The Great Wellington Flood of 1852
A Warning from History
The Great Wellington Flood of 1852, one of many flood warnings, was named as Lord Wellington of Waterloo (1815) died at approximately the same time.
“It seems as if a few houses and the tops of a number of trees (for only the high branches can be seen) were floating on the surface of some boundless river for as far as the can reach nothing is to be seen but water. The Charwell [sic] has overflowed its banks, and continues rising… light boats, rowing nearly up to their college walls ”
For a full size image (new window) left or right click The Great Wellington Flood Of 1852
– “The whole of the surrounding country is flooded – Oxford literally standing in a sea of water. The large meadow of Christ Church is covered with water, the Isis having overflowed its banks, and the river is even now continuing to rise, and there is great fear of the lower part of the college being flooded
This is a call to action – Oxford City Council and Oxfordshire Council and other entities should be URGENTLY taking any and all actions necessary to meet the flood threat NOW before the onset of winter – may be we will be lucky, may be we will not. The Councils need to address this threat as a high priority
In 2013, I wrote Oxford’s Flood History an article mainly concerned with the foolish and still multiplying floodplain developments such as Barton Park and the West End by Oxford City Council, and those that increase water runoff to lower areas. I write this update with increasing alarm as yet more are foisted on surrounding Councils – in particular that of the Land North Of Bayswater Brook.
This year in particular, not a day goes by without Al Jazeera reporting yet another catastrophic climate event in a daily litany that resembles more the roll call of the United Nations than a news report – Australia, Pakistan, Bangladesh, Vietnam, Japan, The Caribbean, Canada, the USA (multiple), most of Sudan where 100,000 homes have been lost and 3 million displaced – no country it seems is spared, although normally too poor for local media to bother reporting about.
Records are now routinely broken, of particular concern is the vast amounts of CO2 released by truly exceptional fires from Brazil to Siberia, California and Australia, Turkey, Syria and Lebanon to name but a few which are both cause and effect of climate change. Awareness is low, only niche channels such as Al Jazeera, not popular but cosmopolitan, internationalist, serious, in-depth, with an eye to the needs of the desperate and forgotten, cover this climate emergency with any depth or breadth.
Once considered acts of God, we have become over-mighty subjects, directly causing climate change.
Oxford has been visited repeatedly by severe flood events which swamped entire suburbs and vast swathes of the surrounding countryside, regrettably, it seems the Councils’ memories go no further back than 1947, therefore the evidence base is fundamentally flawed as many catastrophic events have simply been forgotten, Oxford City Council marches towards the water when it should be in headlong retreat.
Flooding is regular, is very much part of the ecology of the Thames and its tributaries’ catchments, and highly unpredictable in effect for a given area due to Oxfordshire’s gentle topology – the events can be very sudden and intense, and impact a given area only.
Severe flood events in Oxford have occurred approximately 4-5 times a century since records began – this article concentrates on those of the nineteenth century.
The floods of 2007 initiated a nationwide review of flood management, but in the intervening thirteen years only moderate improvements have been achieved.
This article concentrates on East Oxford (Marston, Headington, Cowley, Iffley) area of the city, areas directly impacted by overdevelopment permitted by incompetence on the part of Oxford City Council. A number of updates are anticipated as new information or feedback become available.
Appeal to Action
A flood beyond our current imagining seems not only possible but probable – of which the historical events listed here may be just a minor foretaste.
Whether this happens or not, this year or next, is, of course, an imponderable – but it seems there is a high risk of a high severity event.
This requires an urgent response – so far noticeably lacking from the Oxford and Oxfordshire Councils and the endless agencies responsible.
There are a number of actions Oxford City Council and Oxfordshire Council should be taking immediately to #slowtheflow:
- A ban on any further flood plain developments change plans if necessary
- Inspect each and every car park, industrial and medical facility to reduce run off
- Determine the risk to the community and if proved to be a flood source, demand the reduction or closure of environmentally unfriendly and possibly flood generating car parks at, in particular, the John Radcliffe, Churchill Hospitals, Old Road Campus and the recently expanded Seacourt P&R among others
- Ensure SUDS systems such as surfacing changes, attenuation tanks, bunds etc are able to hold the maximum capacity, ensure procedures are in place to keep retained levels as low as possible at all times
- Demand that large landowners, for example the Oxford University Hospital Trust and Oxford University upgrade SUDS systems where and if required
- Suspend permitted development rights where these are not compatible with flood management in flood source areas (eg: Headington, Peat Moors, Wood Farm)
- Ban verge cutting – these can do much to slow flows into river systems
- Rewild as much and as many parks and open spaces as possible
- Scour ditches and river systems if this is compatible with the needs of other communities downstream (eg:Marston Brook)
- Introduce fines for owners that fail to control runoff, maintain watercourses or charge back remediation
- Launch a campaign of public awareness of what each resident can do to #slowth flow – far too much emphasis is placed on how to defend against floods, not how to reduce source flows, largely as no one is appears responsible.
- Give grants to residents for removal of hard surfaces – driveways, paving, and subsidies for installation of rainwater tanks, SUDS and remediation of misconnects to foul sewers on existing development
- Ensure all Planning Applications and permitted development have SUDS systems in place as per Policy RE4, particularly in areas of high ground such as Headington, Wood Farm and Peat Moors
- Complete the Strategic Flood Risk Assessment for Barton and the West End AAPs (developments) to bring it back into compliance with NPPF – there is NO excuse for deliberately not including these in the 2017 SFRA (Strategic Flood Risk Assessment)
- Design and implement flood relief strategies both at source, and for improved outfall for Cowley and Iffley, high risk areas all but ignored so far
- Review disjointed flood defence strategies and plans
- Calculate the cumulative effects of decades of accelerating overdevelopment and disastrous laissez-faire policies by Oxford City Council on input flows
Longer term the Councils and other entities must:
- Invest heavily in strategic SUDS systems eg Boundary Brook and the Lye Valley (eg: inception ponds recently established) both to enhance nature and slow the flow.
- Urgently finish the Oxford Flood Alleviation Scheme which is proceeding at a scandalously slow snail’s place – 13 years and nothing has yet been achieved while Oxford remains at very high risk
Further, understand that the risk is much greater hitherto believed due to climate change, with flash and surface flooding now a very high risk. It is no coincidence the greatest flood events have been local flooding as below.
Maps, Images and Links
The interactive Google Map is provided below, click top right to open in new window, and back button to return to this article, or use this link: Oxford Rivers, Catchments and Floods
This shows all the details below but as pins rather than labels etc – (de)select features from the left side and zooming in to see specific details, the map can be changed from satellite to plan using the Base Map icon at the bottom left side.
Most images below are also provided in a larger format by clicking on the link which will open in a new tab, or you can right click and select “open in new window” depending on your browser. Some links go to third party sites (eg: OCC) which are current at time of writing.
Setting The Scene
Oxford is near the confluences of the Thames, Cherwell, the Ray, Windrush (to the north) and Bayswater Brook, (at the Barton Park site) part of one of the greatest catchment areas in Britain, rain falling anywhere upstream in this vast area can create a flood event in Oxford.
Clicking here will open a larger image in a new tab Oxford Rivers Overview
The Thames flows north east before hooking around to flow south east to join the Cherwell just below Oxford City. Bayswater Brook flows west, then north-west joining the Cherwell north of Oxford.
A set of brooks, Marston Brook, Peasmoor Brook, Peasmoor Piece, flow directly into the Cherwell via Headington and Marston. (Marsh-Town), Headington Hill Tributary joins Bayswater Brook at the A40 via a culvert.
Lye Brook and Boundary Brook flow via Cowley Marsh and Cowley joining the Thames at Iffley.
Very broadly, London Road (marked “Headington Road” above) marks the catchment boundaries between water flowing north and going through the central Oxford area, and south via, for example, Boundary Brook which did extend up to London Road.
The actual catchment areas are mostly determined by the Thames Water stormwater drainage systems that discharge into the natural watercourses.
The Environment Agency map above shows flood risk from riverine sources, NOT flash or surface water flooding. Dark blue is more than 1:100 chance of flooding – many of these areas have flooded repeatedly in the last few years.
Historical Flood Summary
Serious flooding has occurred every 10-20 years to 1900: – 1692 (Oxford), Jan 8th 1734, Jan 17th 1764, March 10th1774, (Thames)1, Jan 27th 1809, (snow thaw), Dec 21st 1821, Jan 1842, (thaw), Nov 16th (on) 1852, March 29-31st 1862, 1875 and 1894 (Oxford) and occurs very often in November – December : 1
“it is curious coincidence that the three floods of 1852,1875 and 1894 were at their height within hours of each other on November 15th and 16th” 2
The exquisitely named Reverend Clutterbuck of Long Wittenham, a leading light in the Thames Conservatory, made height observations “above the high navigation mark” which are listed after each flood in the appendix for comparison purposes.[ref 1]
A number of deaths occurred due to boating and coaching accidents or infirmity.
To avoid repetition, the full chronology and reports can be found in Oxford Flood History Appendix below.
Certain common themes stand out.
Flooding Was Very Extant
St Ebbes, St Thomas’s, St Frideswide’s, Jericho, Osney, Botley Road, the railway station, Abingdon Road, Cold Harbour and Hinksey are frequently flooded, and of course, Port and Christchurch Meadows with Old Marston often cut off. Parts or all the residential areas listed are in at least 1:1000 year flood risk zone 2 as defined by the Environment Agency.
The railway, although lower than today, was frequently flooded, with damage both to the line and the tunnel at Wolvercote.
“The valley around Oxford has a very solitary appearance, for as far as the eye can reach, nothing is discernible but water, out of which trees and haystacks project in every direction..”
“Oxford, the seat of literature and learning …with its forest of spires ..is for the present at least converted into The City of The Dismal Swamp. The almost incessant rain which has fallen for the last four weeks has caused the rivers Thames, Windrush and Cherwell, and Isis to overflow their banks .. has the appearance of a vast inland sea… Port Meadow..has now from three to four feet of water over its entire length and breadth … nothing but a huge sheet of water can be seen .. From the railway station through Botley, Osney … land with very few exceptions is completely inundated ..the dwellings along Abingdon Road are flooded.. the dwellings at Upper and Lower Fisher Row are threatened with inundation the water.. in some instances entered the houses[Star 1875]”
“In the streets in Osney, Friars, St Thomas’s and Hincksey [sic], the water made its way into hundreds of dwellings, .. four schools were closed by order of the managers during the height of the flood .. about midday on Friday the water was at its highest, and the discomfort and inconvenience it produced in the low-lying portions will not easily be effaced from the memory of the sufferers. In some cases children were taken to school in a boat.. and various articles being handed up to the bedroom windows in baskets it is estimated the planks would extend a distance of about three miles..” 
Flooding Could be Very Rapid
“The omnibus that runs from the railway station to the city yesterday attempted to pass under one of the arches of the railway-bridge [Hythe Bridge Street?], when a large body of water suddenly came down from the neighbouring hills, encountering the vehicle in its course, breaking through the windows and doors and filling it entirely” 
“In the night of Monday last, the floods increased so rapidly, that the greater part of St Thomas’s was under water” 
“She [A Mrs King] had been overtaken by a sudden rush of water while walking in the meadows, and was too old and infirm to gain the high ground.”
“At the commencement of the week the weather was beautifully fine, and in consequence haymaking in the neighbourhood became very general …and about 6 o’clock the rain began to pour down in torrents, which continued almost without intermission, until noon on Thursday. The banks of the Charwell [sic] speedily became overflown…”
“On the way to the Abingdon Races it was noticed by visitors by road fields only partly submerged , were, on the return journey, completely covered” 
Flooding Mostly Affected the Poor
Most of the suburbs mentioned were inhabited by poor people:
“the whole of the garden stock upon which the poor families chiefly depend, is entirely destroyed“
Or in 1894:
“The mayor said they were all aware that the city had been visited by one of the most disastrous floods ever remembered in Oxford. They might have had the waters as high as it was on the present occasion, but they now had hundreds of houses built on the low-lying districts to contend with which they had not had previously. He had seen women wheeled in barrows and children running through the floods to get bread for breakfast…. Mr C. Underhill was quoted as “At the same time, a strong feeling of indignation was passing through his breast with those who permitted buildings and put up buildings in such a miserable situation. “ to which Mr Kingerlee retorted he “had voted that these houses should be built in these very districts, and then he wished to pass a censure upon himself and others who has passed those very plans..” He thought they ought not to blame the people who built, but the authority that passed the plans” 
Flood Risk Types
Surface water flooding is defined as water that flows over the land before arriving in a water course, riverine flooding is of course the result. Flash flooding can be sudden in onset, and frequently nowhere near a flood zone.
Traditionally, we think of flooding as riverine or fluvial flooding, which is relatively reassuring with images of flood defences, emergency services, pumps and sandbags.
Groundwater, where the water table simply becomes higher than the land, cannot be defended against as water wells up from underneath.
The British Geological Survey has categorised most of Oxford City, including parts of the Barton Park site in the highest category of susceptibility to groundwater flooding hazard.
Who is Responsible?
As a direct response to the floods of 2007, Lead Local Flood Authorities (LLFA) were established, with Oxfordshire Country Council acting in that capacity with overall flood responsibility, followed by multiple entities with diffuse and segmented set of duties as illustrated here and here.
Gutters are the responsibility of private landowners, the drains may be the Highways Authority, or Thames Water, it may be different in rural areas. Owners are responsible for ditches, the Environment Agency for main rivers, Oxfordshire for surface water flooding. Oxford City Council for assessing the flood risk from a particular development, and so it goes on.
Whether these bodies are responsible for making sure the infrastructure removes as much water as possible, or retains it, seems to be undefined.
Oxfordshire produced its Preliminary Flood Risk Assessment (PFRA), Report in June 2011 3 (see PFRA report) – its conclusions were, and remain, damning.
It is particularly noticeable that there appears to be no government body responsible or with power to investigate and enforce flood mitigation from flooding sources, unless it is a condition of a planning application. Efforts seem almost entirely concentrated on dealing with the effects of flooding not prevention at source, which in urban areas is not only feasible, but essential.
A destructive flood is simply billions of perfectly harmless droplets.
There is no overall strategic planning, calculation of the cumulative effects of so much new development in Oxford, or means of forcing a landowner to maintain, upgrade or install flood mitigation measures after grant of planning permission – as sites creating the most downstream flood risk are already built, there seems little, beyond civil action, that can be done.
So many government entities are involved in flood management, it is hardly surprising so little is actually achieved, responsibility is divided even by the official category of watercourse. This is a national issue, but the plethora of Councils in Oxfordshire does not assist – hilariously, each produces for example its own Strategic Flood Risk Assessment, with Oxford City Council showing the left bank of Bayswater Brook only.
No one entity could supply a consolidated list of all flood mitigation activities in Oxford, it appears bodies cooperate, but only on an ad hoc basis. There is no central Project Management or control despite the 100s of millions of pounds spent.
Weak Oxford City Council Policy
The recently approved Oxford City Council Local Plan 2020 has exceptionally weak flood management policies, wholly inadequate for a flood prone city such as Oxford.
RE4 below can only serve to increase the net runoff from development.
Policy RE4: Sustainable and foul drainage, surface and groundwater flow
All development proposals will be required to manage surface water through Sustainable Drainage Systems (SuDS) or techniques to limit run-off and reduce the existing rate of run-off
- store rainwater for later use; then:
- discharge into the ground (infiltration); then:
- discharge to a surface water body; then:
- discharge to a surface water sewer, highway drain or other drainage system; and finally:
- discharge to a combined sewer.
Practically, these means in most cases, attachment to a surface water sewer, which increases downstream flood risk as these discharge mostly into natural water courses, or into foul drainage. Only storage and infiltration can even reduce the INCREASE in downstream flooding, not achieve an improvement. It is PERMITTED to discharge -rainwater into a combined foul and stormwater drain although foul drains have increased flows in flood conditions:
Thames Water have observed storm responses within the foul network suggesting that the network is not completely separate.PFRA Level 1 2017 p.2.2.7
The development pressure on Oxford is now so great, that most domestic owners and developers simply cannot afford to leave trees, greenery or allocate land for use by SUDS systems.
Permitted Development Rights
Mean Planning will frequently not even be involved in the process – these include a large range of development types that increase roof, drive and other areas all of which increase flows to vulnerable areas downstream no attempt has been made by the Council to suspend these either to prevent flooding, or to save the Lye Valley SSSI.
Practically, also, drainage details for domestic developments tend to be delegated to Building Control with no overall oversight of strategic flood requirements.
Probable new permitted development rights currently proposed by the government at time of writing could be catastrophic for the Lye and vulnerable downstream communities.
The consequences have been, and will be, every increasing incremental increases into the water system leading to ever higher risk downstream.
Flood Relief Initiatives
Oxford Flood Alleviation Scheme
Understanding The Catchment
The catchment is the entirety of the Thames and its tributaries above and in Oxford. Water flows though a small 800 metre gap at Redbridge (Middle bottom, “The Cut – END” below) causing backup.
Floods and Causes
All the incidents described above in Oxford’s Flood History above.
This ambitious plan (£150m) (“The Cut” below) involves digging an artificial waterway between Botley Bridge near the Seacourt P&R and Kennington (starting mid left of image below) to allow water from the Cotswolds and the catchments above Oxford to bypass the city and remain in attenuation ponds as part of the waterway, allowing slow discharge into the Thames, therefore reducing potential flooding downstream.
Conceived in 2013, nothing has, as yet resulted, clearly there is no feeling of urgency.
A number of important pinch points have been identified and in some cases remedied to improve the flow of water out of Oxford see The Oxford Flood Alliance library in particular Building on Success – although it is not clear which of the medium term schemes described have been complete as no central register of work exists.
In addition to this, several flood defence exercises with temporary flood defences have been conducted and equipment purchased.
Northway and Marston Flood Alleviation Scheme
Understanding The Catchment – Northway and Marston
The above graphic shows combined catchments for Peasmoor Brook, Piece and Headington Hill Tributary in light shaded dark blue. Headington Hill Tributary appears to have been part of Peamoor Piece as can be seen in this 1947 map which was then redirected via the red culvert to Bayswater Brook, the others discharge west into the Cherwell.
Incident and Causes – Northway and Marston
The study which led to the flood alleviation scheme, of which the flood storage area forms a part, included a survey of residents in the area to gather information. Residents stated they had observed an increase in the severity and frequency of flood events in recent years, this may reflect climate change impacts or the increases in urbanisation within the catchment. The impacts of climate change will lead to further increases in the future.Northway and Marston Flood Alleviation Scheme, OCC
Flooding in Oxford Boxing Academy in Stockley Road and others occurred in July 2005, flooding streets and affecting 110 houses, following the path in yellow above from the John Radcliffe area to flood Stockey’s Road and other areas. This incident appears to remain unrecorded in at least some parts of the PFRA.
The SFRA Phase II of 2017 identifies approximately 1000 properties (inc flats and two schools) at risk in this area. [ref: 23. p9, Table 1] as can be seen below:
Oxford City Council’s understanding, supported by the findings of the 2012 Flood Feasibility Study, indicates that the source of flooding is out of bank flow at the inlet structure of the Headington Hill Tributary culvert to the rear of the Oxford Boxing Academy on Saxon Way. The water then flows around the side of the property and down Saxon Way, Westlands Drive, Maltfield Road and finally pools in Stockleys Road. In addition, the Peasmoor Brook Culvert surcharges causing out of bank flow which pools in the Stockleys Road and Maltfield Road area too. 
The speculatively, the cause may have been heavy surface runoff from the John Radcliffe Hospital, marked in dark blue shading ,with it’s football fields of car parking, large buildings, almost devoid of attenuating surfaces – in contrast, the rest of the catchment is ordinary housing and gardens. At time of writing, there is no evidence to presented where the “cause” was assessed as being other than the out of bank flow.
Nearby to above, Marston Brook has not been scoured behind Arlington Drive despite repeated requests and its proximity to the new Swan School:
Marston Brook: A small stream which runs towards Old Marston from the Northern Bypass road. This appears to be a potential flood risk for a number of properties in Old Marston, which are designated as being at medium to high risk of flooding in the uFMfSW.PFRA Phase 1 2017 2.2.2
This completed scheme was entirely taxpayer funded (2.5m) and involved placing attenuation areas as shown on the map above in purple (top centre) with other improvements.
It does not appear the Oxford University Trust (John Radcliffe Hospital) was even assessed for accountability or asked to contribute. IF the John Radcliffe Hospital is the blame, it would represent another 2.5 million pounds of taxpayers money in addition to the Access to Headington Scheme at £21 million spent on maintaining football field car parks which are poisoning our community, bringing daily commute misery, and causing destruction of housing.
The aim of the scheme is to reduce flooding a 1:75 year event based on CURRENT conditions.
See: Northway and Marston flood alleviation project and Planning Applications 16/01320/CT3 (Phase 1) and 16/01549/CT3 (Phase 2) for more details.
Cowley and Iffley Flooding (Oct 2020)
Understanding The Catchment
The catchment drains south from approximately London Road via Boundary Brook and the Lye Brook.
In the past, this would have been grassland, becoming peat moor and fen closer to the Lye Valley, with slowly flowing water draining into Boundary Brook which would wend its way to Cowley Marsh.
This bucolic description of “The Withy” which appears to be Boundary Brook not only shows what we have lost, but the slowness of the water flow in the 1920s in the Cowley area:
The Withy, so far as we could trace, sprang from Lye Hill near the Cowley Marsh [see EA map above] , an open area of land used for recreational purposes. It sparkled through narrow fissures in the hillside, past sedge grass and meadowsweet, tumbling finally into the wide ditch which skirted the Marsh, flowing underneath the main road to Cowley and from then on it became a brook coursing through clusters of willow herb and nettles alongside the allotments. From here it wandered beneath Iffley Road and across fields to join the Thames quite near to the free ferry; but it was the stretch of this waterway bordering the allotments which attracted most of our attention.
In places its banks were bordered on both sides by willow trees whose branches met and entwined over the water, so forming a mysterious green-shaded tunnel: a challenge for the venturesome where the water flowed darkly and the only noise to be heard was the rustle of leaves and the occasional plop of a water rat. The brook was crossed officially in two places by flat concrete bridges, but we scorned these, preferring to cross by strategically placed stepping-stones or to leap from one bank to the other. The banks were sandy and crumbling with tufty grass footholds, so that yellow-stained hands and knees were a common sight, and if misjudgement resulted in a bootful of water, who cared? On the far side of the brook surrounded by tall trees lay a buttercup field and here, …An Oxford Childhood: Pride of the Morning, By Phyl Surman
Now most of the rainwater that landed on grassland and infiltrated into the fen goes directly into Thames Water drains, worse, the artificial catchment is much larger than before.
Boundary Brook becomes partly culverted after Cowley Marsh before discharging rather ingloriously into the Thames as a concrete culvert.
The Lye Brook Thames Water Surface Water catchment (orange above) for example, discharges into the Lye Brook where it does great damage, scouring the base. The red zone is the much smaller natural North Fen SSSI catchment.
See articles The Hymn Of The Lye and any under the Lye Valley menu on the Home page for more information.
Floods and Causes
Oct 3rd 2020 was the wettest October day since records began in 1891, however the exact causes of the sewer overflows at Campbell and Florence Roads has not yet been determined.
The flooding was from overflowing drains, not Boundary Brook per se – as runoff goes into and out of watercourses, the exact source is not yet known.
The Churchill Hospital, Old Road Campus and Park Hospital (marked Churchill Hospital on map) and further off the Nuffield Centre – comprise of football field sized car parks and medical buildings with very little green space, which could lead to very rapid runoff from hard surfaces leading to downstream flooding in Cowley and Iffley.
There are attenuation tanks, on the west side, but it appears these are frequently full and will not capture all run off.
Speculatively, flooding could be caused by the hard surfaces above, and/or the artificially expanded Thames Water catchment and/or other causes.
Very recent work in the Lye Valley above the SSSI has resulted in two interception ponds and desilting, which will slow the flow from at least the Orange Thames Water catchment above.
Although the number of houses and schools vulnerable to flooding is large, in contrast to all other areas discussed NO alleviation scheme has been proposed or implemented which is extraordinary given the statement:
The main flood risk is further downstream in Cowley and Iffley, associated with the culverted section of channel. Significant flooding is predicted within the surrounding residential areas for both the 100 year and 1000 year events.SFRA Phase 1 2.2.1
Further work in the Lye Valley and Boundary Brook to extend the fen, build dams and retention ponds, would be as beneficial to residents as for the Ice Age relict fen, one of the rarest habitats in Britain, slowing flows and reducing flash flooding.
Very regrettably, Oxford City Council seeks to destroy this precious place see menu Lye Valley
Barton Park & Land North Of Bayswater
Understanding The Catchment
The Barton development is on the Bayswater Brook flood meadow or “Headington Meade” as marked on historical maps. The site is 62m above sea level at its lowest, with proposed development at slightly higher levels.
The site has mostly impermeable rock or thick clay underneath and is normally very damp and marshy.
It has high groundwater levels as shown by The PFRA 4, Map 7, “Groundwater Flooding” which identifies the 1 km square in which Barton West is in as having 25% – 50% of its area as susceptible, with much of the this square on higher ground. [ft.2]
Located next to Bayswater Brook between the surrounding hills of Headington and Elsfield, with poor drainage and little height difference with the Cherwell, it may be susceptible to a combination event of high riverine levels and a localised flash flood event, as occurred in the nearby Cherwell valley in 1853 when local farmers lost hay due to flash flooding:
“Mr Greaves of Elsfield, has lost the whole of the produce of 14 acres of land; while Mr Sanders of Water Eaton, Mr Chillingworth of Marston, and others of Water Eaton, have suffered considerable loss.”
However it is not clear where these fields were. Mr Greaves had a very extant 475 acres in total.
As evinced above, the Barton NPPF Flooding Report 5 is quite wrong to assert:
“with the largest flood extents being those from the Spring 1947 event and the New Year 2003 event,”
It goes on to state:
However, in a 1992 event, a small area of land 700m upstream of the site on the right bank of Bayswater Brook was inundated”
The 2012 event, which saw flooding in this area, was caused mostly by 400mm of rain in the Cotswolds only.6
Locals have repeatedly reported severe flooding of Bayswater Brook (Oct 2020 over the footbridge), foundations standing in water. The houses have been raised above ground level. The area is consistently damp, although a local farmer said it had never seen the whole area flood, although the flat nature of the land indicates clearly it is alluvial in nature.
Given the large height differential between the north and south side of the A40, the permeable nature of the embankment, the following assertion seems also dubious:
4.2.16. Land situated to the south of the Site [ie Old Headington] is situated at a higher level and may therefore provide a potential source of overland flood flow. The Site is largely protected however, by the presence of the A40, which will intercept overland flows and divert them in a westerly direction away from the site.”
One observer calculated that 3”of rain in the 1894 flood was 73,000 gallons of water per acre – it seems hard to believe the Barton flood defence of holding tanks and the linear pond could possibly hold this amount of water. The site is in effect both a source for Oxford flood water and destination for runoff from the surrounding Headington and Elsfield hills. Osler Road in Old Headington has resembled a river in severe storm events.
The flooding to which the development may be most susceptible, groundwater, is, as explained above, is the least understood, and the most likely to change if climate models prove correct.
Personal observations and recent events (Oct 2020) shows that the flood risk for the Barton Park development is high – the area is frequently extremely wet unpleasant – in Dec 2019 foundations were flooded.
The surface water flood map shows surface flooding predicted in the area under construction in light blue are 1:100 probability but these have been routinely flooded every year. Raised finishes and improved drainage may mean the actual flood water is below the level of the houses, but it is of concern that the predicted flood levels are so different to personally observed floods.
Development too Near and too Far?
The developments are too near the water and too far from safety.
The Council is obliged by the National Planning Policy Framework to maintain an up to date SFRA – it updated and released this as part of the Local Plan 2016-2036 recently adopted, however if FAILED to include the flood risks to all AAP areas:
3.2 Identification of key sites
The city’s existing Area Action Plans (AAPs) for its strategic sites have not changed. They include 2 large greenfield sites in Barton and Northern Gateway, a potential site in Summertown, and a series of smaller development sites throughout the West End of Oxford.
The council’s preferred option is to largely keep the existing strategic allocations for the AAPs and not re-visit these, this is with the exception of the site in Summertown, which they have singled out as requiring a reassessment in relation to the latest model data.PRFA Phase 1 2017 para 3.2
This utterly unacceptable and contrary to its legal obligations – much has changed since the initial flood risk assessments (which the author vehemently contested during the original Barton Area Action Plan (AAP) examination), mostly our understanding of the the danger of climate change. It is understandable if the Council wants to protect its investment as approximately 20% is already built, but NOT acceptable not to reassess the risk and if necessary modify the plans.
As if this was not dangerous enough, The Land North of Bayswater Brook development (STRAT13) on Elsfield Hill and beyond will cause even more flooding by runoff as below, or be flooded at its lower levels – this is illustrated below:
Should We Be Worried? – Yes
Will flooding in the future be worse or better than the great floods described above?
Extensive clearance and improvement work of locks, mills and weirs coupled with dredging has resulted in a very substantial improvement in water outfall drainage in addition, those undertaken since 2007.
- Temporary flood defences have been supplied and tested
- The Oxford Flood Alleviation schemes above if ever completed will assist to divert some water around Oxford
Warning systems and construction materials are much improved
The water retaining capacity of Oxfordshire and catchment areas further to the north is substantially reduced with very much larger field sizes coupled with hedgerow destruction, causing very rapid runoff
The map of Oxford even as late as the first OS map of 1876 shows little building outside of central Oxford and traditional villages such as Headington and Marston – the water holding fields are all gone, leading to more rapid runoff.
- Severe intensification of development in the last 20 years, each building adds to runoff
Climate change is now severe
In recent times, a very rapid intensification of land use has seen the removal of 10,000s of trees, lawns, gardens and other green infrastructure, with their replacement by extensions and new houses, these are hard surfaces with high runoff, normally draining straight into Thames Water stormwater sewers, or worse, foul water sewers.
Old fashioned soakaways that extended, normally as two clay pipes into the garden, are now illegal, and are replaced with new rear extension development by drains that discharge to directly into the sewers, increasing increase point loading by rapid discharge of water to lower parts of Oxford.
The most dangerous juxtaposition for Oxford would be therefore heavy rain in the Thames river system catchment area leading to ground saturation, followed by heavy rain directly in the local area.
There is incontrovertible evidence that severe flooding has occurred on, or very near to, many of the future developments repeatedly, with the possible exception of Barton, possibly as it was not considered worthy of recording.
Either the Environment Agency’s 1:100 and 1:1000 floodlines have been exceeded so many times it will be millennia before flooding happens again, or the modelling is wrong, or that something has changed – and to an extent , it has.
Drainage is improved, but in the Thames valley stiles go over long gone hedges, vast arable swathes above Barton replace the pocket sized fields Lord North’s Elsfield map of 1703, the sprawl of Headington is where Antony A Wood gathered ears of rye in 1682, fields exist where most of ancient Wychwood used to be. If the water comes, there will be little to slow it as nature’s SUDS systems no longer exist.
Recent flood events have surprised both with their frequency and extent many of which have exceeded the 1:100 and 1:1000 flood lines defined by the Environment Agency.
The conclusion must be that input into river systems will now be much faster, as will their drainage, the risk therefore is not lower, but changed – we are more vulnerable to flash flood events, particular IN Oxford BEFORE the main rivers, occasioned by very heavy rain over short periods, and less vulnerable to prolonged wet periods, at least in isolation.
Flood risk has not declined, but changed. Global warming, bringing heavier and more intense rainfall, this coupled by vegetation loss and its replacement by hard surfaces with high runoff in Oxford means vulnerability to flash flooding via ground and surface water has very substantially increased – put simply, Oxford will be subject to short sharp shock floods. In contrast, the weeks of flooding as seen in Victorian times, due to poor outfall from Oxford, has relatively declined.
What is most concerning is, as admitted by the Local Lead Flood Authority, a very poor state of knowledge regarding flood risk is coupled with an excessive reliance on generalised computer modelling.
This may serve for wide area floods, but does little for localised flash flooding.
The almost complete absence of either awareness or analysis of past events beyond 1947 by either the authorities or developers has lead to complacency.
The Thames is one of the mightiest rivers in Britain, the catchment extending fover hundreds of square miles. When the rain comes, no power on earth will be able to withstand it, so we must be as prepared as possible.
A bunch of blokes in “hi viz” manning flood defences at Osney may be a comforting visual metaphor for a caring patriarchal state, but those are river defences – when the water goes by, but there is little defence for groundwater which comes up from under, and surface water, that flows over.
She has surprised again and again with the sheer magnitude of flooding events – we should take action now before it is too late, but never, never ask:
“How Could That Have Happened?”
You have just been told.
Headington Heritage, A personal blog
 The Dec 4th 1852 vista of Oxford in flood appears to be extremely accurate in its representation of individual buildings, although they are exaggerated and would not be visible as shown. Clearly drawn from the hills above Hinksey, however the building alignments appear impossible from any given angle.
Possibly the artist combined various views to achieve the vista shown – by Dec 4th the floods had receded.
 However, The British Geological Survey states “The susceptibility data should not be used on its own to make planning decisions at any scale, and, in particular, should not be used to inform planning decisions at the site scale. The susceptibility data cannot be used on its own to indicate risk of groundwater flooding.”
Sources, particularly newspapers outside of Oxford, must not be considered reliable. All the material should be treated with caution both as it is based on partial information and the author has no qualifications whatever in the subject area.
Important Copyright Notice
The images used are under copyright and may NOT be reproduced without permission of the copyright holders identified in the captions.
Text in this article is licenced under Creative Commons CC BY-NC-SA ( http://bit.ly/YLfYPW )
The author has no academic status or qualifications in history or hydrography and no other help has been received, therefore all misinterpretations and erroneous conclusions remain his alone.
Permission to use images owned by Oxford University is very gratefully received.
Clearly, this help does not imply endorsement of either the article or content of the Headington Heritage web site.
The Oxford Flood Alliance and an Oxford Flood Officers were helpful in their responses.
M.G. Rowley’s compilation of U.K. weather was useful as a point of departure in particular for the BGS data from the Metrological Office – this is unfortunately now shutdown but available from the British Library and as a zip download:
as was Stephanie Jenkins’s Oxford History site at:
A number of images are available at the Oxfordshire History Centre and using the search terms “Henry Taunt flood.”
1. Clutterbuck JC, 1801-1885. The perennial and flood waters of the upper thames. London: London : Printed by William Clowes and Sons; 1864.
2. The floods, serious destruction of property. Oxford Chronicle. Nov 24 1894 1894:8.
3. England’s most dreadful calamity by the late floods electronic resource] : Being a most lamentable account of the great damages sustained by the fearful invndations, caused by the unparalell’d rain which fell on the 24th of april, 1682 : And the late rains which have lately hapned : Containing the several houses, barns, cattle, out-houses, stacks of hay and corn, being carried away : Together with the number of persons drowned, and of some thousands of acres of ground layed under water : Giving a relation of the particular damage sustained in the city of london, and the suburbs thereof, at branford, camberwell, dulwich, depford, on the river thames .. London?: London? : Printed for P. Brooksby ..; 1682.
4. Oxfordshire County Council. Preliminary flood risk assessment report final report June 2011. . 2011;3.
5. WSP. NPPF FLOOD RISK ASSESSMENT land at barton, oxfordshire. . 2013.
6. Environment Agency. Flood event report – winter 2012/13 west thames area. . 2013. www.environment-agency.gov.uk.
7. Records of the past 1764. Jackson’s Oxford Journal. Dec 28 1895.
8. Jackson’s Oxford Journal. January 28, 1809 1809.
9. The weather. The Times. Dec 31, 1821 1821:3.
10. Inundations. The Times. Nov 17, 1852 1852.
11. Great floods at oxford. Jackson’s Oxford Journal. Nov 20th 1852 1852.
12. The inundations. The Times. Nov 27, 1852 1852:7.
13. The innundations. Bell’s Life. Nov 27th 1852 1852.
14. The floods. Daily Star. Nov 29th 1852 1852.
15. The floods – oxford. The Times. Dec 20th 1852 1852.
16. The inundations. The Times. Jul 16, 1853 1853.
17. The floods – latest details. The Standard. Jul 24, 1875 1875.
18. The great floods of 1852 and 1875. Jackson’s Oxford Journal. Nov 24th 1894 1894.
19. The floods – serious destruction of property. Oxford Chronicle. Nov 24th 1894 1894:8.
20. The floods. Jackson’s Oxford Journal. Nov 24th 1894 1894.
21. Northway and Marston, Flood Alleviation Scheme – Phase 1/2 Flood Risk Assessment,Oxford City Council, 8 June 2016
22. An Oxford Childhood: Pride of the Morning, By Phyl Surman
23. Level 1 Strategic Flood Risk Assessment, Oxford City Council, Nov 2017
24. Northway and Marston Flood Alleviation Scheme – Phase 1, Oxford City Council, 06 May 2016
Appendix – Flood History 1662 – 1900
On 24 April 1682 “it began to rain (as it indeed it has for the greatest part of this spring) .. till at last it fell with such unwonted fury, that several people were beaten down with its Impetuosity…as a water spout.. long hovering in the air..the River Isis at Oxford over-flowing, laid most of the Level under water which continued for the space of three days and likewise by the Rain which was there accompanied by Thunder and Lightning, much damage was sustained in the City..”
and concludes it is a divine punishment :
“the clouds sucked up the sea, and poured it down in streams; or as Moses has it “The Windows of Heaven were open.. the Earth likewise obeying her Creators voice opening every watery part; when Rivers gushes [sic]” 3
On Jan 7th 1764, “the long continued rains have kept the floods out upon all the rivers in these parts for a longer time than ever before.. and such a vast extent of the country under water, forms as it were, a little ocean “ [Dec 28 1895]7
On Jan 28th 1809, “the sudden thaw of a great accumulation of snow, accompanied by much rain, has produced in this neighbourhood a flood of greater extent and depth than has occurred here for the last thirty years. Several streets in the suburbs of the city have been inundated, particularly St Thomas’s parish, where water runs in torrent thro’ the streets, the inhabitants being obliged to remove to their upper apartments.
The beautiful walks round Christchurch and and Magdalen meadows, which have been considerably heightened, and judged to be above the high water mark, are completely covered.” 8
1809 : Clutterbuck : 9’ 1”
The Times reported on Dec 31 1821 “the late heavy rains have caused the river to near this city to overflow to a most alarming degree. In the night of Monday last, the flood increased so rapidly,that the greater part of St Thomas’s was under water, boats were rowed backwards and forwards, the inhabitants compelled to take refuge upstairs… The road from Holly Bush to Botley Turnpike was totally impassable to passengers” 9
1821 : Clutterbuck : 8’ 10”
The Great Wellington Flood of November/December 1852
The great Wellington flood swept the country in November and December 1852 so named due to his death on the 14 September 1852 and subsequent funeral on 18 November of the same year.
The Times reported on Nov 17th :
“The whole of the surrounding country is flooded – Oxford literally standing in a sea of water. The large meadow of Christ Church is covered with water, the Isis having overflowed its banks, and the river is even now continuing to rise, and there is great fear of the lower part of the college being flooded. From the force of the current a boat full of undergraduates was upset, and one of them, belonging to Jesus College, unfortunately drowned. The omnibus that runs from the railway station to the city yesterday attempted to pass under one of the arches of the railway-bridge [Hythe Bridge Street], when a large body of water suddenly came down from the neighbouring hills, encountering the vehicle in its course, breaking through the windows and doors and filling it entirely. Fortunately no passengers were inside, or they must have been drowned, as in a very short time the water so accumulated it was six feet deep under the arch, and spread for a long distance on all sides.
It seems as if a few houses and the tops of a number of trees (for only the high branches can be seen) were floating on the surface of some boundless river for as far as the can reach nothing is to be seen but water. The Charwell [sic] has overflowed its banks, and continues rising… light boats, rowing nearly up to their college walls. …. The floods continue to pour into Oxford at this moment and the inhabitants of even the central parts are beginning to feel apprehensive” [end]10
Jackson’s Nov 20th [INDB] “GREAT FLOODS AT OXFORD – … in the last three weeks we have been almost surrounded by water and it was only in elevated parts that grass could be observed…” 11
Nov 24th – more rain and two feet on line, on Times Nov 27th “after a brief cessation, the heavens began again last night to pour down their torrents…so the floods are again rising… Thanks to the “gentle eminences” on which Oxford is situated, she is still able to hold her head above water, but if the present rate of rain continues much longer, she will soon be in greater difficulties.
At this point [Abingdon and London Road Bridge] the valley of the Isis is lowest and the confluence of waters greatest in seasons of flood, a condition of things which does not appear to have entered into railway reckoning in constructing the line” [ Nov 27th 1852] 12
Bell’s Life on Nov 28th 1852 reported “The valley around Oxford has a very solitary appearance, for as far as the eye can reach, nothing is discernible but water, out of which trees and haystacks project in every direction..” 13
The Daily News of Nov 29th 1852 quoting the Oxford Chronicle, reported the waters still to be high, with damage to the rail line 1 mile south of Oxford. “South and west of the suburbs large breaths of meadow land is still submerged, and boats are seen rowing where the eye was accustomed to recognise tracts of fine pasturage” 14
Six lives were lost according to The Morning Post Nov 29th 1852 “The greatest excitement prevails in this city in consequence of the floods, which have risen to an alarming extent. The Cherwell and Isis are more like seas than rivers, for the width of each could now be measured by miles instead of yards. … On Thursday last, a boatman found the body of a Mrs King. She had been overtaken by a sudden rush of water while walking in the meadows, and was too old and infirm to gain the high ground. In the course of the inquiry the coroner said it was the third inquest he had held during the day alone on the bodies of persons who had been drowned. … Yesterday the driver of a waggon was suddenly jerked from his seat into the road, owing to the vehicle dropping into a deep pool. The poor man was killed on the spot. No fewer than seven boats have been upset ..and several of the occupants have escaped with the greatest difficulty. The railway passengers have for several days been rowed to and from the station to the city in boats…”
Times Dec 20th “although the floods have considerably abated from what they were some weeks ago,.. they cover the fields around Oxford…Cases of fever are reported to have occurred from low-lying houses near the river near the water, and attention to this cannot be too earnestly given.
A house in Summertown ..was undermined by the long continuance of water in its cellars .. but the inmates were very providentially alarmed by a boy in the house, who, finding his bed sinking under him, sprang up and alarmed the family who had time to make their escape in their night clothes.”15
The Cherwell Flash Flood of 1853
Times, Jul 16, 1853 – Banbury – “the country immediately contiguous to this town is now completely inundated, and for miles on the Eastern side there is little to be seen but a vast expanse of water. At the commencement of the week the weather was beautifully fine, and in consequence haymaking in the neighbourhood became very general …and about 6 o’clock the rain began to pour down in torrents, which continued almost without intermission, until noon on Thursday. The banks of the Charwell [sic] speedily became overflown, and before 9 o’clock at night the meadows adjoining were flooded in all directions. The immense quantity of hay outlying ready for being carried has been in the majority of cases completely swept way by the force of the current.”16
The Standard Jul 20th 1853 “SERIOUS EFFECTS OF THE FLOOD. – OXFORD, JULY 19th The valley of the Cherwell, and also of the Isis, has been much flooded in the last few days, to the very serious injury of the farmers occupying the meadows adjoining. Yesterday and Sunday the rain fell in Oxford and the adjacent neighbourhood in exceedingly heavy showers, very considerably adding to the floods in these low lying districts. On the banks of the Cherwell hundreds of tons of hay have been swept away by the sudden swelling of the water. In the immediate neighbourhood of this city great damage has been done. One farmer, Mr Greaves of Elsfield, has lost the whole of the produce of 14 acres of land; while Mr Sanders of Water Eaton, Mr Chillingworth of Marston, and others of Water Eaton, have suffered considerable loss. King’s Weir on the Cherwell [This seems to refer to King’s Mill, not King’s Weir on the Thames] , and within ½ mile of Oxford was Sunday and yesterday and completely blocked up with an immense quantity of newly-cut hay, the growth of several meadows between that weir and the village of Islip, so much so that Cox, the occupier of the weir, thought it worth his while to something like a dozen hands to get it out of the water. The blockade of the stream in the rear of the stream was so complete that a person could walk, without the slightest difficulty, on the top of it, right across the stream, the embankment ..being upwards of eight feet. The quantity that Cox has already secured is something like 30 tons … an immense quantity has been washed over…Port Meadow.. is virtually covered with water..the meadows and fields are inundated.” (Morning Chronicle Jul 19th v. similar)
1852: Clutterbuck 7’ 10”
1875 – Summer and Winter Floods
The Standard, July 24th 1875, “The floods in Oxfordshire have vastly increased due to a great rise in the river Cherwell.. the result is perhaps the greatest summer flood ever known. The fields and meadows are completely inundated. On the way to the Abingdon Races it was noticed by visitors by road fields only partly submerged , were, on the return journey, completely covered” 17
The Star Nov 18th 1875 reported “Oxford, the seat of literature and learning …with its forest of spires ..is for the present at least converted into The City of The Dismal Swamp. The almost incessant rain which has fallen for the last four weeks has caused the rivers Thames, Windrush and Cherwell, and Isis to overflow their banks .. has the appearance of a vast inland sea… Port Meadow..has now from three to four feet of water over its entire length and breadth … nothing but a huge sheet of water can be seen .. From the railway station through Botley, Osney … land with very few exceptions is completely inundated ..the dwellings along Abingdon Road are flooded.. the dwellings at Upper and Lower Fisher Row are threatened with inundation the water.. in some instances entered the houses.. At Marston the roads have been almost impassible, people on Saturday morning having to wade knee-deep to get into town.. on Sunday afternoon the junction between Cranham and Union Streets were rendered impassible due to a dense mass of water that had rushed down from Walton …” 17
See also : 18
1875 : Clutterbuck 8’ 1”
The Great Flood Of 1894
Oxford Chronicle, Nov 24th 1894 “The Mayor said they were all aware that the city had been visited by one of the most disastrous floods ever remembered in Oxford. They might have had the waters as high as it was on the present occasion, but they now had hundreds of houses built on the low-lying districts to contend with which they had not had previously. He had seen women wheeled in barrows and children running through the floods to get bread for breakfast…. Mr C. Underhill was quoted as “At the same time, a strong feeling of indignation was passing through his breast with those who permitted buildings and put up buildings in such a miserable situation. “ to which Mr Kingerlee retorted he “had voted that these houses should be built in these very districts, and then he wished to pass a censure upon himself and others who has passed those very plans..” He thought they ought not to blame the people who built, but the authority that passed the plans”19
Jackson’s Oxford Journal, Nov 24th 1894, “– the volume of it, however, was so unusually large that in all the low-lying meadows, especialy those adjacent to the rivers, and in the basements and cellars of many houses it has by no means disappeared. In the streets in Osney, Friars, St Thomas’s and Hincksey [sic], the water made its way into hundreds of dwellings, .. four schools were closed by order of the managers during the height of the flood .. about midday on Friday the water was at its highest, and the discomfort and inconvenience it produced in the low-lying portions will not easily be effaced from the memory of the sufferers. In some cases children were taken to school in a boat.. and various articles being handed up to the bedroom windows in baskets it is estimated the planks would extend a distance of about three miles..
The roads on Botley-road and Abingdon-road particularly were considerably damaged by the water, .. the waters passed over the line as it were a weir.. 20
1894 : Clutterbuck : 4”-5” of rain 8 p.m. Nov 11 – 8 p.m. Nov 14th only 24 hours without rain.
1894 : Clutterbuck 8’ 8”
Appendix – The PFRA Report
The main points to emerge were:
- It was not clear which agency collected historical flood evidence due to unclear responsibilities, and “little incentive” therefore data is sparse [3.3.2]
- Very little knowledge or analysis of historical flooding events, relying almost entirely partial data of the 2007 flood event – only the 1894 event is even mentioned [4.3.2]
- Global warming will lead to more intense rainfall events [5.7.4] with three times more heavy rain days in winter, with storms containing 40% more water, increasing local surface run off
- No local future flood risk monitoring has been undertaken [5.1.2][5.2.3]
- No parish flood reports for the 2007 event were submitted for the Oxford City Council area, ie no evidence was collected
- Flood risk from ordinary watercourses, eg: Bayswater Brook are not well represented
- The Oxford area is in the highest level of hazard/risk of groundwater emergence [5.4.3]
The limitations of the preliminary report are acknowledged, and include no analysis whatever of the actual historical realities of Oxford’s flooding, relying instead on computer modelling. Further, the subsequent flood of 2012 could not be included.
[3.3.1] The main data limitations from the perspective of the PFRA are with the recording of past flooding information. Prior to the Pitt Review (2008) there was uncertainty regarding responsibility for collecting data on local sources of flooding and little incentive for any party to collect such data.
[3.3.2] This means the availability of past flooding information is generally sparse. Due to the historically poor recording of incidents of flooding from non-main river sources many of the flooding records are descriptive, incomplete, or not geographically referenced..”
[3.3.5] In particular it seems that flooding from ordinary watercourses may not be well represented in either dataset”
[5.1.2] There is little locally specific information on future flood risk for Oxfordshire.
[5.2.3] It is important to note that the choice of the Flood Map for Surface Water as the “locally agreed surface water information” is solely made for the purposes of the PFRA and high level strategic work. More detailed flood risk studies should utilise the best available local information and carry out more detailed modelling as appropriate to the level of the study.
[5.7.4] …. For example we understand rain storms may become more intense, even if we can‟t be sure about exactly where or when. By the 2080s, the latest UK climate projections (UKCIP09) are that there could be around three times as many days in winter with heavy rainfall (defined as more than 25mm in a day). It is plausible that the amount of rain in extreme storms (with a 1 in 5 annual chance, or rarer) could increase locally by 40%.
[5.7.7] Wetter winters and more of this rain falling in wet spells may increase river flooding in both rural and heavily urbanised catchments. More intense rainfall causes more surface runoff, increasing localised flooding and erosion.
[5.9.3] It is concluded that there are no major developments planned of the kind described in section 5.7.15 that would be expected to increase flood risk from local sources.
[5.4.3] … However it is reasonable to say that large areas of the county [Oxford] are in the highest category of risk of groundwater emergence.
[4.5.1] “ The flood was especially notable on the Assendon Spring because the watercourse is normally dry. Prior to 2001, the stream had last flowed in 1969. ”
Appendix – A Frozen Thames
Extraordinary events are not only flooding:
Appendix – Floods Mapped To General Weather
This information was derived from the http://www.booty.org.uk site:
The Little Ice Age
The very substantial flooding in the last half of the nineteenth century could be related to the ice melt occurring at the end of the mini ice age which lasted approximately 1350 – 1850 [Fagan] ,which was, in effect, a global warming event – a situation not unlike the current period.
Oxford, Flood, Oxford Flood History, Barton Park Development, Oxford City Council, Oxford County Council, Westgate, Oxpens.
Initial release: 18/10/20