Flood Risk Assessment in Chester-le-Street

Beneath Chester-le-Street's Market Place runs a river most visitors never see. The Chester Burn, also called the Cong Burn, was culverted in concrete in the early 1930s and then built over again through the 1960s as a market place, supermarket and car parking went in above it — a decision the town paid for on 28 June 2012, when more than 100 homes and businesses at the north end flooded. We prepare a flood risk assessment in Chester-le-Street for planning applications, property purchases, mortgages and insurance, and BREEAM, alongside sequential and exception tests and surface-water drainage strategies, for architects, developers, landowners, homebuyers and businesses working anywhere in the town.

If you would like a quote or want to talk a site through, contact one of our experienced flood risk consultants on 01293 214444 or enquiries@unda.co.uk. Chester-le-Street sits within the wider flood risk assessment in County Durham picture, and we also work across neighbouring Sunderland, Newcastle upon Tyne, Darlington and Northumberland — see our full areas we cover.

A culverted river running beneath a town centre, a June 2012 flood that hit over 100 homes and businesses, and a £6.2 million scheme built to hold it to a one-in-100-year standard — Chester-le-Street's flood story is written directly into the ground the town centre stands on.

• Main watercourse: the Chester Burn (Cong Burn), a tributary of the River Wear, culverted beneath the Market Place and running through the town centre before joining the Wear east of the town.
• Local planning authority and Lead Local Flood Authority: Durham County Council, a unitary authority responsible for both planning decisions and flood risk management across the whole of County Durham.
• Flood zone note: parts of the town centre and land near the Chester Burn and River Wear sit within the Environment Agency's higher flood zones — check any specific site using the live checker below.
• The scheme: a £6.2 million Chester Burn flood prevention scheme, completed in three phases between January 2019 and winter 2020, funded by Durham County Council, the Environment Agency and the European Regional Development Fund.
• Speak to one of our experienced flood risk consultants on 01293 214444 for a free, no-obligation quote.

Live flood risk checker for Chester-le-Street

Chester-le-Street is outlined below. Enter any postcode in the town to screen it against Environment Agency data covering rivers and sea, surface water and the planning flood zones, with a climate outlook to 2125. This is an indicative first look, not a substitute for a site-specific flood risk assessment. You can also check current river conditions on the live river levels map.

The Chester Burn: a river hidden beneath the town centre

The Chester Burn, also known as the Cong Burn, is a tributary of the River Wear. It rises to the west, flows around the northern flank of Waldridge Fell and along the western edge of Chester-le-Street, then turns through the town centre before joining the River Wear immediately east of the town. For most of that final stretch, it is invisible: the Burn was first enclosed in a concrete culvert beneath the Market Place in the early 1930s, and further built over through the 1960s as a market place, supermarket and car parking were developed directly on top of it. A watercourse carrying the runoff of a wide rural catchment now runs, largely unseen, beneath one of the busiest parts of the town.

That matters for anyone assessing flood risk here, because a culverted urban watercourse behaves differently to an open river. Culvert capacity is fixed and can be restricted by debris, silt or structural constraints, so once inflows exceed what the buried channel can carry, water has nowhere to go but back up and out across the surface above it — exactly the mechanism that drove the town centre flooding in 2012. Durham County Council is the Lead Local Flood Authority for the whole of County Durham, including Chester-le-Street, and it is also the Local Planning Authority — a dual role that makes it the single most important consultee on any development here. It maintains the county's Strategic Flood Risk Assessment and a Surface Water Management Plan covering the town, while the Environment Agency's gauging station on the River Wear at Chester-le-Street has recorded a maximum level of 4.055 metres, logged at 12:00 on 18 July 2009. Water and sewerage in the town are provided by Northumbrian Water, relevant wherever sewer flooding or a surface-water drainage strategy is part of the picture — every flood risk assessment we prepare also looks at groundwater as one of the sources that can affect a site, alongside rivers, surface water, sewers and reservoirs.

A history of flooding in Chester-le-Street

Chester-le-Street's flood history is older than the culvert. Chester-le-Street Heritage Group records a "Great Flood" in November 1771, when the River Wear extended roughly 200 yards from north to south through the street, flooded the local collieries and drowned more than 30 horses. In 1789, the Wear was recorded as more swollen than at any time since 1771: lowlands flooded, an iron forge-mill at Braken Hill was swept away, and damage was put at around £800. In February 1822, a tempestuous south-westerly wind combined with heavy rain to push the Wear above the arch of the town's new bridge and more than a quarter of a mile from the river channel.

• November 1771 — the "Great Flood". The River Wear extended around 200 yards through the street; collieries flooded and over 30 horses drowned.
• 1789. The Wear rose more than at any time since 1771; an iron forge-mill at Braken Hill was destroyed and damage cost around £800.
• February 1822. Strong south-westerly winds and heavy rain pushed the river more than a quarter of a mile beyond its channel, over the new bridge's arch.
• 28 June 2012. More than 100 homes and businesses at the north end of Chester-le-Street flooded, with the Chester Burn the main cause — Front Street, the Market Place, Cone Terrace and Hopgarth were all affected.
• February 2022. The Environment Agency monitored prolonged high levels on the Lower River Wear after heavy rain, with levels at Chester-le-Street forecast to peak — a reminder that this reach is actively watched rather than a one-off after 2012.

The June 2012 event is the one that reshaped the town. It is also the clearest illustration of why a desk-based flood map check is not the same as a site-specific flood risk assessment: national mapping struggles to capture how a culverted watercourse actually behaves once it is overwhelmed.

The £6.2 million Chester Burn flood prevention scheme

In direct response to the June 2012 flooding, Durham County Council delivered a £6.2 million flood prevention scheme for the Chester Burn, jointly funded by the council, the Environment Agency and the European Regional Development Fund. The work ran in three phases and was modelled with the Environment Agency to reduce the risk of flooding from a one-in-100-year storm event.

It is worth being plain about what this scheme does and does not do. It was designed and modelled to hold the Chester Burn to a one-in-100-year standard of protection — a significant, publicly funded upgrade that has changed the town centre's flood behaviour. It does not remove residual flood risk altogether: rarer events, climate change over a development's lifetime, and blockage or exceedance of the culvert remain real possibilities that any flood risk assessment in Chester-le-Street needs to address directly, not assume away because a defence scheme exists nearby. Residual flood risk of this kind can still affect property values and the availability of standard insurance, which is one reason the Flood Re scheme matters to homeowners in previously flooded parts of the town.

Planning policy and your Lead Local Flood Authority in Chester-le-Street

Durham County Council holds both roles that matter most to a development in Chester-le-Street: it is the Local Planning Authority that decides the application, and the Lead Local Flood Authority that must be satisfied on drainage and surface water. That dual role means the council's own Strategic Flood Risk Assessment and its county-wide Surface Water Management Plan carry direct weight in how a site here is assessed, and the council is a statutory consultee on drainage for major development.

The Surface Water Management Plan's own appendix for Chester-le-Street identifies specific local mitigation measures — road re-grading, landscaping and permeable paving near the hospital — alongside the 630-metre Chester Burn culvert running beneath the Market Place, Hopgarth Gardens and Cone Terrace. Any surface-water drainage strategy for a site in the town needs to work with, not against, that existing culverted network and its known constraints, following the SuDS drainage hierarchy and the current national standards for sustainable drainage systems. Getting this wrong is one of the more common reasons an LLFA objects to a planning application, so early engagement with Durham County Council's flood team pays off. Local planning authorities and SuDS requirements are also evolving nationally, and our note on local planning authorities, flood risk and SuDS sets out how that context applies to a site in Chester-le-Street.

Development and flood risk in Chester-le-Street

Riverside Park and the Riverside Ground — home of Durham County Cricket Club — sit on the River Wear floodplain on the edge of Chester-le-Street, a clear local example of development built and managed within a functioning floodplain rather than outside it. It is a useful illustration of a wider point: floodplains in and around the town are already built on, so new development has to be designed to cope with the water the land was always going to see, not assume the risk has been designed out.

The same logic applies to the town centre's culverted drainage. As higher-density sites come forward across Chester-le-Street, the combined and surface-water network that already carries the culverted Chester Burn takes on additional loading from new roofs, roads and hardstanding. A robust assessment of ground conditions and infiltration potential — using tools such as the BRE 365 infiltration rate calculator and Unda's wider drainage calculators — helps establish early whether a site can discharge sustainably, or whether it will be competing with the town's existing culverted watercourse for capacity.

Flood risk assessments for every situation in Chester-le-Street

We prepare a flood risk assessment in Chester-le-Street for planning submissions, property purchase and homebuyer due diligence, insurance, and BREEAM requirements, alongside sequential and exception tests and surface-water drainage strategies. A flood risk assessment, a sequential or exception test and a drainage strategy are three distinct reports. They often travel together in a planning submission, but they answer different questions: is the site safe from flooding, should the development be here at all given lower-risk alternatives, and where does the surface water go once it leaves the site.

• Planning FRAs. Submitted alongside a planning application to satisfy the NPPF, addressing every source of flooding relevant to a Chester-le-Street site, including the culverted Chester Burn.
• Property purchase and homebuyer reports. For buyers and lenders wanting to understand the actual flood risk to a specific building, beyond the national datasets used in standard conveyancing searches.
• Insurance-focused assessments. For brokers and underwriters where premiums have risen, cover has been restricted, or a property has flooded before.
• BREEAM flood risk assessments. Structured around BREEAM's flood and surface water management credit, which is assessed differently to a standard planning FRA.
• Sequential and exception tests. A locational check of whether a lower flood-risk site is reasonably available before development proceeds in a higher-risk area.
• Surface-water drainage strategies. Engineering the site's discharge, using SuDS principles to work within the capacity of the town's existing culverted network.
• Groundwater and flood modelling. Groundwater is assessed as part of every flood risk assessment we prepare, and flood modelling is used where national mapping cannot capture how a site — or a culverted watercourse like the Chester Burn — actually behaves.

How Unda helps with flood risk assessment in Chester-le-Street

Our flood risk consultants know Chester-le-Street's flood history well — the culverted Chester Burn, the June 2012 event and the three-phase scheme that followed it, and the wider River Wear catchment the town sits within. That local knowledge means we can assess a site here quickly and defend the conclusions to Durham County Council's flood team, whether the report is needed for a planning application, a property transaction, an insurance query or a BREEAM submission.

Local flood risk management and emergency contacts in Chester-le-Street

Several organisations share responsibility for flood risk in Chester-le-Street, and it helps to know which to approach for what. Durham County Council is both the council flood team (Lead Local Flood Authority) and the Local Planning Authority; the Environment Agency manages main river flooding and issues flood warnings; Northumbrian Water is responsible for sewer flooding and the public sewer network; and Floodline provides live flood warning information around the clock.

• Durham County Council — LLFA and council flood team. Manages surface water and local flood risk, and maintains the county's flood risk management pages and the Strategic Flood Risk Assessment maps.
• Environment Agency. Monitors the River Wear at Chester-le-Street via its gauging station and the River Wear at Chester-le-Street flood warning target area; check current conditions at check for flooding — Chester-le-Street.
• Northumbrian Water. Provides water and sewerage services to Chester-le-Street; contact them directly to report sewer flooding.
• Floodline. Call 0345 988 1188 for live flood warning information, and sign up for flood warnings for the Chester Burn or River Wear.
• Emergency routes. Call 999 in a flood emergency where there is danger to life; call 105 to report a power cut caused by flooding.

Frequently asked questions about flood risk assessment in Chester-le-Street