Information started emerging in March 2026 about a potential water supply issue in relation to some areas of East Hampshire where water is supplied by South East Water.
We continue to receive questions on this topic. These Q&As are meant to answer some of those frequently asked questions and to keep residents informed.
We are keeping these Q&As updated as information becomes available. These Q&A were last updated 11 September 2026.
What is the ‘water’ issue?
The availability of water in the northern part of East Hampshire including the Alton and Four Marks area, has come under increasing scrutiny following South East Water's response to Basingstoke and Deane Borough Council’s Regulation 18 Local Plan consultation in March 2026.
South East Water stated that the area known as WRZ4-W, which covers Basingstoke and extends into Hart and parts of Alton and the surrounding area, is forecast to face a supply-demand deficit. In simple terms, there are concerns that future demand could exceed the amount of water that can be supplied sustainably without putting pressure on the environment.
The issue is not that homes and businesses have run out of water today. Rather, it is about whether there will be enough water available in the future to provide a secure and reliable supply for existing customers while also supporting new homes, employment development and community facilities.
Over time, increasing demand for water, environmental restrictions on water abstraction, and the effects of hotter and drier weather have placed growing pressure on available supplies. As a result, South East Water has advised that additional investment is needed to improve the resilience of the network and secure future supplies.
The council is therefore engaging with South East Water, the Environment Agency, Natural England and neighbouring authorities to understand the implications of the water supply constraints and the solutions being developed. This will help ensure that future growth can be planned and delivered in a sustainable way while maintaining a secure water supply for existing residents and businesses.
How has the water issue developed?
The water supply issue in the WRZ4-W area has developed gradually over many years. More people and businesses need water, while at the same time there are tighter environmental rules on how much water can be taken from rivers and underground sources. Hotter, drier weather and longer periods without rainfall have also increased pressure on available supplies. Alongside this, the Government is pursuing a growth agenda, and has significantly increased housing numbers, requiring more new houses to be delivered.
As a result, South East Water has identified that, in parts of this area, there is currently insufficient water available to both maintain a secure supply for existing customers and support all planned future growth without further investment in new water infrastructure. Addressing the issue will require a combination of water network improvements, new supply schemes and measures to reduce water demand.
What area does this affect?
Please see map of WRZ4-W.
How does it affect residents living in the affected area?
South East Water reassured the council in June 2026 that there is no immediate threat to the water supply.
The concern is that pressure from new development in the future could impact on the secure supply for existing customers, if infrastructure improvements are not put in place.
What does it mean for future development?
As the Local Planning Authority, the council needs to understand the relevant material planning considerations when making decisions. Where there are legitimate concerns about water supply, this is a material planning consideration. For local plans and future development, this is an infrastructure constraint that requires further research, and could potentially influence the future phasing of development.
Water supply concerns do not automatically prevent development from taking place. However, the council must be satisfied that planning applications can be determined lawfully having regard to all relevant evidence, national policy and consultation responses.
What is the council doing to gather more information?
The council is working hard to establish the facts, and to seek information from the organisations involved with the relevant expertise, particularly South East Water, the Environment Agency and Natural England.
The council is actively participating in cross-organisation steering group meetings, involving the affected authorities (Hart, Basingstoke and Deane, South Downs National Park and East Hampshire), Environment Agency, South East Water, Natural England and Defra.
The council, together with neighbouring authorities affected by the issue, commissioned specialist legal advice from King's Counsel. The advice has now been received and considered. As with other legal advice obtained by the council, it is not intended for publication due to legal privilege. The advice is one of a number of factors that help inform decision making and does not determine the outcome of planning applications by itself.
The Leader of the council has met with the Chief Executive of South East Water. The discussion has been helpful in improving understanding of the challenges facing the water supply network and the infrastructure solutions being developed. This discussion will continue, and we hope to meet again with the Chief Executive of South East Water.
What is the council doing about individual planning applications in WRZ4-W?
Planning applications within the affected area are being reviewed in light of the latest evidence available, including information from South East Water, the Environment Agency, Natural England, legal advice and the updated NPPF.
As part of this process, in July 2026 the council reconsulted the Environment Agency, Natural England and South East Water on pending planning applications within WRZ4-W.
The Environment Agency and Natural England confirmed that they do not object to these applications on water resource grounds, and the Environment Agency advised that the additional water demand from individual developments is very small compared with overall demand across the area and is unlikely to cause significant environmental harm.
However, the Environment Agency has highlighted ongoing concerns about the long-term security of water supplies within WRZ4-W and the risk of future water supply deficits.
To support their individual responses to planning applications, the Environment Agency produced a position statement.
The position statement advises that the additional water demand from individual developments is very small compared with overall demand across the area and is unlikely to cause significant environmental harm.
South East Water did not formally respond to the reconsultation process, and has not objected to the pending planning applications.
When will decision making resume for applications in WRZW-4?
The council will continue to assess planning applications carefully on a case-by-case basis.
Decisions will be made when the council is satisfied that it can reach a robust and defensible conclusion. It is important to note that decision making cannot be held indefinitely, and is likely to resume soon.
Can planning applications be refused because of water supply concerns?
National planning policy requires planning applications to be determined on the basis of the evidence available and the impacts of the specific development being proposed.
The issue is not immaterial, but it must be weighed in the balance with all other material planning considerations.
It is not impossible for a water supply constraint to be a reason for refusing a planning application. As with all reasons for refusal, however, there must be a clear evidential basis for concluding that the constraint is sufficiently proven and direct to justify refusal, and the decision must be consistent with the relevant planning policies and guidance.
While concerns remain about the long-term security of water supplies within WRZ4-W, there is currently no cogent and compelling evidence that individual planning applications would result in unacceptable environmental impacts.
What is the council doing in the longer term?
The council is continuing to work with neighbouring authorities, South East Water, the Environment Agency and Natural England to understand the longer-term implications of the water supply constraint for future growth in the affected area.
This work will help inform both the council’s approach to current planning applications and the preparation of future local plans, water cycle studies and other evidence base documents that help ensure development is planned sustainably and supported by appropriate infrastructure. This includes understanding what infrastructure improvements may be needed, when they may be delivered, and whether additional measures such as higher water efficiency standards for new homes could help reduce demand for water. For example, water cycle studies play an important role in identifying the availability of water resources, the capacity of water supply and wastewater infrastructure, and the potential environmental impacts of growth. They also help identify measures that could reduce demand for water, including higher water efficiency standards for new homes, so that less water is used.
The evidence will help ensure that future development is planned in a way that reflects available water resources and can be supported by the infrastructure needed to serve communities and businesses.