Groundwater

The Pillhill Brook Association (PBA) monitors groundwater behaviour within our catchment on a weekly basis. Groundwater level is important because it dictates the height of water in the brook and hence flow and also how quickly rainfall will soak away into the ground, preventing flooding. We monitor levels at 5 local boreholes: 

1. Clanville Gate in Clanville

2. High View in Kimpton

3. Stanbury Road Water Pumping Station (WPS) in Kimpton

4. Haydown Farm in East Cholderton

5. Monxton WPS in Monxton

See map below for locations.

Current groundwater situation in the Pillhill Brook Catchment

The EA's groundwater trigger point of 84 m above sea level was exceeded at Clanville Gate on 21 October 2024. 

Groundwater at Clanville Gate exceeded 86 m above sea level on 1 December 2024 and the Environmental Agency are now issuing regular briefings on groundwater flooding. 

The latest Groundwater Flood alert for the villages surrounding Andover was issued on 14 April - read that here or sign up to receive your own EA Flood Warnings here.

The exceptionally wet start to 2025 had meant that groundwater was heading toward the unprecedented levels seen last year - 216 mm versus an expected average of 124 mm of rainfall. However March has been exceptionally dry - only 6 mm of rain fell on the catchment vesus an expected average of 59 mm. Combined with the trees coming into leaf this has thankfully meant that groundwater is now falling. Groundwater level at Clanville Gate is predicted to drop below 89 m early in April. 

Historic Groundwater Story

The last Groundwater situation for Hampshire in 2024 was issued on 6 June 2024. 

The Environmental Agency (EA) use the groundwater level at Clanville Gate to inform them of the risk of flooding in the villages surrounding Andover. The EA also use a groundwater level of 84 m above sea level as the trigger point with Southern Water for the risk of major groundwater infiltration in the sewer network. Click on Andover Villages (Clanville) for the latest groundwater data. 

The last flood alert in 2024 was removed on Tuesday 28 May 2024 with a groundwater level at Clanville Gate of 89.27 m.