Water use and quality

Policy PODM4: Water quality and foul drainage

  1. Development will be permitted only where it can be demonstrated that it will not have an adverse impact on waterbodies, including surface and ground water, in terms of quality and quantity. This should include the requirements of the Water Framework Directive and Habitats Regulations.
  2. Applicants are required to demonstrate there is adequate sewage treatment provision to serve the development or that this can be made available in time for the occupation of the development, and to demonstrate that there is available capacity within the foul sewerage network or that capacity will be made available.
  3. Development is required to be connected to a foul sewer unless proven not to be feasible. If connection to a foul sewer is proven to not be feasible, only then will other arrangements of package sewerage treatment works, and septic tanks be considered and only in that order. These will be permitted only if the Authority is satisfied that these systems will work for the expected use and there would be no adverse effects on the environment. A statement explaining and justifying the approach taken is required to be submitted as part of any relevant application.
  4. Extensions that increase occupancy and proposals for replacement development, as well as proposals to intensify an already permitted use, are required to improve the existing method of foul drainage of the entire property if feasible, in line with the hierarchy as set out in part 3 of this policy.
  5. The Authority encourages proposals to consider the use of constructed reed beds as a filtration system to remove nutrients before the wastewater from small sewage treatment plants and package treatment works enters waterbodies. Production of a management plan will be required to demonstrate the constructed reed beds will continue to function as intended in perpetuity.
  6. To ensure the protection of Habitat Sites, no new development that increases foul water flows requiring connection to the public foul drainage system within the Horning Knackers Wood Water Recycling Centre Catchment will be permitted, until it is confirmed that capacity is available within the foul sewerage network and at the Water Recycling Centre to serve the proposed development.

Reasoned Justification

The water bodies and wetland environments of the Broads are particularly sensitive to water pollution. Diffuse pollution, including from sewage treatment, remains a problem. This has the potential to have a detrimental impact on water quality and biodiversity and thereby adversely affect the Authority’s ability to meet its obligations under the Water Framework Directive and the Natural Environment and Rural Communities Act 2006.

This policy applies to residential and commercial development and to new build as well as replacements and extensions. In the case of replacement dwellings, the current foul water drainage system is expected to be improved in line with Government guidance, with the aim being to connect to the public sewer. The policy also requires betterment for an entire property because of an extension that will increase the occupancy of the building. By increasing the occupancy, it is likely that more foul water will be generated. The works associated with an extension or replacement to a building will provide an opportunity to improve the foul water drainage system.

The National Planning Practice Guidance[8] sets out a hierarchy of drainage options that must be considered (and discounted as appropriate) in the following order:

  1. Connection to the public sewer
  2. Package sewage treatment plant
  3. Septic tank

The first presumption should be to provide a system of foul drainage discharging into a public sewer to be treated at a public sewage treatment works. A private means of foul effluent disposal is only acceptable when foul mains drainage is unavailable. Anglian Water Services should be consulted regarding the available capacity in the foul water infrastructure.

Due to the low-lying nature of the area and remoteness of some settlements, connection to a public sewer is not always possible in the Broads. The alternative non-mains drainage proposals, including the use of septic tanks, can have an adverse effect on the quality of controlled waters, the environment and amenity, particularly if the property is close to watercourses, there is a high-water table at any point of the year, or the site is susceptible to flooding.

To minimise the likelihood of development having an adverse impact on water resources, new development will only be permitted if it can be properly serviced. If an application proposes to connect a development to the existing drainage system, details of the existing system are expected to be provided and confirmation provided that sufficient capacity exists. If the development would necessitate any alterations to the system or the creation of a new system, detailed plans of the new foul drainage arrangements must also be provided. The costs of providing these systems will, where appropriate, fall on the developer. Anglian Water will have the responsibility for the provision and adoption of any new foul sewers provided as part of a new development.

Where development involves the disposal of trade waste or the disposal of foul sewage effluent other than to the public sewer, a foul drainage assessment will be required to demonstrate why the development cannot connect to the public mains sewer system and to provide details of the method of effluent storage, treatment, and disposal. The statement should include a thorough examination of the impact of disposal of the final effluent, whether it is discharged to a watercourse or disposed of by soakage into the ground. An Environmental Permit or exemption will be required from the Environment Agency if it is proposed to discharge treated sewage effluent to controlled waters or ground. Further guidance on the information that should be incorporated into this statement is available on the Agency’s website[9]. Where development proposes non-mains drainage, early liaison with the Environment Agency is expected. The method of non-mains disposal should be the most appropriate to minimise the risk to the water environment. Septic tanks should only be considered if it can be clearly demonstrated by the applicant that discharging into a public sewer to be treated at a public sewage treatment works or a package sewage treatment plant is not feasible.

Reed bed filtration systems (reed beds constructed for the purpose of being a filtration system and not natural reed beds) are a way of treating sewerage that provide multiple habitat and landscape benefits, as well as being a low energy and low carbon option. While it may take more space than other treatment options, the end discharge from a reed bed system could be similar and, when combined with other methods, even better quality than other methods on their own. Constructed reed bed systems should only be formed where there is no impact on the wetland habitat of the Broads.

As set out in the next policy, all new/replacement/converted or extended buildings are required to incorporate greywater recycling and rainwater harvesting unless it is not feasible or not viable to do so.

Nutrient Enrichment is referred to throughout this Local Plan. At the time of writing, in some parts of Norfolk planning applications for overnight accommodation and some other types of development are not able to be approved without mitigation due to the issue of Nutrient Enrichment. Mitigation schemes are being worked up both locally (Norfolk Environmental Credits) and nationally (led by Natural England). More information can be found here: Nutrient Neutrality (broads-authority.gov.uk).See Policy PODM17: Mitigating Nutrient Enrichment Impacts later in this Local Plan.

Horning Knackers Wood Water Recycling Centre (WRC) discharges to the River Bure and contributes nutrient loads to the downstream watercourses as well as the Bure Broads and Marshes Site of Special Scientific Interest (SSSI), a component of the Broads Special Area of Conservation (SAC)/ Broadland Special Protection Area (SPA). Concerns regarding development in the catchment of the WRC relates to the potential impact of rising nutrient loads on the river and sensitive downstream receptors and excess flows caused from water ingress into the system (from surface water, river over topping and the resultant groundwater infiltration which is compounded through defects in the public and private network). The environmental permit limits for Knackers Wood WRC are set to preserve the quality of water in the watercourse downstream of the discharge point both to ensure that there is no deterioration in Water Framework Directive (WFD) status and that decisions support measures to help the waterbody to achieve good ecological potential, nor deterioration in Conservation Objectives. The permit limits are several, set against modelled conditions specific to that waterbody and interdependent with each other. Currently, one of the permit limits, Dry Weather Flow is in exceedance by a significant amount. At present, the section of the River Bure that receives the discharge from Knackers Wood has an overall WFD status of ‘moderate’ and also ‘moderate’ for ecological potential. As a minimum, our objectives are to ensure that there is no deterioration in water quality in the river and that the water quality thresholds set out in the Conservation Objectives for Habitat Sites continue to be met or bettered. Both Anglian Water and the Environment Agency agree that the WRC does not currently have capacity to accommodate further foul flows. Anglian Water Services (AWS) have investigated why the WRC is receiving excessive flows, and there is a Joint Position Statement setting out more detail including actions undertaken and proposed to address the issue. The Authority will keep informed of progress on this issue.

Reasonable alternative options

Original policy

No policy

Sustainability appraisal summary

The following is a summary of the assessment of the policy and alternative(s).

A: Original policy: 3 positives. 0 negatives. 0 ? Overall, positive.

B: Amended policy: 3 positives. 0 negatives. 0 ? Overall, positive.

C: No policy: 0 positives. 0 negatives. 3 ?

Why has the alternative option been discounted?

Given that much of the area is water and the importance that water has to the environment, society, and economy, to have a policy that seeks to protect water quality is prudent. The amendments are minor and help to clarify the policy.

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Policy PODM5: Boat wash-down facilities

  1. Where development is proposed for recreational boating club facilities (new, rebuild or extensions) that increase the use of the club, there will be a requirement to designate and sign a suitable area for wash-down of vessels as part of good biosecurity practice.
  2. Where development is proposed (new, rebuild or extensions) that increases the use of existing boatyards, marinas and mooring basins that have facilities to take boats out of the water, or maintain boats on site, or is related to maintaining or washing down boats, there will be a requirement to designate a suitable area with adequate facilities to enable the filtration of waste water from the washing of boat hulls, with the ultimate aim of preventing anti fouling paint residues (including paint flakes) entering the water and to stop the spread of invasive species.

Reasoned Justification

When vessels are removed from the water they tend to be washed down as part of the maintenance regime. Wash-down of vessels is also important to stop the spread of invasive aquatic species such as the killer shrimp. The equipment used ranges from a pressure hose to a closed loop system that filters contaminants.

Biosecurity in this instance means taking steps to make sure that good practices are in place to reduce and minimise the risk of spreading invasive non-native species. Non-native species (such as killer shrimp, Zebra Mussel, and New Zealand Pygmyweed) can devastate populations of native species and change whole ecosystems, for example by competing with and displacing native species, spreading disease, altering the local ecology and physically clogging waterways. A good biosecurity routine is essential, even as the life stages of some invasive non-native species are microscopic and are not always apparent.

Recreational boating club users (e.g., sailing, rowing, wind surfing, water-skiing) tend to remove boats/ vessels from the water when not in use or transport them to other water bodies. Users should be aware of the good practice of ‘check, clean and dry’ to help stop the spread of invasive aquatic species. The policy seeks the designation of areas that are signed and equipped to help in the biosecurity process. The Authority considers that requiring boating clubs to provide such facilities is not onerous.

Anti-fouling paints are applied to boat hulls to prevent growth of organisms, such as algae and mussels. They work by creating a toxic barrier that prevents organisms attaching to the hull. Fouling increases the resistance of the hull to its movement through the water, which slows the boat and reduces its energy efficiency and manoeuvrability. When boats are maintained, antifouling paint could run off into the nearby waterbody. Recent research shows that past use of antifouling paints, such as TBT (tributyltin) based products, had a severe impact on wildlife in the Broads. Although today’s anti-fouling products are less persistent, they are still potentially harmful to aquatic life. For example, increased copper levels are now being found in the sediment, which can have harmful effects on water snails.

The policy requires commercial operations to have the facilities in place to prevent anti-fouling paint from entering the watercourse. The Green Blue Guide[10] provides more information and gives detailed advice and guidance on wash down systems. There is a range of ways to tackle the issue of anti-fouling paint entering the water at a range of costs and the Authority can provide advice. The best practice measures are expected to be taken in accordance with the scale of the wash down operation, the type of work to be undertaken and its impact on the water environment. Applicants are required, as part of their application, to address the issue of boat wash down and justify the chosen system.

Reasonable alternative options

There are no reasonable alternatives. Given the importance of addressing the issue of biosecurity and anti-fouling paint, so not to have a policy is seen as an unreasonable alternative.

Sustainability appraisal summary

The following is a summary of the assessment of the policy and alternative(s).

A: Original policy: 3 positives. 0 negatives. 2 ? Overall, positive.

How has the existing policy been used since adoption in May 2019?

According to recent Annual Monitoring Reports, the policy has been used and applications have been in conformity with the policy.

Why have the alternative options been discounted?

No reasonable alternative options.

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Policy PODM6: Water efficiency and re-use

  1. All new/replacement/converted dwellings (including holiday/visitor accommodation) will be designed to have a water demand equivalent to 110 litres per head per day. Measures to reduce water demand further will be supported.
  2. All new/replacement/converted or extended buildings are required to incorporate greywater recycling[11] and rainwater harvesting[12] unless it is not feasible or not viable to do so.
  3. Washing up provision and toilets and showers associated with camping, caravanning and glamping sites are required to be designed to be water efficient.
  4. All new/replacement/converted non-domestic buildings are required to be designed to be water efficient.

Reasoned Justification

All new homes must meet the mandatory national standard set out in the Building Regulations (125 litres/person/day). The NPPG says ‘Where there is a clear local need, local planning authorities can set out Local Plan policies requiring new dwellings to meet the tighter Building Regulations optional requirement of 110 litres/person/day’[13]. The policy seeks 110 l/h/d and the reasons for this are set out in the Local Infrastructure Study and summarised below[14].

The Water Stressed Areas Classification (Environment Agency, 2021)[15] summary table shows that the areas of Essex & Suffolk Water and Anglian Water are water stressed.

There is clear support from Anglian Water and Essex and Suffolk Water in adopting this approach. Demand management, such as reducing leakage, and encouraging customers to use less water is an important component of Water Resource Management Plans and helps to ensure that there will be sufficient water resources for future population growth, coping with the impacts of climate change, and to ensure a healthy and flourishing environment.

New development needs to incorporate measures to minimise water consumption. Water management systems, including grey water recycling and rainwater harvesting, should be incorporated into new development unless proven unfeasible.

The Authority will consider site constraints, technical restrictions, financial viability, and the delivery of additional benefits to the Broads where requirements of the policy cannot be met. The Authority will expect developers to make a case on a site-by-site basis.

Also see open space policy– this states that artificial pitches that are designed to require water will not be permitted. Other new pitches that required watering will need to demonstrate how water will be supplied and used sustainably.

And in terms of landscaping, landscape policy the states: to reflect that the East of England is an area of water stress, new landscaping/planting is expected to follow sustainable planting principles and be adaptive to climate change and be water-smart: using plants that are not dependent on additional watering/do not require a large amount of water.

This guide may be of use to applicants: Developing water efficient homes (pdf | watersafe.org.uk). So too could the Norfolk and Suffolk ‘Reclaim the Rain’ project: Reclaiming the Rain (reclaimtherain.org). More details on implementing the policy are included in Appendix 5.

The Authority is aware of the work going on in the Cambridge area where a standard of 80 l/h/d is being explored. New development is currently on hold in Greater Cambridge on the grounds of water availability and the need for new developments to be more water efficient owing to deteriorating condition of water bodies under WFD. The Authority will keep informed of progress and may introduce a lower than 110l/h/d standard.

Reasonable alternative options

Original policy

No policy

Sustainability appraisal summary

The following is a summary of the assessment of the policy and alternative(s).

A: Keep original policy: 3 positives. 0 negatives. 0 ? Overall, positive.

B: Amended policy: 3 positives. 0 negatives. 0 ? Overall, positive.

C: No policy: 0 positives. 0 negatives. 3 ?

Why has the alternative option been discounted?

Given water supply issues in the area, a policy is prudent. The amended policy ensures that all types of development consider and address water efficiency.