River Test Aquifer Research

In 2023, Whitchurch Conservation Group (WCG) won a Hampshire and Isle of Wight Wildlife Trust (HIWWT) Watercress & Winterbourne Community Grant to commission an independent review of the 2022 Water Cycle Study carried out by Basingstoke and Deane Borough Council. The review was conducted by Archon Environmental, and the wider project was overseen by hydrogeologist David George.

Key Findings:

• River flows and groundwater levels are declining in the Upper Test catchment, and this will likely be exacerbated by climate change.
• The Upper Test’s water quality is being adversely affected by various pressures, but understanding of this is limited by shortfalls in water quality monitoring and analysis.
• Nitrate concentrations are increasing in the Upper Test and in the catchment’s groundwater. Agriculture appears to be the leading cause, followed by wastewater treatment works.
• Phosphorus concentrations are increasing in the Upper Test upstream of Overton, but decreasing downstream of the town. Continuing sources of phosphorus may be historic depositions bound up in sediment, and the Oakley wastewater treatment works.
• The Upper Test has been contaminated by various trace organic compounds (TOrCs), including mercury and polybrominated diphenyl.
• The ecology of the Upper Test is under stress, as evidence by chemical testing, riverfly census data, and the condition of the River Test Site of Special Scientific Interest (SSSI).
• There are large evidence gaps due to data being either unavailable or not collected through the current monitoring programmes.
• Basingstoke and Deane Borough Council’s 2022 Water Cycle Study is not fit for purpose and requires significant revision.

Read the full report here