Section 19 Flood Investigations

A Section 19 investigation is the statutory review undertaken by the LLFA following a significant flood event.

It establishes:

• What happened
• How the flooding occurred
• If risk mapping accurately predicted the event
• Which authorities have flood risk management functions
• Whether those functions have been exercised

Every Section 19 Investigation is different.

Sometimes it results in a single report covering the whole event. In other cases, particularly where several communities or mechanisms are involved across a county, it may be appropriate to produce more than one report so the issues are addressed clearly and proportionately.

The investigation should reflect the event.

A Section 19 investigation is typically considered where:

• Flooding has affected multiple properties
• There is public concern about how the event was managed
• The mechanism of flooding is disputed or unclear
• Multiple authorities may have relevant responsibilities

In practice, these reports often follow significant rainfall events or named storms. They aim to provide formal clarity before progressing mitigation, funding bids or further catchment work, and stand as a historic record of what occurred for future reference.

Each investigation is tailored to the event, but typically includes:

• Site visits and inspection of flood pathways
• Review of rainfall data and available modelling
• Engagement with affected residents
• Liaison with the Environment Agency, water companies, highways and other RMAs
• Review of asset performance where relevant

The output is usually a structured report that sets out the mechanism of flooding, the impact and the relevant responsibilities, together with any agreed next steps.

Section 19 of the Flood and Water Management Act 2010 places a duty on the Lead Local Flood Authority to investigate flooding where it considers it necessary or appropriate.

In simple terms, if a significant flood occurs, the authority must look at:

• which risk management authorities have relevant flood risk management functions, and
• whether those functions have been exercised or are proposed.

If an investigation is undertaken, the findings must be published and the relevant authorities notified.

A Section 19 report is how that duty is discharged. It provides a clear, proportionate record of the event and the response.

(a) Publish the results of its investigation, and
(b) Notify any relevant risk management authorities.

For us this is not an abstract statutory exercise.

Our Director founded FPS Environmental Ltd after his family home – a recently built property with no mapped flood risk at the time – was flooded in 2007 and uninhabitable for almost a year. It is a direct example of how flooding affects households long after the rain has stopped, and why clear investigation and accountability matter.

Flooding is not something only one person in the business has experienced. Our Marketing Director’s home – built in the 1980s, long before detailed risk mapping and mitigation standards were in place – has also been flooded. The concern about how flood risk is managed, investigated and communicated is shared across our senior leadership team.

Section 19 reports need to be clear and proportionate. The aim is to establish what happened and record it properly.

We bring practical site experience, engineering judgement and local authority delivery into that process.

Our work with Cranfield University on community flood groups also informs how findings are communicated and understood locally.

Read more about the Cranfield study here.

The County of Lincolnshire has suffered extensive flooding as a result of two major storms. Storm Babet occurred between 16th October 2023 – 21st October 2023 and Storm Henk took place on 2nd January 2024. Many properties, residential and commercial, and huge areas of land were inundated by flood water. As a result, Lincolnshire County Council (LCC) tasked FPS Environmental to undertake Flood Investigations in order to determine the issues and propose recommendations in response to the flooding.

It wasn’t a single issue. Different communities were affected in different ways, so separate reports were prepared rather than trying to collate everything into one document.

The focus in each location was the same – what happened, how the water got there, how assets performed and which authorities had relevant responsibilities.

We walked the sites, spoke to residents and worked with the Environment Agency, the water company and highways to piece together what had occurred. Rainfall data, sewer records, and local records were reviewed alongside what we saw on the ground.

Section 19 investigations are one part of our work for councils.

FPS also prepare Strategic Flood Risk Assessments to support Local Plans, review site-specific Flood Risk Assessments for planning authorities and undertake Flood Surveys following storm events. In more complex locations we prepare detailed Flood Investigation and Management Strategies where a deeper catchment review is required, or work with communities to implement catchment schemes, or Natural Flood Management.