Flood investigation reports

1.0 Introduction

This report presents a formal flood investigation conducted under Section 19 of the Flood and Water Management Act 2010 in response to a significant surface water flood event on 20 July 2025 at the junction of Rockingham Road and Britannia Road in Kettering, North Northamptonshire.

The purpose of this report is to:

• document the circumstances of the flood
• assess impacts on people, property, and infrastructure
• investigate likely causes
• clarify the roles and responsibilities of Risk Management Authorities (RMAs)
• recommend actions to mitigate future risk

The investigation draws on council records, technical datasets (where available), and anecdotal information from affected residents. All resident-reported evidence is clearly indicated as unverified pending technical confirmation. The report is intended for public release.

This report was produced by Kier on behalf of North Northamptonshire Council and has been prepared by suitably qualified drainage and flood risk engineers. The report has been independently technically reviewed and approved by a Chartered Engineer in accordance with good industry practice and the requirements of Section 19 of the Flood and Water Management Act 2010.

Any information included within this report was up to date as per completion date of the report. All links to other documents are relevant at the time of publishing.

2.0 Event summary

Table 1: Event Summary

On the afternoon of 20 July 2025, a short but intense convective storm caused surface water flooding at the Rockingham Road/Britannia Road junction. Heavy rainfall quickly overwhelmed highway gullies and the combined sewer system, leading to surcharge and overland flow. Appendix C shows the believed overland flow routes and the associated areas of concern.

Floodwater entered one property (XX Rockingham Road - confirmed in two resident reports). Depths have been estimated at 20-30cm in parts of Britannia Road from video footage received. Due to a lack of evidence, actual depths cannot be confirmed, however the road level depth is estimated between 0-49mm (based off Flood Submission Report). Residents stated that the junction (where Britannia Road and Rockingham Road intersect) became impassable for smaller vehicles. Flooding peaked between 5pm to 5:30pm and had largely reduced by 5pm.

The event is said to be consistent with earlier surface water flooding incidents in this location (2013, 2020, 2023), underlining the area’s vulnerability to short duration, high-intensity rainfall.

3.0 Previous flood events

Table 2: Previous Flood Events

4.0 Key stakeholders

Table 3: Key Stakeholders

5.0 Flood mechanism summary

Primary Source: Surface water (pluvial) flooding.

Secondary Influences:

• Combined sewer capacity exceeded (supported by Anglian Water monitoring data)
• Gully efficiency reduced by spacing, on-street parking, and maintenance challenges
• Topography: steep gradients on Britannia Road, Charles Street and Pollard Street funnelling flows towards Rockingham Road
• Potential runoff from recent development at the former Kettering Town Football Club site (infiltration drainage design-below)
• Highway camber changes potentially altering runoff routes
• Properties along Rockingham Road (XX-XX) particularly exposed to overland flow paths.

Source(s) of flooding

Pluvial Water (Surface Water)

Figure 1 Surface water map - EA Flood Maps for Planning

Pluvial flooding is believed to be the main source of flooding. From resident accounts the surface water flows straight down Britannia Road and across Rockingham Road straight into property XX. However, in Figure 1, this is not currently reflected in the modelled data from the EA.

Fluvial Water Risk (River)

Figure 2 Flood zones map - EA Flood Maps for Planning

It is not believed the flooding is from a fluvial source due to the site location being upstream of the existing watercourse shown in Figure 2.

Sewer

The surcharged sewer is a combined sewer (conveying both foul (wastewater) and surface water flows in a single pipe). This means a risk of foul flooding is present. Residents have also expressed concern about the sewer capacity along Rockingham Road, the locations of which can be seen in Figure 3 below.

Summarised comments from Anglian Water representative (supporting evidence found in Figure 4 below.

“My personal view of this issue is down to location of the property, The property is situated at a low point on Rockingham Road/Britannia Road, with a dropped kerb creating a low spot where highway runoff can collect. Gully maintenance is hindered by parked cars covering the grates, reducing drainage effectiveness and causing blockages from debris. Monitoring data from the foul/combined sewer over the past three months, including during recent heavy rainfall, shows no exceedance of the spill level, indicating the main sewer is operating normally. Any peaks observed returned to baseline levels promptly.”

Figure 3 Anglian Water Foul, Surface and Combined sewers map

Figure 4 Anglian Water data from monitoring equipment in combined sewer

Groundwater Flood Risk

Initial discussion with the residents was over whether the flooding was groundwater oversaturation or surface flooding. Based on observations, and due to the event coinciding with rainfall events, it is unlikely that the flooding is solely
groundwater flooding as the sites are dry during periods of no rain.

Figure 5 Groundwater Vulnerability Map - Magic Defra website

However, Figure 5 does highlight a soluble rock risk and high groundwater risk for the locations opposite the property.

If active dissolution is not happening but the area has potential for dissolution this should be taken into account before starting new buildings or changes in land use:

• Maintain drains, water mains, swimming pools and ponds to ensure they do not leak
• Ensure building foundations are designed to span likely cavities
• Determine the nature of rockhead before construction
• Do not dispose of surface water to soakaways
• Do not create concentrations of surface water draining from hardstanding, roads or paths that may infiltrate the ground at a single point
• Do not lower the water level in the ground, change the ground water flow or the surface water flow without considering the consequences for dissolution hazards

Figure 6 Extract from BGS Hazard Information

This includes an area of recently redeveloped land. A review of the planning application shows that the current drainage system relies on infiltration. However, in areas of soluble rock risk, the guidance is as seen in Figure 6. Below identifies the application Development Drainage Strategy (Former Kettering Town Football Club, Planning Ref KET/2020/0101) in line with Figure 6 information:

• Infiltration drainage adopted following trial pit testing in 2018 and 2021 (BRE365), indicating favourable infiltration in Northampton Sand Formation
• However, desktop research shows the site lies within a high groundwater risk and soluble rock hazard area. Guidance advises against concentrated infiltration in such settings due to dissolution and groundwater risks
• This presents a conflict between site-specific test data (favourable) and broader geological guidance (cautionary). Further independent review is recommended

Seagrave Developments provided comment on potential influence of groundwater vulnerability can be found below (Table 4).

Table 4: Seagrave Developments’ response to flood event

Seagrave Developments (Developer Response, Sept 2025)

No flooding has been reported to the developer by residents or site staff.

One previous flooding report from Anglian Water was investigated but related to an incorrect address.

Provided technical evidence including:

• Flood Risk Assessment Rev H (2018) with single trial pit infiltration testing
• Infiltration Testing Report (2021) with five trial pits tested in accordance with BRE365
• Drained Area Plan and soakaway sizing calculations (2021)
• Results demonstrated good infiltration potential in the Northampton Sand Formation
• Developer concluded infiltration drainage was a suitable design solution and contest any link between the development and reported flooding

6.0 Summary of incident reports - Rockingham Road, Kettering

Incident reports were collated from residents of Rockingham Road following the flood event. These have been summarised below, with the full accounts to be found in Appendix C:

XX Rockingham Road – Resident: XX

• 2013 - Heavy rain caused surface water to pool at the front of the property and enter the lower floor through the wall around a service pipe - water also entered laterally from the neighbouring property beneath paving slabs - the
  soakaway was overwhelmed - blocked gullies on Rockingham Road contributed to the problem - manual clearance of leaves reduced some of the flow but did not prevent flooding
• 2023 - A severe storm resulted in rapid overland flow from both Rockingham Road and Britannia Road - water entered through the garage and flooded the basement, causing significant damage (insurance claim of approximately £20,000) - a private drain was installed along the garage frontage, and a shared drain was added with the neighbour
• 2025 - An intense short-duration downpour led to calf-deep water on the highway - road drains were either blocked or inaccessible due to depth and flow - clearing gullies had minimal impact - water also affected nearby properties (XX, XX) - the resident noted this event demonstrated that highway drainage capacity is inadequate during storm events

XX Rockingham Road – Resident: XX

• Long-term flooding issues over a 27-year period, with water entering the carport area during every heavy rainfall event
• A wall was previously constructed to deflect flows, but pooling continues (approximate depth 6.5 cm)
• Debris is consistently deposited at the front and rear of the property
• Identified blocked upstream gullies, tree and leaf debris, and downhill topography as contributing factors
• Dropped kerbs allow water to flow into lower-lying properties

XX Rockingham Road – Resident: XX

• After heavy rain, surface water travels down the road and into the driveway and garage, carrying dirt and leaves
• Recurrent clean-up is required following rainfall events

XX Rockingham Road – Resident: XX

• 2023 - Floodwater entered through side and front doors
• 2025 - Water rose through the basement floor, damaging flooring and electrics

XX Rockingham Road – Resident: XX

• Since 2018, experienced several near-flooding events with water rising up to two or three brick courses
• Manual sweeping is required during storms to divert water away from the property
• Neighbouring properties have experienced internal flooding
• Observed heavy debris accumulation in nearby gullies, uncertainty around the maintenance status of a drain on the footpath, and potential increased runoff from new development opposite the property
• Flooding is exacerbated by topography and upstream drainage issues

XX Rockingham Road – Resident: XX

• Repeated flooding incidents since 2021, resident stated with overland and foul water (while a combined sewer runs along Rockingham Road, there is currently no evidence to suggest that sewage surcharging has occurred)
  entering the garage and garden.
• Flooding originates upstream at XX Rockingham Road and flows down
• Sandbags are permanently in place to manage risk
• Resident notes increasing frequency and severity of incidents

XX Rockingham Road – Resident: XX

• Excess rainwater has flooded front and back paths, which has then washed the sand and subsequently dropped the path
• The path is now damaged

Key Common Themes

• Repeated surface water flooding during heavy or intense rainfall events
• Main source of flooding is highway runoff from Rockingham Road and Britannia Road
• Blocked or undersized drainage infrastructure upstream significantly contributes to flooding
• Topography results in water flowing downhill into properties that sit lower than road level
• Residents frequently rely on private mitigation (e.g. drains, walls, sandbags, sweeping) to reduce damage
• Reports indicate increasing frequency and severity of events over time
• Debris accumulation and poor gully maintenance are recurring issues
• There is uncertainty regarding drain adoption and maintenance responsibilities

7.0 Key causes

Following our review of all available information, and data. It is believed the following factors are the reason for the repeated flooding.

Table 5: Key Causes

8.0 Stakeholder roles and responses

Following the flooding event, North Northamptonshire Council, in its role as LLFA, undertook a site visit and subsequently produced a post-event report to assess the circumstances and impacts of the incident. The council’s Highways team carried out gully clearance and maintenance works to ensure continued surface water drainage capacity. It was determined that the Emergency Planning team required no further action in response to the event. Anglian Water completed a sewer survey in September 2024, provided monitoring data to assist in the investigation, and gave comment to support the flood event as a surface water issue. The Environment Agency maintained monitoring and alert operations throughout the event and confirmed that no fluvial flooding had occurred, as water levels at the Slade Brook gauge remained below trigger thresholds. Emergency Services reported no required or undertaken actions in relation to the incident. Seagrave Developments, identified as a relevant stakeholder, contested any association between their development activities and the reported flooding.

9.0 Actions and next steps

The actions outlined below are recommended for delivery by the relevant Risk Management Authorities (RMAs) to effectively reduce flood risk and prevent recurrence of similar events.

Table 6: Actions and Next Steps

10.0 Important links

Get flood risk information for planning in England - Flood map for planning - GOV.UK
Check the long-term flood risk for an area in England - GOV.UK
Magic Defra

Appendices

Appendix A: Table showing incident reports from residents

Table provides information from the impacted parties of Rockingham Road, including previous reports from flood events from 2013 and 2023.

Resident: XX
Address: XX Rockingham Road, Kettering, NN16 XX

Year: 2013
Statement: Around 6am as XX about to leave for work noted extreme amount of water on drive at front of house. This was right up against the house. The same problem was noted at the front of XX.

The weather had been very windy with heavy rain. It was still raining at this point.

Immediately went downstairs to check the lower floor.

Noted water on the toilet floor and behind the baton at the back of the room. Then noted a constant trickle of water coming through the wall around the water pipe.

Immediately started to clear the water to minimise spread. Could not get a bowl under the flow. Could not mop as fast as flow.

Subsequently noted moisture coming up though the carpet in the hall area in front of the toilet and along the hall area towards the back door.

After about ¾ hour estimate, the water in the toilet area slowed and I was able to clear it up. At this point noted the water in the Utility area.

Friends arrived shortly after at which point took panel off stair wall (this was not dripping). No water came out through this area - looking for assurance that no significant pooling was evident.

In the meantime, I opened the shed door at the side of the house to check for any problems. Noted slight amount of pooling which I expected to just clear down the garden. Our friend realised that this water was not clearing down the garden but apparently into the house. We immediately started sweeping the water down the garden and cleared the shed area to identify source of water. This appeared to be coming from under next doors fence. We asked next door to do the same to see if they could see the source of the water. I went round next door to help (they also had flooding). Pooled water was evident at the bottom of their stairs and in their internal shed (opposite side of their house). Next to our house we could see that the water appeared to be coming up under the paving slabs and flowing under our fence. Sweeping continued on both sides until the flow of water was stemmed.

Once flood at the front of the house was noted XX immediately cleared the drain on the road and road gulley of leaves and ensured the flow of water down drain / Rockingham Road. Cleared This stemmed the flow of visible water down onto our drive.

Our soak away was overwhelmed, so no action could be taken at this point.

XX highlighted the problem to our neighbours at XX, at which point they discovered their own flooding.

Action was taken to clear the leaves from the drains surrounding the front of their house.

The water was not sitting on top of the shared area between the houses. Drain in this area was lifted (once rain subsided), speaks for itself, large void. No pooled water so not sure where water which accessed would have gone.

Year: 2023
Statement: Severe storm with thunder and lightning and strong winds. A weather warning had been issued. I personally had cleared the surface of all drains on Britannia Road and Rockingham Road up to and including the drains at the bottom of Charles Street and Pollard Street.

Strong waters flowed from both Rockingham Road and Britannia Road intersecting outside our driveway and then flowed onto our driveway.

Note, that we were powerless to stem the flow due to the speed of water onto the driveway, despite trying the clear road drains. At the time it appeared that having cleared the debris from the drain at the bottom of Britannia Road and placing a broom behind that the water rather than flowing over the drain started to go down it.

Water flow on our driveway tends to flow toward the left-hand side (towards XX and XX). The fact that, in this instance, the significant water damage caused by the flow of water through our garage and into our basement evidences the speed and strength of flow of the water.

At our own expense, we subsequently had a large drain placed along the front of our garage draining into the rear of the property.

This was not the only source of water ingress but was the route that caused the most damage (insurance claim around 20k). Water levels at the side of the house (XX/XX) also rose sharply despite our efforts to keep this below the side door level. As a result, our neighbour had a hole knocked through the wall between the properties and a large drain installed to take water into the rear garden.

Year: 2025
Statement: Sudden downpour.

We understand from our neighbour that the duration of the water flowing onto our drive was only around 7 minutes (information derived from his security camera).

Obviously our first action is to check that drains in the immediate vicinity are free from debris. What was obvious was that the depth of water flowing both along Rockingham Road and down Britannia Road made locating the drains very difficult. I cleared the (new) drain at the bottom of Britannia Road but saw no indication of a change to water flow. I am not sure if this indicated that the drain was not taking water due to depth & speed of the water. The drain further up, on the same side, was underneath a vehicle so I could not see the water flow but noted at the end it was clear of debris. I also noted that the drain on the path outside XX was blocked, this is the drain into which the narrow NNC gulley along the front of our drive links, against the flow of water (2014 element of the council solution).

In this instance that clearing the immediate road drains felt like tinkering at the edges of the issue. I understand from a friend that when she stepped out of her car, parked in front of our house, into the road the water was calf deep. You can see significant depth from the video provided as cars drive through (creating waves).

I understand that XX escaped damage but the gentleman that lives there had to intervene at XX to prevent flooding there. I also understand that action had to be taken at XX (currently being turned into a children’s care home) to prevent property flooding. These are further indicators of the volume of surface water flow on Rockingham Road not being managed through the main drainage channels.

Resident: XX
Address: XX Rockingham Road, NN16 XX

Year: 2025

Statement: We experience flooding every time there is heavy rainfall, be it prolonged or a short, heavy burst. As a result, providing dates would match the forecasted dates for either of the above, the last date being 31/8/25.

We have lived in this property for 27 years and due to flooding soon after moving in, we built a brick wall to re-channel the flow of
water. This helped to a degree however, the water now pools deeply in the car port area of the drive, and on occasion, we have to go out and sweep it down the large drain servicing the kitchen sink waste pipe/outside tap.

A fairly accurate estimate of how deep the water sits is 6.5cm and, it overflows that. (Height of block paving border bricks = 6cm).

After the flood, we have huge deposits of debris both at the front and rear of the property, where the water has streamed between our house and the neighbours’.

I think the cause lies in a number of things. Firstly, there are several blocked drains further up the road which are obviously not drawing any surface water. The road is tree lined, with grass verges and it’s not uncommon to see large vegetation growing out of the draws, possibly due to leaf fall and grass cuttings falling in and germinating seeds.

Additionally, because we are on a decline in the road, the water chases the kerb then, wherever it reaches a dropped kerb, it courses into the properties, many of which are built lower than the road.

Furthermore, due to the lay of the land, a lot of the roads leading off Rockingham Road drain down onto it.

Resident: XX
Address: XX Rockingham Road, NN16 XX
Year: 2025
Statement: After each heavy rain, water leaving the road onto the path farther up from my house picking up dirt and leaves etc, travels down to my house, turning down my drive to the garage, including entering the garage, after which I have an almighty mess to clear up.

Resident: XX
Address: XX Rockingham Road, NN16 XX
Year: 2023
Statement: Flood water creeping in through side & front door.
Year: 2025

Statement: Water coming up through floor of basement office floor ground which is at garden level - caused damage to wooden flooring and knocked out mains electricity through wires/plugs on floor.

Resident: XX
Address: XX Rockingham Rd, NN16 XX
Year: 2025

Statement: We have lived at this address since January 2018. We were not informed of any previous flooding history during the buying process but have since been informed by neighbours, the property had flooded previously.

We have not experienced internal flooding as yet, but have had 4/5 instances over the last 7 years whereby torrential rain has overwhelmed the property and water has risen up to 2/3 brick courses. During these events, we have had to 'push' the water away from the property diverting it to the side entrance to go down the steps leading to the back garden. On two occasions the water was rising rapidly in the back garden also.

Our neighbours either side have experienced water coming into their properties. I understand the requirements for photo/video evidence but unfortunately it isn't your first thought when you are dealing with an immediate risk of flooding.

I recall Anglian Water putting some kind of sensor device into a drain on my property. I have no idea what data this is collecting, if any, I can only imagine it would record the levels of rising water? We also have the new development of houses opposite where the old football ground was. I remember looking at the initial plans and it appeared that a lot of underground drains in the surrounding area converged at the bottom of Brittania Rd.

There will always be debris, leaves etc as this is a main 'tree lined' Rd. Whenever we have long periods of hot weather, the ground will be parched so any subsequent heavy rainfall has a big impact. Drains in the side streets, Charles St for example, were fully impacted with debris, we looked at them. There are certainly areas around this area that always flood and I'm sure you are aware of these. As these side roads run down to Rockingham Rd as it were, you will get rainwater running down this way, if it has nowhere to drain properly.

There is also an open drain on the public footpath directly outside my property in the corner next to a verge. I spoke with one of the drain clearance team a couple of years ago to ask them to jet it. They did do that but also said the drain didn't appear on their records, giving the impression it isn't 'adopted' for maintenance?

We have no idea as to the schedule for drain maintenance and street clearance of fallen leaves etc but have felt we don't see/hear them often.

Resident: XX
Address: XX Rockingham Road, Kettering, NN16 XX
Year: 2025

Statement: I have lived at the current address since 2021. Over the years we have had flood water slushing down the road on numerous occasions; these occasions are becoming more frequent. The water crosses the path from the road, the drains, and the road cannot take the water. The water has debris in it and on occasion sewer water. The water floods into my garage causing a nasty stench and on two occasions the water has gone into an ornamental pond; this has come down XX Rockingham Road, passing down their garage and flooding the garden. I permanently have sandbags in the front and rear garden.

Resident: XX
Address: XX Rockingham Road, Kettering, NN16 XX
Year: 2025

Statement: Excess rainwater has flooded front and back paths, washed sand hand have dropped due to level of water. Path now damaged.

Appendix B: Photographic evidence from residents affected by floods

Pollard Street - 2023 - Filled with debris - Note as of 2024 - resident states gully is still blocked.

Pollard Street - 2023 - Leaf litter present  2024 - resident states gully is still blocked.

Pollard Street - 2023 - Unclear image due to presence of vehicle. Noticeable leaf litter - 2024 - resident states gully is now clear.

Pollard Street - 2023 - Leaf litter present - 2024 - resident states gully is now clear.

Pollard Street, adjacent to the Athletic Club - 2023 - Leaf litter present - 2024 - resident states gully is now clear.

Charles Street - 2023 - Leaf litter present - 2024 - resident states gully is now clear.

Charles Street - 2023 - Gravel and debris infill 2024 - resident states gully is now clear.

Charles Street - 2023 - Infilled gully - 2024 - resident states gully is now clear.

Charles Street - 2023 - Gravel infill - 2024 - resident states gully is now clear.

Charles Street - 2023 - Resident states that water level has not decreased 24 hours post rainfall event. No additional precipitation within that 24-hour period 2024 - resident states gully is now clear.

Charles Street - 2023 - Leaf litter present - 2024 - resident states gully is now clear.

Charles Street - 2023 - Image unclear - resident states presence of gravel blocking water flow - 2024 - resident states gully is now clear, but is prone to having standing water after rainfall event.

Appendix C: Overland flow routes and area of concern

Flow path map for 20 July 2025 flood event.

Glossary

• Adoption (Drainage) - The legal process by which a drainage asset (e.g. sewer, gully, manhole) is formally taken over for maintenance by a public authority such as Anglian Water or a highway authority
• Anecdotal Evidence - Information based on personal accounts and observations rather than measured or independently verified technical data
• Asset - Physical infrastructure such as gullies, pipes, manholes, sewers, or drainage basins that form part of a drainage or flood management system
• BRE365 Testing - A field infiltration testing method based on BRE Digest 365: Soakaway design used to assess soil infiltration rates for the design of soakaways and other infiltration features
• Camber (Highway) - The slight convex shape of a road surface designed to direct surface water runoff toward the edges and into drainage gullies
• Capacity Exceedance - When the volume or flow of water entering a drainage system exceeds the system’s designed capacity, leading to surcharge or flooding
• Combined Sewer System - A drainage network designed to convey both foul (wastewater) and surface water flows in a single pipe
• Convective Storm - A short-duration, high-intensity rainfall event caused by rapid upward movement of warm air, often producing localised flash flooding
• Culvert - A covered channel or pipe that allows water to flow beneath a road, railway, or embankment
• Debris - Material such as leaves, gravel, silt, or litter that can obstruct drainage systems and reduce hydraulic efficiency
• Dropped Kerb - A lowered section of kerb line at property entrances or pedestrian crossings that can act as a preferential flow path for surface water runoff
• Fluvial Flooding - Flooding resulting from watercourses (rivers, streams, or brooks) overtopping their banks or defences
• Flood Risk Assessment (FRA) - A technical study evaluating flood risk to and from a development site and proposing appropriate mitigation measures
• Flood Zones - Mapped areas defined by Environment Agency to indicate levels of fluvial flood risk (e.g. Zones 1–3)
• Foul Sewer - A drainage system that conveys wastewater (e.g., from toilets, sinks, and baths) to a treatment facility, separate from surface water in a separated system
• Gully - A grated inlet along roads designed to collect surface water runoff and convey it into the drainage network
• Gully Maintenance –-Regular cleaning and inspection to ensure gullies are not blocked by debris, vegetation, or parked vehicles
• Groundwater Flooding - Flooding caused by rising groundwater levels that emerge at the surface or infiltrate structures from below ground
• Hazard Information - Data or mapping provided by British Geological Survey indicating potential risks such as soluble rock or groundwater emergence
• Highway Drainage - Drainage infrastructure located within or serving the public highway, managed by the local highway authority
• Infiltration Drainage - A SuDS (Sustainable Drainage System) technique where runoff is directed into the ground through soakaways or permeable surfaces rather than piped sewers
• Incident Report - A record of flooding provided by residents or organisations, detailing observations such as time, depth, source, and impacts
• Internal Flooding - When water enters the interior of a building (e.g., basement, ground floor), as opposed to affecting only external areas
• Lead Local Flood Authority (LLFA) - The local council with statutory responsibility for investigating and managing local flood risk (surface water, groundwater, ordinary watercourses). For this event: North Northamptonshire Council
• Maintenance Responsibility - The organisation legally responsible for upkeep of drainage infrastructure, which can vary between the highway authority, water company, private owners, or developers
• Overland Flow Path - The route taken by surface water as it flows over the ground during rainfall or flood events, typically towards low-lying areas
• Pluvial Flooding (Surface Water Flooding) - Flooding caused by rainfall that is not absorbed by the ground or drainage systems and flows overland
• Ponding - Localised accumulation of standing water on the surface due to insufficient drainage capacity or topographical depressions
• Property Level Protection (PLP) - Flood resilience measures installed at individual properties, such as sandbags, barriers, or private drainage
• Rainfall Intensity - The rate at which rain falls, typically measured in mm/hr. Intense short-duration rainfall can overwhelm drainage systems
• RMA (Risk Management Authority) - Organisations with statutory responsibilities for flood and coastal erosion risk management, including the LLFA, Environment Agency, Anglian Water, and the Highway Authority
• Runoff - Rainwater that flows over land surfaces towards drainage systems or low points, particularly during intense rainfall events
• Section 19 Investigation - A formal investigation required under Section 19 of Flood and Water Management Act 2010 when significant flooding occurs, outlining causes, responsibilities, and recommended actions
• Sewer Surcharge - When the hydraulic grade line within a sewer system exceeds ground level, causing water to back up or escape through manholes or property connections
• Soakaway - A drainage structure designed to allow water to soak into the ground, often used in infiltration drainage systems
• Soluble Rock Risk - A ground condition where rocks such as limestone or gypsum can dissolve, leading to instability or groundwater interaction issues
• Topography - The physical shape and elevation of the ground, influencing surface water flow paths and flood risk
• Trigger Level - A threshold reading on a monitoring system (e.g., river gauge) indicating when action or alerts are required
• Unverified Information - Statements or data provided by residents or stakeholders that have not yet been confirmed through technical or site based verification
• Watercourse - A natural or artificial channel through which water flows (e.g. river, stream, ditch)
• WRMP - Water Resources Management Plan; strategic plan by water companies to ensure supply-demand balance, potentially relevant for flood management context