Topographic map with hillshade of the area around Rockley

Measuring water levels in a Chalk valley, the Rockley site is considered a characteristic site for observing groundwater surface water interaction.

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



Show data from :-
1932 to 2015 1970s 1980s 1990s 2000s 2010s

Information about the well

Wellmaster ID SU17/57
NGR 4165 1717
Datum 146.57 m AOD
Monitoring details
Type Groundwater Level
Aquifer Chalk
Confinement Unconfined
Depth 17.6 m
Monitored by EA Thames
Records commence 1932
Records end Active

Hydrogeological setting

Geological map of the area around Rockley

Rockley measures the water level in the Holywell Nodular Chalk Formation and New Pit Chalk Formation (undifferentiated). The well is located in a dry chalk valley not far from the River Kennet, and there is significant evidence of surface water groundwater interaction.

Well or borehole construction

An original well,  17.6 metres deep, brick lined with a diameter of 1.52 metres, was replaced in 1993 by a purpose drilled 60 metre deep observation borehole.

Hydrograph response

The Chalk is unconfined and the hydrograph has an annual sinusoidal response with a seasonal variation generally of about 12 m. At high water levels flow has been recorded in the dry valley. Low levels are thought to be controlled by a marl band within the Chalk.

Data issues

Mainly uninterupted weekly data since 1933. The drilling of the observation borehole in 1993 meant that it was possible to measure levels during drought that were previously not observable, as they were below the base of the well.

Topographic map with hillshade of the area around Rockley


Contact Andrew McKenzie for further information