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In the book 'Wells and Springs of Dorset', published in 1926, the entry for the Tarrant Valley is:- "the water level is close to ground level, and good supplies may be got by sinking shallow wells. 'Winterbourne' conditions exist in this area. The Tarrants cluster along the small stream running south from Cranborne Chase to the Stour at Tarrant Crawford. They all get adequate supplies of good water from shallow wells in the Chalk or in the thin strip of gravel which floors the bottom of the valley. A borehole just north of the church at Tarrant Rawston gets a good supply of water from the Chalk at 15 to 20 ft."
Long time residents of the valley confirm this description and describe graphically the odd exceptional year when the wells dried and water had to be fetched from wells at Spetisbury on the opposite bank of the Stour.
The Tarrant flow may conveniently be divided into three regions. In the highest region it is a winterbourne and drying takes place down to just below Tarrant Hinton. From there to Keynston a stream normally flows while the third stretch between Keynston and the confluence with the River Stour dries progressively starting just upstream of the confluence. It is this third region which is unusual.
The three regions existed before any abstraction took place but there is evidence based on people's recollections that the problems have subsequently increased. In particular that there was normally water all through the year at Tarrant Monkton and that drying was less common on the lower stretch.
In 1948 a Stubhampton borehole was drilled to 142m depth (Chalk and Upper Greensand) but because "fine sand" was drawn from the Upper Greensand it was plugged with concrete and gravel below 78m depth. All the water then came from the chalk. Borehole No 2 was drilled to 72m depth. Test pumping for 7 days at 2.2 Ml/d produced water that showed a Go to home page
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