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This formed part of Thomas Telford's improvement of the Birmingham Canal and was built around 1828. The work incorporated the 3.6 mile long Smethwick Cutting, at the time one of the largest earthworks to have been carried out.

The Engine Arm intersected the line of the new cut, but was needed for two main reasons – firstly to maintain a supply of coal to the Smethwick Pumping Engine, and secondly to maintain the water supply from Rotton Park Reservoir into the old summit level.

The aqueduct consists of a cast iron trough, 8 feet wide, supported on a cast iron arch of 52 feet span consisting of 5 ribs, three of which support the trough with the outer ones supporting the towpaths and bracing to the sides of the trough. The towpath support consists of an arcade of Gothic arches with quatrefoil spandrels.

As with most of the bridges erected as part of the Telford rebuilding, the ironwork was cast at the Horseley Iron Works at Tipton.

The aqueduct is Listed Grade II* and is also designated as a Scheduled Monument. The Listing includes the brick arch towpath bridge at the junction.

The Birmingham Canal was built from 1768 to 1772 by James Brindley from the then edge of Birmingham, at Paradise Wharf (also known as Old Wharf) near to Gas Street Basin to meet the Staffordshire and Worcestershire Canal at Aldersley, near Wolverhampton. The canal was upgraded and straightened by Thomas Telford between 1824-7.
The canal forms part of the Birmingham Canals Navigation, a network of canals in and around the city.
Wikipedia: Link

Listed buildings and structures are officially designated as being of special architectural, historical or cultural significance. There are over half a million listed structures in the United Kingdom, covered by around 375,000 listings.
Listed status is more commonly associated with buildings or groups of buildings, however it can cover many other structures, including bridges, headstones, steps, ponds, monuments, walls, phone boxes, wrecks, parks, and heritage sites, and in more recent times a road crossing (Abbey Road) and graffiti art (Banksy 'Spy-booth') have been included.

In England and Wales there are three main listing designations;
Grade I (2.5%) - exceptional interest, sometimes considered to be internationally important.
Grade II* (5.5%) - particularly important buildings of more than special interest.
Grade II (92%) - nationally important and of special interest.

There are also locally listed structures (at the discretion of local authorities) using A, B and C designations.

In Scotland three classifications are also used but the criteria are different. There are around 47,500 Listed buildings.
Category A (8%)- generally equivalent to Grade I and II* in England and Wales
Category B (51%)- this appears generally to cover the ground of Grade II, recognising national importance.
Category C (41%)- buildings of local importance, probably with some overlap with English Grade II.

In Northern Ireland the criteria are similar to Scotland, but the classifications are:
Grade A (2.3%)
Grade B+ (4.7%)
Grade B (93%)

Read more at Wikipedia Link