The area of the two is 1¾ square mile.
The area to be drained by natural outfall comprises, then, 25⅙ square miles as regards rainfall, and the same extent as regards sewage; while the area to the drainage of which steam power is to be applied comprises 14⅓ square miles of rainfall, and 16⅙ square miles of sewage; the two united areas of rainfall and sewage respectively being 39½ and 41⅓ square miles.
The length of the great “high-level sewerage” will be, as regards the main sewer, 19 miles and 106 yards; that of the “low-level sewerage,” 14 miles and 1501 yards.
I will now describe the course of each of these constructions.
On the eastern bank of the Lea the sewage of both districts is to be concentrated. The high-level sewer will commence and cross the Lea near the “Four Mills.” It is then to proceed “in a westerly direction under the East and West India Dock Railway and the Blackwall Extension Railway, beneath the Regent’s-canal, to the east end of the Bethnal-green-road, at the crossing of the Cambridge-heath-road, at which point it will be joined by the proposed northern division of the Hackney-brook, which drains an extensive district up to the watershed line north of London, including Hackney, Stoke Newington and Holloway, and part of Highgate and Hampstead; from thence the main sewer proceeds along the Bethnal-green-road, Church-street, Old-street, Wilderness-row (where a short branch from Coppice-row will join) to Brook-street-hill; from thence to Little Saffron-hill, where a distance of about 100 yards is proposed to be carried by an aqueduct over the Fleet-valley; thence along Liquorpond-street, at the end of which it will receive a branch from Piccadilly, on the south side, and a diversion of the Fleet-river, on the north side; thence along Theobald’s-road, Bloomsbury-square, Hart-street, New Oxford-street, to Rathbone-place (where it will receive a diversion of the Regent-street sewer from Park-crescent), along Oxford-street, and extending thence across Regent-circus to South Molton-lane (where it will intercept the King’s Scholars’ Pond sewer), continuing still along Oxford-street to Bayswater-place, Grand Junction-road, Uxbridge-road, where it is joined by the Ranelagh sewer, the sewage of which it is capable of receiving, and at this point it terminates.”
It is difficult to convey to a reader, especially to a reader who may not be familiar with the localities of London generally, any adequate notion of the largeness, speaking merely of extent, of this undertaking. Even a map conveys no sufficient idea of it.
Perhaps I may best be able to suggest to a reader’s mind a knowledge of this largeness, when I state that in the district I have just described, which is but one portion (although the greatest) of the sewerage of but one side of the Thames, more than half a million of persons, and nearly 100,000 houses are, so to speak, to be sewered.
The low-level tract sewerage, also, concentrates on the Lea, “near to Four Mill’s distillery, taking the north-western bank of the Limehouse Cut, at which point it receives the branch intended to intercept the sewage of the Isle of Dogs; thence continuing along the bank of Limehouse Cut, through a portion of the Commercial-road, Brook-street, and beneath the Sun Tavern Fields, into High-street, or Upper Shadwell; thence along Ratcliffe-highway and Upper East Smithfield, across Tower-hill, through Little and Great Tower-streets, Eastcheap, Cannon-street, Little and Great St. Thomas Apostle, Trinity-lane, Old Fish-street, and Little Knight Rider-street; thence beneath houses in Wardrobe-terrace, and on the eastern side of St. Andrew’s-hill, along Earl-street to Blackfriars-road. From Blackfriars Bridge it is proposed to construct the sewer along the river shore to the junction of the Victoria-street sewer at Percy-wharf; which sewer between Percy-wharf and Shaftesbury-terrace, Pimlico, becomes thus an integral portion of the intercepting line; at Bridge-street, Westminster, a branch from the Victoria-street sewer is intended to proceed along Abingdon and Millbank-streets, as far as and for the purpose of taking up the King’s Scholars’ Pond and other sewers at their outlets into the Thames. From Shaftesbury-terrace the Victoria-street sewer is proposed to be extended through Eaton-square and along the King’s-road, Chelsea, to Park-walk, intercepting all the sewers along its line, and terminating at a point where the drainage of Kensington may be brought into it without pumping.”
The lines of sewerage thus described are, then, all to the west of the Lea, and all, whether from the shore of the Thames, or the northern reaches in Highgate and Hampstead, converging to a pumping station or sewage-concentration, on the east bank of the Lea, in West Ham. By this new plan, then, the high-level sewer is to cross the Lea, but that arrangement is impossible as respects the second district described, which is below the level of the Lea, so that its course is to be beneath that river, a little below where it is crossed by the high-level line. To dispose of the sewage, therefore, conveyed from the low-level tract, there will be a sewer of a “depth of forty-seven feet below” the invert of the high-level sewer. This sewer, then, at the depth of 47 feet, will run to the point of concentration containing the low-level sewage.