Flood Risk Assessment in St Neots

A flood risk assessment in St Neots starts with more than the Great Ouse. Six smaller watercourses join the river in or beside the town. When Cambridgeshire County Council investigated the floods of December 2020, it traced much of the damage to the Fox Brook, the Hen Brook and the Duloe Brook overtopping and to drains that could not empty, as well as to the river. Our consultants write flood risk assessments in St Neots for planning, for buyers and mortgage lenders and for insurers, along with sequential and exception tests and surface water drainage strategies. Reports for sites in St Neots come from Unda Consulting Limited, a CIWEM Business Partner.

St Neots, Cambridgeshire, grew out of four old settlements on both banks of the river: St Neots itself around the Market Square, Eynesbury to the south, and Eaton Ford and Eaton Socon on the west bank. Love's Farm and the newer Wintringham neighbourhood stretch east beyond the railway, and the whole town shares the PE19 postcode district. Little Paxton, a separate village just north across the river, is covered by the same Huntingdonshire flood evidence, and in December 2020 it shared a Great Ouse flood warning with the town.

On 27 December 2020 the Great Ouse at the St Neots gauge reached 1.85 m, the highest level it has recorded. The Environment Agency's own threshold for property flooding there is 1.84 m.

For a free quote on a St Neots site, call one of our consultants on 01293 214444 or email enquiries@unda.co.uk.

The Great Ouse and the six brooks that meet it in St Neots

The county council's investigation reports describe St Neots as sitting in the Great Ouse valley, liable to river flooding "particularly to the west of the river", at the meeting point of six tributaries. Four of the seven channels are main rivers, which the Environment Agency regulates; the other three are ordinary watercourses, where the county council and the owners of the banks are responsible.

The Great Ouse is the St Neots river most people picture, but the brooks matter because they cannot drain while it is high. When the Great Ouse stays up for days, the Hen Brook, the Duloe Brook and the surface water sewers that feed them back up, which is how streets well away from the riverbank flood. Our River Great Ouse page follows the river from Bedfordshire to the Wash, and our live river levels map shows the St Neots and Eaton Socon gauges and any warning in force.

Look up a PE19 postcode on the flood map

Enter a postcode below to screen an address in St Neots against Environment Agency data for rivers, surface water and reservoirs, or open our full flood risk map for anywhere in England. The coral outline is the town as the Office for National Statistics maps it in 2022: Eaton Socon, Eaton Ford, Eynesbury and Love's Farm fall inside, while Little Paxton is mapped as a village of its own and much of Wintringham was built after the outline was drawn.

St Neots floods on record, 1947 to the 2020 major incident

The county council lists 1947 and 1998 as the town's major floods, with smaller ones in 1978, 1982, 1993, 2000, 2001, 2003, 2004, 2007, 2008, 2012 and 2014. The recent events are the best documented:

1. March 1947. The snowmelt flood that swamped much of the Great Ouse valley. The St Neots Museum calls it the worst flooding in living memory, with many people rescued from their homes, and aerial photographs from that year show water around St Mary's Church. Our article on the 1947 floods covers the wider event.
2. 1998. The most significant flood of its scale before 2020. That Christmas, several Great Ouse gauges recorded levels above their 1998 peaks.
3. 13 and 16 August 2020. About 36 mm of rain fell in two hours on the 13th and about 40 mm in under an hour on the 16th, on ground baked hard by a dry summer. Seven homes flooded internally, on Drake Road, Monarch Road and Marchioness Way in Eaton Socon, Howitts Lane in Eynesbury and Hempsals in Eaton Ford, as road drains and Anglian Water sewers were overwhelmed.
4. 23 to 27 December 2020. Up to 52.6 mm fell in 17 to 18 hours on saturated ground and a major incident was declared on the 23rd. Surface water came first, then the river and the brooks on the 24th; the county council received 34 flood reports, 14 of them from homes flooded inside. The St Neots gauge peaked at its record 1.85 m on the 27th.
5. 28 September 2024. The Eaton Socon gauge set its own record of 0.93 m, after a month's rain fell on the upper Great Ouse catchment in under 48 hours. No St Neots flood investigation for that event is listed by the county council.

Sewers are part of the town's flood record too. Huntingdonshire's 2024 Strategic Flood Risk Assessment found the district's largest numbers of recorded sewer flooding incidents in St Neots, Huntingdon and St Ives. In December 2020, homes on Navigation Wharf saw foul water rise through toilets and baths while the river was high. Our guide to sewer flooding explains how an assessment deals with it.

Gauges, embankments and the Riverside car park flood gates

Two Environment Agency stations on the Great Ouse give the town a working scale. They behave very differently, so a reading at one cannot be compared directly with the other:

• St Neots (station 6174). Normal range 0.82 m to 1.10 m; low-lying land may flood above 0.95 m; property flooding is possible above 1.84 m; highest recorded 1.85 m on 27 December 2020.
• Eaton Socon (station 6173). Normal range only 0.04 m to 0.10 m, with low-lying land at risk above 0.10 m; highest recorded 0.93 m on 28 September 2024. No property threshold is published for this gauge.
• Embankments. The Environment Agency's two St Neots embankments are listed in the 2024 SFRA with a 1% (1 in 100 year) standard of protection; in December 2020 the defence line was neither breached nor overtopped.
• Riverside car park. Since 2010 the Riverside car park has acted as a flood storage basin when gates across its entrance are closed, protecting The Paddock in Eaton Ford. The December 2020 report asked the Environment Agency and the district council to review how the gates are closed.

Defences change the picture without removing the need for an assessment. In 2020 the worst depths were on the river side of the defences and in defended streets where sewers surcharged, so a St Neots site behind an embankment still has to show what happens if the river rises above it or the drains cannot empty. Policy LP 5 asks for breach modelling on defended brownfield land, and the 2020 floods show why.

Which policies decide a planning application in St Neots?

Huntingdonshire District Council decides applications in St Neots under Huntingdonshire's Local Plan to 2036, adopted on 15 May 2019. Policy LP 5 sets out the flood risk tests and expects development to be safe for all in a 1 in 100 year flood with climate change, without relying on the emergency services. Policy LP 15 requires sustainable drainage to the Cambridgeshire Flood and Water SPD, and asks for water-retaining features where a scheme drains to the Great Ouse. A replacement plan to 2046 is out for comment until 28 October 2026, with submission planned by the end of December.

• The draft flood policy. Draft Policy LP 21 in the Pre-Submission Local Plan to 2046 adds hydraulic modelling where none exists, a survey of any culvert on the site and its blockage risk, and groundwater monitoring between October and March where a site is at risk. Draft Policy LP 23 ties drainage to the national standards for sustainable drainage.
• The current SFRA. JBA Consulting's Level 1 Strategic Flood Risk Assessment of March 2024 replaced the 2017 study, and a Level 2 assessment followed in November 2025. The site sheets from 2017 that still appear in searches, for Cromwell Road North and the fire station, are earlier work.
• Climate change on the river. With no modelled climate change outlines from the Environment Agency, the SFRA treats today's Flood Zone 2 as a stand-in for Flood Zone 3 in future. For the Upper and Bedford Ouse it lists 2080s peak flow increases of 19%, 30% and 58% on the central, higher central and upper end figures; our note on climate change allowances explains which applies.
• Floor levels. The SFRA repeats the Environment Agency's advice that new floors sit 300 mm above the 1% flood level with climate change.
• County drainage rules. Cambridgeshire County Council's Surface Water Planning Guidance of February 2026 sets an infiltration rate of at least 1 x 10⁻⁶ m/s for soakaways, with their base 1.2 m above the expected groundwater level.

Nationally, chapter 18 of the August 2026 NPPF applies: policy F4 says when an assessment is needed, F5 and F6 set the sequential and exception tests, and F8 expects every development to follow the 2025 national standards for sustainable drainage. How the county council reviews drainage across all five Cambridgeshire districts is set out on our Cambridgeshire County Council page.

St Neots East, Tithe Farm and the other growth sites

Most new housing in St Neots is going east of the railway. The 2046 plan carries forward St Neots East and adds two sites, and each comes with flood and drainage conditions written into the allocation:

Sewage is a constraint as well as rain. The draft plan says the St Neots water recycling centre has no spare capacity for St Neots East and is likely to reach or pass its permit during the plan period, so applications need Anglian Water's agreement that their flows can be treated. A windfall site outside these allocations starts with testing alternative sites if any part of it is at risk.

Brook, river or drain: when a St Neots site needs a flood risk assessment

Policy LP 5 and national policy decide it, and the answer in St Neots often turns on a brook rather than the river. The table reads the rules against the kinds of site that come forward in the town:

Our guide to when a flood risk assessment is needed covers the national triggers, and our explainer on flood zones 1, 2 and 3 sets out what each zone allows.

Reports we prepare for sites from Eaton Ford to Wintringham

Which report a St Neots site needs depends on who is asking for it, and most sites here have to deal with a brook as well as the river. Our consultants are chartered, and a senior consultant reviews and signs off every report.

• Applications by the river and the brooks. Homes, conversions and commercial schemes in the Great Ouse, Fox Brook or Hen Brook flood zones need a flood risk assessment for planning that answers Policy LP 5 and the 2024 SFRA.
• The river, the brooks and the sewers together. A flood risk assessment in St Neots weighs high river levels, brooks that cannot drain, surface water and surcharging sewers as one picture, because that is how the town flooded in 2020.
• Before exchange near the brooks. Searches flag streets such as Navigation Wharf, Hampden Way and Crosshall Road, and a flood risk survey for property purchase answers for one house.
• Homes on land at risk. New housing in Flood Zone 2 or 3 needs the sequential and exception test before the council can approve it. The 2017 SFRA put two-thirds of the old fire station site on Huntingdon Street in Flood Zone 2.
• Drainage evidence for the council. The county council reviews major schemes against its February 2026 guidance, and the mudstone under much of the district drains slowly, so most St Neots applications need drainage strategy work of some kind.
• Greenfield rates east of the railway. The Tithe Farm and Potton Road allocations must hold runoff to greenfield rates, and a surface water drainage strategy sizes the balancing ponds, swales or tanks that do it.
• After permission. Where a Huntingdonshire permission carries a drainage condition, discharge of drainage conditions supplies the details and the maintenance plan the council asks for.
• Brooks with no model. The ordinary watercourses at Potton Road and north of Wintringham Hall have no detailed model, and the 2025 SFRA says modelling may be needed at the application stage; flood modelling provides it.
• Warnings that arrive late. The December 2020 river warning went out close to or after the first homes flooded, and a flood warning and evacuation plan sets out what a building does before and after the alert.
• Homes that have flooded. With 21 homes reporting water inside across the two 2020 events, a flood risk assessment for insurance gives an insurer evidence for one property rather than a postcode.
• Shops and offices round the Market Square. Water stood 106 cm deep outside a riverside business off the Market Square in December 2020, and a business continuity flood risk assessment plans how a firm keeps trading through a flood.
• New employment land. St Neots East includes 22 ha for offices, workshops and warehouses, and a BREEAM flood risk assessment covers the Pol 03 credits on those buildings.
• Sewage capacity. With the St Neots water recycling centre near its permit, a foul drainage strategy shows Anglian Water and the council where a scheme's wastewater goes.
• Land before an offer. On a large greenfield site such as Tithe Farm, a flood risk feasibility study shows early how much of the land the brook and its flow paths leave for building.

Reporting flooding and getting warnings in St Neots

If floodwater threatens anyone in St Neots, call 999, and call 105 if the power goes off. Otherwise, each body below looks after a different part of the town's flood risk:

Owners of land along the Duloe Brook and the other ordinary watercourses carry the maintenance duty themselves. In April 2026 a St Neots homeowner was reported to face a five-figure bill after the county council found the Duloe Brook in poor repair, a case our article on riparian rights and responsibilities opens with.

The wider county is covered on our Cambridgeshire page. Upstream, the Great Ouse comes in from Bedfordshire; downstream, past Huntingdon, it reaches St Ives, whose own gauge record also dates from Christmas 2020. Cambridge and Peterborough have pages of their own. Every other town and county we write about is in the list of areas.

Flooding in St Neots and Eaton Socon: what clients ask us

Unda Consulting Limited prepares flood risk assessments, sequential and exception tests and drainage strategies across St Neots, on both banks of the Great Ouse and east of the railway at Love's Farm and Wintringham. To talk about a site, call 01293 214444 or email enquiries@unda.co.uk.