GU31 4AD — East Hampshire

200 monitoring boreholes within 25 km. The three most useful (nearest, preferring active boreholes with a surveyed ground datum):

Also within range: Newbarn Cottage (5.4 km, New Pit Chalk Member) · Harting Common (6 km, Hythe Formation (Lower Greensand)) · East Meon (7.3 km, West Melbury Marly Chalk) · Uppark Deerkeepers (7.4 km, Chalk Group (undivided)) · Chalton (7.5 km, Chalk Group (undivided)) · Drayton (7.9 km, Seaford Chalk Member) · North Cottage (8.3 km, Seaford Chalk Member) · Compton (8.8 km, Chalk Group (undivided)) · Idsworth Farm (9 km, Newhaven Chalk Member) · HMS Mercury (9.1 km, Lewes Nodular Chalk Member) · North Marden (9.3 km, Chalk Group (undivided)) · Whitewool Farm (9.6 km, Zig Zag Chalk Member)

What this is: real measurements at the named boreholes, in metres above ordnance datum (mAOD), with depth below ground derived from each borehole's surveyed datum. It is the water table AT THOSE BOREHOLES, in the aquifer each monitors — a water table is a surface with shape, and local perched water or a different aquifer under your land can put first water shallower or deeper than any of them.

The BGS 1:625,000 hydrogeology map puts this point on LOWER GREENSAND GROUP, classed 1A — highly productive aquifer. Significant intergranular flow.

In the BGS's own words: "Sandstone, commonly glauconitic, aquifer yielding up to 50 L/s. Quality usually soft, except where limestone present, and can be ferruginous."

This is the 625k-scale regional picture — the right tool for "is there an aquifer here at all", not for siting a drill rig. A drilling contractor will consult borehole logs before quoting; the nearest monitoring borehole here was drilled to 107.88 m, which is one real local depth datum.

This point is not in any EA groundwater source protection zone. No extra groundwater-protection constraint applies to soakaways, septic systems or a private borehole here beyond the normal rules below.

• !landslide/slope instability — significant potential at this point.
• !shrink–swell clay — significant potential at this point.
• !soluble rocks (dissolution) — significant potential at this point.

Water is usually the mechanism behind these: shrink–swell clay moves with soil moisture, running sand flows where the water table is high, dissolution follows groundwater pathways. A changing water table and these hazards are one story, not two.

• ✓Up to 20 m³ per day needs no abstraction licence in England — around 20,000 litres, comfortably above most domestic, smallholding and garden-irrigation use. Above that you need an Environment Agency abstraction licence.
• !Boreholes for water are notified to the BGS — a well or borehole deeper than 15 m comes with a notification duty under the Water Resources Act; established drilling contractors handle this as routine.
• !Drinking supplies must be registered with the local council, which risk-assesses and samples private water supplies under the Private Water Supplies Regulations. Budget for treatment: raw groundwater is commonly fine but is never assumed potable.
• ·What drives the cost is depth to reliable water — which is exactly what the measured levels above tell you. Quote a driller the aquifer name and the depths on this page and you are a better-informed customer than most.