It exists that much I know, because it is there in contemporary accounts from the 19th century and even showed up in a joint local authority report on “strategic flood risk assessment.*
Our local historian Thomas Ellwood mentions it in one of his articles in 1885 linking it to a “footpath from West Point to Brooks’s Bar as a means of communication between Hulme and the village, along which a brook ran, afterwards arched over and utilised by Mr. Brooks as a main sewer for his property, which he drained into the watercourse called Black Brook. The brook frequently flooded the footpath during heavy rain, and old William Hesketh, who lived at the Pop Cottage, was often awakened at night by the cries of travellers for help and guidance through the water.”**
And just a year later turns up in a letter to the Manchester Guardian from a T. Clarke of Athelstone House, High Lane, who drew a connection between the watercourse and “fevers of a malignant character.” “If you take the Manchester Road, in the Black Brook, immediately by the ‘Oswald’ you will have a place of danger and offence. I believe the ‘The Oswald’ has several times been visited by fevers of a malignant character”***
‘The Oswald’ or Oswald Field was roughly a little north of the library and extending to Oswald Road. From the early 19th century there was a row of cottages here and by the 1880s Oswald Lane ran from Manchester Road up to Oswald Road.
Looking at the 1841 OS it is possible to see the course of the Black Brook, hugging the edge of Oswald Field before running into the biggish pond and onto Longford Park.
By then it was fully culverted. Tracking it back further east is difficult. It flowed for a while along what id Manchester Road and must have headed north to towards Upper Chorlton Road, but this would take it directly across the path of Longford Brook.
And that is the problem. That wonderful book The Lost Rivers of Manchester by Geoffrey Ashworth mentions a Black Brook but that is much further east and any way becomes Cringle Brook out by Burnage which leads me to another communication with the Environmental Agency and a closer scrutiny of the SFRA document.
Meanwhile someone will write in to tell me the exact course and the mystery will be solved.
Picture; Oswald Fields, from the OS map of Lancashire, courtesy of Digital Archives, http://www.digitalarchives.co.uk/
*Manchester City, Salford City and Trafford Councils Level 2 Hybrid SFRA, Maps Index, Final March 2011
**Thomas Elwood, History of Chorlton-cum-Hardy, Chapter 6, Roads, December 12th 1885
***The Sanitary Condition of Chorlton-Cum-Hardy, Manchester Guardian May 19th, 1886.