In this blog, we will be looking at water neutrality statements and why they are necessary for residential developments in the Arun Valley.
What is a water neutrality statement and why might I need one?
A water neutrality statement is a statement which provides evidence that a residential development will achieve water neutrality so that the total water use in the region after the development is equal to or less than the total water use before the development.
Due to concerns that public water supply abstraction in the Sussex North Water Supply Zone ('SNWSZ') may be impacting on wildlife within protected sites in the Arun Valley, and following Natural England's Position Statement in respect of water neutrality from September 2021 ('NE's Position Statement') any proposed residential developments within the SNWSZ have been put on hold until they are able to demonstrate water neutrality, by way of a water neutrality statement.
HOW CAN WATER NEUTRALITY BE ACHIEVED?
There are two methods by which water neutrality can be achieved:
- Reduction of water usage
Although NE's Position Statement suggests that all new builds should demonstrate water consumption of 85L/pp/d (litres, per person, per day), the Sussex North Water Neutrality Study: Part C – Mitigation Strategy from December 2022 suggests that they will not insist on 85L/pp/d given the limitations and potential costs of such an approach, and will instead impose a limit of no more than 110L/pp/d in accordance with the Building Regulations Optional Standard.
However, it does make it clear that 'water demand should first be reduced as low as practicable, before the remaining demand is offset in the wider area in this case the water resource zone'. As such, this should be looked at before off-setting (see below) is considered.
Reduction of water usage can be achieved by, for example:
- Installing efficient fixtures and fittings (bath/shower, toilets, washing machine etc) with maximum capacity/flow rates;
- Grey-water harvesting; or
- Rainwater harvesting (see 'off-setting' below for further details on rainwater harvesting).
An Arun Valley Water Neutrality Development FAQ from March 2022 has also suggested that if the land where the residential development is being built has or had an existing water use, and water bills for that existing use are available, then it may be possible to subtract the existing water use from the new development's water use. However, this is yet to be tested and does not feature in the Sussex North Water Neutrality Study: Part C – Mitigation Strategy. In these circumstances, the developer should liaise with the relevant authority to determine if this is possible.
- Off-setting
Off-setting involves reducing the amount of water used/consumed from the main water supply on a different area within the North Sussex Water Area. Types of development that could be used for this include:
- Offsetting on private occupied property with Southern Water supply within the SNWSZ;
- Offsetting on Council owned property with Southern Water supply within the SNWSZ;
- Offsetting on Registered Provider property with Southern Water supply within the SNWSZ;
- Offsetting on commercial property with Southern Water supply within the SNWSZ;
- Offsetting on farms with Southern Water Supply within the SNWSZ (See the 'Dedisham Farm Example' below).
Off-setting is usually achieved by way of rainwater harvesting which involves the capture of water falling on buildings, roads, or pathways that would normally be drained via a surface sewer, infiltrate into the ground, or evaporate for domestic or commercial use (excluding as drinking water), such as for toilet flushing and washing machines, or used as a substitute for water presently drawn from the mains as part of dairy operations on a farm or other water-intensive operations. This could include, for example:
- Attaching water butts to a drainpipe on a house;
- An underground storage system with pumps to supply water;
- The harvesting of rainwater from large roofs etc.
The Arun Valley Water Neutrality Development FAQ from March 2022 stated that 'once the water neutrality strategy has been agreed it is hoped that [paying an off-setting charge] will be available'. However, this does not appear to have been incorporated into the SNWSZ's strategy and so, while this option could be discussed with the relevant authority, it appears unlikely that this will be an option.
The Dedisham Farm Example
The Dedisham Farm example involves a proposed development of 83 dwellings in Billingshurst, for which planning application was rejected for a number of reasons prior to Natural England's position statement. An appeal was lodged in September 2021, the same month that NE's Position Statement was released, and the developer was required to find a way of making the development water neutral.
In a water neutrality statement prepared by Motion, the developer was able to achieve water neutrality through a combination of water reduction measures (installing rainwater harvesting systems to provide 35L/pp/d of water) and off-setting. The off-setting in this case involved creating a rainwater harvesting system at Dedisham Farm, a dairy farm within the SNWSZ, the water from which was used to supply drinking water for the cows.
This combination was found to be sufficient to make the development water neutral and planning permission was granted in January 2023, with a condition that planning permission is first obtained for the off-setting works at Dedisham Farm.
WATER NEUTRALITY MATTERS FOR RESIDENTIAL DEVELOPERS TO CONSIDER
Obtaining planning permission can already be a lengthy process, but residential developers who submit applications within the SNWSZ without first considering how they are going to achieve water neutrality risk further delays as they negotiate with land owners and the relevant authority. They also risk having to wait for planning permission on the off-setting site to be granted before being able to implement water off-setting measures, as in the Dedisham Farm example above.
Therefore, residential developers should consider such matters and communicate with landowners, whose land has the potential for water off-setting, at an early stage so that any planning application can be made to the relevant authority with the relevant plans for achieving water neutrality. It may be that developers will be able to reach contractual agreements with landowners, prior to making a planning application:
- Enabling the developer subsequently to enter the land and implement water off-setting measures;
- Obliging the landowner to co-operate in any planning application necessary for the water off-setting measures;
- Obliging the landowner to join a future section 106 agreement in connection with the proposed residential development.
How we can help
If you are a residential developer making, or intending to make, an application to build residential homes within the SNWSZ area and need assisting with:
- understanding water neutrality;
- negotiating with landowners the terms on which the off-setting measures are to be agreed; or
- drafting or negotiating an agreement, including a Section 106 agreement.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.