The Crown decided to sell it in 1812 to help fund the Napoleonic Wars, but local people with rights to graze sheep and cattle on the common land objected.

12.6 square miles (33 km2) were sold to cover the cost of the Enclosure Commission, and around one third of the total area was offered for sale in 1819.

This network consisted eventually of over 100 miles (160 km) of tracks connecting the farms of Sennybridge and Fforest Fawr (where Christie wanted to improve the land through application of lime), with the charcoal burning centres and coal extraction below Fforest Fawr, with the lime kilns at Penwyllt and ironworks at Ystradgynlais, and the Swansea Canal dock for other industries downstream.

[1] With the development of Swansea harbour from the 1760s, consideration was given as to how the rich mineral resources of the Tawe valley could be moved to the coast.

The plans were opposed by the Duke of Beaufort and other traders, who wanted the canal to terminate further up the river near Landore and Morriston, where they already had wharfs.

[6] The first section of the canal from Swansea to Godre'r-Graig was opened in 1796, and the whole length of 16.5 miles (26.6 km) was completed by October 1798.

[7] Civil engineering works included 36 locks and five aqueducts to carry the canal across major tributaries of the River Tawe, at Clydach, Pontardawe, Ynysmeudwy, Ystalyfera, and Cwmgiedd.

The purpose was to transport limestone from the quarries at Oystermouth and coal from the Clyne Valley, and to develop Mumbles as a harbour and shipping port.

Discussion of the plans played out in the pages of the Cambrian Newspaper, with opponents proposing that it made more sense to further develop facilities at Swansea.

The opening of the canal caused an increase in industrial activity along the valley, with a number of manufacturing companies setting up works by its banks.

[12] There are few records of how much traffic was carried, but estimates based on the amount of coal and culm shipped from Swansea Docks suggest around 386,000 tons in 1839.

[16] Rather than run it down, the Great Western Railway ran the canal well, and it remained profitable until 1895, when losses were first reported, though it recovered a little between 1898 and 1902.

[19] Just five miles (8.0 km) of the canal remains in water, from Clydach to Pontardawe where it is now a popular trail and is part of route 43 of the National Cycle Network.

A project is underway to dredge the canal and to remove the Japanese knotweed that grows extensively around the Swansea Valley.

[23] On 23 October 1998, after heavy rainfall, water levels in the canal rose, and at Pontardawe, spilled over the towpath and down an embankment.

Thirty houses, some industrial units and town centre shops were affected, with the water up to 4 feet (1.2 m) deep in places.

The grant was to fund the dredging of around 1 mile (1.6 km) of the canal from Trebanos to Coed Gwilym Park in Clydach.

[25] The upper terminus of the Swansea Canal was a large basin situated to the west of Aber-craf, close to an 'S'-bend in the River Tawe.

There was an iron works nearby, and two tramways linked it to limestone quarries near the summit of Cribarth, a hill to the north-east.

Differences in level were handled by 18 inclined planes, built at various times between 1794, when the canal opened, and the 1890s, when quarrying ceased.

[32] The double-track Ynysgedwyn incline is one of the most impressive structures of its type in south Wales which still survive, rising 696 feet (212 m) along its 1,400-yard (1,300 m) length.

The road has made the channel narrower, but the remains of six of the seven locks are still visible, and there are other industrial buildings which were associated with the canal still in existence.

[28][29] Around 1 mile (1.6 km) of the canal between the parting and Ynysmeudwy is owned by Neath Port Talbot County Borough Council, and is managed as a nature reserve.

China clay was brought up the canal by barge, and a wide variety of items were manufactured by the workforce, which consisted of 112 people at its peak.

The collieries were disused by 1898, and only a short section of the railway line remained, as the link over the lock and river had been removed.

The canal continues a little further, passing under Herbert Street Bridge and over Upper Clydach Aqueduct, before disappearing into a culvert.

[28] By Coedgwilym Park, the canal turns briefly to the west, to pass under the B4603 Pontardawe Road bridge, and then there was another short culverted section beneath a council depot,[35] which was the location of a lock.

[36] The infilled section above the lock was reopened in late 2023, when the local MP Tonia Antoniazzi cut a rope to formally mark the completion of the work.

Nickel ore was imported from Canada, and the site was chosen because there were supplies of anthracite coal, water, transport links to Swansea, and an available labour force.

The canal turned to the south, to run beside the river, and then to the south-west, where it ran parallel to the Swansea Vale Railway.