II. THE IMPROVEMENT OF LEEDS
Prior to the 1832 Cholera very few streets in Leeds were drained. The few sewers which did exist had been built privately and discharged either directly to the River Aire at Leeds Bridge or to Addle Beck the 'Ganges of Lady Lane' and thence to the River.
Impelled by a growing movement for Improvement, the newly formed Borough Council promoted a series of local Acts of Parliament. As far as sewerage was concerned, the Leeds Improvement Act 1842 was epoch making. Section 153 of the Act stated:
"It shall be lawful for the Council from time to time to cause such common sewers, drains, vaults, culverts, watercourses, wells and pumps as they may think necessary to be made and constructed in or under any streets within the limits of this Act."
Various proposals were considered for using the new powers in order to provide a comprehensive sewerage system. In particular, alternative plans were presented to the Council during the course of 1844 45 by the Borough Engineer (Thomas Walker), Captain Vetch,R.E., and the Leeds based engineer John Wignall Leather.
Walker's plan was distinguished by his scant regard for all the arguments about the condition of the River Aire. His report proposed "... conveying the drainage along the natural hollows, direct into the river, its natural channel". He claimed that "it is altogether impossible to cleanse the River Aire of its impurities, and that no proof whatever can be adduced that the present polluted state of the River Aire has been injurious to the public health". In keeping with this outlook, Walker's plans showed no less than seven new sewer outfalls to the Aire all close to the town centre.
Both Vetch and Leather proposed deep main sewers parallel to the river, picking up (or intercepting) subsidiary shallow sewers from the various streets, and discharging to the river well downstream from the town. Vetch envisaged a 'manure farm' close to the outfall, by means of which a revenue of £10,000 per annum could be raised by usage of a portion of the sewage for agricultural purposes. There were severe misgivings among others however about the viability of his plans for sewage utilisation, given the assumed toxic effect of some of the dyers' wastes in the sewage and the advent of cheap Peruvian guano as an agricultural fertiliser. There was also some doubt about the possibility of getting agreement from private landowners to some of his proposed sewer routes.
Leather's scheme, which avoided these uncertainties and lead the sewage untreated to the Aire, was adopted by the Council in June 1846. In his report of February 1845 on the "Means of Providing an Effectual Sewerage System for the Town of Leeds", Leather set out seven explicit general principles or conditions which he felt were "essential to a sound system of sewerage" and which he had incorporated in his scheme (see Appendix 1).
In these conditions were embodied the principal recommendations in Chadwick's 1842 Report namely, that sanitation should be hydraulic, arterial and water borne. This meant that ideally water had to be piped to every house to flush away the excrement (via a 'water closet'). This water would then carry the sewage away in sewers of curved cross section (rather than the brick arches which were then prevalent).
The cross sections of Leather's proposed sewers were generally egg shaped. This was in accord with the recommendations of Chadwick's technical advisor, John Roe, engineer to the Holborn and Finsbury Commission of Sewers. The egg-shape was intended to give relatively high velocities at low flows and thus improve the scouring action or self-cleansing behaviour of the pipes.
It is interesting to note that the appropriate size for the pipes was a subject of great contention at the time. Rival sets of flow tables were available, which gave vast differences in capacities.
Leather insisted that none of the existing sewers could be incorporated in the scheme. The condition of the Marsh Lane sewer, described by Captain Vetch, was thought to be typical: "2 feet wide, 3 feet high, flat at top and bottom, the sides were built of dry stones full of large interstices, affording an extensive harbourage for rats, and permitting the liquid filth to soak through whatever ground was porous."
It was recommended that individual houses be connected to the street sewers with the relatively new glazed earthenware pipes (6 to 9 inches in diameter).
Despite the Council decision in 1846 to adopt the new sewerage scheme, various factors combined to produce delays. Firstly, agreement was still needed from the Aire and Calder Navigation Company, whose rights over the River Aire and its tributaries would be affected. Secondly, a borrowing limit of £100,000 was imposed on the Council by the 1842 Improvement Act and half of this sum had already been used on other projects. Thirdly, agreement was needed from the owner of the Temple Newsam estate to site the main outfall sewer on his land.
It took 2 years to sort out these difficulties, but by then a downturn in the economy and in company profits had increased the lobby against the levying of a sewerage rate. Motions to proceed were lost in the Council meetings in January and February 1849. The fresh outbreak of Cholera in October 1849 however, in which 2000 died in Leeds, may have helped to concentrate minds: The Streets Committee authorised the first contracts for construction work to be let in 1850. Leather's scheme was completed at a total cost of £137,000 by 1855.
The part played by the new breed of mapmaker in enabling the scheme was indispensible. Up to the commencement of the Nineteenth Century very few reliable maps or plans of the Township of Leeds were available. Yet the visionary civil engineering feats of the Industrial Revolution needed the skills of the surveyor as never before. Accurate scale plans were essential for the construction of new communications canals, railways and turnpike roads. Plans were needed for the use of the new official bodies such as the Local Boards of Health and the Poor Law Commissioners. Plans were needed too for the public sewer and waterworks schemes.
It is thought that the first plan of Leeds drawn from an accurate survey was that of Netlam and Giles in 1815. An 1832 record of the town's drainage system , is superimposed on Charles Fowler's 1821 plan, which in turn appears to have been based on Netlam and Giles' plan. Not until 1850 did the Ordnance Survey produce plans of Leeds (60 inch to 1 mile plans, based on a survey done in 1847 by Capt.R.E.Tucker). The earliest comprehensive public sewer records held in Leeds were superimposed on the 1850 O.S. sheets.