Local Flood Risk Management Strategy

Our objective is to develop and promote better understanding and awareness of flood risk from all sources, now and in the future.

As a result, Risk Management Authorities will be better informed in strategic flood risk planning and prioritising local flood risk management. The public will have an improved awareness of flood risk enabling them to better prepare and respond to flood events and to the changes brought about by climate change. The actions we will be undertaking to address this objective are set out in our action plan.

One of the key aspects of the management of local flood risk is effective coordination across all Council and Partner strategies and activities with clear communication and involvement of the public. By linking with other strategies, the following can be achieved:

• Management of flood risk through the cumulative benefit of a number of smaller schemes
• Identification of opportunities for cross department and organisational working to develop joint schemes. This will deliver cost savings, efficiencies and potentially larger schemes deemed uneconomic.
• Incremental adaptation to the potential impacts of climate change through creative water management
• Raising and maintaining of awareness.

For these reasons, this Strategy has been developed in full consultation with the key delivery partners and with existing priorities in mind.

We have developed a number of flood risk strategies, plans and assessments, including:

• Previous Local Flood Risk Management Strategy, produced in 2017
• Preliminary Flood Risk Assessments
• Surface Water Management Plans for Buckingham, Chesham, High Wycombe and Marlow

Find out more about our flood risk strategies, plans and assessments.

There are a number of key plans and assessments that are led by other Risk Management Authorities in collaboration with us as a Lead Local Flood Authority:

Flood Risk Management Plans are joint plans prepared and developed under the Flood Risk Regulations 2009 by the Environment Agency and Lead Local Flood Authorities. They set out how organisations, stakeholders and communities will work together to manage flood risk in England. They focus on the more significant areas of flooding and describe the risk of flooding now and in the future.

We helped to prepare the Thames River Basin District Flood Risk Management Plan, in relation to the following significant Flood Risk Areas:

• Chesham
• High Wycombe and the Wye Valley

The full plan can be found here:

View the full Thames river basin district flood risk management plan.

The Environment Agency is producing a second National Flood Risk Assessment, due to be published at the end of 2024. It will update national flood risk mapping for rivers, the sea and surface water using updated ground level data and more detailed urban and rural drainage rates. Where appropriate, it will incorporate local detailed modelling that has been carried out by Buckinghamshire Council. It will also include better data on flood defences and other assets which alter the flow of water, such as channels and bridges.

The Drainage and Wastewater Management Plan (DWMP) is a plan highlighting the known and expected future risks to drainage and identifying solution strategies to mitigate. Thames Water and Anglian Water manage wastewater in Buckinghamshire.

View the plan for Thames Water and Anglian Water.

We aim to establish a two-way flow of knowledge, information and data on flood risk with our Risk Management Authority colleagues, other professional partners, and the public. This helps to increase awareness and hence resilience. There are a number of ways in which we can achieve this:

Buckinghamshire Council has a dedicated Strategic Flood Management Group, who coordinate all “local” flood risk management activities. The group is chaired by the Buckinghamshire Council Deputy Cabinet Member for Climate Change and Environment.

We recognise that much of the local knowledge and technical expertise necessary to improve management of local flooding lies with the Environment Agency, water companies, Internal Drainage Boards and other Partner organisations. Involvement of these and other organisations will also provide benefits for the natural and social environment, as well as the cultural heritage of Buckinghamshire.

We are committed to working in partnership with communities on matters relating to the management of local flood risk. This will empower communities to effectively increase their own resilience.

We therefore seek to provide transparency on how local flood risk is managed. Buckinghamshire Council will involve the public directly and through elected member groups as it addresses technical and operational priorities within its area.

Views will also be sought through consultations where this will enhance information gathering, local decision making and management of risk. Examples of what has previously been done and will continue include:

• Web-based consultations on the draft Surface Water Management Plans and Preliminary Flood Risk Assessments
• Involvement of elected members and representatives of residents or other local groups in workshops for the Surface Water Management Plans
• Consultations and local displays to publicise the developing understanding of flood risk.
• Web-based questionnaires and door to door visits as part of flood investigations

The Buckinghamshire Council stakeholder engagement strategy for strategic flood risk management identifies the following objectives for successful collaboration with stakeholders:

• Promote early stakeholder involvement to ensure stakeholders can collaborate and consequently influence the development of our capital programme.
• Implement a collaborative approach by carefully considering the stakeholders, who they are and why they are important
• Apply a clear and considered methodology that facilitates collaborative development and co-creation of projects
• Utilise an approach and methodology that is widely understood and accepted as agreed best practice
• Identify how to manage, engage, record, monitor and evaluate the stakeholder engagement process

There is more information on how to reach us on our website.

Groundwater flood risk is of particular importance in Buckinghamshire, due to the higher risk associated with the Chalk geology of the Chilterns. However, groundwater is the least understood source of flood risk, with less focus historically on recording, modelling, mapping and mitigating groundwater risk. This also makes it difficult to steer new development away from groundwater risk through the planning system.

We have previously carried out detailed modelling studies in some of Buckinghamshire's groundwater flood risk areas to map flood extents and depths for a range of probabilities, the case study presented below discusses some of this work.

Buckinghamshire Council are leading the development of understanding of groundwater flood risk nationally, through Project Groundwater. The modelling and mapping that is being undertaken as part of Project Groundwater will help us to better understand and manage groundwater in high-risk areas in Buckinghamshire as well as providing data to our partners in the Berkshire Downs and the Chilterns.

Project Groundwater is also focused on developing new approaches to monitoring, modelling, mapping, and warning by harnessing new technologies and existing community initiatives. It is our ambition that the outcome from Project Groundwater will influence and strengthen national policy on groundwater flood risk.

In order to increase our resilience to the impacts of climate change on flood risk, as a Risk Management Authority we must better understand these impacts, particularly on ordinary watercourses, surface water and groundwater.

A national flood risk assessment (NaFRA2) is being developed for England by the Environment Agency, and will be available within the Strategy timespan. We are being consulted on the new surface water mapping, and will be able to incorporate our local detailed mapping where appropriate.

Prior to its release, to better assess the impacts of climate change on surface water flood risk in Buckinghamshire, we will carry out updates to the Risk of Flooding from Surface Water (RoFSW) mapping with uplifts for climate change in line with the current guidance.

Keeping a good record of past flooding is key to understanding flood mechanisms and managing flood risk in the future.

It is a statutory requirement under Section 19 of the Flood and Water Management Act 2010 for Buckinghamshire Council as the Lead Local Flood Authority (LLFA) to investigate flooding to the extent that it considers it necessary or appropriate. In Buckinghamshire, we investigate and publish reports into "significant" flood events that meet certain criteria, as follows:

• Internal flooding of five or more residential or commercial properties (not including gardens or garages) in a single event. These properties must be situated in close proximity to each other, where it is reasonable to assume that the affected properties were flooded from the same source, or interaction of sources, of flooding.
• Internal flooding (including to basements) of more than one property for one week or longer
• Flooding of one or more critical infrastructure assets (hospital or health centres, school, utilities, emergency services stations, etc)
• Any flooding event that a risk management authority deems significant but does not meet the agreed thresholds may be assessed for consideration by the Strategic Flood Management Group.

The investigation will cover:

• an overview of the flooding incident and its impact on the drainage infrastructure in the wider catchment
• an overview of history of flooding in the location
• a rainfall analysis
• the roles and responsibilities of all involved

The investigation will aim to:

• describe the flood incident and aim to determine any contributing factors
• identify which authorities, communities and individuals have relevant flood risk management powers and responsibilities
• provide high-level recommendations for each of those authorities, communities and individuals
• outline whether those authorities, communities or individuals have or will exercise their powers or responsibilities in response to the flooding incident

Please note that if the cause of the flooding and the responsibility for addressing it is well understood, it is unlikely that a formal investigation will be undertaken by the Council.

The investigation will not:

• resolve the flooding issues or provide designed solutions
• provide an action plan or strategy for specific actions
• force risk management authorities (the Environment Agency, the LLFA, the relevant water company and highways authorities) to undertake any of the recommended actions
• investigate incidents of structural dampness or where basements are affected by groundwater entering through cracks in the basement walls or floors

It is not within the remit of any Section 19 flood investigation to provide designed solutions.

The process does not provide the council, nor any other organisation, with the funding or mandate to undertake works on the ground. The intention is instead to provide a clear understanding of the issues.

It will be for the relevant responsible body or persons to assess the recommendations within the Section 19 report in terms of:

• their legal obligation
• resource implications
• priority
• the costs and benefits of undertaking such options

Buckinghamshire Council will monitor progress on these recommendations through the Buckinghamshire Strategic Flood Management Committee, but does not have powers to enforce their delivery by others.

View published flood investigation reports.

We receive reports of flooding from the public, parish and town councils, and local members. These reports are collated and maintained in a flood incident database. We are investigating ways in which flood reporting could be carried out online, to improve the consistency of information recorded about the location, source and impacts of the flooding.

Many natural and man-made structures and features exist which can affect the routing of flood waters. Some of these structures or features may have been specifically constructed for the purposes of managing water flow and reducing flooding (e.g. culverts, sluices and flood embankments). Others may have been built for a completely different purpose (e.g. garden walls, railway embankments) but may also affect the route of overland flow and ultimately the location of flooding.

The national Flood and Coastal Erosion Risk Management Strategy calls for greater understanding of asset ownership, better asset management and inspection and better understanding of the responsibilities of asset owners. We are approaching this in a number of ways:

Under Section 21, Buckinghamshire Council as Lead Local Flood Authority has a statutory duty to produce a register of all structures that are likely to have a significant effect on flood risk (e.g. bridges, culverts, outfalls, screens, control gates, highway drainage infrastructure etc.). We will:

• Continue to maintain a record of these structures which contains information about each structure or feature listed in the register such as ownership and state of repair
• Establish and maintain a register of structures or features with an identification or risk to flooding, which act to reduce flooding and which can be designated as fulfilling this purpose
• Ensure that the register of structures will be made available for public inspection, however will retain information on specific ownership under data protection responsibilities
• Aim to investigate asset ownership where it is currently unknown
• Once Schedule 3 of the Flood and Water Management Act is implemented, our duties as a SuDS Approval Body (SAB) will entail adoption of SuDS assets. Therefore, SuDS asset data will be also recorded in our flood risk asset register.

The compilation of an asset register and record helps to ensure greater co-ordination of information between partners, regulatory bodies and the public. Holding this information at County level aims to avoid situations where ambiguity exists over which organisation has responsibility for flood risk management assets or functions.

View the public drainage asset register.

Where we are aware of a flood risk asset in poor condition, we will liaise and communicate with asset owners to make them aware of their responsibilities, and encourage them to adequately maintain those assets.

Find out more about flood and sea defences on GOV.UK.

We will support Buckinghamshire Highways to develop a more proactive risk-based approach to highway drainage asset capital works and maintenance, by sharing our knowledge on flood risk and the impacts of climate change and collaborating on the design and maintenance of retrofit sustainable drainage to improve flood risk and water quality from road runoff.