Research and analysis

Solent and South Downs water situation report: February 2025 summary

Updated 12 March 2025

Applies to England

• Publication for Northern Ireland
• Publication for Scotland
• Publication for Wales

1. Summary

Solent and South Downs (SSD) had average rainfall in February, receiving 112% (65mm) of the LTA (58mm). Monthly mean river flows across SSD ranged from normal to above normal and the end of month groundwater levels ranged from normal to notably high. Soils across SSD ended the month wetter than the average for February. End of month reservoir stocks were above average at Ardingly Reservoir (Ouse) and around average at Arlington Reservoir (Cuckmere).

2. Rainfall

SSD had average rainfall in February, receiving 112% (65mm) of the LTA (58mm). The East Hampshire Chalk areal unit in the west of SSD received the highest rainfall with 143% (89mm) of LTA (62.5). The Isle of Wight areal unit received the lowest rainfall with 85% (51mm) of LTA (60.4).

During the first 10 days of February there were some moderate rainfall totals across the area. From the 10 until 18 February it was largely dry. The remainder of the month was mostly wet with 21 and 23 receiving the most rainfall. The highest daily rainfall totals were recorded on 23 February at the following locations:

• 32.8mm at Princes Marsh (Western Rother Greensand)
• 32.3mm at Duncton (Western Rother Greensand)
• 31.9mm at Petersfield (Western Rother Greensand)

The last 12 months (March to February) were seventh wettest on record for the Test Chalk areal unit.

Figures for 18-month period (starting September) were the second highest for SSD and all the Hampshire areal units. For the 24-month period (starting March) it was the wettest for SSD and all the Hampshire areal units. For East Sussex the early 2000’s remains the wettest 24-month period while for West Sussex the 24-month period ending in 2014 is the wettest.

All these statistics are based on records going back to 1871.

3. Soil moisture deficit and recharge

Soils across SSD ended the month wetter than the LTA for February.

4. River flows

Monthly mean river flows across SSD ranged from normal to above normal.

Flows were normal on the:

• River Lymington at Brockenhurst
• River Meon at Mislingford
• River Wallington at North Fareham
• River Medina at Blackwater
• River Adur at Sakeham
• River Ouse at Goldbridge
• River Cuckmere at Cowbeech

Flows were above normal on the:

• River Test at Chilbolton
• River Test at Broadlands
• River Itchen at Allbrook and Highbridge
• River Arun at Alfoldean
• River Rother at Iping Mill

The monthly mean flows for February were the seventh highest on record for the River Arun at Alfoldean (1970) and River Adur at Sakeham (1967).

5. Groundwater levels

End of month groundwater levels for February ranged from normal to notably high.

Groundwater levels were normal at:

• Catherington (East Hampshire Chalk)
• Carisbrooke Castle (Isle of Wight)
• Beeding Hill (West Sussex Chalk)
• Houndean Bottom (East Sussex Chalk)
• Cornish Farm (East Sussex Chalk)

Groundwater levels were above normal at:

• West Meon (East Hampshire Chalk)
• Harting Common (Western Rother Greensand)

Groundwater levels were notably high at:

• Clanville Gate (Test Chalk)
• Lopcombe Corner (Test Chalk)
• Youngwoods Copse (Isle of Wight)
• Preston Candover (East Hampshire Chalk)
• Chilgrove (West Sussex Chalk)

The notably high groundwater level at Preston Candover was the fourth highest for February in a record going back to 1975.

6. Reservoir stocks

End of month reservoir stocks were above average at Ardingly Reservoir (Ouse) and were around average at Arlington Reservoir (Cuckmere). Ardingly Reservoir (Ouse) was at 100% of total capacity (LTA 96%), and Arlington Reservoir (Cuckmere) was at 98% of total capacity (LTA 98.4%).

7. Environmental impact 

Abstraction licence restrictions:

During February there were a total of two licence restrictions in force, one cessation and one reduced abstraction rate. The cessation was in force on the River Lymington (New Forest) and the reduced abstraction rate restriction was in force on the River Meon (East Hampshire).

Flood alerts:

During February there were 11 fluvial flood alerts issued in the SSD area. There were 2 flood alerts in Hampshire and 9 in Sussex.

Also, there was 1 groundwater flood alert issued in Hampshire.

Flood warnings:

During February there were 2 fluvial flood warnings issued in the SSD area. There was 1 flood warning in Hampshire and 1 in Sussex. 

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.