consumption of 136 pppd, based on their customers’ metered usage;

2. far below national average use data from the water industry of 146 litres pppd;

3. far below the Building Regulations Part C target consumption figures for new builds of 110 litres pppd;

4. far below the actual data of 166 Iitres pppd collected in a pilot scheme conducted in Crawley on behalf of Crawley, Horsham and Chichester District councils (within the SNWRZ area), where 100 Council properties were retrofitted with flow restriction devices.

 

The manipulation

What is now happening, of course, is that developers are submitting applications based on  the Natural England target of 85 litres pppd but are not being required to prove that this vastly lower consumption will ever be achieved. They merely have to show that, in theory, it could be. Recently submitted development applications reveal that, to meet the theoretical 85 litres target, the developer’s calculations simply reduce the number of baths to be taken, showers taken and shower duration, and WC flushes to well below the actual average use data. The lower the theoretical water use target, the easier it is for the developer to “demonstrate” water neutrality, so this unrealistically low NE target is a gift for developers. The developer’s theoretical calculations are not tested, unless there is an obvious mathematical error.

 

To illustrate this fictitious and fundamentally flawed approach, a newbuild development application based on the Natural England 85 litres target, which was recently approved by Natural England and Horsham District Council, included the following water use calculations (all pppd);

 

Baths – 14 litres. This would mean roughly 2 ½ inches of water in a standard sized bath. A normal bath, half-filled, will use 80-100 litres so this daily allowance would permit one decent bath every 6/7 days. Survey data collected by the Energy Saving Trust (EST) on actual bath use showed that consumers in the Thames water region took a bath 4/5 times a week.

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Showers – the developer limited shower use time to 4.37 minutes per day. The Energy Saving Trust actual use survey revealed an average duration of around 7 ½ minutes per shower.

 

WC flushing – the developer limited WC flushing to 4 ½ times per day - around half the national average.

 

External water use (e.g. Garden/Car washing/Pressure washing) - the developer allowed 5 litres pppd. A car wash using a hose will use around 250 litres and very recent research from SW shows that a hose used for watering/garden sprinkler can use up to 1000 litres per hour.

 

Another application recently approved by Horsham District Council provides an even starker example of this absurd manipulation. The application was for permission for the erection of 6 3-bed dwellings in Rusper. To satisfy water neutrality requirements, the applicant proposed to offset against the additional water demand from the new properties by retrofitting  8 basin taps in the washrooms of a commercial office building in Horsham with low-flow taps.

 

The application claimed, and Horsham District Council Planning appears to have accepted without question, that this would reduce total water consumption per person per day to 4.97 litres. This consumption approximates to 1 wc flush without any tap use per person per day.

 

Actual water use data obtained for the building based on metred billing over a 3 year period revealed an average total daily water use of around 1900 litres or 31.66 litres per person per day based on the occupancy figure accepted and used by the Horsham Planning department. So the application was accepted and approved on the basis that for the very modest cost of fitting 8 new sink taps,water consumption pppd would reduce from 31.66 litres pppd to 4.97 litres pppd. Simply incredible!

 

Turning a blind eye

Natural England has abdicated all responsibility for monitoring actual water usage in new builds for comparison with its totally hypothetical target figure. It has stated that enforcement is the remit of local planning authorities. But the idea of enforcement is meaningless since people are entitled to use, and will use, as much water as they want and cannot be, and nor should they be, “penalised” for consuming above the unrealistic 85 litres target.

 

Horsham District Council made it clear, in agreeing the first development application mentioned above, that it will not monitor actual water usage, either. This is hardly surprising, given that actual use data would clearly explode the myth of achieving 85 litres pppd (based on the previous studies of actual water use) and of the water neutrality of the application approved by the Council.. This would be a very inconvenient truth for Natural England and Local Planning Authorities. This “blind eye” approach, and the lack of any actual use monitoring, will inevitably encourage and result in the removal of water flow restriction devices by home owner/occupiers further exacerbating the problem. This is already happening in many new build developments where devices have been fitted.

 

So where does that leave us - the residents, present and future, of the SNWRZ?

Natural England’s target of 85 litres pppd completely flies in the face of easily available actual daily pppd data. Although the Local Planning Authority is the decision maker on any particular development application, NE is positively promoting, and endorsing applications based on this figure, so it is unsurprising that Local Planning Authorities will support this approach, as Horsham District Council is doing.  Save Rural Southwater has contacted both NE and HDC seeking clarification of the evidence relied upon in setting the NE 85 litres target and the only actual use data we have been referred to is the Energy Saving Trust technical study and the Crawley Pilot scheme, neither of which get anywhere close to supporting the NE target and in fact clearly contradict it.

 

If, as the available actual use data indicates, the 85 litres pppd target is unachievable in practice, then the outcome for our area, the SNWRZ, is that many development applications will be approved which are not, and have no chance of being, water neutral. This will mean even more pressure on the already hugely overstressed water supply in the SNWRZ.

 

Remember what happened in May 2023? Over 20,000 homes were without water for a number of days - a stark reminder of how vulnerable our water supply is already, even without further large-scale development.

 

We shouldn’t forget that the above points apply equally to offsetting by retrofit, which will exacerbate the problem in many developments where retrofitting is relied on by the developer, such as those mentioned above recently approved by Horsham District Council.

 

Water neutrality is a sensible and necessary concept, and is robustly defined by NE in their guidance. If applied in practice, it would greatly help address the SNWRZ water supply problem. The stark reality, however, is that the concept is fundamentally flawed in its design and implementation - through sole reliance on aspirational and theoretical assumptions which ignore the available evidence of actual water use and water use behaviour.

 

The lifeboat of water neutrality, which could have played such an important role in protecting our finite water resources, until long term and sustainable water supply arrangements have been put in place and proved, is well and truly holed below the waterline.