Flood investigation policy

Introduction

The Flood and Water Management Act (FWMA) 2010 designates all county and unitary authorities as Lead Local Flood Authorities (LLFA) and sets out a number of powers and duties for flood 'risk management authorities'.

Flood risk management authorities in Lancashire County Council's area include:

  • Lancashire County Council* as the Lead Local Flood Authority and local Highway Authority
    (Blackpool Council and Blackburn with Darwen Council are Lead Local Flood Authorities and Highway Authorities for their administrative areas.)
  • District Councils which include Burnley, Chorley, Fylde, Hyndburn, Lancaster City, Pendle, Preston City, Ribble Valley, Rossendale, South Ribble, West Lancashire and Wyre Councils.
  • Environment Agency
  • Water and Sewerage Companies, including United Utilities and Yorkshire Water
  • Internal Drainage Boards (IDB), such as in Earby and Salterforth

You can read more about the roles and responsibilities of flood risk management authorities in our Local Flood Risk Management Strategy.

 An introduction to flood investigations

The Lead Local Flood Authority, upon becoming aware of a flood, has a duty under Section 19 of the Flood and Water Management Act 2010 to investigate a flood in its area to the extent that it considers it necessary or appropriate.

The purpose of an investigation under Section 19 of the Flood and Water Management Act (2010) is to establish:

  • which risk management authority(s) has relevant flood risk management functions, and;
  • whether each risk management authority(s) has exercised, or is proposing to exercise, those functions in response to the flood.

The policies in this document set out the extent to which Lancashire County Council, as the Lead Local Flood Authority, will investigate a flood incident and publish its results in accordance with its duty. Policies are clearly stated in blue policy boxes.

This document is intended to be read alongside other guidance and information on our website.

Why it is important to report a flood incident

The term ‘flood’ is defined in Section 1 of the Flood and Water Management Act 2010 as:

"includes any case where land not normally covered by water becomes covered by water."

It does not include flooding from a burst water main or any part of the sewage network (unless caused by the volume of rainwater entering the system).

Lancashire County Council, as the Lead Local Flood Authority, strongly encourages all flood incidents to be reported to us so that we can investigate these in accordance with the county council's duty and policies outlined in this document.

If you have flooded but don’t report the flood incident to us, we are unlikely to be able to validate and investigate. You can read more about the importance of reporting flooding on The Flood Hub.

Investigation approach

Upon receiving a report of a flood incident, the Lead Local Flood Authority will undertake an initial assessment to establish and validate the extent and location of the flood incident, in accordance with Policy INV1.

In its role as the Lead Local Flood Authority, Lancashire County Council will take a tiered approach to investigating reported flood incidents in Lancashire as set out in Policy INV2. Both the scale and the frequency/duration of the flood incident will determine the subsequent output produced from the investigation.  

Officers may contact those affected and other flood risk management authorities to get more information so we can understand what has happened.

Undertaking a flood investigation takes time, so officers may signpost those affected to where they can access advice and support in the meantime.

Flood risk management authorities and those affected by flooding are encouraged to take appropriate and proportionate action(s), where needed, arising from any research of their own into the flood incident. Flood risk management authorities and those affected should not wait for the output of the Lead Local Flood Authority's flood investigation before taking any necessary action.  

Flood investigation policies

Flood awareness  

The Lead Local Flood Authority requires a minimum level of valid information direct to the Lead Local Flood Authority in a reasonable time to become aware of a flood in its area.

Further information on how to make the Lead Local Flood Authority aware of a flood can be found in the guidance document.

This policy explains the information required to make the Lead Local Flood Authority aware of a flood in its area.

INV1: Flood awareness information policy

A minimum level of valid information direct to the Lead Local Flood Authority within a reasonable time is required for the Lead Local Flood Authority to be made aware of a flood.

The minimum level of information is all of the following:

  1. Date, time and duration of the flood
  2. Location and/or address of flood
  3. Number and type of residential dwelling and/or business / commercial building and/or critical infrastructure and/or agricultural land affected
  4. Whether the flood is internal or external, or both
  5. Whether flooding has occurred before in the same location or address
  6. Whether the flood is related to a burst water main or any part of a sewerage system, or domestic drainage

For the avoidance of doubt, no investigation will be necessary or appropriate due to:

  1. Flooding from any part of a sewerage system, unless wholly or partly caused by an increase in the volume of rainwater, including snow and other precipitation, entering or otherwise affecting the system.
  2. Flooding caused by a burst water main, within the meaning given by section 219 of the Water Industry Act 1991.

Flood investigation  

To prioritise and focus resources on investigating a flood known to the Lead Local Flood Authority, a tiered approach will be taken. This aims to provide transparency about the extent to which a flood is investigated as necessary or appropriate and ensure that the outputs of all flood investigations are proportionate and informative.

INV2: Flood Investigation Policy

The Lead Local Flood Authority will investigate reports of flooding only when:

a) Policy INV1 has been satisfied;

and

b) the threshold for any one of the Tiers in Table 1 in this policy has been met, indicating that an investigation is necessary or appropriate;

and

c) there is satisfactory evidence of internal flooding to any residential dwelling or business / commercial building affected. For the purpose of this policy:

  1. 'Internal flooding to the residential dwelling' refers to a habitable room inside a dwelling that is affected by flooding.

    (Rooms that are not usually used for living in are not considered habitable, such as garages, cellars and porches. Rooms converted for habitable use must have a building regulations certificate.)
  2. 'Internal flooding to the business / commercial building' refers to an effect of flooding directly causing significant business interruption to the business/commercial enterprise involved.
  3. The 'internal flooding' definition is not applicable to externally located critical infrastructure5 in Tier 2, for example, roads and railway lines;

and

d) where it is reasonable to assume that any affected dwellings and/or business / commercial buildings were flooded from the same source or same interacting sources, except for Tier 5.

For the avoidance of doubt, no investigation will be necessary or appropriate due to:

  1. Flooding from any part of a sewerage system, unless wholly or partly caused by an increase in the volume of rainwater, including snow and other precipitation, entering or otherwise affecting the system.
  2. Flooding caused by a burst water main, within the meaning given by section 219 of the Water Industry Act 1991.
Table 1: Flood Investigation Tiers
Tier Threshold Published investigation Output
Scale Frequency or duration

1a

Between 1 and 4 residential dwellings and/or business / commercial buildings

Repeated within 5 years

Flood incident register

1b

Best and Most Versatile (BMV) agricultural land classified as Grade 1 and/or Grade 2 and/or Grade 3a affected by flooding of 1 hectare or more

Repeated within 5 years

Flood incident register

2

Critical Infrastructure
(Critical Infrastructure investigations under Section 19 will not take place if the infrastructure owner or operator is conducting their own investigation. Critical Infrastructure refers to: Railway lines and stations; resilient route network of vehicular highway, trunk roads and motorways; utility infrastructure including electricity generating power stations, power lines, substations and wind turbines, water treatment works and sewage treatment works; police, ambulance and fire stations and command centres; telecommunications installations; hospitals; Universities, colleges and schools; Local authority main offices; Residential institutions such as care homes, children’s homes, social services homes, prisons and hostels.)

affected for 3 or more consecutive hours

Once

Flood incident register

3

Between 5 and 9 residential dwellings and/or business / commercial buildings

Once

Flood incident register

4

10 or more residential dwellings and/or business / commercial buildings within the same area

Once

Flood incident register

and

Flood investigation report

5

An identified wide-scale flood incident as defined by the Lead Local Flood Authority

Once

Flood incident register

and

Flood investigation report

Flood incident register

The flood incident register will be published online to improve transparency and confidence in how flood incidents which meet the criteria set in Policy INV2 are investigated by the Lead Local Flood Authority.

Section 19 of the Flood and Water management act requires the Lead Local Flood Authority to:

  1. publish the results of its investigation, and;
  2. notify any relevant risk management authorities.

An investigation is required to identify:

  1. which risk management authorities have relevant flood risk management functions, and;
  2. whether each of those risk management authorities has exercised, or is proposing to exercise, those functions in response to the flood.

The Lead Local Flood Authority will satisfy these requirements using the flood incident register. The register will be published on the County Council's Website and the relevant Risk Management Authorities will be notified.

In addition, there may be a flood investigation report published online in accordance with Table 1 in Policy INV2.

INV3: Flood incident register policy

The Lead Local Flood Authority will produce and publish a register of reported flood incidents which satisfy any one of the Tiers set out in Policy INV2.

The register will contain:

  1. Flood location - to the extent of a road name or locality;
  2. Date of the incident - to the extent of the month and year in which the incident occurred;
  3. Number of residential dwellings and/or business / commercial buildings – to state the number of dwellings or buildings internally flooded;
  4. Flood Source – where this is known, to identify the primary source(s) of flooding;

and

  1. Responsible Risk Management Authority(s) – which risk management authority(s) were identified as having a relevant flood risk management function(s), the date they were notified and whether it has exercised or proposing to exercise their function.