Incentives & Planning Applications
The installation of a RWH system does not in principle need planning permission. In fact, in gaining planning permission for a new-build or major renovation project, the inclusion of rainwater harvesting in the project can help towards approval. Rainwater harvesting ticks two boxes for planners. Not only is rainwater harvesting seen as a means to save on mains water consumption, but also, and often nowadays, of more importance to planners, as a way of alleviating flood threats.
Planners favour Rainwater Harvesting
As of December 2007 councils are directed to give expeditious and sympathetic handling of planning permission to applications which include rainwater harvesting, as follows:
“40. An applicant for planning permission to develop a proposal that will contribute to the delivery of the key Planning Objectives set out in this PPS should expect expeditious and sympathetic handling of the planning application”.
“42. In their (i.e. planners) consideration of the environmental performance of the proposed development …..give priority to sustainable
drainage systems, paying attention to the potential contribution to be gained from water harvesting from impermeable surfaces and encourage
layouts to accommodate grey water recycling”.
(Planning Policy Statement: Planning and Climate Change 17/12/2007)
The Code for Sustainable Homes
The Code for Sustainable Homes (introduced in April 2007) sets a target of reducing drinking water consumption per person per day from the current average of 150 litres to an optimum 80 litres. In the public sector, Code Level 3 (maximum consumption of 103 litres a day) has been adopted as the current “Best Practice” standard and since May 2008, all social housing is required to meet level 3 as a minimum.
As of 1 May 2008, this Code is mandatory:
“A rating against the Code for Sustainable Homes, which measures nine categories of sustainable design including energy, water and waste, will be required for all new homes. Homes which exceed the sustainable standards in existing Building Regulations will be awarded up to six stars. Those homes that have not been assessed against the Code will score a nil-rating”
The Code for Sustainable Homes applies to new homes only and it is not obligatory for the private sector to follow the code. However all buyers must now be given info on the sustainability of the home and planners will certainly favour a home with a good Code rating.
New Building Reg regulates water use
In 2010, a change in the Building Regs has reinforced official support for rainwater harvesting. Building Regulations Part G (April 2010) makes 125 litres per person per day of mains water consumption the maximum. This is not too demanding in comparison to the Code for Sustainable Homes targets (eg 103 litres for level 3). But, nonetheless, for the first time in new construction, water consumption becomes a legal obligation, and rainwater harvesting helps achieve this target.
The Flood and Water Management bill (April 2010) aims to encourage the uptake of sustainable drainage systems by removing the automatic right to connect to sewers. Council approval must be given before a developer can commence construction. Rainwater harvesting is seen as one method of absorbing excess rainwater, and, therefore, as a plus if in the planning application.
In 2008, the permitted development rights that allowed householders to pave their front garden for hardstanding without planning permission were changed. Planning permission is now required to lay traditional impermeable driveways that allow uncontrolled runoff of rainwater from front gardens onto roads, because this can contribute to flooding and pollution of watercourses.
If a new driveway or parking area is constructed using permeable surfaces such as permeable concrete block paving, porous asphalt or gravel, or if the water is otherwise able to soak into the ground, planning permission is not required. Again rainwater harvesting is seen as a way of dealing with surface water from paved surfaces, another route to pleasing the planners. (From "Guidance on the permeable surfacing of front gardens" Communities and Local Government publication).
British Standard 8515
This was introduced in February 2009, the first of several proposed standards on water recycling, including greywater. It gives guidance on the design, installation, testing and maintenance of rainwater systems supplying non-potable water in the UK. It is a Code of Practice and not mandatory, but if the local authority requires planning permission, then the rainwater harvesting system should conform to these recommendations.
Water Supply Regulations
Backflow Protection. The most important regulations that a rainwater harvesting system has to comply with are The Water Supply (Water Fittings) Regulations 1999, Section 6. This section covers Backflow protection to protect mains water from contamination by “unwholesome water”. As rainwater is normally categorised as “Fluid 5”, that is to say the worst water (water storage for agricultural purposes), this backflow protection has to be a “type AA air gap” i.e. an “air gap with unrestricted discharge which means a non-mechanical backflow prevention arrangement of water fittings where water is discharged through an air gap into a receptacle which has at all times an unrestricted spillover to the atmosphere.”
So any RWH system has to conform to this wherever there is a mains top up to the RW system. A tundish (such as the one pictured right) meets the type AA reg. A tundish is supplied as standard with the System 2 Mains Water Backup kits (float switch and mains solenoid valve) from RainWaterHarvesting.co.uk.
Distinguishing pipework. All pipework must distinguish clearly between mains and rainwater. Rainwaterharvesting.co.uk can supply the correct rainwater piping and labels to conform with requirements. See our range of warning labels here.
Other Regulatory Requirements
Location of underground tank. An underground tank should not be installed any closer to a house than a line drawn at a 45 degree angle from the base of the house. It usually works out that the closest part of the tank should not be closer to the building than the overall height of the tank. For example, a tank 2 metres deep from its base to turret should not be closer than 2 metres from the side of the tank to the side of the house.
Although in principle planning permission is not required, it is still worth checking with your local authority before you go ahead with an installation.