A winters scene over the Upper Ivel in early January 2025 taken by one of RevIvels members ,Liz McCaul.
As you know, in recent years, the river Ivel has been dry in its upper reaches with increasingregularity and duration; this is largely due to Affinity Water abstracting (taking) too muchwater from the aquifer at the headwaters of the river.
Four and half years ago, the RevIvel community group (we) formed with the aim of restoring flow to the upper Ivel, enabling iconic species such as brown trout, to thrive in our river once again.
Four and half years ago, the RevIvel community group (we) formed with the aim of restoring flow to the upper Ivel, enabling iconic species such as brown trout, to thrive in our river once again.
Our goal might now be within touching distance.
Timeline of our Journey
June 2018 to December 2019; the upper Ivel was dry
2020; RevIvel set about gathering evidence to make the case that, historically there
had been significant rates of flow in the Ivel all year round. However our efforts were
largely not listened to
2021; thanks to your donations, we were able to bring in reinforcements in the form
of industry expert, John Lawson, to perform analysis and write a report
Summer 2022; John Lawson issued his report and also proposed a solution to
restore flow to the Ivel. Key findings:
o The upper Ivel is amongst the most over-abstracted chalk streams in the
world, and
o There is an elegant, almost “oven-ready” potential solution following the latest
innovative thinking (“Catchment Based Approach” and “Chalk Streams
First”). See diagram attached to this email.
June 2022 to January 2023; the upper Ivel was again dry
2022; RevIvel assembled a partnership working group to take forward these findings
comprising inter alia, Affinity Water, Anglian Water, the Environment Agency, John
Lawson and Charles Rangeley-Wilson (broadcaster and author)
2023 – 24; the water companies were persuaded/ kindly agreed to finance
Feasibility studies;
o Phase 1: Groundwater modelling performed by an environmental consultancy
(WSP) confirmed and further strengthened John Lawson’s analysis (e.g. also
suggesting that c.five other chalk streams would benefit from flow recovery in
the Ivel)
o Phase 2: review of engineering and compliance requirements. Status;
progress has slowed but “no blockers” have been evidenced to date
Latest Developments
Seizing the day, RevIvel applied to the Rural Payments Agency Water Restoration Fund for approximately £1.5m to implement the solution, comprising a;
o Development phase (flow gauges and telemetry etc to collect data and
evidence), and a
o Delivery phase (a 24-month trial of the proposed solution)
Our bid was supported by unreservedly positive feedback from 10 stakeholder groups, with the 11th (Affinity Water) endorsing the development phase but seeking to delay the delivery phase. August 2024, senior figures within OFWAT/ RAPID and the Environment Agency contacted RevIvel, requesting a presentation of the outline of the bid, which was enthusiastically received.
If the scheme were to be implemented, it would require some of the deployable output
(water) from Grafham Reservoir, which has prompted master developers, Urban&Civic to
request a meeting with RevIvel to understand how the scheme might impact planned
developments both locally and in Cambridgeshire.
Conclusion and Next Steps
We await to hear the outcome of the bid;
o If successful, it would enable flow to be restored to the Ivel, be a pilot of
(water) from Grafham Reservoir, which has prompted master developers, Urban&Civic to
request a meeting with RevIvel to understand how the scheme might impact planned
developments both locally and in Cambridgeshire.
Conclusion and Next Steps
We await to hear the outcome of the bid;
o If successful, it would enable flow to be restored to the Ivel, be a pilot of
national significance and inform the way forward
o If not successful, the bid has put the scheme firmly on the radar of key
national decision makers, who have expressed support for the scheme,
potentially opening the door to other ways forward
We are closer than we could ever have believed possible to restoring flow in the Ivel. It is a testament to what a small community group can achieve through teamwork, persistence and audacity. A further vital ingredient is your ongoing support – so thank you!
We welcome any questions or feedback you might have. Please address these to
education@revivel.org or tech@
o If not successful, the bid has put the scheme firmly on the radar of key
national decision makers, who have expressed support for the scheme,
potentially opening the door to other ways forward
We are closer than we could ever have believed possible to restoring flow in the Ivel. It is a testament to what a small community group can achieve through teamwork, persistence and audacity. A further vital ingredient is your ongoing support – so thank you!
We welcome any questions or feedback you might have. Please address these to
education@revivel.org or tech@
Photo: Mink with water vole prey, North Lincolnshire; credit Graham Catley / WRT
It's a year since we last reported on the mink situation, and we're happy to say there's been huge progress both on the Ivel and in the East of England generally.
As a reminder, the invasive non-native American Mink Neovison vison is a vicious predator which has caused the loss of a wide range of river wildlife in Great Britain, particularly Water Voles which were once a common sight on the Ivel, but no more.
For a long time, mink eradication was thought to be impossible, but a project started in Norfolk just five years ago using some new tech has changed everything to the extent that eradication of mink from the whole of Great Britain has become a distinct possibility in the next ten years.
The Waterlife Recovery Trust (WRT) is leading this incredibly successful effort, and we strongly recommend you subscribe to their newsletters; The latest one, No. 7, has just been published, and all of them are a fascinating read.
The Environment Act 2021 includes a legally binding target on species abundance for 2030, Water Voles are one of the target species, and Natural England (NE) is the government agency tasked with implementing it in England.
It's the same old story all over again, the fundamental problem with our river is over-abstraction, but instead of trying to do something about the unpalatable truth, all anyone wants to do is 'habitat renewal' which generally involves multiple desktop studies going on for years and years, and eventually, diggers, neither of which will get perennial water back in our river. And so it is with NE who favour water vole habitat renewal and reintroduction which anyone with any knowledge of mink behaviour will say are just expensive mink feeding schemes unless the mink are removed first.
Faced with incontrovertible evidence that the WRT approach really works, NE did finally grant some support in the middle of 2023. This has enabled WRT to purchase a bunch of new traps and hire several area coordinators on18 month contracts to expand the active area of Norfolk, Suffolk and Cambridgeshire, out to Essex, Hertfordshire, Bedfordshire, Northamptonshire and south Lincolnshire.
RevIvel is the 'first responder' for eight smart traps on the Ivel above Henlow and Cat Ditch. Two of them are coordinated by the Herts & Middlesex Wildlife Trust, the rest, in Bedfordshire, directly by WRT. In the last eleven months we have sent off 23 mink for scientific analysis, and there's been equivalent success by our colleagues in the rest of the Ivel catchment. Judging by the Norfolk experience, where no mink have been caught in any of the 500 traps there for more than a year, there's a good chance there will be no mink left on the Upper Ivel by 2026, or at least so few mink they are not a viable breeding population.
Meanwhile, NE have still not committed to a national campaign. Outside the core area WRT have been supporting miscellaneous wildlife trusts and groups who have found the funds to acquire a few smart traps of their own, but it is all a bit fragmented, which isn't ideal; NE really must get their act together if they are to achieve the task given them by Parliament.
There's general agreement that water vole numbers had diminished by at least 95% across the country, and that they had been completely extinguished in some areas. Given this situation, two hugely important, linked questions follow: If mink are removed, will water voles recover and, if so, will they return naturally, or will they need artificial help in the form of human-controlled re-introduction?
To the extent that water voles have become so common in some areas cleared of mink that keeping them out of the mink traps has become a problem, the first question is answered (captured water voles are of course released unharmed). As for the second question, once the mink have gone, WRT have found water vole populations sometimes appear to materialise out of thin air, even in places where none have been recorded in years or decades, but it's still too early to say whether this will happen everywhere.
The logical conclusion to this is that first you need to get rid of the mink, then watch what happens for a while. If, after a few years there's no sign of a reappearing water vole population in a particular area then reintroduction should be considered. There is therefore some scope for the beloved desktop studies, but one thing is quite certain, once the mink are removed, water voles are perfectly capable of looking after themselves and need no help from do-gooders with diggers.
Event Duration Monitors
On 30 December 2023 DEFRA published a press release Storm overflows monitoring hits 100% target – Every storm overflow across England’s water network is now monitored it says: Event Duration Monitors [EDMs] increase transparency by measuring how, when and for how long a storm overflow is in operation. This shows the public when discharges are happening…
Storm overflow data has been available for a few years, but only as annual returns which isn’t very helpful if you want to know if a particular water body might be safe to swim in today. There’s been a lot in the press about this so water companies have been prevailed upon to start publishing real-time data from their EDMs.
Anglian Water's storm overflow map
On 9 May 2024 Anglian Water published a news item: Information at your fingertips: Our new storm overflow map which says: The map shows where our storm overflow monitors are located and provides near real time information on any activations. Updated hourly, it gives customers, stakeholders and those passionate about their local environment, a way to see how our network is operating, so they can make an informed decision about how they interact with their local river or bathing water.
The overflow map itself shows all 1471 Anglian Water's overflow locations, and more information if you click on one of them.
revIvel heard about this map a bit earlier than the official launch and sent a question to a contact at Anglian Water:
The preamble to the new storm overflow map said on 30th April: The full data for each sensor can be found on storm overflow information page. I couldn't find that page and looking again today, 2 May, the preamble text seems to have changed to: History for monitors that have been triggered since then is displayed in the box that shows when you click on an icon. but the box seems to only show the Most recent activation. Where can I find the activation history for a site? (and I mean this real-time data, not the annual return spreadsheets which are just a belated summary).
The reply on 10 May was: the visualisation system can currently only display the history for the most recent activation and does not have the ability to store a complete history for each sensor. We publish the history of each sensor, each year.
In other words, they're not publishing any real time history even though they must have it.
Letchworth Sewage Treatment Works
This works discharges into Pix Brook which rises in Letchworth, runs through the middle of Stotfold and joins the Ivel close to the railway bridge at Henlow. Today, 24 May, if you click on Letchworth STW on the map, it says: Most recent activation: Started 22 May 2024 21:30, Ended 22 May 2024 21:30 Duration: 0 days, 0 hours, 0 minutes.
On that Wednesday 22 May it rained a lot, a proper downpour, all day. Looking at the map now, a user will probably think that Anglian Water are doing quite well to have had no storm overflow at this sewage works after significantly more than an inch of rain fell in the Letchworth area that day.
But did they really have no overflows?
Because the map only shows the most recent EDM activation data, a revIvel member interested in overflow history recorded the readings of a few overflow sites which drain into the River Ivel. Not long after it started raining on 22 May, several overflows were activated. All went well for a while, and then the member started noticing strange things happening to some of them, notably Pirton, Hitchin (Ashbrook) and Letchworth STW. A section of the log for Letchworth STW is reproduced here.
The first two columns are the row number (for our reference below) and the time the log was made. The other four columns are the data collected from the map, all times are BST.
The first two rows show how things had been proceeding for some time as one might expect, the overflow had started at 12:02 and if you had clicked on the map at 18:23 you would have seen the overflow had been going on for 6 hours and 21 minutes.
But if you clicked on the map a few minutes later at 18:31 you would have seen something different; now the map is saying (row 3) the overflow started at 16:46 and has been going on for just 1 hour and 44 minutes; nearly four hours and 44 minutes of overflow had vanished!
It's not like the overflow stopped and started in the time between logging rows 2 & 3 because then you would expect to see a duration of just a few minutes in row 3, but no, the start time was way before, at 16:46.
At 19:26 this happened again, the overflow had reached 2 hours and 33 minutes duration (row 10) and then the start time was bumped forwards to 17:31 (row 11) meaning the duration dropped to 1 hour and 55 minutes - another 45 minutes of overflow had vanished!
At 19:54 (row 15) two things happened: On the map you would have seen there was no current overflow, and it said the most recent overflow lasted for just two minutes, by now a total of 6 hours and 11 minutes of overflow had vanished.
It gets wierder: Between 20:01 and 21:18 (rows 16 - 27) someone clicking on the map would have seen the last overflow as lasting variously 2 minutes, 0 minutes or 3 minutes, and then at 21:25 (row 28) it is overflowing again, but this is not a new overflow because it said it started at 19:31 (ie between rows 10 & 11) which was before the last overflow stopped. This suggests the overflow had not actually stopped at all but had been going on continuously since 12:02, that's 9 hours and 23 minutes duration, rather than the 1 hour and 53 minutes claimed.
The overflow had stopped by 22:56 (row 41) but said the last overflow lasted just under 2 minutes. Even though there's no evidence of any further overflows, at 23:31 (row 46) the data said the most recent overflow lasted 0 minutes, 0 seconds (in the raw data it is actually 115 micro seconds which is a bit unlikely), and that is what we see two days later on 24 May, and perhaps will continue to see until the next time it rains.
It appears no less than 10 hours and 54 minutes of overflow from Letchworth STW on Wednesday 22 May totally vanished!
Is Anglian Water telling the truth about overflows?
It doesn't look like it, does it?
The main purpose of making water companies publish this stuff is to identify so-called "dry spills" which are illegal. A ‘dry spill’ is when a storm overflow is used on a ‘dry day’ – which is usually defined as no rainfall above 0.25mm on that day and the preceding day (24 hours). On a day when there was something between 30 and 40 mm of rain in the area, the spill detailed above was almost certainly within the discharge licence, but if Anglian Water can't record legal spills correctly, what chance of anyone ever seeing an illegal one?
An Event Duration Monitor is a simple thing, either there is an overflow or there is not, and all it has to do is report when that overflow started and when it stopped. It would have been better had the government required the water companies to measure, record and publish overflow volume as well, but unfortunately they didn't. Nevertheless, what the EDMs are doing is better than nothing, and the IT involved in this sort of thing is not rocket science, especially not for a £multi-billion company like Anglian Water.
It appears their EDMs are reporting the current status about 1 hour and 40 minutes after the fact, which could explain some of the apparent vanishing of overflow, but very short events are obviously nonsense. With their Storm overflow map, Anglian Water seem to have implemented something which should be simple, could be helpful to lots of people, but appears to be totally unfit for purpose in its present form.
Not only that, at least in the case of overflows from Letchworth on 22 May as evidenced here, it would appear to be an outright deception: Contrary to what Anglian Water say, a casual user trying to make an informed decision about how they interact with their local river to see if it was OK for them and/or their children and/or their dog to swim in Pix Brook that evening might have thought it was fine when in reality it could easily have been chock full of toxic raw sewage.
Whether Anglian Water's many other EDMs do the same thing is difficult to say at this time, but with systems like this it makes operational and financial sense to set up both hardware and software in a consistent manner, so it would not be a surprise to find all their EDM reporting is similarly deceptive.
For casual users, an overflow total time for the day so far, or over a rolling 24 hour period would likely be far more informative than what we see today. For revIvel and the many other other people and organizations who have an interest in the state of our rivers, access to the full overflow history of each site would give a proper meaning to the 'transparency' which DEFRA would like to see. It would also help to mitigate any allegation that the figures contained in annual returns are 'massaged', as massaged they must be with a data muddle like we see in this example.
It would be interesting to know, after proper review, the duration Anglian Water think there was an overflow from Letchworth STW on that rainy Wednesday 22 May: Was it something close to 10 hours and 54 minutes or was it nearer 0 hours and 0 minutes?
And, dear Anglian Water readers; What about publishing overflow volumes too?
Dear Members and Supporters,
I thought, in the light of the huge changes to the River Ivel in Baldock, you might appreciate an
update of what RevIvel’s view of these developments is and where we go from here. Many of you
may have seen my short piece in the February copy of On Our Doorstep. This is a more detailed
discussion of where we are, and what we plan to do in the future.
RevIvel’s headline aim is to restore flow to the Ivel to allow the re-establishment of Brown Trout
and other critical species in our much-neglected river. That requires year-round flow of
suƯicient quantity and quality such has not been seen in the Ivel for many years, maybe many
decades. A quick stroll across the wildflower meadow currently reveals the result of the recent
Ivel makeover, courtesy of AƯinity Water and their contractors, Five Rivers. Much money has
been spent on landscaping, digging out and lining the main river channels with gravel and
creating potential wetland landscapes where the boardwalk crosses the river. And the river is
flowing as vigorously as many of us can remember with much of that coming from the Ivel
Springs themselves. So, you may feel that RevIvel’s work is done – the river is flowing, the water
looks clear (most of the time) and once the landscaping has healed and is covered in greenery
all will be well. We can pack up our bags, move on and stop bothering everyone about chalk
streams and their ecosystems.
It would be very nice if this were true. But you must remember that AƯinity are still abstracting
huge amounts of water from the aquifer which has only recovered this year because we have
just experienced the wettest winter on record. This has replenished the aquifer at a rate that
even AƯinity are not allowed to exceed. As spring moves into summer, the aquifer level will drop
as the rate of abstraction exceeds the rate of replenishment, although because of the wet winter
there is a good chance the Ivel springs will continue to flow throughout the season, albeit at a
much-reduced rate. Another dry winter and the river will once again be reduced to the dry
channel so familiar from recent summers and AƯinity’s landscaping will have been all in vain.
In addition to over-abstraction, there remains the risk of further leaks from the poorly
maintained Baldock sewage pumping station. This facility pumps all our foul waste to the
Letchworth sewage plant and over the past three years there have been several incidents where
raw sewage has leaked from this system, either from breaks in the rising main that takes the
sewage to Letchworth, or directly from the pumping station where the infrastructure requires a
radical updating. You may have noticed the growth of brown algae lining much of the recently
excavated channel of the Ivel, particularly near the boardwalk. This is a direct result of sewage
leakage from the pumping station adding extra nutrients to the water which encourages algal
growth. The gravel bed of a chalk stream should be clearly visible through the water and be free
of such unpleasantness. When the flow reduces the negative eƯects caused by any sewage
spillage will become more marked simply because the sewage is less diluted by the clean flow,
and it hangs around for longer. Flow-rate and water quality are clearly inter-related.
RevIvel’s plan for the restoration of natural flow in the upper Ivel and the Ivel Springs is for
AƯinity to cease abstraction from their Baldock boreholes, allow the aquifer to replenish
naturally and the springs and river to return to their more natural state. Water could then be
taken from the Ivel further downstream, piped into Grafham Water and subsequently fed into
the water supply via existing pipework. This scheme was described in detail by John Lawson, our
consultant in his report of 2 years ago. By contrast, AƯinity Water’s plan to maintain flow in the
Ivel is called augmentation, in which the aquifer depletion caused by abstraction is compensated by water from a newly drilled borehole near the springs pumped into the river
when the flow drops below a critical level.
We have several criticisms of this plan, not the least of which is the pathetically low flow rate
they are planning to supply – 0.5 Megalitres/day – while John Lawson’s modelling shows the
minimum flow should be almost 10 time this amount. Recently this figure was corroborated by a
study using a diƯerent modelling technique in work commissioned by AƯinity and Anglian Water
to investigate the feasibility of implementing the Lawson plan. While we await the written report
from this work, all parties are aware of the results but seem reluctant to modify their original
augmentation scheme. So, you can see, that the while we have made some inroads into
exposing the weaknesses in AƯinity Water’s overall plan, there is much work to be done if we are
to get back to something like a natural flow year-round in the Upper Ivel.
Another threat to the Ivel, and indeed the whole of Baldock is the proposed new housing
development and the potential doubling in size of Baldock over the coming decades. Three
thousand more houses will require a lot of water and will generate a lot of sewage. Where will
the water come from and where will the sewage go? How will this aƯect the Ivel? Moreover, if
you build houses and roads over porous agricultural land, this produces more storm run-oƯ that
rapidly finds its way into the river, unless something is done to stop it. What is being done to
manage run-oƯ? RevIvel has been posing these questions to Urban and Civic, the Master
Planners currently in charge of mapping out the new development on behalf of the Council. We
have developed good relations with U & C over the past 18 months and have submitted a
document to them with 19 ‘Blue Asks’ that require positive answers if they are to live up to their
stated claims of sustainability and environmental care. So far, our consultations with them have
been positive but we remain vigilant that our proposals become integrated into the final plans.
Meanwhile we continue our lobbying of the water companies, the Environment Agency and
various Quangos related to the water industry. To aid in this work we retain the services of John
Lawson, together with support from Charles Rangely-Wilson who heads up the Chalk Streams
First initiative and chairs various panels and committees concerned with water quality and the
health of the nation’s rivers. Without this expertise and other connections, we would not be able
to have the influence we exert or contribute to discussions concerning our river and rivers more
generally.
As for our plans, this year we will construct a water flow gauge at Radwell on that stretch of the
river owned by Richard-Meredith Hardy, one of our founder committee members. The upper Ivel
currently has no flow gauges, and this addition will allow us to quantify how river flow varies
throughout the year on this previously unmonitored stretch. In addition, we aim to introduce a
programme of regular environmental monitoring, sampling for river fly, e. coli and hopefully
water chemistry, thereby giving us a picture of the overall health of the river which we can then
feed into various national and regional programmes focussing on river ecosystems.
Finally, a note on various forthcoming events. In addition to the members walk on 28th April,
there is another walk as part of the Baldock festival on16th May. We’ll have a stall in the Street
Fair on Saturday 18th May and there is the Bubbly Concert in aid of RevIvel, kindly organised by
Catherine Wilmers in St Mary’s Church, Baldock. This will be on Sunday 12th May at 5.30. We
also plan to be at the Stotfold Steam fair in October and the Letchworth G. C. Classic and
Vintage Car event on June 8th. This will be held at Fairclough Farm, Halls Green, near Weston.
Do come along and have a chat, or if you’d like to volunteer to help at one of these events or with
our future programme of environmental monitoring then send us an email.
I must end with a big thank you to all members and supporters. Your donations and
subscriptions allow us to campaign on behalf of the community to raise awareness of the plight
of our local river and help restore it to something resembling its natural state. Here’s looking
forward to the return of Brown Trout to Radwell and Baldock!
Nick Rogers,
RevIvel Chair
10th April 2024
Recently , the Biggleswade Home Education Group were very grateful to get the opportunity to join Nick Balmer of RevIvel in some water testing.
They picked two popular paddling spots along the Ivel and took turns filling test tubes. Samples were tested primarily for E-coli.
Afterwards the group had the opportunity to ask questions and look at previous samples within the area. There were around 16 families present with children aged 0-16, many of them passionate about conservation.
They think the study has put many of them off paddling locally and definitely increased their interest in water quality.
2023 has been a year of significant progress for RevIvel in its aim of restoring year-round water in
the Ivel Springs and flow to the river. Importantly our membership numbers and those of our
supporters grew so that there are now about 200 individuals contributing financially towards our
activities. We are increasingly known in the district and within the broader ‘water community’ as an
effective and active organisation fighting for river remediation and restoration. And our work with
the water industry through our various contacts and our consultant, John Lawson, has led to a better
understanding of how the Ivel works and what needs to be done in the future.
The year started off with a major event in January at which we launched our film (Restoring theUpper Ivel – YouTube). This had been commissioned by RevIvel in 2022 and made by Parick Rangely
and Kathryn McKenzie of RevIvel. We had ambitiously booked the hall at Knights Templar School
with three scheduled screenings at hourly intervals throughout the afternoon and were anxious that
no-one would come. Fortunately, even though the weather was, to say the least, inclement, the hall
was packed for much of the afternoon. The audience of about 250 included many members and
non-members from Baldock, as well as county and district councillors and interested parties from
much further afield. Not to mention representatives from Affinity Water and the Environment
Agency who were there to see what we were getting up to. There was a real sense that RevIvel’s
message was getting through.
Our major fundraising event of the year was a concert of classical music put on by Catherine Wilmers
in St Mary’s Church. Catherine is a well-known and highly regarded cellist who plays regularly at
concerts in the UK and across Europe and this was the second such concert Catherine has organised
for our benefit. She assembled a group of professional musicians who presented us with a beautiful
evening of music by a variety of composers which entertained us for over two hours. The
programme also featured a new work written by Frances Matthews, the daughter of Nick Balmer,
one of our committee members. Entitled Cry me a River, it involved some audience participation and
given the cause of the event, was very well received by the 150 or so present.
Later in the summer, a chance encounter with local political activists, supposedly across the kitchen
table at Radwell Mill, provided Richard Meredith Hardy the opportunity to press the case for the Ivel
and Chalk Streams in general. This set a series of subsequent meetings in train involving Sir Oliver
Heald, who chairs the All-party committee on The Protection of Chalk Streams, plus supporters of all
parties in the House of Lords. The result was the addition of a clause in the Levelling Up and
Regeneration Bill that afforded legal protection for all Chalk Streams across the UK.
The River Ivel achieved further fame nationally when Kathryn McKenzie represented RevIvel in a
feature on Chalk Streams and the pressures they face on the BBC programme, Countryfile (BBC iPlayer – Countryfile – Porthcawl Surf and Sand). The feature was broadcast in June and lasted 13
minutes (starting 10 minutes into the programme) with Kathryn being interviewed on the banks of
the Ivel – yet another example of the reach our organisation is achieving.
Most recently, during November and just in time for the AGM, we were briefed on the results of Ivel
catchment modelling that Affinity Water and Anglian Water commissioned as a result of the Lawson
Report (Ivel-report-21.6.21-BHs-redacted.pdf (revivel.org)). You may recall that the Lawson Report
proposes a model whereby water abstraction from the boreholes near Baldock should be limited to
10% of the current rate and the aquifer and river allowed to recover naturally. Water could then be
abstracted from the river at Offord, where it joins the Ouse and fed into Grafham Water and hence
into the drinking water system. The new modelling is based on a revised and improved data set of
river flows, rainfall and geology and, in a nutshell, confirms the conclusions John Lawson reached
last year. We are now putting more pressure on Affinity to take this investigation from the desk to
real life and switch off the water abstraction to let the river flow again. This in line with an approach
known as Chalk Streams First (Chalk-Streams First – Chalk-Streams (chalkstreams.org)), and if
applied to the Ivel, could be a pilot study that could then be applied to rivers elsewhere.
In addition to the highlights above, members of RevIvel have continued to present our case through
talks and other activities to general interest groups locally and throughout the region. Revival has
also make representations to Urban and Civic, master planners for the ‘Growth of Baldock’ scheme,
regarding effective waste-water management and ‘blue’ infrastructure in the development.
As I hope you will appreciate from the above examples, much of what we do is planned, while other
achievements have been opportunistic. The strength of our organisation is that we can tap into a
wide range of experience, expertise and contacts in our core committee and in the wider
membership to take advantage of opportunities as and when they arise
Our future activities are now geared to pushing the water industry to implement the Lawson Report,
installing a flow monitoring station closer to the source of the Ivel and developing a programme of
river quality monitoring, once flow has been restored.
Finally, I would like to thank everyone involved in RevIvel for their support, work and dedication over
the past year. I am continually amazed by what you have achieved. Here’s to even greater progress
in 2024!
Nick Rogers
ReIvel Chair
November 2023
There is very little understanding on the part of our government and water company staff of the
importance of the Cat Ditch catchment to the Ivel.
This is illustrated by the following map published by the Upper & Bedford Ouse Catchment
Partnership map, that incorrectly labels the Cat Ditch as the River Ivel, while not identifying the Ivel
branch that runs into Baldock at all.
DEFRA & the EA recognise that the River Ivel is made up of several discrete water bodies &
catchments.
The branch of the River Ivel that flows up via Radwell to Baldock is called the “Ivel (US Henlow)
Water Body.
DEFRA & the EA assign the following catchment areas to the Henlow to Baldock branch of the Ivel.
DEFRA & the EA then go on to assign the following key attributes to the Cat Ditch catchment.
Taken together the total lengths and areas appear to be as follows.
As recharge & runoff is a function of areas, it can readily be appreciated how the Cat Ditch is more important to the flows in the Ivel downstream of Astwick (the confluence) than the Ivel.
From the following marked map of the Ivel Catchment which shows the approximate limit of the permeable chalk strata in dark blue, & the Bedfordshire Gault clay that is very much less permeable, in light blue, it can be readily appreciated that the effective chalk catchment area associated with the Baldock Ivel is much smaller still.
Taking into consideration that much of the Ivel Catchment described by DEFRA & the EA (in figure 2) is either underlain by impermeable Gaults, or overlain by impermeable urban areas, it can be appreciated that the key attributes of the Baldock Ivel & Cat Ditch are as follows.
At less than 29% of the effective permeable area underlying the former Ivel catchment no longer available to recharge, it can be appreciated why Ivel Springs have failed for the past three years. In the face of unsustainably high levels of abstraction by Affinity Water, there is little or no chance of these springs returning.
The situation by 2040 will be even more dire, as the effective Ivel Catchment over Chalk will reduce
from 1737 hectares in 2023 to 1611 hectares.
We have to protect the Cat Ditch Catchment, & then enhance its physical properties by working with the existing land owners to farm for water as a crop, rather than casting it aside as a problem.
1 https://ubocp.org.uk/catchments/ivel/
2 https://environment.data.gov.uk/catchment-planning/WaterBody/GB105033037720
3 https://environment.data.gov.uk/catchment-planning/WaterBody/GB105033037720
4 https://environment.data.gov.uk/catchment-planning/WaterBody/GB105033037740
Kindly produced by Nick Balmar
Water situation for Upper Ivel – September 2023.
All data presented courtesy of the Environment Agency and Met Office (Crown copy right 2023)
Rainfall:
There was a heatwave in early September, with the highest temperatures of the year in East Anglia being recorded during the month. During the second half of the month, high pressure gave way to the low-pressure systems coming in from the Atlantic this being more typical of autumn conditions. This resulted in above average rainfall (130%) in
the Upper Bedford Ouse catchment.
Soil Moisture Deficit (SMD)
The soil moisture deficits [SMD] by the end of September had reduced to 70-80mm and was considered in the normal range for this time of year.
Soil Moisture deficits for week ending 30 Sept 2023. Data based on weekly MORECS data for real land use and compared to an analysis of historic 1961 – 1990 LTA dataset.
Definitions:
Soil Moisture deficit (SMD) – The difference between the amount of water in the soil and the amount of water that the soil can hold (field capacity).
Ground Water (GW):
The groundwater levels across East Anglia’s western region continued to recede through September as expected for this time of year but remain in the normal range compared to historic levels.
Springs and River Flows:
The main spring at Ivel Springs in Baldock started to flow on 14 th January 2023 but has ceased to flow as of 24 th June 2023, effective flowing for only 23 weeks in the year. This spring should flow year-round albeit at reduced flow levels in late summer / early autumn….Historically the mill at Blackhorse (closed in 1870s) would have milled wheat
year-round for the people of Baldock and surrounding villages.
The second spring at the Ivel Springs nature reserve (upstream of culvert) in Baldock started to flow on 1 st January 2023. Surprisingly we have continued to see a minimal flow into September, albeit at extremely low levels. This is important as it has allowed a slow recovery of flora and fauna in the upper reaches.
Flow at Blackhorse mill started by the end of the first week in January 2023.Again we are pleased to report that there is still minimal flow at Blackhorse mill at the end of September 2023.
The river Ivel flows are officially measured at Blunham. Heavy rain events in the second half of September saw a spike in flow which returned to normal by the end of the month(Green Zone).
Reservoir Stocks:
Water from the Ouse is transferred at Offord into Grafham Water reservoir. After twelve months of reduced capacity Grafham Water reservoir has finally returned to full capacity during June – Sept 2023 (90% -blue line on graph) which is in line with the normal operating levels.
End of Sept 2023 Grafham Water reservoir stock compared to the Normal operating Curve, Drought Curve and 1995-1996 stock levels.
Looking forward:
The upper reaches of the Ivel have managed to maintain a minimal level of flow throughout the summer months. This is the best outcome we could have hoped for considering the previous 18 months and continued abstraction practises of Affinity Water.
Looking forward this autumn Affinity Water will start the river restoration at Ivel Spring Nature Reserve so look out for some channel improvement works. Also, we can expect “testing’ of the augmentation scheme to get underway. So, look out for activity at the Ivel Spring. The current planned augmentation of a mere 0.54 Ml /day is far short of the desired re-naturalisation of flow Revivel demand but at least we should no longer see a dry riverbed all the way to Radwell.
Affinity Water have appointed the FiveRivers team and they will be starting the seasonal wetland and river restoration construction on Monday 6th November at Ivel Springs Nature Reserve. The latest information and detailed designs are available on their website: https://www.
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