The Irwell. Story of an industrial river

Item Type monograph

Publisher North West Water

Download date 24/09/2021 13:03:21

Link to Item http://hdl.handle.net/1834/27236 S tory of an in d u strial river How a salmon fishery became notorious for pollution

THE IRWELL was ‘born’ about three hundred million Ship Canal, from the City’s docks to Barton-on-lrwell. Its It has to be realised that modern methods of treating years ago when shallow seas covered most of south east principal tributaries are the entering on the sewage were not known at that time. The familiar Lancashire and Europe was much closer to the equator left bank below Bury after 21 miles, the revolving filter seen at sewage works first made its than it is today. Over the years the sea floor subsided and entering on the right bank below after 27 miles, appearance at at the turn of the century the deposits of mud and sand became beds of shale and the entering from the left bank in the centre of following experimental work at and elsewhere. sandstone—up to 300 feet thick—alternating with the at 38 miles and the River Medlock, part of The discovery and development of the activated sludge sandstone and gritstone still seen as outcroppings on which enters Knott Mill in Manchester at the point where process for sewage treatment at works was both sides of the valley between Bacup and Summerseat. the Irwell becomes the . supplemented by work at Bury. This prehistoric sea disappeared completely leaving only a spring in the hillside on the Pennine Moors and The Irwell passes through heavily populated and fossilised remains of marine life from that age as proof industrialised areas. Yet, until the early 19th century the RECREATION of its existence. Irwell was relatively unpolluted, with fishing being an important industry. Salmon were caught in Manchester The first people to live along the Irwell were the until the end of the 18th century. Over the years the condition of the Irwell has gradually Brigantes, a Celtic tribe, who farmed the uplands and improved. The improvement so far is mainly because lower reaches of the river around 79 BC. fewer trade premises discharge directly into the Irwell INDUSTRIES due to rationalisation of industry, the disappearance of The Irwell’s lower stretches are some of the region’s coal gasification plants and connecting wastes from most polluted. It starts as a spring in the hillside at Irwell other works to the sewers for treatment at the sewage Farm on the A671, one and a half miles north of Bacup, During the early 19th century, however, there was a treatment works. There have also been improvements in and initially appears as a small pool about three feet tremendous growth of industry and population. The quality of treated effluent leaving our ten sewage works wide but widens to about six feet by the time it reaches nature of the Irwell valley with its vast underground discharging into the river. One of the most significant Bacup. It is a fairly short river—39 miles—winding its resources of coal and a climate favourable to cotton improvements in sewage effluent was the opening of way through industrial Lancashire .to the Manchester spinning led, with the Industrial Revolution, to the Bolton sewage works, near Ringley Fold in 1965. establishment of Lancashire’s great cotton industry, as well as numerous bleach and dye works, paper mills, tanneries, chemical and gas works. Wastes from these The Bolton works now deals with sewage previously industries were discharged directly to the river, together handled by five dilapidated sewage plants as well as with crude sewage from an ever increasing population. In trade effluent from many premises in the area which 70 years from 1821 to 1891, Manchester and Salford's previously discharged direct into the river. population more than quadrupled from 187,000 to 809,000. Small wonder then that by the early 19th century The sewage works discharging treated effluent into the all fish life and virtually all aquatic life had disappeared Irwell and major tributaries are:— from the river. The condition of the river became so notorious that in 1868 a Royal Commission was established to examine the problem and, as a result, the firs t Rivers (Pollution Prevention) A ct was passed in 1876. The Act was not, however, effectively enforced by the local authorities, who were among the worst polluters and in 1891 the Mersey and Irwell Joint Committee was established to enforce the act.

An anonymous verse said to have originated at an early board meeting of the Joint Committee gives an impression of the Irwell at that time: “ If with a stick you stir well The poor old , Very sick of this amusement You will very soon become; For foetid bubbles rise and burst But that is really not the worst, For little birds can hop about Dry-footed on the scum.”

Although drinking water is not abstracted from the at Salford. This long and complicated scheme has Irwell itself, about 72.1 megalitres (16 million gallons) taken over 20 years to complete. Six miles of the river a day are licensed for abstraction for public supply have been improved by widening the channel, rais­ from 39 impounding reservoirs near the sources of ing floodbanks, eliminating a sharp bend and even A somewhat different aspect many of the tributary streams in the catchment. “The demolishing property which was restricting its width. of the Irwell than the one on Authority has also granted licences to 113 firms who our front cover, familiar to are licenced to abstract upto 51,640 megalitres Although not one of our most attractive rivers, stret­ Mancunians. But recent (11,362 million gallons) a year from the Irwell and its ches of the Irwell are used regularly for recreation. improvements in the quality tributaries for various industrial processes, including Rowing, canoeing, an annual regatta and the annual o f the river has resulted in fish paper and board manufacture and the textile boat race between Salford and Manchester univer­ life returning to its middle industry." sities are some of the activities on the Irwell. and upper reaches.

The Irwell drains 274 square miles of south east Lan­ The gradual progress towards a cleaner Irwell con­ Facing page: Regular cashire, north and east of Manchester. Flooding is tinued with the completion in the late 1970's of new recreation activities on the rare now but over the years floods have caused a sewage treatment works at Rochdale and Bury. The Irwell include the annual boat great deal of damage, particularly in the Salford area. former has enabled us to abandon four over-loaded race between Salford and The Irwell’s worst recorded floods were in 1946 and sewage works and connect their flow to Rochdale as Manchester Universities. 1886. In the flood o f 1886 trees were uprooted, pro­ well as permitting any trade wastes to be discharg­ perty ruined and families in Salford had to be rescued ed to sewer. It has made a significant contribution from their homes by boat. Work has been carried out to the condition of the River Roch and its major on the Irwell for many years deepening and widen­ tributaries. The Bury works provides capacity for con­ ing it—to make- its passage smoother and less necting two grossly overloaded works at Heywood prone to flooding. and also for additional volumes of trade waste. The overall effect of these works has been to improve the The most important scheme to relieve flooding was quality of the Roch and of the Irwell itself in the densely populated area of Lower Broughton downstream of the Bury sewage works discharge.

Published by Public Information Unit, North West Water Authority, Dawson House, Great Sankey, Warrington