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Dr Martin Burton, Water Resources specialist at Upper Itchen Restoration CIC, is monitoring rainfall, groundwater level and flow in our river after the drought we experienced in Summer 2025.
By comparing rainfall from September to May with previous years, Martin can predict the likelihood of a drought next year. This is important as many species in our sensitive chalk streams depend on flowing, oxygenated water.
Learning from criticism of late action in the 2022 drought, Southern Water took action earlier in 2025 and formed a Communications Group to increase public awareness of the drought and promote water saving. This shows the value of early prediction.
We update this page every month with latest predictions. Check back regularly for the latest !
Larva of the Sandfly, Rhyacophila dorsalis, a Caddis fly species sensitive to low flow
Photo credit : Dr Cyril Bennett, Wildfish
November 2025 Update
November 2025 Update
Headline
Overall, not good. Cumulative rainfall is above 2021-22, but flow level is well below November 2024. The quantity of rainfall in the next 2 - 3 months will be critical.
Rainfall
Cumulative rainfall (red line on the graph) as measured at Bishop's Sutton close to the source of the River Alre, from 1st September to 30th November is now 295 mm.
This is more the 232mm recorded in 2021-22 (a previous drought year) and but less than the 373 mm in 2024-25 (last drought year).
This suggests that unless we get good rainfall in the next 2 - 3 months, we are at risk of a drought in 2026.
Groundwater
Groundwater level, as measured at the Environment Agency borehole in Bishop's Sutton, is 76.137 m AoD which is below the level this time last year of 76.927 m AoD, a difference of 0.79 m.
Groundwater level has started to rise in recent weeks after a prolonged decline.
Flow
Discharge on the Upper River Itchen is 2.45 m3/s, as measured by the Environment Agency, which compares with 4.05 m3/s in 2024, a difference of 1.605 m3/s.
River flows are starting to rise after a near continuous decline since the peak in February 2025 of 6.03 m3/s.
What's Drought Watch ?
What's Drought Watch ?
Dr Martin Burton, Water Resources specialist at Upper Itchen Restoration CIC, has been monitoring rainfall after the drought we experienced in Summer 2022 and 2025.
Martin uses a process of accumulating daily rainfall from 1st September each year and comparing the data with previous years. This allows the early prediction of a likely drought at the end of May, based on winter rainfall, groundwater level and flow in our river. Our chalk streams are fed by an underground aquifer, which is re-charged by winter rains.
With climate breakdown, we are seeing lower average rainfall punctuated by dramatic heavy rain events. This tends to increase run-off from fields and urban areas into rivers, with decreased re-charge of the aquifer.
Why does this matter ?
Low flow in our chalk streams during drought impacts life in the river, as many chalk stream species depend on flowing, oxygenated water. It also has the effect of concentrating pollutants in the river. Our colleagues at Wildfish describe the year-on-year impact of water shortages on chalk streams.
It is worth remembering that water is abstracted from the Itchen and its aquifer for drinking water, a major pressure on our sensitive ecosystem.
Martin's modelling is important because we all need to make adjustments for a future where water is becoming scarcer. In 2025, Southern Water did not impose a hosepipe ban until July, which we believe was too late to protect our river from harm due to low flow.
We all need to do what we can to reduce our water use - see our Publications page for some simple ideas everyone can do !
Where does the data come from ?
The rainfall and groundwater data are obtained from the Environment Agency’s rainfall and groundwater measuring stations in Bishop’s Sutton. The River Itchen flow is the summation of the flows at the four measuring stations located in the Upper Itchen at the tail ends of the River Alre at Drove Lane, the Cheriton Stream at Seward’s Bridge and the Candover Brook at Borough Bridge.
Data are taken from the Environment Agency’s hydrology database: https://environment.data.gov.uk/hydrology/explore
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