Leaky dams - preciousness, vanity and tree persecution
Coming across some senseless persecution of trees can set me off in a rage. I am immediately suspicious of its purpose – is it some over-zealous safety measure, or is it a sign of the dogma of the conservation industry that easily sacrifices trees in pursuit of its more favoured species? Given the increasing frequency of flood events, the importance of trees associated with drainage areas, flood plains and watercourses in slowing the flow is seen through their action in promoting greater infiltration of water. In addition, as trees age and turnover, the large woody debris that falls into watercourses can lodge and form leaky dams that also slow the flow. You could imagine beaver contributing to this in natural systems by their activities in creating leaky wooded dams. All that doesn’t fit with the impatient timescale of humans, and so the chain saws come out and the natural systems are circumvented and foreshortened. Throw in some cute animals and photoshoots, and the vanity of these interventions is apparent.
The differing aspect of my local woodlands offers a span of bluebell flowering that ensures I get to enjoy this immense pleasure over a number of weeks, watching the green lawn of their emergent leaves then turn blue with flowers that scent the air. I was walking critter trails a couple of days ago - it is the best way to see bluebells. Apart from anything, it gets you way from the once a year woodland walkers, but more importantly these trails, resulting from the frequent passage of roe deer, are narrow and take you through an immersive experience of the bluebells that you can’t get from one of the big paths that seem to run besides rather than within. This wood has lots of standing and lying deadwood – many of the oak trees having vast lances of dead branches that soar up at diagonals to the trunk; a dead tree almost rotted completely and absorbed back into the ground can be mistaken for a critter trail. It is this deadwood, along with the communities of plant species that tell you it is a little disturbed woodland that has no history of grazing with livestock, its swathes of bluebells, the interspersal of patches of wood anemone, the large yellow flowers of marsh marigold and the yet to flower wild garlic, a couple only of Goldilocks Buttercup plants, the emerging patch of yellow archangel, all are indicator plants that this is ancient woodland (1).
In memory of Neil
I remember Neil Fitzmaurice at this time of year, the critters and the woodland so resonant of his own predilections. It’s been a year since he died, and I miss his acute observations of the nature he would see walking Blacka Moor, a wild place at the edge of Sheffield that he would defend against all defilers (2). I’ve been fearful that his blog would disappear, but it is still there for the moment, still available to get a measure of the man and his commitment to that wild place, its red deer gracing the woodland (3). I’ve been thinking that it may become an annual occurrence for me to reflect on what Neil may have found of interest or importance over the preceding year. There will have been things that would have caught his eye and which he would have held up alongside his wild place as a gauge to its impact. It won’t be about his wild place, as I haven’t wanted to, nor had the stomach to, monitor it in his absence. Instead, I want to remember it as he saw and valued it.
As I have explained before, Neil wasn’t a rewilder – he had his wild space, a publicly owned area free from the dead hand of agriculture and management since the 1930s. Neil was against dewilding – the slavish dogma that a wildlife trust brought with it when given control over this space (4). Neil would document each new wound that the wildlife trust would inflict, the annual persecution of birch trees being a recurrent disgust. We shared an abhorrence of tree killing. I often wondered at how oppressed he must have felt in knowing that he would inevitably come across it after the winter work parties (5). It is the same feeling of oppression I have when I come across tree persecution, especially since I am not one to walk where I know it is a persistent fate for trees. It thus comes as a shock when I do see it - I have to diagnose the alleged purpose of the action that just seems sheer malice. The sight of the monolith trees that were created on Neil’s wild place by the wildlife trust would be confusing for most, until you work out that this is the killing of a mature tree by ringing or girdling, followed by debranching to create safe standing deadwood (6-8). I have written before that the products of old growth can be manufactured by ringing the bark of trees (9,10) but this smacks of the usual impatience of the conservation industry to bend nature to its timescales, and its preciousness in wanting to try out yet another destructive intervention to serve those ends. You can now even get a forestry grant under the Higher Tier of Countryside Stewardship for veteranising, at £175 per tree, but you have to halo clear around the tree by removing any existing scrub (11). Dreadful dogma.
A few weeks ago, I was walking an oak ravine woodland that is also ancient, and which has the attraction that it has almost no non-native trees. Unfortunately, it has little in the way of woodland wildflowers because of the heather moorland above on either side that will have been grazed by sheep, and these would have had access to the woodland (the wildflowers in Shipley Glen woodland are also poor because of the access that sheep had from Baildon Moor). The moorland does have the feel of a sheep common, and it is described as Common Land in the Landscape Character document of the local authority (12) but if it ever was so, it escaped re-registration as a common during the 1960s and thus has no commoners now (13). Over the years, in the absence of that grazing, it has seen a bristling of birch trees seeding in to the heather, a few oak from the ravine, and also some Scots pine that have jumped across the ravine from estate plantings adjacent to the heathland on the eastern side. The woodland and moor are publicly owned, and were likely part of the St Ives estate that all came into public ownership when it was bought by the now defunct Bingley Urban District Council in 1928 (14-16). It’s been enjoyable to watch this gradual reclamation of the moor by birch, a reclamation that is signally underwhelming on my local now ungrazed moorland common. There is always the fear, though, given the obsession of the conservation industry for heather, that I would come across this burgeoning birch having been cleared off the moor, as had been done through local authority zealotry on the heathland of the estate. With each year, however, the area on the moor that would need to be cleared of birch has expanded such that you feel it is safe, that it would be too great a task to clear it, even for the zealots.
Trees upend on their own
The blow instead this time was to descend on my circular walk back down from the moor into the ravine and come across evidence of tree felling alongside the narrow watercourse in the woodland. The watercourse is Deep Cliff Hole in Deep Cliff Wood, and it soon became apparent that the felling had been carried out to provide material in the creation of two leaky dams across this narrow and shallow beck, the lower dam from random felling along the watercourse, widening a passage which would now be without tree cover, the upper dam obviously constructed by felling two mature birch trees, one either side, and dropping them and their associated brash across. It seemed nonsensical - trees upend on their own on the lower section along this watercourse from having insubstantial purchase in the marshy ground when they get to a particular size. The first thing I did after seeing and recognising the purpose of this massive intervention was to look upstream! The beck drains land from the open grassland fields of Cliff Farm above the top end of the ravine, but there did not appear to be evidence of any complementary activity in those fields. Thus it was only this publicly owned woodland that was bearing the burden of what just reeked as essentially a token vanity project in natural flood management, the latest bandwagon of preciousness to jump on.
Neil had once bemoaned that the surface water he saw running over his wild place raised the question of whether a greater proportion of it would have been absorbed if more trees had been allowed to remain? He explained that this was the part of Blacka where approaching a hundred trees had been poisoned, the recent cuttings of shrubs there having not helped either (17). What I had seen in Deep Cliff Wood would be if Neil had come across a similar intervention along Blacka Dike, the watercourse that runs through woodland on Blacka that, along with Redcar Brook flows down into Oldhay Brook and on through the residential area of Totley Brook and into the River Sheaf. It’s about 4km downstream from Blacka before there is any flood warning monitoring on the River Sheaf, at Dore and Totley Station (18) by which time the river has been joined by Needham’s Dike and the many tributaries of Totley Brook that together drain large areas of upland. Would slowing the flow on just one artery such as Blacka Dike make much difference to the cumulative flow of the River Sheaf at that point?
I have asked myself the same about the leaky dams on Deep Cliff Hole. The nearest flood warning monitoring is 3.8km away at Beckfoot on Harden Beck just before it joins the River Aire (19). However, before that point, Midgram Beck arises and runs through private farm fields below Harden Moor and drains into Deep Cliff Hole before it joins Harden Beck. Locally, Manywells Beck and Ellar Car Beck flow into Cow House Beck which then runs into Harden Beck before Deep Cliff Hole, and Wilsden Beck turns into Mytholme Beck that runs into Harden Beck after Deep Cliff Hole. We need to go higher up into the Pennine edge to see what turns into Harden Beck. Thus Denholme Beck runs into and out of Doe Park Reservoir before it and Milking Hole Beck run into Hewenden Reservoir. Hewenden Beck runs out of Hewenden Reservoir, turns into Hallas Beck which then turns into Harden Beck after the junction with Cow House Beck. Would slowing the flow on just Deep Cliff Hole make much difference to the cumulative flow of Harden Beck just before it flows into the River Aire down near Bingley?
Multiple hyperbole unfulfilled by action
I’ve searched back in vain for any evidence of
information in justification for these leaky dams on Deep Cliff Hole, but what
I have found confirms my suspicion of a token vanity project. There were local
newspaper reports last August that Harden Moor was among five sites chosen for
a pilot scheme that would explore natural measures to reduce flood risks, the
enhancement of woodland and wetland areas on the upland being among moves to
be tested as part of the project, led by the Environment Agency and Leeds City
Council, in partnership with Bradford Council as the owners
of the woodland and moorland (20,21). The context was Phase 2
of the Leeds Flood Alleviation Scheme (22). The local newspaper reports said
the proposals featured wetland areas and drainage improvements to help ebb the
flow into Harden Beck, a major tributary to the River Aire, Cllr Alex
Ross-Shaw, Bradford Council’s executive member for regeneration, planning and
transport being quoted as saying (21,22):
Chris Milburn, project executive at the Environment Agency, went further by saying - “We are committed to reducing flood risk and improving the environment. Many of our flood alleviation schemes feature a mixture of hard and soft engineering and natural flood management to protect communities whilst creating habitat for wildlife. This pilot project in the Aire catchment, which uses natural flood management, provides us with a fantastic opportunity to work with farmers and landowners to secure potential sites to trial new techniques and develop local plans for the future”. Leader of Leeds City Council Councillor Judith Blake, also stressed working with landowners and stakeholders, but I’m just wondering what farmers were worked with, especially since as I have noted above there was no evidence of any complementary activity in the farm fields of Cliff Farm above Deep Cliff Wood, nor were there any measures on Midgram Beck running through farm fields when it is that beck that patently drains Harden Moor and not Deep Cliff Hole.
It was noted that a management design for Harden Moor, being developed by Bradford Council through the White Rose Forest, would be going out to public consultation, and two local consultation events were flagged for August 2018 where this design would be presented. I can only quickly find a copy of the design and no supporting documents, nor any consultation responses without trawling through many local authority documents. The Long term Management Plan design for Harden Moor shows four leaky dams across Deep Cliff Hole within the woodland, and with a possible new wetland associated with the western side of those dams (23). I’m not sure how a wetland can develop up hill – it would be more likely to develop on the eastern side of the watercourse where the land is flatter. Chillingly this design also shows the loss of regenerating birch woodland on the western moorland, as it is zoned solely for heathland. An update newsletter in December 2018 on the Bradford Flood Programme notes that Harden Moor was identified as one of five pilot Natural Flood Management projects funded by Leeds City Council and being implemented throughout the River Aire catchment (24). It says that the design for Harden includes interventions aimed at "slowing the flow" of water into Harden Beck using natural methods to “provide improvements to the site which are sensitive to the surrounding landscape” and which include “blocking drainage features and leaky dams to reduce water run-off and re-wet land” and “woodland creation and sphagnum planting to increase water absorption” as well as “land management to maximise woodland cover through natural regeneration and rewetting of heathland where feasible, so that the runoff is reduced and the landscape can hold more water in times of flood”. There is a claim that existing habitats would be kept and minor amendments would be made to reduce surface water runoff and erosion and improve water absorption in the area. That the proposed works for the pilot scheme would take place solely within the Local Authority owned boundary was confirmed, but that adjacent landowners had also been consulted – but obviously not engaged to contribute some natural measures on their land. Nor do I see where this “woodland creation” and “land management to maximise woodland cover through natural regeneration” is going to take place when existing trees were felled and it seems the intention is to clear the burgeoning natural regeneration of birch woodland on Harden Moor. It only surprises me that there is no evidence that the local authority sought to screw forestry funding for the leaky dam building as there are grants under the Higher Tier of Countryside Stewardship for building them in catchments targeted for flood risk measures, at £461.39 for a small dam, and £764.42 for a large dam, and there are even indicative designs for the dams (25-27).
The vanity of this perfunctory project is revealed by the so-precious use of an 8 year old North Swedish Forest Horse called Ghalm to “help move very large trees around the site to construct leaky dams” (28,29). Using a working horse on the pretext that it is “a really environmentally sensitive way to moving felled and fallen timber whilst reducing damage to flora and watercourses without pollution” is a sure sign that a project is seeking publicity, and so it did with media outlets as diverse as The River Restoration Centre, the Environment Agency, Horse and Hound, Waterbriefing, Asian Sunday and local press, all regurgitating from a local authority press release the same gushing story about this beast (28, 30-36). I was intrigued at reading of the involvement of this horse, as it had appeared to me that the leaky dams had been created pretty much from trees felled closeby that would not need moving far at all. Fascinated to see what this horse had contributed, I have watched the videos in some of the press reports, as well as in a longer video posted on Youtube (29,32,37). It looks to me that the horse was dragging a few token felled trees northwards along the flat heathland that exists above Deep Hole Cliff on the eastern side, and with a clutch of press photographers angling to get a cute shot. I don’t see, and it is not shown in any of the videos, how the horse was able to then drag these trees down into the ravine to where the leaky dams were built, as there is no easy route through or around the large rock-field strewn on the eastern face of the cliff. In addition, none of these videos or other press photos show the dams in construction, but then the photoshoot with the horse may have occurred before the dam building began. If you want to see a photo of one of the completed dams, then it appears in an Appendix to a report to the Yorkshire Regional Flood and Coastal Committee meeting in April, along with the admissions that “a media opportunity was arranged for the first day that Ghalm was on site” and “We made a short video with Rosa Foster which was shared on social media and also with photos was viewed over 20,000 times” as well as the now very familiar rhetoric about far from achieved objectives of “tree planting, wetland creation and the installation of leaky barriers to slow the flow of water into Harden Beck” (see page 40 in (39)).
Beaver, dams and bunds in Cropton Forest
I’ve written before about how land owners are generally resistant to implementing flood alleviation measures identified at specific sites, and why a key factor in the selection of the Pickering Beck catchment for the project Slow the Flow to alleviate the serious flooding that took place in Pickering in 2007 was the nature of land ownership - the advantage of the Pickering Beck catchment was that around half of the land was either in public ownership (by the Forestry Commission and the North York Moors National Park Authority) or owned by the Duchy of Lancaster Estates, providing greater flexibility and likelihood of success (40). A key part of Slow the Flow has been installing over 170 Large Woody Debris dams mostly in Cropton Forest, part of the Public Forest Estate, as well as two timber-based mini-bunds (41,42). Large Woody Debris Dams are just another way of saying leaky dams, and the earlier ones constructed in Cropton Forest were similar to those across Deep Cliff Hole in mimicking the kind of natural debris build up that happens in water courses when trees upend and branches fall in (see photos of a few in (43)) while later ones were more engineered, using plantation timber logs laid horizontally and leaving a set gap between them so as not to affect low–moderate flows, and securing the logs in place by wedging and wiring to bankside stumps or posts (see Fig 2 for a dam in (44)). The larger proportion of Large Woody Debris dams were constructed on watercourses in Cropton Forest that drain into Pickering Beck, amongst these being Stape Beck, Short Gill and Long Gill that drain into Raindale Beck, Scarfill Beck, Sole Beck, Yaul Sike, Newton Dale Spring ((45) and see the flood warning monitoring of Pickering Beck in Pickering in (46)). Another 30-odd Large Woody Debris dams were constructed on watercourses in Cropton Forest, such as Little Beck and Sutherland Beck, that drain instead into Cropton Beck that then drains into the River Severn that has flooded down steam at Sinnington ((47) and see the flood warning monitoring of the River Severn in Sinnington in (48)). The two timber bunds were constructed on Sutherland Beck, the downstream bund is 16.5 m wide, while the upstream is 57.5m (47). Both have a maximum height of around 1.5 m that tapers down towards each end, and is constructed from a wall of stacked logs that are braced against and secured to adjacent tall tree stumps and/or posts, the log bund extending across the full width of the river floodplain (see Fig. 3 for a bund in (44)). Logs were provided by felling plantation trees on the site.
You have to feel that the sheer amount of this activity alone in just Cropton Forest on its many watercourses will have some effect in the long term of alleviating the flooding at Pickering and Sinnington. It dwarfs the token effort at Deep Cliff Hole, and is much less objectionable when the materials used in the constructions will have been plantation trees destined for harvest, rather than the robbing of native woodland trees out of the ecology of Deep Cliff Wood. The flooding initiatives at Cropton Forest, though, are not immune from a vanity when there is another bandwagon of preciousness to jump on. A few weeks ago, Forestry England announced the arrival in Cropton Forest of two beavers trapped in Scotland, describing the “introduction of a cornerstone species that has been absent from our landscape for over 300 years” as a “landmark occasion” (49). The press release went on to say that Forestry England had unveiled plans for a trial reintroduction into Cropton Forest last October, and had since then been granted a licence by Natural England to release beavers into a secure site of 10ha that encompassed a 824m length of beck. The beaver would be there during a five year trial that will “assess the impact of the beavers’ activity on the long-term sustainability and maintenance of the “slowing the flow” artificial wooden dams”. It is not stated in the press release which beck the beavers are located on, nor does it appear in any of the usual rash of publicity given to this because a cute animal is involved and, while there is much regurgitation of the Forestry England press release, there is no real sense that these are captive beaver - none of the photographs or videos show any aspect of this site that is alleged in the press release to be “secure” (50-55). There is, instead, the sense given that beaver have returned to Yorkshire, and many less attentive people will laud this as some triumph for the return of beaver when in reality they will not be free living. In terms of the reason for their presence, the Forestry England webpage for the beaver trial explains that the “man-made dams at Cropton Forest have already been helping to reduce flooding however, they are expensive and time-consuming to look after. So beavers are being released into a secure area in Cropton Forest to maintain the existing dams and create their own. As the first project of its kind, we're very excited to see how the beavers interact with man-made structures already in place” (56). I will have to contain my excitement at this irony! While photographs of a Large Woody Debris dam and a timber bund are shown, presumably structures that the beaver are expected to maintain, there are no clues given as to which water course they are on, although the photograph of the timber bund might suggest Sutherland Beck (see above).
I have to thank the North York Moors National Park Authority for having attached a copy of the project method statement for the licence application made to Natural England for the trial release of beaver into an enclosure in Cropton Forest when they discussed their support for it in an agenda item last October (57). The report confirms that the release site for the trial is Sutherland Beck in Cropton Forest, and that it will be enclosed with a 1.2m high post and tensile wire fence that adheres to the minimum standards required to contain beaver, as set by species specialists and Natural England. Potential escape routes upstream and downstream, such as ditches, culverts and drains were to be blocked using in-water engineered solutions, such mesh boxes, grilles and other barriers, the latter structures requiring planning permission. The report notes that there are two semi-engineered man-made timber bunds in place across the beck, one just downstream of the enclosure, and that there would be installation of two new wood dams (presumably Large Woody Debris dams) within the enclosure. The aspect of the costs associated with installing and the subsequent maintenance of woody debris dams and associated structures is raised in the report as an issue that hinders adoption of Slow the Flow projects. It is asserted, however, that there is evidence from the Bridge Creek Restoration Project in Oregon, that beavers will adopt, maintain and reinforce man-made structures. Thus one of the main reasons for the trial is to investigate whether the beavers adopt and reinforce the man-made structures in Sutherland Beck. The hope is that if they do, it then becomes a process of flood alleviation in the future of strategically placing these structures and then having them maintained, extended and developed further by beavers. It implies a proliferation of beaver enclosures wherever these strategically located dams are built, the beaver being used as tools behind the fences.
Mechanistically utilising the functional trait of a wild species
I should point out that there is a bit of a misrepresentation in using the Bridge Creek Restoration Project as justification. At issue was that the incised and degraded habitat of Bridge Creek caused by human land use was known to be limiting for its population of steelhead, an endangered fish (58). A logical restoration approach was to improve their habitat through reconnecting the narrow erosion channel with portions of its former floodplain to increase both stream and riparian habitat complexity. Earth moving would be a costly and invasive method, and so the project sought to enlist the help of a small, free living population of beaver. Unfortunately, their population was being limited by high discharge events in the Creek that caused the beaver dams to fail within their first season. Thus the intention was to assist them in building longer-lived dams through installing 85 beaver dam support structures, dam analogues constructed with material that was similar to what beaver use to build their own dams. These beaver dam structures included a line of posts driven in across the creek; post lines with wicker weaves; construction of starter dams of willow branches woven between vertical posts and the back side sealed with rock and clay; reinforcement of existing active beaver dams; and reinforcement of abandoned beaver dams. The horizontal stacking of comparatively large diameter logs of the dams and bunds in Cropton Forest bear no physical relationship to these beaver dam support structures in Bridge Creek, and so it is hard to see how the beaver in the enclosure will interact with them.
Either way you look at it, the Bridge Creek Restoration Project was seeking mechanistically to utilise the functional trait of a wild species, but at least the beaver there were free living, had free choice, which is not the case for the exploitation of beaver at Cropton Forest. I have written before that the beaver released into an enclosure in the Forest of Dean, another Forestry England site, as well as in an enclosure in Cornwall, were to be used as enfenced, slave labour, a tool to provide an ecosystem service, which at the Forest of Dean site was to “hold back enough water to help with flood alleviation for Lydbrook” (59). I wondered then whether there was any difference between these captive beaver and the cattle that are used in fenced fields as a conservation grazing tool by the conservation industry. Now, in the case of the Cropton beaver, doesn't anybody feel extremely uneasy about the beaver being trapped in the wild in Scotland and then being dumped into captivity in Yorkshire? Isn't this loss of freedom degrading enough for a wild animal without then expecting it to perform an unrealistic function?
The irony of beaver allegedly maintaining artificial, man-made structures in Cropton Forest would not be lost on Neil, and I am sure we would have exchanged some wry smiles at this nonsensical justification for yet another enclosure of beaver. It is as if they are the plaything of researchers looking for their next opportunity to cash in on a currently fashionable animal. It’s the vanity of it all, the impatient human interventions of veteranising of trees; associating a working horse with felling native trees to create a few, token leaky dams; facilitating beaver to reverse the effects of river incision caused by human land use; and now expecting captive beaver to maintain man-made dam and bund structures. All these smack of the endless circular churning of humans in feebly trying to compensate for their original disruption of naturally functioning ecosystems. When we haven’t left wild nature alone, we then can’t seem to commit to leave it alone, but must become the mechanism, the tinkerer, the damaging meddler, rather than restore and then leave the natural mechanism alone.
Mark Fisher 27 April 2019
(1) Glaves, P., Rotherham, I.D., Wright, B., Handley, C. & Birbeck, J. (2009) The identification of ancient woodland: demonstrating antiquity and continuity- issues and approaches, A Report to the Woodland Trust
(2) The loss of a great activist against dewilding, Self-willed land May 2018
(3) Blacka Moor
(4) Contemplation of natural scenes, Self-willed land January 2012
(5) ......before a fall, Blacka Moor blogsite 2 January 2014
(6) Pepper, H.W. (2008) Girdling, Constriction and Ring Barking. Arboricultural Advisory and Information Service. Arboricultural Practice Note 13
(7) Dead standing trees – to keep or not to keep? Marco Bartolini, The Arboricultural Association 13 August 2018
(8) Humphries, D. (2014) Standing dead trees in the urban forest, Science & Opinion, Ancient Tree Forum Autumn-2014 25-31
(9) Habitat fragmentation and the ecology of artefacts, January 2015
(10) Agnew, J.M. and Rao, S. (2014) The creation of structural diversity and deadwood habitat by ring-barking in a Scots pine Pinus sylvestris plantation in the Cairngorms, UK, Conservation Evidence 11: 43-47
(11) TE13: Creation of dead wood habitat on trees, Countryside Stewardship, Rural Payments Agency and Natural England, April 2015
(12) Landscape Character Supplementary Planning Document Volume 9: Wilsden, Local Development Framework for Bradford October 2008
(13) The Commons Registration (General) Regulations 1966
(14) St Ives Estate, Historic England
(15) Harden Moor (Open Country) CBMDC
(16) St Ives Estate, Walks in Parks and Woodlands, CBMDC
(17) Washed Out, Blacka Moor blogsite 30 January 2014
(18) River Sheaf at Dore Station, River Levels UK
(19) Harden Beck at Beckfoot, River Levels
(20) Harden Moor part of anti-flood scheme, Keighley News 16 August 2018
(21) Flood reduction scheme to be trialled on Harden Moor, Telegraph and Argus 14th August 2018
(22) Leeds Flood Alleviation Scheme: Phase two, Leeds City Council
(23) Harden Moor - Long term Management Plan 16 August 2018
(24) Harden Moor Natural Flood Management (NFM) Pilot Project, Keeping you informed – Bradford, CBMDC, Yorkshire Water, Environment Agency December 2018
(25) RP32: Small leaky woody dams, Countryside Stewardship, Rural Payments Agency and Natural England, March 2017
(26) RP33: Large leaky woody dams, Countryside Stewardship, Rural Payments Agency and Natural England, March 2017
(27) Annex 2c: Indicative designs for leaky woody dams, Countryside Stewardship: Higher Tier Manual, DEFRA 2019
(28) Horse power helps to reduce flood risk in the Aire catchment, Seherish Mahmood, Asian 1 March 2019
(29) Horse Recruited To Help Bingley Flood Management Work, Pulse1 5 March 2019
(30) Horse power slows the flow in the Aire catchment, Environment Agency Press Release 5 March 2019
(32) Horse power used on Harden Moor to cut flooding, Tim Quantrill, Telegraph and Argus 6 March 2019
(33) Horses called in to help protect homes from flooding, Lucy Elder, Horse and Hound 6 March 2019
(34) Leeds Flood Alleviation Scheme pilots natural flood management approach, Water Briefing 7 March 2019
(35) Horse power slows the flow in the Aire catchment, The River Restoration Centre 26 March 2019
(36) Horse power helps to slow the flow and reduce flood risk in the Aire catchment, CBMDC Press Release 4 March 2019
(37) Heavy horses at Harden Moor, Yorkshire Post, YouTube 5 March 2019
(38) Horse Power Helps to Slow the Flow – Harden Moor, Appendix 4, Item 4, Agenda and Papers, (39) Yorkshire Regional Flood and Coastal Committee meeting 25 April 2019, Environment Agency 16 April 2019
(40) Flooding and cherry picking, Self-willed land February 2014
(41) Project background, Slowing the flow at Pickering - About the project, Forest Research
(42) Restoration of large woody debris dams, Slowing the flow at Pickering - Catchment measures, Forest Research
(43) Slowing the flow at Pickering - Photo gallery - Examples of large woody debris dams
(44) Nisbet,T., Thomas, H. and Roe, P. (2017) Case study 12. Slowing the Flow at Pickering
(45) Appendix 14.3: Report on quantifying the contribution of the large woody debris dams to flood water storage, Project RMP5455: Slowing the Flow at Pickering. Final Report: Phase II, Defra FCERM Multi-objective Flood Management Demonstration project, May 2015
(46) Pickering Beck at Pickering, River Levels UK
(47) Appendix 14.4: Quantifying the Potential Storage of Flood Water from the Construction of Timber Bunds on Sutherland Beck, North Yorkshire, https://www.forestresearch.gov.uk/documents/1008/FR_STF_Pickering_P2_App14.4_May2015.pdf
(48) River Seven at Sinnington, River Levels UK
(49) Beavers arrive for Yorkshire trial, Forestry England 17 April 2019
(50) Beavers released in Cropton Forest as pioneering UK trial gets underway, Ben Barnett, Yorkshire Post 17 April 2019
(51) Beavers reintroduced to Yorkshire in 5 year experiment to tackle flooding, Sarah Knapton, Daily Telegraph 17 April 2019
(52) Beavers released in North Yorkshire as part of flood defence scheme, ITV 17 April 2019
(53) Cropton Forest is the site of Forestry England beavers project, Andrew White, The Northern Echo 18 April 2019
(54) IN PICTURES: Beavers released into Cropton Forest, Sue Wilkinson, Yorkshire Post 18 April 2019
(55) VIDEO - Beavers brought back to North Yorkshire, Cat Soave, Minster FM 18 April 2019
(56) Beaver trial at Cropton Forest, Forestry England
(57) Yorkshire Beaver Enclosed Release Trial, Item 14 - North York Moors National Park Authority 1 October 2018
(58) Pollock, M.M., Wheaton, J.M., Bouwes, N., Volk, C., Weber, N. and Jordan, C.E. (2012) Working with beaver to restore salmon habitat in the Bridge Creek intensively monitored watershed: Design rationale and hypotheses. National Oceanic and Atmospheric Administration Technical Memorandum no. NMFS-NWFSC-120
(59) The continuing destruction of our native trophic pyramid, Self-willed land February 2018