River Lune Flooding & Flood Risk

Flooding from the River Lune is fast, powerful and difficult to hold back. The Lune drains a steep, rain-soaked catchment off the Howgill Fells and the eastern Lake District, and it delivers that water to Lancaster within hours. On 5 December 2015, during Storm Desmond, it produced one of the largest floods ever gauged on an English river and put much of the city under water. Unda prepares flood risk assessments, drainage strategies and related reports for sites across the River Lune floodplain, from the upper dales down to the estuary. Reports for sites along the River Lune come from Unda Consulting Limited, a CIWEM Business Partner. To talk a site through, call 01293 214444 or email enquiries@unda.co.uk.

On 5 December 2015 the River Lune at Caton peaked at around 1,700 cubic metres a second, among the highest flows ever recorded on an English river. It overtopped Lancaster’s defences and flooded the Caton Road electricity substation, cutting power to roughly 61,000 homes and businesses across Lancaster and Morecambe.

• A flashy upland river. The Lune rises high in the Howgill Fells and falls fast through the Lune Gorge, so heavy rain on the fells reaches Lancaster in hours rather than days.
• A Main River from the fells to the sea. The Environment Agency regulates the Lune, so the 8 metre byelaw margin and Flood Risk Activity Permits apply to work near it.
• A record-setting flood catchment. The December 2015 peak at Caton was one of the highest river flows ever measured in England, and the river has passed 1,100 cubic metres a second at Caton five times since 1995.
• Live Environment Agency gauges the length of the river. Lunes Bridge at Tebay, Killington near Sedbergh, Caton above Lancaster and Skerton Weir all appear on the map below with their latest levels.

Check flood risk along the River Lune

The map below draws the River Lune in coral, from its source in the Howgill Fells down to the estuary at Glasson, with the Environment Agency’s live river gauges positioned along it. Click any gauge to see its latest level, its typical range and its record peak. Enter a postcode near the river to zoom in and screen that location against the Environment Agency’s flood data for rivers and sea, surface water, reservoirs and the flood zones used for planning. It is an indicative screening tool, not a flood risk assessment.

The December 2015 flood and the River Lune’s flood record

The River Lune’s modern flood history is dominated by a single night. On 5 December 2015 Storm Desmond parked a warm, wet Atlantic front over Cumbria and the Pennines and held it there. Honister Pass, in the fells to the west, recorded 341.4 millimetres of rain in 24 hours, a UK record that still stands. All of that water ran off the steep ground into rivers that were already high, and the Lune responded as violently as any of them.

At the Caton gauge, just upstream of Lancaster, the river reached a level of 8.17 metres against a normal range of roughly 0.28 to 3.60 metres, at a flow of around 1,700 cubic metres a second. That flow was one of the highest ever gauged on an English river. Three north-country rivers broke the previous England and Wales record of about 1,520 cubic metres a second that night: the Eden, the Lune and the Tyne. Lancaster’s existing defences had been built for a smaller flood, and the water went straight over them.

The consequences went well beyond wet carpets. Floodwater reached the Caton Road primary electricity substation and shut it down, cutting mains power to around 61,000 homes and businesses across Lancaster, Morecambe and Carnforth for up to two days. With the power went mobile networks, cash machines, traffic lights and heating, in the first week of December. Around 332 properties and businesses flooded within the city itself, and across Cumbria and Lancashire together the December 2015 floods put water inside more than 5,200 properties. Lancashire County Council’s Section 19 flood investigation report set out the sequence in detail.

Desmond was the worst, but it was not an isolated event. The Caton gauge has recorded five of its largest floods since 1995: around 1,700 cubic metres a second in December 2015, 1,395 in January 1995, 1,202 in January 2005 (the same spell that flooded Carlisle on the Eden), 1,169 in November 2017 and 1,152 during Storm Ciara in February 2020. For some riverside properties around Lancaster, 2020 was the third flood in five years. A river that can do this repeatedly is one that any nearby development has to take seriously.

Why the River Lune floods so fast

The Lune floods the way it does because of the ground it drains. It rises at around 240 metres above sea level near Newbiggin-on-Lune, on the flank of the Howgill Fells, and gathers the runoff of some of the wettest, steepest country in England. It then squeezes through the Lune Gorge, the narrow trench that also carries the M6 and the West Coast Main Line, before opening out into the broad valley of Lonsdale on its way to Lancaster and the sea. Over roughly 85 kilometres it drains a catchment of about 1,223 square kilometres.

Two things make it flashy. The first is the rain. The catchment above Caton receives around 1,520 millimetres of rainfall a year, and the higher fells a good deal more. The second is the ground. The catchment is steep, largely rural, and has almost no lakes or reservoirs to hold water back, so rain runs off quickly rather than soaking in or being stored. Hydrologists capture this in a handful of numbers: a base flow index of around 0.40, meaning a large share of storm rainfall runs straight off; a steep average drainage-path slope; negligible reservoir storage; and barely any urban cover. Together they describe a river that rises sharply within hours of heavy rain and carries an enormous volume when it does.

The Lune also gathers strength from a string of substantial tributaries. Birk Beck joins in the upper gorge; the River Rawthey, draining the Howgills and joined by the Clough and the Dee, comes in below Sedbergh; the River Greta arrives near Burton-in-Lonsdale; and the River Wenning, itself fed by the Hindburn and the Roeburn, joins just south of Hornby. Each adds its own fast-responding upland catchment to the main river, so a wet spell across the wider region loads the Lune from several directions at once.

Below Skerton Weir in Lancaster the river becomes tidal, and flood risk in the lower city and the estuary is a combination of river flow and tide. When a large flood on the river coincides with a high tide in Morecambe Bay, the tide holds the freshwater back and levels rise higher still. That is why the tidal reach through Lancaster, and the estuary at Glasson and Conder Green, has to be read as an interaction rather than as river risk alone.

• River Lune at Caton. The main gauge above Lancaster (records from 1968) has a normal range of about 0.28 to 3.60 metres; on 5 December 2015 it reached 8.17 metres at a flow of around 1,700 cubic metres a second.
• River Lune at Killington New Bridge. Near Sedbergh in the upper catchment, this gauge recorded a peak flow of about 627 cubic metres a second in December 2015.
• River Lune at Lunes Bridge, Tebay. High in the gorge, the gauge reached its record level of 5.62 metres during Storm Desmond.
• River Lune at Skerton Weir, Lancaster. The weir marks the tidal limit; below it, flood risk is a mix of river flow and tide.

Which communities the River Lune puts at risk

Flooding from the Lune is felt the length of the river, and the Environment Agency runs a formal warning service across the whole catchment. Two flood alert areas cover it: the Upper River Lune, from Tebay to Kirkby Lonsdale including Sedbergh and Killington, and the Lower River Lune and Conder, from Kirkby Lonsdale to Galgate including Hornby, Gressingham, Carnforth and Lancaster. Within them, more precise flood warning areas let the Environment Agency warn individual communities at Halton, at Lancaster Quay and at Skerton. The table below summarises the main settlements at risk from source to mouth.

If your site sits within one of these areas, the Environment Agency’s flood map for planning is likely to place it in Flood Zone 2 or 3, which triggers the need for a site-specific flood risk assessment. You can screen any address against the live Environment Agency data using the map above. The upper river runs through Cumbria and the lower river through Lancashire, and both counties are covered in more depth on our area pages for Cumbria and Lancashire.

A Main River from the fells to the sea, and what it means for your site

The River Lune is a designated Main River along effectively its whole length, which means the Environment Agency, rather than the local council, is the regulator for the channel and its immediate margins. That distinction is not academic if you are building nearby. Works within 8 metres of the top of the bank on the non-tidal river, and 16 metres on the tidal reach below Skerton Weir, generally need a Flood Risk Activity Permit from the Environment Agency before they start, sought alongside planning permission rather than instead of it. A site in the river’s floodplain will normally need a flood risk assessment to support a planning application. The many becks, gills and ditches that feed the Lune are ordinary watercourses instead, regulated by the Lead Local Flood Authority (Westmorland and Furness Council or Cumberland Council in the upper catchment, Lancashire County Council lower down) and by the riparian owners whose land they cross. Getting that classification right at the outset saves time later.

• The byelaw margin. Building, excavation or structures near the Lune usually require a Flood Risk Activity Permit within 8 metres of the bank, and within 16 metres on the tidal reach through Lancaster.
• Flood zones drive the assessment. A site in Flood Zone 2 or 3, or a larger site in Flood Zone 1, needs a flood risk assessment for planning.
• Know which watercourse you are on. The Lune is Environment Agency territory; a tributary beck or ditch is an ordinary watercourse under the Lead Local Flood Authority instead. We confirm this for every site.

Managing flood risk on the River Lune: policy and defences

Several bodies share responsibility for flood risk on the Lune. The river sits within the North West River Basin District, and the Environment Agency’s Lune Catchment Flood Management Plan and North West Flood Risk Management Plan set the catchment-scale strategy. The Environment Agency regulates the Main River, publishes the flood map for planning and issues flood warnings; the Lead Local Flood Authorities of Westmorland and Furness, Cumberland and Lancashire deal with surface water, groundwater and ordinary watercourses; and United Utilities is the sewerage undertaker for the catchment.

After Storm Desmond, Lancaster City Council and the Environment Agency delivered the £12.1 million Lancaster Flood Risk Management Scheme, completed in 2021. It improved 2.8 kilometres of flood defences and better protects more than 170 homes and businesses along the Lune, and the Caton Road substation was rebuilt on a raised platform so a repeat of 2015 could not black out the city again. Higher up the valley, Sedbergh, Kirkby Lonsdale and Caton rely largely on flood warnings rather than engineered defences, which is one reason a site-specific assessment matters so much there.

Flood risk and drainage services for sites near the River Lune

A development near the River Lune can call for several different reports, and it helps to be clear that they answer different questions. 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 address separate things: whether the site is safe from flooding, whether the development should be located here, and where the surface water goes. Unda prepares each of them for sites across the Lune catchment.

• Flood risk assessments for planning. Site-specific assessments dealing directly with the Environment Agency’s requirements for development in the river’s flood zones. See our flood risk assessment for planning service.
• Assessments for property purchase and insurance. Independent reports for buyers, owners and lenders through our flood risk survey for property purchase and flood risk assessment for insurance.
• Drainage strategies and SuDS. Surface-water designs that manage runoff and meet the discharge limits set by the Lead Local Flood Authority, through our sustainable drainage strategy service.
• Sequential and exception tests. Locational justification where policy requires it, through our sequential and exception test reports.
• BREEAM and groundwater. A BREEAM flood risk assessment for the Pol 03 credit, and a groundwater flood risk assessment where a high water table is in play.

Where national mapping is not enough, which is common for a site right beside a Main River like the Lune, we can bring in hydraulic flood modelling to derive accurate flood levels and extents, and prepare the detailed scheme needed to discharge a drainage condition. Everything we do is framed by the NPPF and its planning practice guidance, and you can read how climate change is factored into flood levels in our guide to climate change allowances.

How Unda helps with flood risk on the River Lune

Unda understand how an upland river like the Lune behaves in flood, and what the planning system and the Environment Agency expect from the reports that follow. We know how quickly this river responds to rain, where its floodplain bites hardest through Lancaster, Halton and the lower valley, and what a robust, compliance-led flood risk assessment has to demonstrate to carry a development through planning. We prepare assessments and drainage strategies for developers, planning consultants, architects, agents and homeowners with sites the length of the river.

Every assessment rests on the same evidence the regulators use: the Environment Agency’s flood mapping, the river’s gauged levels and modelled flows, and the local planning policy that applies to the site. If you are working on a site near the River Lune, talk to one of our experienced flood risk consultants about what your application will need.

Live levels and emergency contacts for the River Lune

• Live river levels. Check the river’s gauges on the Environment Agency service, at the Lune at Caton and the Lune at Skerton Weir, or use our own live river levels map.
• Flood alert areas. Sign up to Environment Agency warnings for the Upper River Lune and the Lower River Lune and Conder.
• Screen a location. Try our free flood risk map, and for drainage the drainage calculators, the BRE 365 infiltration calculator and the soakaway ground conditions map.
• Flood warnings. Register for Environment Agency flood warnings and call Floodline on 0345 988 1188.
• In a flood emergency. Call 999 if life is in danger, and 105 for power cuts.

River Lune flood risk: your questions answered