Cam Valley Forum

I have been invited to talk to the Cam Valley Forum on the 25th March about all things chalk stream but particularly about the chalk stream restoration strategy I have been helping to develop with our CaBA Chalk Streams Restoration Group. The talk is an open forum and you can book your ‘virtual’ place by following the link in the invitation below from Alan Woods the Forum Hon secretary.

(The picture above is of the Mel, one of a chain of lovely little chalk streams that rise along the edge of the chalk downs between Cambridge and Royston.)

“Dear friend

Please find attached an invitation to our Annual Talk, which will follow the Cam Valley Forum’s AGM on Thursday 25 March.

This year’s talk is being given by Charles Rangeley-Wilson, Chairman of the National Chalk Stream Restoration Group. Charles is a leading environmentalist and advocate for Chalk streams. This meeting will provide an early opportunity to hear about his expert Group’s draft national plan to restore Chalk streams.

His Group’s proposals are expected to be ambitious and far-reaching and will be highly relevant to our own Chalk streams in the Cam Valley.

Bookings can be made via Eventbrite at https://www.eventbrite.co.uk/e/cam-valley-forum-agm-annual-talk-national-chalk-stream-restoration-plan-tickets-144011509301. Zoom invitations will follow a few days beforehand.

We hope that you will be able to attend.”

Update on a New Chalk Stream

Timely, given the beaver controversy, that I had actually spent a few hours on Friday drawing aerial diagrams of my recent river project to animate a presentation I’m planning on the possibilities of ambitious chalk river restoration.

This project is the latest phase of a piece-by-piece catchment restoration of the River Nar, funded this time by a Water Environment Grant and managed by myself as designer and the Norfolk Rivers Drainage Board as project facilitators (they did all the difficult stuff like Health and Safety, managing the finances etc.) particularly Paul George, Helen Mandley and Caroline Laburne.

The primary driver was the creation of hydrological or lateral connectivity around a part of the river that had historically been diverted to the edge of the floodplain to build up a head of water to drive a mill. This type of channel diversion is very common on chalk streams, but it has the effect of divorcing the river from the floodplain, and lowering the gradient over long reaches in order to build up the head at the mill. More or less universally this creates a sediment retention issue, especially nowadays that the mills are not worked.

Add late 20th century dredging or zealous weed management to the mix and you end up with a channel that flows slowly, is full of sediment and burr-reed, cannot scour itself clean and is disconnected from the floodplain.

The drawings below show Phase 1, the uppermost part, which we carried out in late 2019. We finished Phase 2 in autumn 2020. We came in under budget, so hopefully now there will be a Phase 3.

The top diagram shows the river before the works, the red lines marking the edge of the floodplain. You can see how the river has been diverted to the very edge of the northern (left) part of the floodpain. With the river thus diverted and also overdeep as a result of dredging, the option to restore the gravel bed of the river in situ would have been enormously expensive, unsustainable and not ideal anyway, given that the channel was kind of in the wrong place.

I designed a new channel planform flowing roughly where the river would once have been (the very upper hundred yards actually cuts a corner, but it does that because only at that point could I come off an undamaged part of the original channel bed and start with a good baseline level). I based the meander shapes on field measurements of as many local original meanders as I could, including some lost original meanders.

I calculated the gradient from the very uppermost point to the return point which would be 2000 meters downstream. This phase illustrated is about 450 metres. Based on the number of meanders at the estimated wavelength I ended up with a fairly easy to measure 5cm fall from one inflection point to the next. Between these we cut the bends about 30 cm deeper on the outside below the undercut bank. We also ended up with piles of gravel here and there from the channel excavation and these we tossed back in at the end to give the river some grit to work with.

Look carefully at the diagram and you’ll see we only cut off the top fifty yards of the old channel. It still has flow: it is spring-fed from groundwater seepage and some quite significant springs at the corner. So, to add to the channel types and biodiversity of the floodplain as a whole, we put a high bar of gravel just upstream of where the new channel runs back in: this has backed up the water in the old channel and created a more fen-like habitat, or pseudo oxbow.

Finally, a few months after it had all settled in we pinned a very large number of trees and branches to the new river bed: not as many as I would have liked to, now I go back and take a look. I plan to do more in the new channel and the old, to get as much complexity in there as possible and in the old channel to pack it out and saturate the floodplain.

Early results from invert and fish surveys courtesy of the Norfolk Rivers Trust look really good: a healthy size range of trout (lots of juveniles and a few old snorters) and good invert numbers and diversity.

I’ll write about the next phase in the next blog post, when the overall design will be made clearer, especially why we had to run this to phase back into the old channel. In the next phase we end up with three channels side by side and some pseudo beaver ponds too. And a short “Stage Zero”.

The pictures below the diagrams probably say more than lengthy explanations can.

The first cut.
A dumper followed the line of the emerging channel and took the spoil off site to fill in an old, dry quarry pit.

The sequence above shows the same bend as it is cut, then in the autumn 2019 just after the works had finished (top right) spring 2020 (next one down) summer 2020 (bottom left) and one year on, autumn 2020 (bottom right).

The sequence above also shows several shots of the same reach, just as we are tidying up (autumn 2019) (note the pile of LWD ready to go in), summer 2020 (bottom left) (we have Konik ponies to help manage the floodplain), autumn 2020 (middle right) and under high flows winter 2020.

LWD being distributed along the river bank as the machinery leaves the site.
Pinning the LWD into place the following spring.
Mid-summer 2020 and the channel is starting to look like it belongs there.
Aerial photo of the new channel stitched out with LWD. The take-off point / old river is the very light patch to the left of the channel at the top of the image.

The Hampshire Whitewater

And here is a chart for the Whitewater in Hampshire, a chalk stream rated as Good for Phosphate. But that “Good” is an average. In fact the river is at High status upstream at Dipley and Moderate status downstream at the Devil’s highway just upstream of the Blackwater confluence. In between lie three sewage treatment works (STWs), two of which do strip phosphate, albeit but they are largish works at Hartney Witney and Fleet. The third works at Hounds Green, I’m not so sure, but I suspect it is too small to get phosphate removal.

The River Whitewater in Hampshire shows a less extreme but in some ways clearer version of the pattern on the Misbourne … see earlier post. There are numerous small discharges upstreams of Dipley, but no sewage treatment works. 

The lower Assessment Point near the Blackwater confluence is impacted by three STWs, Fleet and Hartney Witney via a tributary called the River Hart and also Hound Green.

The phosphate peaks upstream at Dipley tend to coincide with or even follow winter rainfall, while the phosphate peaks downstream quite clearly coincide with late summer and precede autumn / winter rain. The peaks and troughs are in a clear inverse pattern

Note how the peak loading from the diffuse / disparate sources at Dipley matches the downstream readings as the point sources become diluted by the same high flows, but that between high flows the readings downstream are approx four times greater.

Small STWs on a Norfolk chalk stream

I’ve been putting together a few more graphs to try to understand a bit more about the relative impact of small sewage treatment works on Cinderella chalk streams: by that I mean the chalk streams not protected by either SAC or SSSI designation or the Urban Waste Water Treatment Directive.

The first chart shows the River Stiffkey, a small stream in my home county of Norfolk.

This data is taken from EA monthly readings, although as you can see the readings are not at all monthly (each vertical red or blue line is a reading / the tracker line is the rolling average). They are inconsistent and the data series vanishes here and there, which is a great shame. Nevertheless a picture emerges.

The chart for the upper River Stiffkey compares readings in the upper river at Great Snoring, with readings a few miles downstream at Wighton. Between the two Assessment Points there are four small STWs – Little Snoring, East Barsham, Houghton St Giles and Great Walsingham.

The Great Snoring data is inconsistent, but it is nevertheless clear that upstream readings are considerably lower and that the difference is more obviously attributable to P discharges from the STWs: the upstream spikes lag behind those downstream and coincide with winter rain. The downstream spikes rise through the summer when the difference between the two is at its greatest. A slight exception is late 2007, a very wet early autumn which followed a dry winter, which could explain high late summer levels from point-source discharges, immediately followed by high early autumn levels driven by diffuse run-off. Unfortunately the Great Snoring readings stop mid-winter 2007 and so the blue line tails off when it might actually have continued to be high.

The cumulative impact of four small sewage treatment works, none large enough to merit the investment of phosphate stripping, is only too obvious.

The impact of a Sewage Treatment Works on phosphate levels in a chalk stream

I’ve been making charts of phosphate readings on chalk streams to try and get some sense of the comparative scale of point-source to diffuse pollution on different chalk streams. The Misbourne tells a clear story of this relative impact in a very populated part of the country. On other rivers, especially the chalk streams protected by designation, the picture is more nuanced. But the charts below speak for themselves: the sewage treatment works at Gerrard’s Cross on the River Misbourne (a chalk stream which also suffers from low flows) does not (to my knowledge) feature a phosphate stripper.

Not far upstream of the sewage works the EA Assessment point data shows consistently low phosphate readings, while downstream of the STW the readings are very high.

There are also some clear, and revealing patterns. Upstream the peaks, such as they are, clearly coincide with high flows in the mid-winter, whereas downstream the peaks coincide with low flows in late summer, indicating that the primary source of phosphate upstream is from diffuse, landscape sources while downstream the primary source is quite obviously the sewage treatment works.

The phosphate concentrations go up and down in inverse relationship to each other. At the upstream assessment point increasing flow leads to increasing amounts and concentration of phosphate, whereas downstream increasing flow decreases phosphate concentrations through the effect of dilution.

To remove P or not to remove P, that is the question.

Phosphate: to those like me who answered their Chemistry O level multiple choice by rolling a pencil down the desk because that way they tended to get higher marks, phosphate is just another chemical. But in terms of river ecology in general and chalk stream ecology in particular, phosphate is very, very important.

That’s why I’ve spent the past few weeks adding info to the Abstraction Sensitivity Band table I published in the previous post in December. The Chalk Stream Table now includes the Water Framework Directive (WFD) status for Flow and Phosphate.

Flow is a “supporting element” and so it is adjudged either to support or not to support Good Ecological Status. In WFD lingo these are the acronyms SG or DNSG. The column for the WFD ‘element’ Phosphate (P), is classified as either High (which means High status and therefore low phosphate concentrations), Good, Moderate, Poor or Bad (Bad means a high phosphate concentration). Phosphate is a pass or fail element: if P readings are Moderate, Poor or Bad the waterbody can’t be deemed to meet Good Ecological Status. There are no absolute readings used to assess status: it is somewhat tailored to each stream. Generally however, P needs to be lower than 0.036 mg/l for the chalk stream to achieve High status.

(Note: I have indicated which Sewage works remove Phosphate as best I can with the information available. The table may include some errors in that regard. Also I have included the actual P readings from the Dorset streams but not the rest (not enough time in the day), but I will in due course. There is no one source of information on this important issue of Phosphate and sewage treatment standards, which is something I hope the new chalk stream hub we are developing will resolve.)

I’ve taken P here as something of a totem for water quality in general, although that is a massive oversimplification. Nevertheless P has a huge impact on the ecology of our chalk streams. If you want to read an authoritative explanation from the expert on this subject I refer you to Phosphorous and River Ecology by Chris Mainstone. This is my Ladybird Book simple version:

Phosphorous is the key chemical that drives nutrient enrichment of chalk streams. That enrichment has a number of deleterious effects on a river’s ecology which increase in line with increasing P enrichment. All plants need P to grow, but different plants and plants communities either thrive or conversely suffer and are out-competed at differing levels of P concentration.

Higher order and important chalk stream plants like Ranunculus thrive at very low, background natural P concentrations. The first effect of P enrichment is actually an increase in the growth-rate of the higher order plants, but with commensurate weakening in root growth – making the plants vulnerable in high flows. As P levels increase further the river’s ecology shifts towards a dominance of the higher order plants that are most tolerant of nutrient enrichment, and that leads to a reduction in the overall bio-diversity of the plant community. 

Finally, if P concentrations keep on rising, the river’s ecology will switch over to an algal-dominated plant community. Benthic algae smothers the river bed and the interstices in the gravel in which many insect species live and epiphytic algae cloaks the leaves and stems of the higher order plants, reducing their ability to photosynthesise. The prevalence of algae will also cause extreme diurnal variations in dissolved oxygen levels, with really low oxygen levels at night and in the early morning, which stresses fish and insects alike. There comes a point where, if the P is very concentrated, the river turns into an anoxic soup and nothing much survives.

P is very limited in a natural chalk stream system. But P is contained in human sewage (treated and raw) and animal slurry, as well as in agricultural fertilisers. P is used in cress farms and there is P in the food used in fish farms and in the poo from those fish. There are other diverse sources of P: our drinking water is dosed with P, for example. Consequently there is much more P in our anthropogenically impacted river systems than might be considered natural. Relatively modest increases in P can cause the ecological changes outlined above. Any reduction in P will benefit the ecology of a chalk stream, but if P levels are high, or there’s loads of it still washing around the system, you might have to reduce P by an awful lot before you start noticing the difference.

There are also complex relationships between different states of P, which might be dissolved within the water column (Soluble Reactive P) or bound to organic and inorganic particles which accrete on the river bed: P can move between these two during its journey through a river system, meaning that P locked away within the sediments on the river bed can be reanimated in high flows when the river bed is disturbed.

P gets into a chalk stream through “Point Source” and “Diffuse” pathways.

The main Point Source supply of P is through the human sewage system, but fish farms and cress farms are also Point Source suppliers: a large fish farm (40 tonnes annual production), for example, can generate as much P as a secondary Sewage Treatment Works (STW) serving 1000 people.

Diffuse Source P, on the other hand, flows in multiple pathways from the wider landscape, and particularly from farmland. The majority of Diffuse P gets to the river by surface or shallow sub-surface flow during the wet winter months, when soil is saturated. 

A clear pattern you will see in this table is the correlation between chalk streams where there are no sewage treatment works (STWs) or chalk streams where the STWs includes a tertiary P stripping phase which tend to be of Good or even High status for P.

And conversely between chalk streams which have one or several STWs which do not remove P and which tend to be of Poor, Moderate or Bad status for P.

On some rivers I have noted in the r/h column where the P readings were markedly different upstream and downstream of a STW. One stark example is the Misbourne and I will publish a revealing chart of that in the next post.

There are other clear patterns: the relatively higher status for P on the larger systems as you move in a downstream direction. This is because the Urban Waste Water Treatment Directive which has driven investment in P removal over the last two decades applies to larger sewage catchments of 10,000 people or more. Many to most chalk streams do not have towns of that size on them, or if they do it will be in the middle to lower reaches of the larger river systems. Although its a good news story for P removal, it has tended to benefit the lower reaches of larger systems leaving the headwaters and smaller rivers behind.

Another clear pattern is the difference in % of STWs on a given river or in a given catchment that feature P removal and the designated status of the river. All chalk streams are a Priority Habitat, but some are also SSSIs (Sites of Special Scientific Interest) – the Frome, Test, Kennet, Nar and Driffield Beck and some are SACs (Special Areas of Conservation) – the Itchen, Avon, Lambourne and Wensum. These two designations are much more powerful. SSSI and even more so SAC protected status has driven an investment in P removal in smaller-scale sewage treatment works which is clearly reflected in the WFD assessments.

That is not to say that our SSSIs and SACs are perfect. They clearly still suffer phosphate issues as some charts I will publish in due course show. But it does make the point very clearly that if we want to effect real change for all our chalk streams, right across the map from Dorset to Yorkshire, we need to look at the protected status of all chalk streams, not just the shining examples. Much of the anger and frustration felt by people who care about chalk streams is driven by the condition of the Cinderella streams that are still bedecked with sewage works (there are 175) which do not remove Phosphate. Priority Habitat as it stands is clearly not a sufficient imperative to action. Protected status is symbolically important, but more than that it drives investment. And investment is what these rivers so desperately need.

How Sensitive is Your Chalk Stream?

Above: the River Nar in Norfolk: a “protected” chalk stream not very sensitive to abstraction … apparently.

Did you know that in order to assess if a river’s flows support Good Ecological Status (GES) using the Environmental Flow Indicator (EFI) every river is now put in one of three Abstraction Sensitivity Bands (ASBs)?

RIVER TYPEQ30Q50Q70Q95
ASB3 HIGH SENSITIVITY24%20%15%10%
ASB2 MODERATE SENSITIVITY26%24%20%15%
ASB1 LOW SENSITIVITY30%26%24%20%

The % figures in the table above indicate the reduction from natural flows deemed to be acceptable as a result of abstraction for the given river still to support GES. The Q number refers to the % of the time a given flow is exceeded: so Q30 equals relatively high flows and Q95 low flows. Flows in a high sensitivity river (ASB3) should deviate by no more than 10% below natural low flows.

The ASB banding is based on an assessment of three components: physical including gradient, catchment size, rainfall, and base-flow; macroinvertebrates; and fish communities.

One would expect, therefore, that all chalk streams would fall within the same ASB banding given that they are, almost definitively, of a type when it comes to the natural physical characteristics, which then define the macroinvertebrate and fish communities. In the original flow target matrix devised by UKTAG (from which the EFI evolved), all chalk streams fell within a single river type, divided between headwaters and downstream reaches.

So, I was surprised when I took a look at the ASB table to find that my local chalk stream, the River Nar, a protected site (SSSI) and arguably East Anglia’s finest chalk stream was in ASB1, the least sensitive to abstraction. This seems an anomaly to me.

But the River Nar is not the only river to have fallen into ASB1 in what actually appears to be a rather random assessment process. Can it really make sense that within a single chalk stream catchment we find rivers that are physically much alike spread across three different Abstraction Sensitivity Bands? The Wissey is one such case. But elsewhere, on the Frome say, we have the Wraxall and the Hooke (physically similar rivers) in two different bands. Likewise the Sydling and Cerne. If the assessment for ASB really is based on physical, macroinvertebrate and fish community assessments then this doesn’t make sense.

Below is a link to a table I have made of the ASBs for every chalk stream in England. Check it out to see what ASB your local chalk stream has been given. You can read the table by looking for the catchment your river is in. For example Thames / Colne etc. It starts at the River Bride in the southwest of Dorset and proceeds north east to end at the Gypsey Race in Yorkshire.

I suspect that those chalk streams in ASB1 are there by honest mistake: they are all in Kent, Norfolk, Lincolnshire and Yorkshire, in lower gradient catchments where the chalk reaches of rivers glide into fen-like rivers and often the waterbodies are lumped together. So, perhaps someone somewhere thinks the Nar is a cyprinid river because the waterbody division between the upper and lower river is in the Fens? Maybe. Even so, there are also a lot of chalk streams in ASB2 as well and I wonder why that is. In my opinion all chalk streams should be in Abstraction Sensitivity Band 3

Greater Protection for Chalk Streams in the Environment Bill

Sir Charles Walker MP recently sent the letter below to his colleagues in the All Party Parliamentary Group for Chalk Streams seeking their support for an amendment to the Environment Bill that would strengthen the protection of chalk streams by widening the definition of environmental damage to include damage caused by low flows due to unsustainable abstraction.

Can I encourage any of you who care about chalk streams and who live in a constituency with a chalk stream in it, to write to your local MP and encourage them to support Sir Charles’ amendment?

Next Steps for English Chalk Streams.

Redbourn Gauging Weir on the River Ver in May 2017: one of several Chilterns chalk streams still suffering from unsustainable abstraction. But maybe the tide has turned? Will the Ver be flowing properly again by 2027?

I’ve been asked by the Environment Agency, the Rivers Trust and CaBA to chair a national chalk stream restoration group whose first task will be to produce a national chalk stream restoration plan: it will be used to drive progress by government and regulators, water companies, landowners, NGOs and river associations right down to the grass roots level of individuals who are passionate about their local river … people like me.

So, a few weeks ago I was asked to talk about “Next Steps for English Chalk Streams” at the Chalk Stream Conference hosted by the Chilterns AONB. I discussed the same ideas earlier this week when Sir Charles Walker invited me to speak to the All Parliament Parliamentary Group of MPs for Chalk Streams.

I spoke about how there have been a number of action plans over the years and yet here we are … with our chalk streams still in crisis. I wonder what I can add to what has been said before, but will do my best. We are currently assembling a panel that is representative of the regulatory side of things, and of the water industry too and also of the national NGOs who have so long fought the good fight for chalk streams. I’m hoping the NGOs will drive ambition and that the regulators, and industry will respond positively to that vision. We will also draw on the expertise of a panel of experts in the field of chalk stream science, from hydrology to hydromorphology to ecology. Finally, we will share the drafts of our emerging action plan with a wide forum of stakeholders, from rivers trusts to grass roots river groups and individuals (I’m assembling that list and if you’re reading this and involved in a chalk stream advocacy group you’re probably on it, but drop me a line just in case).

You’ll see below in the words of my talk that I am keenly aware we need action above all else, that we have had action plans. But I think there is room to take stock of where we have got to and to analyse why certain key asks made again and again over the years have not been answered yet. I have some ideas as to why not.

Occasionally I have had a hand in previous reports on chalk streams: I helped WWF with their campaigns Rivers on the Edge and Flushed Away and with the 2014 State of England’s Chalk Streams report. But in terms of restoration plans I pulled together the plan that has driven our catchment restoration of the River Nar in Norfolk since about 2011. That’s the plan I can draw real life experience from.

And if I were to approach a national restoration plan as I have that local plan, I would say a vital first task is to break down the journey into assailable tasks, simply expressed. A lot of the ideas behind our Nar plan had been pulled together years before in the form of a much more involved and detailed plan that was brilliant in every respect other than in how it communicated its ideas to the places where they would actually make a difference: the general public. But that’s where the power to make change really resides. A growing sense that more and more people passionately care about chalk streams is what has driven the shift in tone and receptivity to change that we are seeing from our regulators right now.

Having worked out what needs to be done, we need to be strategic about the order in which we do things. Make a few early, doable and hopefully iconic gains and start to get a sense of the possible. I’d say we also need to be honest about the scale of the task, but not timid in the face of the realisation. We definitely need to be ambitious: but ambitious with an informed sense of what ambition actually means … and it doesn’t mean blaming everything on climate change, or publishing endless reports on systems-based thinking or coming up with more acronyms, or talking jargon behind closed doors. It means actually doing something, even if it’s a little thing and then doing another something, until all the little things add up to a big thing.

We’re not going to put our chalk streams back into excellent ecological health by next year, or the year after or even within five years and anyone who ever thought we could didn’t realise what was wrong with them. We’re certainly not going to do it by wishful thinking.

But river by river, reach by reach, we can do it. There are of course some things that could happen at a government and national level that would make a big difference: ending unsustainable abstraction as opposed to talking about ending unsustainable abstraction is one of them. Ending the scandal of CSO’s is another.

But maybe, just maybe this could happen … There’s been a surge of interest, lately, in the state of our chalk streams. All rivers being lovely, but chalk streams being potentially the loveliest of all. If you’re reading this blog you’ll already know that chalk streams are a very distinctive type of spring-fed river, almost unique to southern and eastern England. Between the beautifully named River Bride in Dorset and Yorkshire’s Gypsey Race there are just over 200 chalk streams ranging in size and character from the majestic River Test to hidden streams you’d have to almost fall in to notice, Lilliputian rivers with more lovely names like the Mel, Hiz or Gadder. They add up to most of the chalk streams in the world, a globally unique ecosystem that is ours to preserve and – because chalk streams have suffered greatly as south-eastern England has filled with people, business and industry – ours to restore to good ecological health. We seem to have really woken up recently to the duty we owe a natural environment that has suffered so much over recent decades.  But chalk streams feel to me like the ultimate test of our commitment. They are on our back door-step, they are struggling and they need protection. Are we up to it?

If so, what should the next steps be for our English chalk streams, steps that will lead them back to good health? Here’s my talk …

“As I often remind myself with regard to river restoration, to make good decisions about the future of a chalk stream, it is worth pausing to consider the past that has brought it to its current state. So, I hope you won’t mind if I spend a few minutes talking about next steps by talking about past steps. Because there’s a lot of frustration about what little progress we have made with regard to looking after our chalk streams. I want to consider why we are where we are, before offering some ideas on what we need to do next.

I fell in love with chalk streams many years ago, when I was given a Collins Encyclopaedia of Angling and found in it a picture of the River Lambourn: an ordinary little picture, nothing special, but one that captured that blowsy, English beauty of a summer’s day beside a brimful chalk-stream and which also captured my river-obsessed, childish imagination. 

Ten years later I moved to Dorset for my first job and fell in love with the wet reality of real chalk-streams. I started to fish them and to restore bits of them and this is where my exploration of the past begins, in the summer of 1995. 

Every day on the way to work I drove over a little chalk-stream called the River Tarrant. I got to know it very well. I rented half a mile of fishing from the farmer and would spend an hour or two there whenever I could. But this particular summer it started to dry, from the top down and from the bottom up, leaving a section in the middle full of magnificent trout caught in the trap of their drying river. 

The National Rivers Authority didn’t have the manpower to do much about it, but they did lend me some nets. So, as things got critical I went down there with my wife, Vicky, and together we netted the pools, rescuing the trout into buckets which we then put in the boot of my car and drove as fast as we dared down to the River Stour. Over a long week we rescued hundreds of trout against the clock of a vanishing river, until on the Saturday evening we had to stop, leaving one long pool only half done: it was late, and getting dark and we were totally exhausted. Vicky was heavily pregnant, after all. We’d get them the following morning, we thought. But by the next morning, it was too late. The pool had just vanished through the drying river bed, leaving dozens of trout, dead and dying in the mud.

I’ve sent my photos from that day to so many magazines that I have none left (slide film then and the magazines never return them) but I found this one online, taken by me in June 1995.

The River Tarrant had two abstraction stations on it: at the upper and lower ends of the river, exactly where the epicentres of the drying process had begun. I knew that abstraction had killed those fish, and I wrote angry letters to all and sundry saying as much. Vicky wrote an article in The Field

But in those days the official line was that abstraction didn’t actually cause chalk-streams to dry up or not enough to make the difference. Notwithstanding that I didn’t buy any of this – I did know that pulling trout out with nets and driving them around in buckets was not a sustainable way to protect them each time we had a dry summer. I also noticed that a pond beside the drying river had remained full all summer, simply because it was deep enough to pick up the groundwater that had deserted the perched river bed.

So, in between berating them about abstraction, I brokered a grant of £5000 from Wessex Water to excavate beside the river a series of inter-connected groundwater ponds into which I would put the rescued trout each summer and from which they could swim back to their chalk stream when the springs started to flow again. It was a no brainer scheme that couldn’t have but worked. But before I could get permission the Rivers Authority compelled me to commission a feasibility study including groundwater modelling. This study used up all my Wessex Water grant money and concluded that further research was necessary before we’d know the answer.

I learnt a lot that summer, about the issues facing chalk streams: the three-dimensional issues in the landscape, and the two-dimensional issues of the bureaucratic process which tends to complicate solutions to the point where nothing happens. You may have started to see how this story is a neat parable for explaining why, 25 years later, we are sadly still railing about unnaturally drying chalk-streams. 

First, we have long denied the cause of the problem. 

And then we have made the process of enacting solutions needlessly complicated. The latter sometimes to aid the former. And so it goes on.

In about 2006 I published a book on chalk-streams and drove through the Chilterns photographing them. With the exception of the Chess and Wye, I found mostly dry furrows in the landscape. 

In 2008 I helped WWF with their campaign against the over abstraction of chalk streams. We called it Rivers on the Edge. I wrote a speech which I gave bedside a dry chalk stream in Hertfordshire in which I said that our chalk streams were our burning rain forests, our melting ice caps. I hoped that idea would resonate and it did. 

The River Beane in 2008

Not so much, however, that in 2017 I was able to walk beside a River Beane with water in it. Whitehall was as dry in 2017 as it had been in 2007. And 1997 no doubt. As was the Hiz, the Mimram, the Misbourne, the upper Chess, the Ver.

The River Beane in 2017. At least it’s not overgrazed this time! But that pool of water … it isn’t flowing.

Will they still be dry in 2027? Dare we hope not? 

Because we have made some progress. The River Piddle dried often in the late 1980s, but now flows all the time, and as a result parts of it are close to chalk stream perfection. The River Og was bone dry when we campaigned for Rivers on the Edge. It flows again now. Other abstraction reductions have been made on the Chess, the Ver, the Darent. 

There are trout in London’s River Wandle when twenty years ago there were not. Some of our urban chalk streams are as clean as they have been since before the Industrial Revolution. 

River restoration is no longer seen by the authorities as a rogue activity pursued by eccentrics in smelly waders. It is encouraged and sometimes funded by the government to the degree that we can attempt projects now which were beyond our dreams twenty years ago.

So, there has been some progress and there is also now, I sense, a shift in mood. Nature and the environment are no longer niche concerns.

For my part I have been beavering away – quite literally, I suppose – on my local chalk stream in Norfolk and now I have been asked to chair a new national Chalk Streams Restoration Group, whose first task is to write a chalk stream restoration plan. 

Over the years I have to admit we’ve had a few of these. We’ve had in 2004 a report into the State of England’s Chalk-Streams. Then in 2009 we had WWF’s campaign Rivers on the Edge, followed in 2013 by the Angling Trust’s Chalk Stream Charter and in 2014 by a reinvestigation of the State of England’s Chalk Streams. And now most recently CRAG’s action plan. All good work. We kind of need another action plan like we need a hole in the head. What we really need is action.

But, if the momentum is here and there’s room for something that will help to catalyse that action, right now, I’m more than willing to have a go. 

Our end goal is healthy chalk streams we can all be proud of. It’s really very simple: there are three things that go to make a healthy chalk stream: 

water quantity, 

water quality, 

and good physical habitat. 

They are all interrelated, of course, and each one is shaped by the other. 

But the fundamental is water. Without water you have no river and in the case of the chalk-streams in London’s orbit, we frequently have no river. Or such diminished rivers that they are shadows of what they should be. This has gone on for too long, but one big reason why we have never quite cracked this abstraction nut is because the whole dark art of understanding abstraction and its impact on river flow has been hidden behind smoke and mirrors. Remember how I said that in the 1990s we were told abstraction wasn’t actually responsible for our unnaturally dry chalk streams? It seems incredible but only yesterday I bumped into a 1992 report on the upper Kennet that did just this, ascribing the cause to more or less everything but abstraction, wrapping the issue in a cloud of scientific radar chaff so that no-one without a PhD in geomorphology could disagree. 

I would like to see us democratise the knowledge. It’s not actually that complex. And knowledge, presented in such a way that it is easily comprehensible by the ordinary people who care passionately about their chalk streams, is what will harness the power to effect change. 

Right now you try getting hold of, let alone processing the information that will tell you the extent of the abstraction in a given valley, or the effective rainfall, or you try to understand the official assessment of whether a given river is over abstracted or not or even what actually defines unsustainable abstraction, and you’ll be set for a head-mangling exercise.

Instead, we should have a simple, national audit of the current abstraction regimes and rainfall data for all the English chalk-streams presented in an online map in an effortlessly comprehensible way, so we can see exactly what is coming in from the sky and exactly how much of that is not going out down the river? That would focus the debate, because it would put knowledge on both sides of the table.

And how about, in addition to the laudable but somewhat piecemeal abstraction reductions we have seen of late, giving ourselves a great big endorphin rush of an early hit by just getting on with the total no-brainer proposal of Chalk-Streams First? Chalk Streams First would amount to a total cessation of groundwater abstraction in all the chalk valleys of the Colne and Lea, a re-naturalisation of flows across the most beleaguered chalk stream region of all and for only a moderate loss to overall supply. It would offer us a model of how to do it elsewhere. What’s not to like? It’s such an easy win, the chance we have been waiting for to make progress on a significant scale.

As for water quality, remember that it took the Great Stink of the Thames to persuade the government of 1858 to invest in adequate sewer infrastructure. Perhaps it is a shame that we cannot, as Hercules might have, simply divert a river of Combined Sewer Overflows through Parliament. It hardly needs saying that the overuse of CSOs is a scandal. The Guardian recently reported the shocking headline figure that untreated sewage was released into English rivers 200,000 times in 2019. That Victorian sewage system catalysed by the 1858 stink is giving us problems some 170 years later. It is high time we updated it. To do that will be expensive, but Ofwat needs to understand that people care about not having poo in their rivers as well as their water bill.

Fakenham sewage outfall on the upper reaches of the River Wensum, one of only four chalk stream SACs

Further afield there is mounting evidence of the impact diffuse agricultural pollution is having on chalk-streams. We need to educate farmers, with independent, confidential advisory programmes backed up by warning and litigation if necessary. 

Over the road is a ditch and at the end of the ditch are the headwaters of the River Nar, one of only 14 SSSI chalk streams.

We also need to survey and fix the vast numbers of under-performing rural septic tanks, and sub-standard local sewage works.

Finally, and on to familiar territory for me, we need to lift our game when it comes to the physical restoration of chalk-streams. The degree to which they were dredged and canalised and the debilitating impact that has had on the bodily health of our chalk streams is poorly understood and massively under-estimated. 

A naturally meandering river, with an intact gravel bed and in-touch with its flood-plain is miles more healthy than a canalised, and entombed river, even if all the other factors are constant. It is perfectly possible, with funding and vision, to return our chalk-streams to a much more natural condition, even within the constraints of their man-made heritage. 

This is the River Nar taken out of its dredged and diverted course and put back down the centre of the floodplain. The old channel is now a spring-fed backwater full of sticklebacks and dragonflies. The new channel is full of current-loving chalk stream species like ranunculus, trout and riffle-dwelling mayflies and stoneflies.

To me this is the perfect chalk-stream: wild and unkempt, running free, but somehow also a palimpsest carrying the history of their mills and water-meadows and river-keepers.

Wouldn’t it be great if every water company were to adopt a chalk-stream as an exemplar of what is possible and work with the Rivers Trust and river associations to deliver a series of full catchment restorations, addressing that simple trinity of water quantity, quality and habitat as imaginatively and ambitiously as possible? 

Affinity Water and Thames Water will soon – I hope – meet this challenge on the River Chess. Will the other water companies join them and rehabilitate rivers like the Allen, the Cam, the Stiffkey, the Great Eau, the Foston Beck? Trojan Horse schemes on rivers like these would set the bar, showing beyond doubt that we can, with will and determination, find room for wild chalk-streams in our busy landscape, and through that enrich our lives immeasurably.

Thank you.”

The Index of English Chalk Streams

Good to see that the official Priority Habitat Map for chalk streams is receiving some attention, in part in order to include additions I made to the original 1999 Environment Agency map which listed 161 chalk streams (this map was used in the State of England’s Chalk Rivers published in July 2004). My version of a revised index was published in my anthology Chalk Streams with Medlar Press in 2005 and then later – with the helpful input of Dr Haydon Bailey – in revised form in the 2014 WWF State of England’s Chalk Streams Report. That list (which isn’t exhaustive, I’m sure) ended up at about 220 named rivers.

This is the link to my 2014 index, a version of which was in the WWF report.

The new guidance says the original 1999 list did “not provide adequate coverage of small chalk streams in headwater areas, including seasonally flowing winterbournes” which are important for biodiversity and deserve protection. I agree, although in fact what the original list mostly missed were the numerous scarp-face chalk streams that rise along the spring line on the north-east facing edge of the chalk massif. It also mixed up a few of the rivers in Yorkshire listing some several times with different names (because the local convention is for the river to take the name of the parish it is flowing through) and some not at all. In addition there were a few tiny little streams here and there which were missed, probably because you’d have to fall into them to find them. All these were easy omissions or confusions, but being a chalk stream nerd I could see the 1999 list was incomplete in the two areas I knew really well – Dorset and Norfolk – and started working on improving it.

For my 2005 version I used OS maps and driving around the country looking off bridges. For my 2014 version I had the advantage of online satellite maps (making looking off bridges much easier and faster), a new online publication of highly detailed geological maps and a complete series of OS maps from 1946, maps which pre-dated the post-war land drainage works that can complicate things. I took the names from these OS maps where I could.

In 2014 I also, with Dr Haydon Bailey’s help, refined what we mean by chalk stream. The River Nadder – as any fule knows – is a very different river to its neighbour, the Ebble. And yet they are both considered chalk streams. In fact no chalk stream is exactly like another, but as I went through the physical differences one river to the next, Haydon was able to help me group them into geological types.

I feel we need to move away from the too vague statement “any stream or river that has a flow regime dominated by natural discharges from the chalk aquifer should be included on the map” – (which could arguably include the Thames, or Ouse?) and towards the groups of chalk stream type as proposed below, because although these ideas might need some refinement, it is a more helpful and precise way of understanding what makes a chalk stream a chalk stream and what causes their subtle differences, one river to the next. Ultimately, this grouping could well help refine restoration and conservation strategies (and designations?) by river sub-type?

When we think of a chalk stream we think of a river of a certain size – medium to small mostly, though the lower Avon is a large river that preserves it’s chalk stream character almost all the way to the estuary – that is clear-watered most of the time; that is equable in its flow patterns – ie that isn’t ‘flashy” in its response to localised rainfall, but rather has a distinctly seasonal flow regime, at its highest in spring after the winter recharge, falling away through the summer and early autumn, before building again through the winter; that flows close to bankful most of the time, with in-river weed-growth bulking up flow volumes through the summer; and with a channel form that reflects this spring-fed flow regime – wide, shallow, gravelly, stable (the cross-sectional channel shape of a river is largely determined by the ratio of high flows to low flows: the higher the ratio the more incised the channel, and so chalk streams tend not to be that deeply incised).

If you know your chalk streams you’ll know that the Itchen fits this bill to a tee, but that the Nadder veers away somewhat, is more flashy, colours after, and is immediately responsive to, localised rain and is more naturally incised. It’s still a chalk stream – by reputation and according to our definitions – but maybe more a 9 carat plated chalk-stream than 24 carat solid. The difference is all down to subtleties of geology.

What makes a chalk stream a chalk stream, what gives the stream these characteristics as outlined above, is particularly the fact that the chalk body feeding our chalk streams lies very close to the surface, and the rivers which rise from it are not much influenced by superficial surface deposits: although some are more affected than others. This particularity in turn relates to the geographical relationship between the chalk body, and the limit of the last glacial maximum and the action of the glaciers and explains why there are chalk streams in England and Normandy, but not really anywhere else, in spite of the fact that there are great plains of chalk across eastern Europe. Basically the “cleaner” the chalk body from which the stream flows (ie very thin topsoil and not much in the way of superficial geologies or layers) the “purer” the chalk stream. The influence of other geologies will take a given river away from that purest expression which is typified by, say, the upper River Itchen or Test. Given that almost all chalk streams bump into other geologies somewhere along their route, this begs the question, when is a chalk stream not, or no longer, a chalk stream?

The River Nar, for example, flows for half of its length (the lower half) across the Fens, but gathers hardly any extra flow throughout that lower course – a few small tributaries which are also chalky in origin. For a large part of that lower course the channel is essentially man-made: in prehistoric times there wouldn’t have been a river so much as a freshwater segueing to salt marsh. Is that lower river a chalk-stream? I think so, but it is a sub-type.

The Fontmell Brook, as another example, rises off the scarp slope of the downs between Blandford and Shasftesbury, and for a few hundred yards is the prettiest Lilliputian chalk stream you could imagine, but then it drops onto sandstones and Gault clay and though it is always a lovely little river, its lower course is much more incised and moody: if you looked at it near Marston and knew nothing of its origins you would never describe it as a chalk stream.

By contrast the River Nadder and its numerous headwater tributaries flow across a mosaic of chalk and also Gault formation sandstones and mudstones before it squeezes through the pure chalk hills nearer Salisbury: it gets more and more chalky the further downstream you travel.

What this suggests is that the definition of a chalk stream is not binary: it is rather a spectrum condition with a suite of characteristics which fade the more a river is influenced by other geologies and geographies than the pure chalk downs.

Anyway, this is how we grouped England’s chalk streams:

Group A comprises streams that rise directly from the chalk, flow over chalk and subsequently flow over younger Tertiary (sand and clay) deposits. This group would include the majority of the Hampshire Basin Streams and the majority of those which flow in to the Thames Basin. These tend to be the slope-face streams and are generally longer than scarp-face streams. Note that most of the iconic chalk-streams like the Itchen or Test or Kennet are in this group.

Group B comprises streams which rise beyond the chalk and subsequently flow over / through the chalk – a minority of streams but the Great Stour in Kent is a good example, rising on the Gault clay / Greensand and then flowing through the chalk. The Nadder is another example, as is the Hampshire / Wiltshire Avon and the Dorset Frome. These streams will have less equable flow regimes than Group A streams, will tend will colour after heavy rain and take longer to clear too. The flow regime makes these rivers subtly more deeply incised in the landscape than the classic Group A streams.

Group C comprises streams rising from chalk which was directly impacted by major glacial action during the Pleistocene Ice Age. This would include some northern Chiltern streams and the East Anglian, Lincolnshire and Yorkshire streams. This chalk is more compressed and fractured with higher transmissibility than further south. Group C could be further subdivided into streams which flow from chalk over glacial outwash deposits and those that flow from chalk onto older (pre-glacial) river deposits, such as the pre-glacial Bytham River which flowed eastwards from the Midlands across Norfolk and emptied into the North Sea north of Lowestoft.

Group D comprises the scarp slope streams which all tend to run for a very short distance over older (clay rich) chalk and then flow out onto the underlying Gault Clay and Greensand beds. The Fontmell Brook and Iwerne stream in Dorset are scarp-slope streams, as are the streams north of the Chilterns, the westward flowing streams in north-west Norfolk, and all the streams east of the Yorkshire Wolds.

It seems that I listed a few streams which are proving tricky to find:

My index was arranged so that you could see where a given river was on a river system. The main river is the lead name and then the tributaries are indented below it, with the uppermost tributary listed first.

So the Bassingbourne is a tributary of the River Rhee (which is easy to confuse with the Cam because both the Cam and the Rhee seem to have interchangeable names on the map: even on the latest incarnation of Apple’s “Maps” the Rhee which rises at Ashwell Springs suddenly becomes the Cam after it flows under the Northfield Road). Anyway, to the west of Bassingbourne is a street called, tellingly, Brook Road and this is the river flowing under it:

And this is the geology that it flows from and across:

The springs are quite obvious in satellite images to the south but weirdly, the river does seem to vanish into a network of drains to the north of Bassingbourne.

The Binham Stream is actually a fairly obvious tributary of the River Stiffkey, in Norfolk, that flows west from Binham towards Warham.

The Bullhill Stream is a tributary of the Allen River (the Wiltshire Allen), a tributary of the Avon: it rises east of Cranborne and flows north-east through Lower Daggons and Bullhill. To be honest, I’m not sure it counts as a chalk-stream as the geology in that area is very mixed. The Allen River that it flows into is much more unambiguously a chalk stream.

The Crichel Stream is an obvious tributary of the Dorset Allen that flows down through Moor Crichel to Crichel Lake. See the screenshot below (all screenshots thanks to the miracle of Google StreetView and used here for the public good!)

The Gowthorpe Beck is a tricky one because of that Yorkshire habit of naming rivers by the parish: it’s also called Garrowby, Awnhams and Fangfoss! It’s also tiny and probably ephemeral and it’s only chalky at the foot of the downs. It’s just north of the A166 near Bishop’s Wilton in Yorkshire. This is a picture of it from the air:

The Iwerne Stream is unmissable: its a chalk stream that flows through Iwerne Minster, the next village and chalk tributary south from the Fontmell Brook. Look for Watery Lane! See pic below.

The Melbourne is another tributary of the Rhee but you can’t miss it if you find the village of Melbourne. It’s also called the Mel, so that can be confusing. See pic below.

The Otby Beck is another tricky to find, ambiguously named scarp-face chalk stream, tributary of the Ancholme, just north of Walesby, the next scarp-face stream north of the Rase in Market Rasen. Here’s a picture of it under Park Road on the way from the A46 to Claxby Park.

The River Chalgrove is easier to find. Just look for Chalgrove in Oxfordshire. It is made up of three small, scarp-face tributaries that rise in Lewknor, Shirburn and Watlington.

The Wyn is the next tributary downstream from the Tadnoll on the Dorset Frome. It flows over a mixed geology from Winfrith Newburgh and downstream, but it rises on the chalk near Chaldon Herring.

The Walsham is a tributary of the Little Ouse that rises at Walsham Le Willows in Norfolk. It flows over a very mixed geology that includes chalk, but it may well not quite count as a chalk stream. It is incised and clearly ephemeral, but has some nice meander patterns here and there.

The West Compton Stream is a tributary of the Frome, rising in the chalk hills of West Compton (south west of Wynford eagle and Maiden Newton) and looks like this:

The Wraxall Brook is also a headwater tributary of the River Frome, rising in the chalk, mudstone and sandstone formations of west Dorset near Rampisham. Although it flows over a fairly mixed geology it is definitely a chalk-stream and it picks up dozens of chalk springs along its route. See pic below.

The Beachamwell Stream is hard to find but it is a tributary of the Wissey, the next chalk tributary downstream from the Gadder which flows past Oxborough Hall. A lovely little chalk stream, it rises just south of Beachamwell and flows south west under the Gooderstone and Eastmoor Roads. See pic below.

I can’t find a Bishop Stream in my index, but there is Fonthill Bishop Stream, a tributary of the Nadder in Wiltshire which is very easy to find if you look for Fonthill Bishop. There is also a Bishop’s Wilton Beck, which is also easy to find if you look for Bishop’s Wilton in Yorkshire. It is small, I have to admit, as you can see:

The Charlton Marshall Stream is very hard to find. It is a tributary of the Stour near Charlton Marshall, in Dorset and by reputation was once an important salmon spawning stream for the main river. It is only a few hundred yards long, rising at the foot of the downs to the west of Spetisbury CE Primary School. I have a good photo of it somewhere as I go fishing near there every year. I’ll try to find it.

It was really only the name which made me think the Fulbourne must be a bourne. It is clearly ephemeral as the images on google maps show a dry stream bed, but the surrounding geology is definitely chalk. It is a tributary of the Quy water and rises in Fulbourne just to the east of Cambridge.

The Gussage Stream is another tributary of the Dorset Allen. It flows from Cashmoor through Gussage St Michael and Gussage All Saints. You can’t miss it really. See pic below.

The Kneeswell Stream, by contrast, is very, very hard to find. It’s near the Bassinbourn (see above), rising from springs at the base of the the same low chalk hills in Cambridgeshire, in the village of Kneesworth.

The North Bourn is a tributary of the Great Stour in Kent. Look for Northbourne near Shoulden. It’s chalk springs feed a veritable maze of lowland dykes but if ever there was a site for the restoration of this type of minor chalk stream it is here. In the picture below you can see the original river flowing through a drained field, with the ditches that now cary the water to either side. If the locals want to restore this, I’d be happy to help!

The Pakenham Fen is another chalk derived, fen-like river (perhaps we need a category of chalk stream that captures these rivers as there are lots of them) which rises near the Walsham (see above) flowing through Pakenham to Ixworth and into the Black Bourn and then the Little Ouse, in south Norfolk. See pic below.

The River Shep is a tributary of the Rhee (also called the Cam, but not THE Cam!). It flows through Shepreth. See pic below.

The Sapiston Brook is also known as the Blackbourn and it is the river into which the Walsham and the Pakenham Fen flow. It then flows into the Little Ouse. See pic below.

The West and East Hendreds, also called the Lockinge, are scarp face tributaries of the Thames that rise at East Lockinge, West Ginge and East Hendred to the east of Wantage. See pic below.

Finally, the Whitewool Stream is a tributary of the Meon that flows through the Meon Springs fishery from just north of Coombe.