Chipstead GWL (Well House Inn)

Location of Chipstead GWL (Well House Inn)

This is a new observation borehole, complementing records from a well that was dug into the Chalk aquifer over 130 years ago in the garden of the Well House Inn Pub, on the North Downs.

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Show data from :-
1942 to 2015 1970s 1980s 1990s 2000s 2010s

Information about the well

Chipstead GWL (Well House Inn)
Wellmaster ID TQ25/86
NGR 5258 1552
Datum 132.27 m AOD
Monitoring details
Type Groundwater Level
Aquifer Chalk
Confinement Unconfined
Depth 140 m
Monitored by EA Thames
Records commence 1999 (extended back to 1942)
Records end Active

Hydrogeological setting

Geological map of the area around the Well House Inn (click for key)

This well measures water level in the North Downs Chalk. It penetrates the Newhaven and Seaford Chalk Formation, Lewes Nodular Chalk Formation and New Pit Chalk Formation.

Well or borehole construction

This is a drilled observation borehole, 140 m deep. It complements the Well House Inn site (TQ25/13), a dug well, which is 50.6 metres deep and was constructed before 1877 in the garden of the Well House Inn Pub. Monitoring has been carried out in the well since 1942. The record presented here shows observation borehole data with data pre-1999 inferred from the older well.

Hydrograph response

The water level in the well normally exhibits a 10 metre annual fluctuation, a relatively stable maxima develops in many years at around 30 metres below ground level, hinting at some degree of structual control, possibly a zone of enhanced porosity. The annual sinuosity is superimposed on a longer period response to significant drought episodes, typical of relatively poorly drained chalk blocks.

Data issues

Data is an amalgam of monthly data from TQ25/13 (Well House Inn) until 1999, weekly data for TQ25/86 (Chipstead GWL) from 1999 to 2002, and subsequently daily data. The site is equipped with Environment Agency telemetry. The two sites show an excellent correlation except during the driest conditions, when it is though that TQ25/13 levels are slightly higher than they should be. This has been corrected in the amalgamated record, but levels fall below the depth of the new sensor during droughts.

Topographic map with hillshade of the area around the Well House Inn


Contact Andrew McKenzie for further information