Sustainability Appraisal of the Sandwell Local Plan 2024-2041
15 Water
15.1 Introduction
15.1.1 National water policies are primarily driven by the aims of the EU Water Framework Directive 2000/60/EC, as translated into national law by the Water Framework Regulations 2003. Key objectives include improving the quality of rivers and other water bodies to 'good' ecological status by 2027; considering flood risk at all stages of the plan and development process in order to reduce future damage to property and loss of life; and incorporating water efficiency measures into new developments. Key PPPs for the SLP area include the Severn[125] and Humber[126] River Basin Management Plans (RBMPs) which provide information on the status of surface and groundwater bodies and how water quality can be improved.
15.2 Baseline and key issues
Water resources
15.2.1 It is likely that the demand for water and the volume of wastewater will increase during the Plan period owing to the increasing population. Wastewater treatment plants will need to ensure there is the capability to withstand the additional capacity and be expanded, if necessary, prior to development taking place.
15.2.2 Sandwell is supplied with water by Severn Trent Water and South Staffs Water. Severn Trent Water[127] and South Staffs Water[128] plan to manage and meet future demand through encouraging water use efficiency, for example by installing water meters, and reducing leakage.
15.2.3 Undertaking a Water Cycle Study (WCS) can help to inform local plans and wastewater infrastructure delivery requirements, water resources and water efficiency requirements to plan for sustainable growth. Through understanding environmental and infrastructure capacity, a WCS can identify joined up and cost-effective solutions that are resilient to climate change[129].
15.2.4 A Phase 1 WCS Scoping Study was undertaken to support the preparation of the former BCP[130], and an updated Phase 2 WCS for Sandwell[131] has now been prepared to inform the SLP drawing on the recommendations made in the Phase 1 WCS. The WCS (2024) considered water supply capacity, wastewater capacity and environmental capacity, considering future demonstratable solutions to key constraints including policy recommendations. No significant constraints were identified that are likely to impact water supply.
Water quality
15.2.5 The River Tame (Oldbury Arm) and its tributaries the Hockley Brook and Tipton Brook run through the borough (see Figure 15.1). The River Stour is located along the south western boundary of the borough. The Walsall Canal, Birmingham Canal and Titford Canal also pass through the area. Construction activities in or near watercourses have the potential to cause pollution, impact upon the bed and banks of watercourses and impact upon the quality of the water[132].
15.2.6 The ecological status of the sections of the River Tame within Sandwell was 'moderate' in 2024 although the majority of canal sections were 'good'[133]. The chemical status of all watercourses in Sandwell is classed as 'fail' when ubiquitous, persistent, bioaccumulative and toxic substances (uPBTs) are considered[134].
15.2.7 The vulnerability of groundwater to pollution is determined by the physical, chemical and biological properties of the soil and rocks, which control the ease with which an unprotected hazard can affect groundwater. Groundwater Source Protection Zones (SPZs) indicate the risk to groundwater supplies from potentially polluting activities and accidental releases of pollutants. SPZ 3, known as the 'Source Catchment Protection Zone' is found in the south east of the SLP area which represents "the area needed to support the protected yield from long-term groundwater recharge"[135](see Figure 15.2).
Key issues for water include:
- New development and an increased population would be likely to place pressure on water resources and may result in a deficit between supply and demand if not carefully planned and managed alongside the water companies.
- There is a need to give close consideration to the impacts of development proposals on wastewater treatment in the local area, and the capacity of treatment works, as well as the consequences of new wastewater generation for local water quality and the ecological status of ground and surface water bodies.
- Culverted watercourses have the potential to become blocked by debris during periods of heavy or sustained rainfall. They also offer little biodiversity or recreational interest relative to more natural watercourses. In such cases, environmental and water quality benefits can be secured at minimal cost.
- Most forms of development reduce the amount of rainfall that is intercepted by vegetation on the ground and can have detrimental implications for surface water run-off.
15.3 Impacts on water
15.3.1 Box 15.1 presents a plan-wide summary of the adverse impacts on water that have been identified through the SA process. These adverse impacts are those identified prior to mitigation considerations. Box 15.2 lists the policies within the SLP which will be likely to mitigate, either fully or partially, some of the identified adverse impacts on water. Where the policies do not fully mitigate the adverse impacts, a residual adverse effect is identified. Box 15.3 explores the nature of these residual effects.
Box 15.1: Summary of identified impacts on water
Impact on water
Summary of identified impact
Reduction in water quality and ecosystem services
Water provides a range of essential ecosystem services, including providing the basis for vegetation to flourish and supporting biodiversity. Development and urbanisation can be associated with adverse impacts on water quality, primarily induced by nitrates from agricultural sources, including risks of water pollution associated with runoff from roads, and from water outflows during storm conditions.
The construction and occupation of new development, especially for the 21 allocated sites located less than 10m from a watercourse, has the potential to increase the risk of contamination and pollution of waterways. This is primarily due to the potential loss of soil and surface water / pollutant runoff.
The Phase 2 WCS (2024)[136] also indicates there is a poorly performing storm tank overflow located at Roundhill Wastewater Treatment Works (WwTW), which has potential to worsen water quality if the operations of such overflows increase.
Some 13 allocated sites are located within a groundwater SPZ, where new development could potentially lead to an overall increase in the risk of groundwater contamination or pollution.
Increased demand for water and wastewater management
The proposed development of 10,434 new dwellings set out in the SLP is likely to lead to population growth, which is likely to increase water demand as well as demand for wastewater treatment across the Plan area.
The Severn Trent Water and South Staffs Water WRMPs[137] [138] show a supply-demand deficit regarding water resources, if no action is taken.
The Phase 1 Scoping WCS (2020)[139] noted that some wastewater treatment works serving the Black Country area have limited capacity. Although South Staffs Water indicated that there were no constraints to water supply at the time of writing, early engagement with water companies and further assessment work was recommended in the WCS.
The Sandwell Phase 2 WCS (2024) indicates that Severn Trent Water have also not identified any water supply constraints within Sandwell, stating they "do not anticipate issues connecting new development" to their water supply network for sites within their water resource zone. However, it is noted that South Staffs Water, which covers the majority of Sandwell, have not directly commented at this stage.
The Phase 2 WCS (2024) highlights the limited capacity of a number of WwTWs in Sandwell, and infrastructural upgrades to WwTWs may be required to accommodate growth. Early engagement is recommended with relevant water companies to ensure WwTWs with limited treatment capacity are addressed prior to an increase in wastewater demand being generated from new development.
15.4 Local Plan mitigation
15.4.1 Policies within the SLP aim to prevent the decrease of water quality and improve water efficiency in new developments within the Plan area. These policies are discussed in detail in Box 15.2.
Box 15.2: Mitigating effects of the Local Plan policies on water
Policy mitigation for water
Summary of mitigating effect
Reduction in water quality and ecosystem services
Various SLP policies including SNE1: Nature Conservation, SNE2: Protection and enhancement of wildlife habitats, SNE3: Provision, retention and protection of trees, woodlands and hedgerows, SDM1: Design Quality, SDS7: Sandwell's Green Belt and SDS8: Green and blue infrastructure in Sandwell encourage enhancements to the provision and connectivity of GI/BI, which will help to support ecosystem service functions such as the filtration of water and could potentially result in improvements to water quality.
Policy SNE6: Canals requires development proposals to protect and enhance the canal network, including the water quality of canals.
Policy SCC5: Flood Risk seeks to ensure that no development is permitted within a groundwater SPZ that could physically disturb an aquifer. This is supported by Policy SCC6: Sustainable drainage which outlines requirements for the inclusion of SuDS in development proposals which can play a role in improving water quality as specified.
Increased demand for water and wastewater management
Policy SDS2: Increasing efficiency and resilience seeks to improve water efficiency through employing high environmental standards in the design of new developments.
Policy SCC3: Climate adapted design and construction sets out the requirement for all non-residential development of 1,000m2 or more to achieve a BREEAM New Construction Certification of 'Very Good' or 'Excellent' depending upon the nature of development, which includes full credits for water efficiency.
Policy SHW1: Health Impact Assessments will ensure an HIA is undertaken for the majority of new developments, to ensure that the construction and occupation of new residencies will have sufficient capacity to meet the needs of residents such as water supply
Policy SHO9: Accommodation for Gyspies, Travellers and Travelling Showpeople are required to ensure there is adequate provision for on-site services such as water supply
Policy SDM7: Management of hot food takeaways assists with the prevention of fats from reaching the wastewater system in order to minimise blockages.
15.5 Residual effects on water
15.5.1 Residual effects with regard to water are expected to remain following the implementation of the SLP policies. Further details regarding these effects are discussed within Box 15.3.
Box 15.3: Residual effects for water
Residual effects
Further details of the residual effect
Reduction in water quality and ecosystem services
As outlined in Box 15.2, several SLP policies will be expected to help protect and enhance water quality either directly or indirectly, by ensuring that development proposals incorporate sustainable drainage systems and increase the provision of multi-functional GI.
A negative impact on the quality of the receiving watercourse can result from an increase in the discharge of effluent WwTWs from new development. The Phase 1 WCS (2020) states that the "increased discharges at the WwTWs, serving growth across the Black Country area, have the potential to impact the downstream water quality of receiving waterbodies... in particular, consideration should be paid to those which already have a 'poor' or 'bad' status and are forecast for increased growth".
Although no SSSIs lie within Sandwell itself, a number of SSSIs lie within close proximity to the borough and have potential to be subject to effects of development upstream. According to the Sandwell WCS (2024), the main sources of water pollution in Sandwell are from sewage discharge, and from urbanisation and transport. Water quality modelling carried out as part of the WCS found that "growth alone will not prevent good ecological status" providing that improvements in upstream water quality are made. Water quality modelling indicates growth during the Local Plan period is unlikely to result in any significant deterioration in water quality at any modelled WwTWs, and less significant levels of deterioration can be prevented by improvements being carried out for the treatment works.
The WCS (2024) recommends annual monitoring reports regarding new development are provided to WwTWs which take into the account the full volume of growth within the catchment area. SLP policies are also expected to partially mitigate reductions in water quality such as through SuDS provision which will help to treat diffuse pollution at the source to avoid adverse impacts on water quality. However, development is also likely to increase the quantity of raw sewage being disposed of in river channels, which will require additional monitoring. A residual adverse impact on water quality and ecosystem services is therefore identified, in line with the precautionary principle.
Deterioration in water quality and ecosystem services has the potential to be a long-term but potentially temporary significant effect.
Increased demand for water and wastewater management
The increased population within the Plan area is expected to increase water demand, such as for drinking water supply and wastewater treatment, despite measures within national policies and the SLP policies to improve water efficiency.
The Phase 2 WCS (2024) does not expect water supply to be a constraint to new development within Sandwell. The study recommends SMBC and developers should engage with water companies at an early stage to ensure adequate water supply infrastructure and distribution systems are in place to accommodate for the increased development resulting from the SLP, as is reflected to some extent within SLP policies.
Wastewater collection infrastructure has limited capacity which may lead to minor deteriorations in WwTWs which can be improved, providing that upgrades in treatment technology are in place. However, the SLP policies are not expected to fully mitigate these deteriorations. In addition, risks associated with storm overflows have been identified at some locations which can be partially mitigated by incorporating SuDS into the design of new development, as supported by Policy SCC6.
Increased pressure on wastewater treatment has the potential to be a long-term but potentially temporary significant effect.
[125]DEFRA & Environment Agency (2022) Severn River basin district, river basin management plan. Available at: https://www.gov.uk/guidance/severn-river-basin-district-river-basin-management-plan-updated-2022#:~:text=The%20Severn%20river%20basin%20district%20(%20RBD%20)%20river%20basin%20management%20plan,Wales%20jointly%20manage%20this%20RBD%20 [Date accessed: 08/07/24]
[126] DEFRA & Environment Agency (2022) Humber River basin district river basin management plan. Available at: https://www.gov.uk/guidance/humber-river-basin-district-river-management-plan-updated-2022 [Date accessed: 08/07/24]
[127]Severn Trent Water (2024) Water Resources Management Plan 2024. Available at https://www.severntrent.com/about-us/our-plans/water-resources-management-plan/ [Date accessed: 08/07/24]
[128]South Staffs Water (2023) Water Resources Management Plan 2019. Available at https://www.south-staffs-water.co.uk/about-us/our-strategies-and-plans/our-water-resources-management-plan#:~:text=At%20least%20every%20five%20years,now%20and%20in%20the%20future [Date accessed: 08/07/24]
[129]MHCLG (2019) Water supply, wastewater and water quality. Available at: https://www.gov.uk/guidance/water-supply-wastewater-and-water-quality#water-cycle-studies[Date accessed: 08/07/24]
[130] JBA Consulting (2020) Black Country Councils Water Cycle Study: Phase 1 Scoping Study. Available at: https://blackcountryplan.dudley.gov.uk/media/17929/watercyclestudy_phs1_scopingstudy.pdf [Date accessed: 08/07/24]
[131] JBA (2024) Sandwell Water Cycle Study Stage 2.
[132] World Health Organisation (1996) Water Quality Monitoring - A Practical Guide to the Design and Implementation of Freshwater Quality Studies and Monitoring Programmes: Chapter 2 – Water Quality. Available at: https://www.who.int/publications/i/item/0419217304#:~:text=Water%20quality%20monitoring%20is%20a,of%20field%20and%20laboratory%20methods [Date accessed: 08/07/24]
[133] The Rivers Trust (2024) River Ecological Health. Available at: https://theriverstrust.org/ecology-map [Date accessed: 21/08/24]
[134] Environment Agency (2019) River Basin Management Plan: maps. Available at: https://experience.arcgis.com/experience/73ed24b6d30441648f24f043e75ebed2/page/Introduction/ [Date accessed: 08/07/24]
[135]Environment Agency (2019) Manual for the production of Groundwater Source Protection Zones – March 2019. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/822402/Manual-for-the-production-of-Groundwater-Source-Protection-Zones.pdf [Date accessed: 08/07/24]
[136] JBA Consulting (2024) Sandwell Water Cycle Study Stage 2.
[137]Severn Trent Water (2024) Water Resources Management Plan 2024. Available at https://www.severntrent.com/about-us/our-plans/water-resources-management-plan/ [Date accessed: 08/07/24]
[138]South Staffs Water (2023) Water Resources Management Plan 2019. Available at https://www.south-staffs-water.co.uk/about-us/our-strategies-and-plans/our-water-resources-management-plan#:~:text=At%20least%20every%20five%20years,now%20and%20in%20the%20future [Date accessed: 08/07/24]
[139] JBA Consulting (2020) Black Country Councils Water Cycle Study: Phase 1 Scoping Study. May 2020. Available at: https://blackcountryplan.dudley.gov.uk/t2/p4/t2p4h/ [Date accessed: 23/08/24]
