Water situation for Upper Ivel – March 2023
All data presented courtesy of the Environment Agency and Met Office (Crown copy right 2023)
Upper Bedford Ouse catchment received 256% of long term average (LTA) rainfall resulting the return to recharge of the aquifer and improved spring flow.
March was a very wet month with rainfall in our catchment reaching 256% of the expected long-term-average.
Rainfall across East Anglia was classified as exceptionally high in all hydrological areas except North Norfolk. On
average East Anglia saw 99mm of rain across the region. Many of the regions hydrological areas were ranked in the
top 5 wettest March’s on record.
Following the exceptionally high March rainfall the 3-month average for our catchment is now 128% (above normal)
and the six-month average through the autumn and winter is at 145% of LTA.
Soil Moisture Deficit (SMD)
The heavy rainfall in March resulting in a decrease in the soil moisture deficit (SMD) across the whole of East Anglia.
The area surrounding the Ivel decreased to 0-10mm SMD, evident by standing water in many fields preventing most
spring cultivation and drilling activities. This has resulted in an extended groundwater recharge season and has
improved conditions in our catchment, allowing the Upper Bedford Ouse catchment to move into ‘Recovering
As a result, we are seeing improvements in surface water flows, groundwater levels and ecology recovery. Other
hydrological areas in East Anglia further east and north remain in Drought conditions.
Soil Moisture deficits for week ending 31 March 2023. Data based on weekly
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):
Looking at the regional picture across the East Anglian chalk, Ground Water levels improved during March due to the
exceptional rainfall which has allowed late season recharge, reversing the worrying situation we were facing at the
end of February. The west of the region (including the upper Ivel) has seen the greatest improvement in GW levels
with resulting in noticeable improvements in spring flows, ending the month as “normal”. The North Norfolk chalk
streams remain in a dire situation being “notable low” / “exceptionally low”.
Springs and River flows:
The main spring at Ivel Springs in Baldock started to flow on 14 th January 2023.
The second spring at the Ivel Springs nature reserve (upstream of culvert) in Baldock started to flow on 1 st January
Flow at Blackhorse Mill was seen by the end of the first week in January 2023.
Thanks to the exceptionally high rainfall in March the springs in Baldock, Norton and Radwell are all looking good.
There is currently good flow, and the ecological conditions are improving with Moorhen and Little Egret spotted at
the Ivel springs.
The river Ivel flows are officially measured at Blunham. The river had been low to notable low through the summer
but returned to normal (green zone) during October- January responding directly to significant rainfall events. Heavy
rain events throughout March with significant rain events at the beginning and end of the month resulting in
“notable high/ exceptional high water levels recorded.
Water from the Ouse is transferred at Offord into Grafham Water.
Recovery of reservoir stocks in Grafham Water remains slow with the reservoir currently only 80% full (blue line on
graph) (Notably Low). Despite the March rainfall the current stock levels are a long way from the normal operating
level of 90%+. This is because pumping of raw water into Grafham from the Ouse was stopped on 9 th March as the
level of nitrates level in the river were close to 50mg/l. It is likely that the exceptionally heavy rains resulted in runoff
of spring fertiliser off farmland into the surface water courses.
End of March 2023 Grafham Water reservoir stock compared to the Normal operating Curve, Drought
Curve and 1995-1996 stock levels.
Recharge of the chalk aquifer relies on the amount of rainfall through the autumn and winter months. The autumn
and early winter (Oct- Nov – Dec 2022) were wet months with 150% of LTA. January rainfall was 103% of the LTA,
February was exceptionally dry at only 20% of LTA which had a visible negative effect on the aquifer and spring flows
were reduced. The exception rainfall in March saw a welcome late season recharge of the aquifer. Overall, the last 6
months has seen good recharge conditions with overall 145% of LTA.
The Upper Bedford Ouse catchment has been in official drought since end June 2022. The exceptional rain fall in
March 2023 has thankfully resulted in a change in status to “Recovering Drought, much to the relief of the Affinity
Water and the Environment Agency. Sadly, Affinity Water seem to rely on such exceptional “GET OUT OF JAIL
CARDS”, without any real plan other than continuing to abstract ground water (GW) as much as is legally and / or
physically possible every month.
Since 2019, when RevIvel have been highlighting the plight of the chalk headwaters of the Ivel and Affinity Water
have been making all the right noises, more water has been taken from the aquifer than ever before!
Consequently, the river Ivel and its associated flora and fauna continues to suffer……..
We can’t expect to be saved by a “one in 40 year event” every time!