Stonor Park

The Stonor Park well, measuring levels in the Chalk aquifer near Henley on Thames. Its hydrogeological setting, and the absence of major abstractions in its vicinity, mean it is often cited as a 'typical' chalk observation well.

Our enquiries service can help you to access groundwater level data for this well.

Hydrograph


hydrograph

Show data from :-
1961 to 2013 1960s 1970s 1980s 1990s 2000s 2010s


Information about the well

Stonor Park
Wellmaster ID SU78/45A
NGR 4741 1892
Datum 121.29 m AOD
Monitoring details
Type Groundwater Level
Aquifer Chalk
Confinement Unconfined
Depth 87.5 m
Record
Monitored by EA Thames
Records commence 1961
Records end Active

Map of Stonor Park showing geology and water level contours.

Hydrogeological setting

The borehole monitors water level in the Berkshire Downs Chalk above Henley on Thames. It is drilled into the Lewes Nodular Chalk. The aquifer is unconfined.

Well or borehole construction

The well consists of a 2.2 metre diameter shaft to 60 metres and a 152 mm diameter borehole to 87.5 metres.

Hydrograph response

This hydrograph has a very regular annual sinusoidal pattern, capturing the aquifer's full range of fluctuation, although analysis suggests that there may be a constraint on low levels. As levels don't reach the bottom of the well, the constraint may be hydrogeological.

The relative simplicity of the borehole's response to recharge has meant that it is frequently cited as a typical Chalk well, and used in modelling exercises to link precipitation, recharge and water level. The Chalk block monitored by Stonor is, in fact, slightly atypical in that it is one of the larger blocks without surface drainage, and responses to individual recharge events are damped.

Flow in the Assendon spring is initiated when water levels reach 85.5 metres aod, which tends to occur around once per decade.

Data issues

Uninterrupted weekly data from 1963.

References

A preliminary risk assessment of the potential for groundwater flooding during the winter of 2007/8 — an update.

Contact

Contact Andrew McKenzie for further information