Blackstaff River

[2] In earlier times the Blackstaff flowed into the Lagan immediately above the present-day Queen's Bridge at what is now Victoria Square,[3] and formed a wide, muddy estuary that extended as far up as Sandy Row.

[5] In the 17th century the situation of the Blackstaff became a problem for the newly built town of Belfast, which found its potential for expansion limited by the mud flats on its southern side.

[7] This work, commissioned by the Earl of Donegall during a lean period in order to provide relief for local labourers, allowed development to commence on the southern side of Ann Street, the original limit of the town.

[8][6] In 1767, Henry Joy (whose family published the Belfast Newsletter) purchased a parcel of land at Cromac in order to build a paper mill, which would be powered by the Blackstaff.

[16] In particular on 16 August 2008, a newly opened underpass carrying the M1 motorway onto the A12 Westlink controversially flooded to a depth of 20 feet (6.1 m)[17] during heavy rain with water from the culverted Blackstaff and Clowney Rivers.

An uncovered stretch of the river near the Boucher Road
The open end of a river culvert in the bank of a much wider river, with office buildings and development visible above the waterside.
The culverted mouth of the Blackstaff at the Belfast Gasworks
A 1791 map of Belfast showing the course of the Blackstaff and the situation of Joy's Paper Mill
The Gasworks in 1935, when the lower reach of the Blackstaff was still uncovered