THE RIVINGTON RESERVOIRS

Click this icon for a report about the reservoirs which was written in 1904

Problems with Rivington Reservoir caused it to be drained in Jan 2002. Click the icon to see the pictures.

The following extract was written in 1904. Most of the detail was extracted from the first part of the "Report of the Water Engineer of the Liverpool Waterworks" which was  published in1900

EARLY in the nineteenth century the utterly inadequate character of the water supply of the growing town of Liver­pool was engaging the attention of the Town Council, and numerous schemes were suggested for meeting the difficulty. As a result of a prolonged agitation for a better supply, the Council in 1846 engaged three engineers—Mr. Hawksley, Mr. Cubitt, and Mr. Rendel—to investigate and report upon the various schemes that were proposed. Suggestions to draw the water supply from Bala Lake, the River Alt, and other sources, were discarded, and a scheme prepared by Mr. Hawksley, after­wards known as the Rivington Pike scheme, was adopted. Mr. Hawksley proposed to impound the waters of the rivers Douglas and Roddlesworth, and form a reservoir in the valley between Rivington Pike and Heath Charnock. In the following year the Corporation obtained the necessary Parliamentary powers, but there was an active minority in Liverpool very much against the scheme, and strenuous opposition was offered to the carrying out of the work by those who considered that wells sunk in the sandstone rock within or close to the Borough would afford an ample supply of water. The result was that the work of con­struction was delayed, and although the Act of Parliament was obtained in the year 1847 it was not until August 1857 that the water from Rivington was first delivered in Liverpool. It is curious to hear that when Rivington water was first supplied to the consumers, the greatest dissatisfaction was expressed on account of its brown colour, due to the presence of peat and the decomposition of vegetable organic matters left in the valleys forming the sides and bottoms of the reservoirs. These difficulties were eventually overcome, and the new supply delivered in unexceptionable condition in the matter of colour as well as in other respects, to the general satisfaction of the people of Liverpool; and it is said that they grew so accustomed to the bright Rivington water, derived from the millstone grit forma­tion, that when forty years later the water from Vrynwy was first delivered many of the consumers complained of its insipidness and brown colour.

In 1860 the growth of the population of Liverpool and the increasing demand for water rendered necessary the con­struction of a new reservoir on the River Roddlesworth at Tockholes, six miles to the north of Rivington village. This reservoir afforded additional storage to impound the rainfall of wet years, but did not add to the area of the watershed. It was found in 1867 that further supplies were again needed, and the compensation water, which had hitherto been discharged into the River Roddlesworth, was purchased, and power obtained to construct another reservoir at Rivington in the Yarrow Valley, to the east of Anglezarke, and two new filter-beds. This work was begun in 1868, and finished in August 1875, and the new reservoir filled with water in February 1877.

The Rivington watershed comprises about 10,000 acres of land, and the elevation ranges from 450 to 1500 feet. The principal streams that supply the water, as already stated, are the Roddlesworth, Rake, Yarrow, and Douglas, and the rainfall is collected into reservoirs formed by earth embankments carried across the natural valleys. The area and contents of each reservoir and the principal dimensions of the embankments are given in the subjoined table

Roddlesworth and Rake-brook reservoirs are connected with the Anglezargh by a canal 3.5 miles long and 21 feet wide. The total surface area at the overflow level is 598 acres, and their total length measured along the top water lines is 5.5 miles. The length of the combined embankments is over 3 miles. The highest embankment is that of the Yarrow reservoir, which is 103 feet above the bottom of the valley. The deepest puddle trench is also at this reservoir. Here the trench had to be carried down to a depth of 167 feet below the natural surface before a solid foundation could be obtained; the total height from the bottom of the foundation to the top of the dam being 257 feet.

A description of the method of construction adopted at the Yarrow Reservoir will apply, practically, to all the Rivington Reservoirs.

A suitable site for the embankment having been selected, a trench was excavated on the centre line of the intended work and carried down to the solid rock right across the valley. This was filled with clay deposited in layers of 9 inches, and carefully puddled so as to produce a homo­geneous watertight material. This clay wall, having reached the natural surface of the ground, was continued through the embankment, which was also built in thin layers thoroughly rammed and consolidated on both sides of the clay centre. Before commencing the erection of the embankment all peat and unsound material were stripped from the site. The inner or water slopes of the embankment have been built to an angle of 3 to 1, and outer slopes to an angle of 2 to 1.

The impermeability of the dam depends upon the wall of puddled clay in the heart of the dam tied into the solid rock at the bottom and sides of the valley. The clay wall has been carried up to a batter on each side of 1 inch to every foot vertical, the thickness at the top being 6 feet. The inner slopes of the bank are protected by 15 inch pitching, consisting of the millstone grit of the neighbourhood, laid on a bed of broken stone. The outer slopes have been soiled and grassed over. The outlet from the Yarrow Reservoir is by a tunnel driven through the rock at the side of the valley, and not through the embankment itself as in the earlier reservoirs. The tunnel and valve shaft are both lined with blue bricks.

The bye-wash or overflow is 100 feet wide. The weir and apron and steps are formed of heavy ashlar closely jointed. The pitching forming the bye-wash is of millstone grit, neatly dressed and soundly laid on asphalt concrete. The wing walls are of squared rubble, neatly and closely laid.

          All the reservoir embankments and tunnel outlets at Rivington are sound and watertight, and their excellent condition to-day is evidence of the skill and care exerted in their construction. The waste weirs or bye-washes have proved to be of ample capacity for dealing with the largest floods that have been experienced.

            All the water for the supply of Liverpool has to pass into and through the Lower Rivington Reservoir. From this reservoir the water is drawn off for filtration through sand filters. The original filtration works consisted of six beds, having a total area at the surface of the sand of 182,982 square feet, and two open filtered water tanks, capable of holding 8,384,000 gallons. In 1870—75 two addi­tional filter-beds were constructed. The area of these two beds is 71,302 square feet, making the total filtering area of the eight beds 254,284 square feet. The filtering material consists of 2 feet 6 inches of sand laid on the top of layers of gravel varying in size from 4 inches diameter to 1/8 inch diameter. The average rate of filtration per acre of sand is 2,240,920 gallons per day, or 81 cubic feet per square foot per day.

At 7.45 one dark January morning in 2002 the road to Rivington was closed. A man from the water board was re-directing traffic via Horwich. When asked why he just said "There's something wrong with the reservoir." He would say no more.

The following photo's have been taken in February and March. Sixteen pumps are being used to keep Rivington Reservoir drained. Some surplus water is also being pumped into the River Yarrow.

Looking North West - some water is retained below the level where the problem is..

Looking South West towards Horrobin Lane.

This is the view from the embankment of Horrobin Lane

The River Yarrow - which is deeper than usual due to keeping the reservoir drained.