Winter trees: leaves and fruit

In default of flowers, I’m trying to learn to identify trees – though leafless trees are a special challenge. I acquired a tree app, but it’s often unpersuasive. It suggests a tree might be eucalyptus when I’m sure it’s not. It thinks that a tree, which I ultimately identify as lime, must be hornbeam, or if not hawthorn. Perhaps I’m not answering its questions in the right way.

Some trees hang on to their leaves for a long time: even into December. And some of these are anyway easy to identify: oak; silver birch. Some willows hang on to their leaves, others less so. The pollarded ones seem to lose leaves earlier.

Varieties of willow

I read that beech and hornbeam hang on to their leaves late, but the trees I think are beech don’t have leaves now. Apparently trees have a special process for cutting off their leaves, but oak and others don’t do this to the same extent.

In a row of limes in the Queen’s playing field by Folly Bridge one tree only still has green leaves. Perhaps because a little ditch flows right by its roots?

Trees with fruit or seedpods might be easier to identify in winter than at other times.

Limes, I learn, combine berries and single, winged seedpods. That’s how I identified the Queen;s limes.

By this means, I’ve also discovered that the towpath is full of ash trees, now identifiable because of their dense clusters of seedpods: ‘keys’.

Also lots of alder, easily identifiable when male catkins and hard little female seedpods, like grenades, combine on the same tree. These catkins and seedpods hang so thickly that from a distance you might think the tree was still in leaf. These trees also look reddish from a distance in the right light.


It’s not surprising to find a lot of alder around the river, since it’s said to be a tree that likes water, and can cope with having its roots soaked.

Ash and alder

Redbridge Stream: the history of a COW

A friend whose house backs on to the Redbridge Stream tells me that an official arrived at his house one day and told his wife that he wanted to see their COW. Confused, she said they didn’t have a cow. Probably what he wanted to see (did he use the acronym as a tease?) was their ‘critical ordinary watercourse’ —  though confusingly, when he had explained further and been shown It, he said it wasn’t a COW. Confusingly because, according to the Oxford Floodplan (as reviewed 2008), the Redbridge Stream was allocated to that category.

Minor Oxford watercourses are distinguished by their names into streams, brooks and ditches. A stream seems to be a braid: a watercourse that emanates from and then returns to the main river, the Thames or the Cherwell. Thus, the Seacourt Stream, Hinksey Stream, the various mill streams. A brook starts in the hills, at a spring, and runs downhill: thus Marston Brook, Boundary and Lye Brooks, Littlemore Brook, the Chilswell Brook, the Barleycote Brook. Ditches are straight cuts, artificial drains, that may cut across the lie of the land: like the East Wyck Ditch. (Though, a recurrent theme of this blog, it’s no simple matter to decide what constitutes an ‘artificial’ watercourse).

Back in the early years of the century, under the stimulus of a Treasury spending review, it was decided that the established English practice of leaving to local authorities responsibility for the maintenance of such ordinary watercourses wasn’t working well in the context of flood prevention. It was resolved that instead, a ‘whole systems approach’ should be adopted.  Allocation of reponsibility for water courses would relate to function, not form. If judged to be ‘critical ordinary watercourses’  – critical for flood prevention – they were to become the responsibility of the Environment Agency. This sounds more like a reconfiguration than an abolition of dysfunctional ‘administrative divisions’. (There are other aspects of the plan too, eg involving data collection and monitoring: ‘Through a range of initiatives, the EA is developing a more comprehensive and consistent approach to data acquisition and storage.’)

The task of distinguishing between different kinds of watercourse was addressed, during a few years following, by the compilation of lists.  A list of ‘main rivers’ was compiled, and another list of ‘critical ordinary watercourses’, with some 1800 members across England and Wales. 

The Oxford Floodplan reports that six COWS were identified in Oxford: Boundary Brook, Littlemore Brook, Northfield Brook, Wareham Stream, Redbridge Stream and Holywell Mill Stream. Responsibility for these watercourses was transferred to the Environment Agency on 31 March 2006. Among these watercourses, though the brooks seem major enough (as local brooks go), the streams are all tiny, presumably because the larger streams were already categorized as ‘main rivers’.  The Holywell Mill Stream is about 1km, the Wareham Stream at most 0.3km.

The Redbridge stream is one of the larger in this category, ‘compris[ing] 0.7km of earth channel’. It begins ‘at a confluence with Hinksey Stream north of the old Abingdon Road and rejoins Hinksey Stream adjacent to Abingdon Road Bridge’. The category COW was transitional. Watercourses designated COWs thereafter joined the ranks of ‘main rivers’ for regulatory purposes, and Oxfordshire COWs accordingly feature on the EA’s main rivers map (also available in other formats)   The Redbridge Stream is therefore now a ‘main river’.

Redbridge ‘main river’

Whether or not British policy was developing along sensible lines, in its stately way, the issuing of an EU flood directive in 2007 impelled possibly unhelpful haste. In order to conform to EU guidelines, the Brits punched out new regulations (2009) and legislation (2010) .

A submission by a Windsor and Maidenhead councillor representing the ‘ National Flood Prevention Party’  identifies several problems that (in his view) remain unaddressed:

‘The Thames – … continuous River Thames dredging took place after the 1947 flood event. Unfortunately since responsibility for the Thames transferred from the National Rivers Authority to the Environment Agency in 1995, the specially designed and built equipment has been disposed of, operators terminated and disposal sites closed, all without consultation….

Critical Ordinary Watercourses – To make matters worse, since the Critical Ordinary Watercourses were re-designated as Main Rivers in about 2005, the responsibility for management of those watercourses was transferred from the Local Authority to the Environment Agency who then abandoned maintenance.’

Whatever the arguments for and against this approach, it does seem to characterise what’s happened in relation to the Redbridge stream.

1961 OS map, showing changing context of Redbridge Stream

The Redbridge Stream has quite recently been sectioned off from what was once a longer stream – as can be seen if any OS map up to 1961 is compared with the modern Main Rivers map. Once it flowed from the Hinksey stream to the west of the railway – presumably being culverted under it – then continued on under the Abingdon Road to a junction with the Hinksey Stream (as that flowed south from Hinksey Mill) to join the Weirs Mill Stream, at a point where the stream split to encompass a little island, before proceeding on to join the Thames.

The whole water system there has since been reorganised, probably in conjunction with the building of the ring road. Now the Hinksey Stream has been diverted alongside the railway, till, following an older course, it curves round to join the Thames at a point to the south. The Weirs Mill Stream now joins the Hinksey Stream on its new course shortly before its junction with the Thames. Meanwhile, the Redbridge Stream has been bound more tightly into the reconstructed Hinksey Stream, swerving abruptly westwards to join it just south of the Abingdon Road. Where once the rivers joined and the island was is now the Redbridge Park and Ride.

Wytham Street was developed for housing north to south through the first half of the twentieth century. The land once formed part of the earls of Abingdon’s estate, and takes its name from their base at Wytham. The street backs on to a line of water that has consistently formed the Redbridge Stream. The road gradually converges on the stream (such that back gardens get shorter as Wytham Street heads south). It curves at its southern end to join the Abingdon Road, but a footpath continues towards the recreation ground by Bertie Place.

The railway parallels the road. At the southern end of the street, Redbridge Stream lies between; at the northern end of the street, Hinksey Lake interposes. The neighbourhood is a child of the railway in several senses. The laying down of the railway line prompted the development of housing. And the construction of the railway shaped the topography to the west (including, presumably, having some influence over how the watercourses have evolved).

The railway did not always run along its current line. In the 1840s, the GWR line terminated at Grandpont, having run along what’s now the footpath between Wytham Street and Lake Street; then along Marlborough Road. Another line, the Oxford and Rugby Railway, maintained a ‘[Hinksey] Millstream Station], on what’s now the main course of the track. In the 1850s the GWR began also to use that line. The Millstream Station site came back into use briefly in the 1910s, when a a ‘railmotor’ service was established — operating in carriages into one of which a little steam engine was embedded. The old station site became one of two local mini-stations, ‘halts’: Hinksey Halt. The site can still be reached from the north end of  Wytham st, via what’s now a tarmacked path, succeeded by a muddy causeway across the tip of Hinksey lake, where, when I went to investigate,  I found some boys fishing and larking around.

My friend further notes: ‘During the 30s and 40s [when his house was built] there were quite extensive railway marshalling yards beyond our garden [linked to the larger complex which runs along Hinksey lake]: the people who first lived in this house moved out at the outbreak of war as they thought this part of Oxford might be bombed.’

North end of Redbridge Stream, as it disappears under the railway line

He continues: ‘The piece of open ground lying to the north of the caravan and camping site behind Go Outdoors… was also a dump [additional to the ones noted in my Dumps post] – walking there one comes across bits of bicycle, bottle, cans etc. There are occasional fires (methane?). I don’t know what its name is (I guess it was part of the farm at Cold Harbour?)’

In keeping with my argument in the tree cover post, the tree cover across this rough ground is all recent: on the evidence of aerial photographs, post 1945.

If once you’ve taken the bridge from behind the children’s playground over the stream, my friend instructed me, you turn to the right, ‘you can walk along rough paths (much used by dog walkers) and see the stream at various points. Some householders have put little wooden bridges over the stream and onto the rough ground from the bottom of their gardens. The rough ground is largely brambles and nettles: we pick elder flowers there in the spring and blackberries in the autumn.’ But when I went to see for myself, this rough ground was so overgrown one couldn’t track the stream, merely wander across the terrain of the old dump.

My friend continues: ‘It’s good to have a stream at the bottom of the garden but the river authorities no longer dredge it so it’s dried up the last few hot summers. When we first moved here (1978) it was much deeper, with fish, voles, kingfishers etc and was kept dredged by the Thames Conservancy. The garden is really flood plain and does flood from time to time – last major flood in Dec 2013 I think, which flooded the whole hundred yards up to the steps that lead down into the garden from the house. The Envt Ag has not been much of a guardian since 2006 – I don’t think they’ve done anything at all. There was talk of an EU Directive discouraging dredging to protect wildlife (except those that live in water, when the stream dries up?). … Reeds have begun to spread over the streambed.’

In her book, Landscape: Politics and Perspectives, Barbara Bender writes: ‘struggle over a waterscape is indeed not only about its material resources, but also about the different meanings and values generated by it’. Though in this case the ‘struggle’ remains implicit, I think the tension between (what I take to be) the Environment Agency’s cost-benefit approach to the stream’s role in flood prevention, and the homeowner’s more immediate and vivid perspective has at its heart just such differences over value and meaning.

Homeowner self help: maintaining the stream bed
Redbridge Stream, winter 2008

Thanks to Glenn Black for information and for all the best photos. And to Antonis Hadjikyriacou for the cultural geography reference.

March 2021 update: the Council have been clearing the land along the stream to make it possible for the Environment Agency to dredge. This significant stretch of land has for some time been identified as potentially the site for a new school — another favourite use for floodplain-ish sites in Oxford.

Techno fix: dredging

Flooding in recent years has generated controversy — among other things, about whether to dredge or not to dredge. There have been exchanges about this in many places, eg the Somerset Levels, but also around Oxford. People on the ground often argue that dredging ought to help: it’s common sense; rivers, and canals, get silted up; why not clear them out, let the water flow? Authorities further from the action, or more able to take a general view, argue that dredging provides at best a temporary fix, and that it costs more than its limited benefits justify. There are also concerns about the environmental impact of dredging (though equally, not dredging has its own environmental impact).

It isn’t intrinsically a high-tech operation. It may involve no more than removing recently accumulated silt from watercourses, though if the aim is to deepen them to unaccustomed depths, it may entail removing gravel or more compacted soil. It’s essentially a raking operation which, in some circumstances, can be done by hand. Or with the aid of very simple equipment. A photograph by Henry Taunt of dredging on the river at Oxford in the late nineteenth or early twentieth century shows men on punts with, attached to the punt in the foreground, what looks like a large wooden rake, which would be dragged along by the boat as the boatmen poled it. .

I’m guessing that some kinds of dredging must long have played a part in the improvement and maintenance of local watercourses – not least of man-made ditches, which need to be kept clear to perform their work (though not so clear as to carry off too much soil and nutrient). There were ambitious dredging operations in the ancient world, so in principle a range of more and less ambitious technologies were available. In the Low Countries, for obvious reasons, new techniques were developed and skill built up in the early modern period, and some of that was imported into England. Dredging played a part in the management of East Anglian fens (where some argued in the early eighteenth century that it had made flooding worse, others that more was needed to alleviate flooding. Both could have been right: dredging may help to determine where floodwaters go). 

Archaeological work carried out at Godstow weir found evidence of historic dredging there, possibly in the 1780s. The excavated material had been used to strengthen one side of the channel . An important feature of dredging, as of all forms of excavation, is that it involves reciprocal operations, on the one hand, taking material out and on the other hand, depositing it somewhere else. Sometimes gathering material to deposit is the main point: gravel serves many construction functions, both on land and in water.

Interest in dredging probably grew alongside other forms of enthusiasm for improvement, even in the absence of major technological breakthroughs.  But steam power, when applied to dredging, in the 1830s if not before, probably made an impact too. Dredging machinery could be steam-powered, as well as boats. Moreover, the advent of steam boats increased demand for dredging, because expensive steamers risked getting damaged by river shallows and shoals.

Oldest surviving steam dredger, 1844
Chris Allen / Bertha being demonstrated on the Exeter Canal Basin / CC BY-SA 2.0

Google ngram suggests that the first mention of a steam dredger in a text in its database came in 1832 .Thenceforth, mentions both of dredging and of stream dredgers shot up, though during the twentieth century they fell back again.

The graph — from — shows the proportion of texts in the British-English part of the Google Books corpus using the words ‘dredging’ (in red) or ‘steam-dredger’ (in blue) between 1800 and the present. I’ve multiplied ‘steam dredger’ by 100 to make it visible on the same scale as the much more common ‘dredging’

This is not to say that steam dredging carried the day. Different kinds of dredging remained appropriate for different kinds of job. See, to this effect, not only the Taunt photo discussed above, but also an index entry for the Oxford Journal Illustrated, which reports a picture from 1925 showing two men hand-dredging the Long Bridges’ bathing place. The point of the picture, in a February publication, was to hint, longingly, at summer enjoyments to come; the low-tech operation was not being reported as remarkable in itself.

Nonetheless, the advent of steam dredging as one among other dredging options plausibly helped to increase interest and ambition – in tandem with changing assessments of what dredging was good for, and the appearance of fervent dredging advocates.

A comparison of parliamentary reports on Thames Navigation in 1793 and 1866 suggests a shift in the terms of debate. Though the occasional shallowness of the river was a concern in 1793, dredging as such wasn’t mentioned – whereas by 1866 it was at least an intermittent theme, and there were dredging advocates among those giving evidence.

In the 1790s, Thames navigation had attracted attention because the advent of canals increased interest in the navigability of the river. By the 1860s, the setting was very different. The coming of the railways had ended the heyday of the canals, and reduced river traffic. There was little commercial river traffic above Oxford; the few boats going to and from Eynsham tended to use the canal to bypass the river from the King’s Weir (above Wolvercote) down to the city. Some goods, notably coal, brought to Oxford via the canal, were shipped on down river. But some suggested that the upper Thames could — indeed should — cease to support navigation. The popularity of pleasure boating provided one argument against that. (A table in the parliamentary report suggested that 450 out of 1502 pleasure boats in the upper river were based around Oxford, of which about three quarters were for hire, the rest private boats).

It was possible, some thought (though they didn’t put it in these terms) that a vicious circle was at work. The decline of navigation had reduced income from tolls, so the commissioners responsible for the upper Thames no longer had the money to maintain the river. Although they had once done some dredging, all dredging undertaken by this date was on a commercial basis (it was said), by those whose aim was to excavate gravel for sale. The river was left to silt up, to form shoals and ‘hills’ in its bed. And of course that discouraged navigation.

Engineers in their presentations to the committee had an answer to this, in which repairs to locks and weirs played a part, but dredging was key. Dredging would create a ‘fine, deep’ channel, and then navigation would revive – admittedly at a diminished, post-railway level, but still, water remained an attractive medium for the conveyance of some goods; some revival could be expected. They were prepared to imagine doing away with some, if not all mills, and their associated locks and weirs. The Iffley mill should certainly go, it was argued; then a deep channel could be established between Oxford and Sandford.

The engineers in question were Stephen Leach and Nathaniel Beardmore. Leach was an insider, engineer to the Thames Commissioners, and later to the Conservators who replaced them. Beardmore, reported in Leach’s obituary to have been a long-term friend, was a more exalted character, a man whose skill and confidence won him a series of jobs, consulting positions, advisory roles and professional honours in the rapidly institutionalising terrain of civil engineering and related public service. He wrote what became a standard textbook on hydrology, and rates a Wikipedia entry.

There were plenty of other issues in play. The issue immediately in question – the one which had occasioned Parliament’s involvement – was the proposal to extend the jurisdiction of the Lower Thames’ ‘Conservators’ up-river, doing away with the upper river’s distinct ‘Commissioners’’. These were very different sorts of body: the first compact, run by naval men, with some representation from London shipping and boating interests, as payers of tolls; the second in theory a huge body representing urban interests, the university and landowners, and in practice affording a voice to barge and boat owners and millers (though in terms of the normal conduct of business, it was said, the Commissioners ordinarily followed the lead of engineering advisors). Much discussion in the parliamentary committee revolved around issues of representation: who should be given a voice on the governing body? Could those who knew only the lower river understand the issues of the rather different upper river – with its multiplicity of mills and its troubles with flooding? The view, repeatedly urged on the committee and expressed by its MP members, that the Conservators would staunchly pursue the public interest so there was nothing to fear, didn’t really address the local-knowledge question.

From the viewpoint of residents of the lower river, a major concern was now public health. Some London water companies took water from the river. They therefore didn’t want it to be polluted by sewage from upper river towns, or run-off from paper mills. The sewage problem was getting worse, it was said, as towns shifted from earth closets and cesspools (now feared to be polluting wells) to water closets and sewage drainage.

In the upper river, landowners were troubled by a paranoid fantasy that the Conservators would embank the river, thereby raising the river above the fields, and impeding land drainage, while making landowners pay. (It’s true that some critics said new systems of land drainage took too much water too quickly off the land, leading to floods in winter and a parched river in summer, and it may be that these hints sparked the anxiety). Millers for their part staunchly asserted their property rights. Why should they be allowed to run waste into the river? Well, because they always had; it was a right, whose loss would damage them; it therefore demanded respect. Milling was older than navigation, they said (in a local context).

Some of these issues had recently engaged official attention under other heads. A Royal Commission had enquired into the pollution of rivers, and another into ways of utilising sewage. An 1861 drainage act, responding to the reigning fashion for drainage, had replaced the old system of local ‘commissions of sewers’ with a new system involving on-demand local drainage boards; these could be established on application to the Board of Trade, and then run under the general auspices of the Enclosure Commissioners.

Discussions around these initiatives, and others in and around the metropolis, all played knowledge-forming roles. Among expert witnesses, not only engineers but also academic scientists figured. A professor of chemistry, who was also an advisor to the General Board of Health, shared his understanding of the pollution problem. The geology of the region was invoked. A former pupil of William Buckland (professor of geology), now vicar of Long Wittenham, gave evidence. His map of the Thames was waved around by one MP, and provided the basis for some of his questioning.

Navigation issues loomed quite large in the early part of the committee’s discussions; less so later, as London and millers’ concerns were heard (though millers argued that they were not in competition with navigation; the two interests were complementary, inasmuch as both wanted to keep up the flow of the river).

The act as passed did extend the jurisdiction of the Lower Thames Conservators over the Upper Thames. They took over all powers previously vested in the (upper) Thames Commissioners. In addition (among other things), all locks and weirs were put into the Conservators’ hands, though the right of millers to a sufficient flow of water was affirmed. What the Conservators were to do with their new responsibilities was left open.

The Conservators’ brand by Iffley Lock

Three years’ later, engineers Leach and Beardmore had a go at putting their grand vision into practice. Leach was now engineer to the Conservators; Beardmore had been given a consulting role. They had used the intervening time to flesh out their vision with surveys and estimates. It entailed repair of locks and weirs, removal of Iffley Mill, dredging of the river, and some straightening of its course. For some £30,000, the engineers stated, they could eliminate flood risks; for a few thousand more, they could make additional improvements to render the river efficient for navigation. In their view, their plan recommended itself ‘alike by its completeness and simplicity’. It did not recommend itself to local opinion, nonetheless, and was not adopted.

For Leach, this was clearly a signifcant disappointment, noted in his obituary: ‘The Conservancy fund not being available for the purpose, Mr. Leach was unable to carry out the much-needed works for relieving the valley of the Thames from the effects of the periodical floods to which it is subject; but he did what was possible with the limited means at his disposal, and in designing a new work he took especial care that it should be constructed so as to form a useful part of the comprehensive drainage scheme which he foresaw would some day have to be undertaken.’

Local critics saw things differently. In a letter to Jackson’s Oxford Journal, local landowner Edward Harcourt observed that eliminating flooding from the land was neither practicable nor desirable, though a competent engineer who truly understood the problem might help to ensure that water did not lie on the land for protracted periods. He thought that, whatever they said about reducing flooding, the engineers’ vision was in fact chiefly designed for the benefit of navigation. Its presentation as an anti-flood scheme (he hinted) represented an attempt to make landowners pay for others’ benefit. He observed, tartly, that the Conservators had spent a great deal of money on salaries and expenses, relative to what they had spent on repairing locks and weirs, or the paltry £3000 they had invested in dredging – that moreover chiefly in contexts in which they could turn gravel to profit.

Though the engineers’ vision of a deeply dredged and streamlined river was not realised, under the Conservators’ regime, dredging did resume. And from the 1880s, steamers, previously confined to the lower river, made their appearance on the upper.

Thanks to Stephanie Jenkins for useful references to Jackson’s Oxford Journal, and the Oxford Journal Illustrated Index. Steve Rayner and Simon Wenham, though passing comments (in Simon Wenham’s case, in writing), first set me thinking about dredging.