MJ Abbott

Installation of new private water supply system

Chitcombe Farm, Dorset

Project summary

New gravity fed private water supply

Chitcombe Farm, nestled in the Dorset countryside at the foot of one of Dorset’s greatest viewpoints, had been struggling with an ancient water supply which was prone to leaks. The farm was supplied with water from an open spring chamber which gravitated water to a concrete reservoir barely lower than the spring. The reservoir had multiple outlets to the properties where most then had to re-boost the water to reach their loft tanks.

MJ Abbott was approached by Chesterton Humberts to completely redesign the water supply system so that all parts of the estate could be watered with ease. Taking advantage of the highest point of the site (being some 140m difference from top to bottom) seemed to the simplest option so a new reservoir was installed at the very highest point on the estate.

The old spring chamber was abandoned and a new sealed spring chamber was installed at the location where a spring had issued for many years. The spring water was piped by gravity to a new underground pump sump located near to the electrical power supply where a new borehole pump (with high head capability) was installed which pumps the water up a new 16 bar 90mm HPPE water main to the new estate reservoir. This acted as a “flow and return” main and the return line pressure was reduced to a useable pressure of 3 bar to feed the domestic properties.

The full scope of works comprised:

  • Installation of a new 18,000 litre Carlow Concrete reservoir
  • Installation of a new 900mm Ø x 3m deep perforated spring chamber and sealed raised cover
  • Installation of new 63mm MDPE gravity pipe work from spring  to pump chamber
  • Installation of a new 6,000 litre Carlow Concrete pump chamber with raised turret for AB air gap compliance to allow “mains water back up” in event of spring failure
  • Installation of 575m of 16 bar x 90mm HPPE pumping main over down land to withstand high head pumping pressure
  • Installation of 450m of 50mm MDPE pipe to domestic properties
  • Installation of 2100m of 32mm MDPE pipe to external troughs
  • Installation of 500m of 50mm MDPE from Wessex Water main to pump chamber as back-up supply
  • Installation of Grundfos borehole pump and pump control panel operating on time on/pressure off basis
  • Installation of pressure reduction valves – 16 bar to 3 bar
  • Arterial pipe work distribution around the estate to water troughs
  • Installation of 14 no new concrete water troughs.

Historically the estate has had to bowser in water for grazing to the majority of the estate, where now gravity does just that. The estate owner, Mr Wurfbain, commented:  “What I have seen all looks very professional, and I’m looking forward to now start using the farm in earnest.”