Lacey Green Reservoir
From Lacey Green History
Also click Water to choose from 10 articles telling the full story of how mains water was brought up to the hills, recollections of living here before mains water got here and the uproar when Fleet Street sentenced Lacey Green to death.
and click 1963 Loosley Row Reservoir for this
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LACEY GREEN RESERVOIR research & drawing by Miles Marshall
TWO HORSES MISSING in 1983. It must have been sometime in 1983 that I first noticed that a rather grubby white horse and its chestnut companion were missing from the small paddock at the corner of New Road and Small Dean Lane
THE DRILLING RIG. Not long after this, amongst the familiar red and white painted oil drums which had supported the training jumps, there appeared a drilling rig. The rig was moved around the field drilling borehole after borehole until it was rumoured round the village that ‘they’ were looking for oil. The mind boggled at the desecration of the Chilterns that would ensue as the Dallas types moved in on Walters Ash! However, ‘they’ were only testing the suitability of the sub soil to support a concrete reservoir for the Thames Water Authority but before excavations could commence, some (economically) viable means had to found of disposing of the excavated clay.
TOP SOIL STRIPPED. In the spring of the following year, the contractors moved in to the large field on the other side of New Road and started to strip off the top soil and pile it all up. Then the subsoil was dug away, to a total depth of perhaps three feet, and this was carefully piled up separately. Similar treatment was then given to the site of the reservoir before excavation of the deep clay was commenced in earnest.
TRAFFIC LIGHTS FOR TIPPERS. Traffic lights were installed where the lorrys would cross the road and as the giant excavators dug up the clay a relay of tippers carried it across the road and spread it out in the large field. The dry summer of 1984 was an immense help to the contractors who soon cleared the site out to a depth of perhaps twelve feet below the level of New Road. The new clay in the large field was then bulldozed, scraped and graded to achieve the desired contours before first the original subsoil and the top soil were evenly replaced. The final result was a gentle rise in the centre of the field in addition to an average increase in the level of about eight feet. The result, I think, is rather pleasing.
SLAD LANE VANTAGE POINT. From my vantage point In Slad Lane I have been able to watch the construction of the reservoir on my morning walks and to watch with interest how the civil engineers would tackle each stage of the work. First a concrete base was laid all over the site and then a strip of reinforced concrete floor was laid all along the Small Dean Lane end, thicker towards its outer edge and having steel rods turned at right angles so they would form the lower part of the end wall. Steel rods to reinforce the wall were then woven together in wooden jigs lying flat on the ground. After wiring them firmly together into giant mats they were lifted into position by the tower crane which may be seen on my drawing. The same crane then lifted up prefabricated wooden shuttering with a specially smooth inside surface, and lowered it into position in sections. Then it was bolted together and supported by long aluminium girder struts whilst wet concrete was poured in. No concrete was mixed on the spot but a succession of Premix lorries kept up the supply, filling large hoppers which poured it into the shuttering. The hoppers which had trap doors in their bases to disgorge their contents were also moved by the crane.
CONCRETE AND STEEL RODS. As the concrete set, the crane moved the shuttering along to encase the next piece of reinforced steelwork and so the wall grew, turned the corners at each end and then proceeded towards Walters Ash. The tower crane was mounted on rails so that it could be moved gradually backwards, more rail being laid behind as needed. At the same time, more thick reinforced concrete was laid over the floor and into this was incorporated the steel rods which were to reinforce the bottoms of the many columns which were to support the roof structure. These columns, which may also be seen in my drawing, were cast in ingenious moulds which formed a mushroom head on the top of each column to spread the area which would support the roof. As the columns set, the moulds were removed ready for the next row. All the concrete used in the reservoir was vibrated by one means or another, before it set, to ensure its solidity.
THE ROOF & COMPLETION. The roof, also of reinforced concrete, was laid on shuttering built between the columns in such a way as to give it a slight barrel-shape or crown. Presumably to make the rain water run off or it could be stronger that way. Once the structure was completed, a thick layer of pebbles was laid over the roof. The walls, which rise some twelve feet or so above ground level were banked up with clay and topsoil. This will be sown with grass seed this spring. The new black plastic covered chain linked fence which surround the site is already quite inconspicuous but a hedge is to be planted also to make it less so. The pebble roof will remain bare but of course it cannot be seen from the ground.
EXPLAINATION. The working of this new reservoir was explained to me by Mr. C.P. Davidson of Thames Water who told me that the large pipe (800mm in diameter) which was laid alongside Small Dean Lane all the way up from the Sauderton Valley, will be the only connection to the reservoir. The extension of the old main in Slad Lane up to the cross roads was just for the contractors’ use during the construction and will now be sealed off.
WHAT HAPPENS. At its lower end, the big pipe is connected to the Mid Bucks Trunk Main No.1 which runs up the valley and from this main, at times of low consumption, surplus water will be forced up the hill to a point just beneath the main entrance gates where it divides into two to fill both ends of the reservoir which is divided by a central partition into two halves each holding 4 million gallons. There are control valves for each half but the big main, which operates both as inlet and outlet, is fitted with a flow meter and an electrically operated valve. In the event of a burst on the main, the excess flow over normal is detected and the outlet valve automatically closes to prevent loss of water and flooding. During times of peak consumptions, the water will flow back again down the same pipe. It can back-flow to augment the supply in High Wycombe or flow on up the valley to augment supply if it is needed there. It will not affect the water supply in our village for what does not come from Green Hailey Tower is taken from the Mid Bucks Trunk Main No.2 running alongside, and pumped up the hill by the new electric pump in Woodway.
READY FOR USE. Apart from tidying up the site and the sowing and planting mentioned above, the reservoir is virtually complete and has already had water pumped into it and its main cleaned through. There will be no inaugural ceremony, no Royalty will break bottles of champagne over its bows, but it is ready to be in service.