Solent and South Downs water situation report: August 2024 summary
Updated 13 September 2024
Applies to England
© Crown copyright 2024
This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.
Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.
This publication is available at https://www.gov.uk/government/publications/water-situation-local-area-reports/solent-and-south-downs-water-situation-report-august-2024-summary
1. Summary
Solent and South Downs (SSD) had below average rainfall in August, receiving 80% (48mm) of the long term average (LTA) rainfall (60.0mm). Monthly mean river flows across SSD ranged from normal to exceptionally high. End of month groundwater levels ranged from normal to exceptionally high. Soils across SSD ended the month drier than the average for August. End of month reservoir stock was above average at Ardingly Reservoir (Ouse) and was below average at Arlington Reservoir (Cuckmere).
2. Rainfall
SSD had below average rainfall in August, receiving 80% (48mm) of the LTA (60.0mm).
In August the rainfall across the area ranged from 35mm to 61mm (65% to 101% of the LTA). The areal units in West Sussex received lower rainfall, than those in Hampshire and East Sussex. The highest daily total of 34.5mm was recorded at Bishops Sutton and 33.9mm was recorded at Harestock (both on 1 August, East Hampshire Chalk). The first part of the month featured unsettled conditions with days of thunderstorms and heavy localised rainfall, interspersed with drier weather. The most widespread distribution of rain was between 22 and 25 August. SSD had more than 50% of the month total rain fell on these 4 consecutive days. The end of the month was mostly dry.
The current water year to date, last 11 months (October to August), was the third wettest on record for SSD area, since 1871. All the SSD rainfall units ranked in the top three wettest October to August period on record. The Lymington, Isle of Wight, West Sussex Chalk, Sussex Coast, areal units all ranked as wettest for October to August, since 1871.
Over the longer time periods, the 15-month and 18-month running totals remain exceptionally high, and were the second wettest on record for SSD, since 1871.
3. Soil moisture deficit and recharge
Soils across SSD ended the month drier (92mm) than the average for August (86mm).
4. River flows
Monthly mean river flows across SSD ranged from normal to exceptionally high.
Flows were normal at the:
- River Test at Broadlands
- River Lymington at Brockenhurst
- River Medina at Blackwater
- River Wallington at North Fareham
- River Adur at Sakeham
- River Cuckmere at Cowbeech
Flows were above normal at the:
- River Test at Chilbolton
- River Meon at Mislingford
- River Rother at Iping Mill
Flows were notably high at the:
- River Ouse at Goldbridge
Flows were exceptionally high at the:
- River Itchen at Allbrook and Highbridge
There is no monthly mean river flow data for the River Arun gauged at Alfoldean, as the daily mean flows data records are incomplete.
The monthly mean flows for August were the second highest on record at Allbrook and Highbridge (Itchen), since 1959.
5. Groundwater levels
End of month groundwater levels ranged from normal to exceptionally high.
Groundwater levels were normal at:
- Carisbrooke Castle (Isle of Wight)
- Harting Common (Western Rother Greensand)
- Chilgrove (West Sussex Chalk)
- Beeding Hill (West Sussex Chalk)
- Houndean Bottom (East Sussex Chalk)
Groundwater levels were above normal at:
- Catherington (East Hampshire Chalk)
Groundwater levels were notably high at:
- Clanville Gate (Test Chalk)
- Lopcombe Corner (Test Chalk)
- West Meon (East Hampshire Chalk)
- Cornish Farm (East Sussex Chalk)
Groundwater levels were exceptionally high at:
- Preston Candover (East Hampshire Chalk)
- Youngwoods Copse (Isle of Wight)
Groundwater levels for August were the third highest on record at Clanville Gate, West Meon, Youngwoods Copse and at Preston Candover since 1966, 1986, 1978 and 1975, respectively.
6. Reservoir stocks
End of month reservoir stock was above average at Ardingly Reservoir (Ouse) with 73.7% of total capacity (LTA 73%) and was below average at Arlington Reservoir (Cuckmere) with 57.5% of total capacity (LTA 62.75%).
7. Environmental impact
During August there were 4 licence restrictions in force, 3 cessations and one reduced abstraction rate restriction.
There were cessations in force, on the Loxwood Stream (Arun), on the River Meon and on the Walkford Brook (New Forest).
There was a reduced abstraction rate restriction in force on Wallers Haven at Hazard’s Green (Pevensey catchment).
There were no Flood Alerts or Flood Warnings issued in SSD during August.
Author: HydrologySSD@environment-agency.gov.uk
Contact details: 03708 506 506
All data are provisional and may be subject to revision. The views expressed in this document are not necessarily those of the Environment Agency. Its officers, servants or agents accept no liability for any loss or damage arising from the interpretation or use of the information, or reliance upon views contained in this report.