TMBC Water Supply

Tonbridge and Malling Borough Council (TMBC) has recently published updated guidance on how water supply considerations will be taken into account in the determination of planning applications across the borough.

This reflects growing concerns regarding infrastructure capacity, particularly following input from South East Water, and signals an increasingly proactive approach by the Council to ensure that new development can be adequately served. Read on for more details.

 

Water Supply Now a Key Planning Consideration

TMBC has confirmed that the availability of potable water is a material planning consideration, to be assessed alongside existing Development Plan policies, including Policy SQ5 and Core Strategy Policy CP25. 

 

Planning applications will continue to be determined on their individual merits, however applicants will now need to give greater consideration to how their proposals can be supported by adequate water supply infrastructure.

 

This change reflects wider challenges in the South East, where water companies have raised concerns regarding the ability of existing infrastructure to support planned growth. 

 

New Requirement: Potable Water Demand Technical Note

A key change is the introduction of a requirement for a 'Potable Water Demand Technical Note' to support major applications.

 

This will apply to:

 

• Residential development of 10 or more dwellings or sites of 0.5 hectares or more
• Non-residential development of 1,000 sq.m or more or sites of 1 hectare or more

 

The Technical Note will support the Council in assessing the impact of development on water supply and infrastructure capacity.

 

At this stage:

 

• The Technical Note is not yet part of the Local Validation Checklist
• Applications will not be invalidated if it is not submitted at validation
• However, it will be requested post-validation
• The requirement is expected to be formalised following consultation

 

TMBC has confirmed that further guidance on the content of the Technical Note will be made available. 

 

Proportionate Approach for Smaller Schemes

For non-major development (including minor and householder proposals), a Technical Note will not be required.

 

However, water supply issues will still be assessed by officers on a proportionate basis, ensuring that infrastructure considerations remain relevant across all scales of development. 

 

Role of South East Water

South East Water will be consulted on relevant planning applications.

 

It is important to note that:

 

• South East Water is not a statutory consultee
• A lack of response will not delay determination

 

Nevertheless, early engagement with the water company remains good practice, particularly for larger schemes. 

 

Use of Grampian Conditions

TMBC has confirmed that it may use Grampian-style planning conditions where necessary to secure appropriate water infrastructure before development proceeds.

 

These are likely to apply to:

 

• Residential development of 30 dwellings or more
• Commercial development of 3,000 sq.m or more

 

In such cases:

 

• Conditions will typically be pre-commencement
• Developers will be asked to agree to the condition
• Refusal to agree may result in refusal of planning permission

 

This approach ensures that development is only delivered where sufficient water infrastructure can be secured alongside it.

 

What This Means for Developers

The Council’s updated approach reinforces the importance of:

 

• Early consideration of water supply constraints
• Engagement with relevant infrastructure providers
• Providing clear supporting information to demonstrate deliverability

 

Whilst applications will continue to be progressed, TMBC has emphasised that water supply issues may increasingly influence decision-making, particularly for larger developments. 

 

Our View

This update highlights a growing trend across the South East, where infrastructure capacity—particularly water supply—is becoming a critical factor in the planning process.

 

For developers and landowners, this reinforces the need to:

 

• Address infrastructure matters early in the design and planning process
• Ensure proposals are supported by robust technical evidence
• Engage proactively with local planning authorities and infrastructure providers

 

At DHA Planning, we are already advising clients on how best to respond to these emerging requirements and would be pleased to discuss how this may affect your site or ongoing applications.   If you'd like to discuss this matter further, please get in touch with Hannah Young from DHA Planning.