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