The canal was not as successful as expected.
There were problems with water supply on the summit level, because water from the Lagan was needed by the bleaching industry further down the river, and so could not be used indiscriminately.
Below Lisburn, there were often problems where excess water during periods of high rainfall washed away the new banks.
The Union Locks were not completed, and work continued until 1796, while it was suggested that Owen had prolonged the work for his own benefit.
John Dubourdieu, writing in 1802, concluded that the use of the river was a fatal flaw, and that the navigation would have been much better if the lower section had been built as a canal to the same standard as the upper section.
The canal had been planned to enable coal from the east Tyrone coalfields to reach Belfast, but in practice, higher quality coal was imported through Belfast and distributed to the communities around the canal and Lough Neagh.

A group of businessmen from Belfast took over the canal in 1810.
They investigated costs for a new canal section from Belfast to Union Locks.
Owen estimated that it would cost £42,425, and an application was made for half of this amount to the Directors General of Inland Navigation.
They sent John Killaly to report on the plans, who suggested a new canal section from the Blackstaff river to the second lock, to avoid the tidal section near to Belfast.
Owen's and Killaly's ideas formed the basis for an Act of Parliament obtained in 1814, but the proposals to split the navigation channel from the river and to build a reservoir at Broadwater near Aghalee to supply the summit level were never implemented.
However, improvements were made, towpaths were created, and traffic increased, although there were still some water supply problems.
The canal did not make a profit, and when the Exchequer Bill Loan Commissioners refused to make a loan to fund the work, the likelihood of a new canal at the lower end receded.

In the 1820s and 1830s, there was competition on short-haul traffic from the road network, but it was hoped that the construction of the Ulster Canal, linking Lough Neagh to Lough Erne and the River Shannon, would create long-haul traffic.
The Directors General of Inland Waterways were replaced by the Board of Public Works, and although they took control of the Tyrone Navigation in 1831 and the Ulster Canal in 1851, there was local opposition to them taking over the Lagan Canal.
The old company was replaced by the Lagan Navigation Company in 1843, to ensure that the canal was maintained in good order, but the Board of Public Works supervised its activities quite closely.
They successfully competed with the Ulster Railway, which had reached Portadown in 1842, and ploughed all profits back into improvements until 1859, when they announced a first dividend of one per cent.
The canal was one of only two inland waterways in the north of Ireland that was commercially successful.
Dividends gradually increased, and by the 1870s, traffic figures were more than double those of the 1830s.

The condition of the Ulster Canal worried the Lagan Navigation Company, as almost no trade passed between the two.
This was not helped by the fact that the locks on the Ulster Canal were narrower, and the depth over the cills was less, so that Lagan boats could not work the canal, and goods had to be transshipped.
Although the Board of Public Works controlled the Ulster Canal, and had spent £20,000 on it since they took control in 1865, no additional traffic had been generated.
Between 1878 and 1880, the Lagan Canal built five boats which could work through both canals.
The Lagan Canal was persuaded to take over the Ulster Canal and the Coalisland Canal or Tyrone Navigation in 1888.
Although they spent a great deal on improvements, the additional canals remained in a poor state and continued to make a loss.
The Lagan itself was maintained well, and traffic rose from 153,000 tons in 1893 to 170,000 tons in 1898.
The canal was not as successful as expected. There were problems with water supply on the summit level, because water from the Lagan was needed by the bleaching industry further down the river, and so could not be used indiscriminately. Below Lisburn, there were often problems where excess water during periods of high rainfall washed away the new banks. The Union Locks were not completed, and work continued until 1796, while it was suggested that Owen had prolonged the work for his own benefit. John Dubourdieu, writing in 1802, concluded that the use of the river was a fatal flaw, and that the navigation would have been much better if the lower section had been built as a canal to the same standard as the upper section. The canal had been planned to enable coal from the east Tyrone coalfields to reach Belfast, but in practice, higher quality coal was imported through Belfast and distributed to the communities around the canal and Lough Neagh.
A group of businessmen from Belfast took over the canal in 1810. They investigated costs for a new canal section from Belfast to Union Locks. Owen estimated that it would cost £42,425, and an application was made for half of this amount to the Directors General of Inland Navigation. They sent John Killaly to report on the plans, who suggested a new canal section from the Blackstaff river to the second lock, to avoid the tidal section near to Belfast. Owen's and Killaly's ideas formed the basis for an Act of Parliament obtained in 1814, but the proposals to split the navigation channel from the river and to build a reservoir at Broadwater near Aghalee to supply the summit level were never implemented. However, improvements were made, towpaths were created, and traffic increased, although there were still some water supply problems. The canal did not make a profit, and when the Exchequer Bill Loan Commissioners refused to make a loan to fund the work, the likelihood of a new canal at the lower end receded.
In the 1820s and 1830s, there was competition on short-haul traffic from the road network, but it was hoped that the construction of the Ulster Canal, linking Lough Neagh to Lough Erne and the River Shannon, would create long-haul traffic. The Directors General of Inland Waterways were replaced by the Board of Public Works, and although they took control of the Tyrone Navigation in 1831 and the Ulster Canal in 1851, there was local opposition to them taking over the Lagan Canal. The old company was replaced by the Lagan Navigation Company in 1843, to ensure that the canal was maintained in good order, but the Board of Public Works supervised its activities quite closely. They successfully competed with the Ulster Railway, which had reached Portadown in 1842, and ploughed all profits back into improvements until 1859, when they announced a first dividend of one per cent. The canal was one of only two inland waterways in the north of Ireland that was commercially successful. Dividends gradually increased, and by the 1870s, traffic figures were more than double those of the 1830s.
The condition of the Ulster Canal worried the Lagan Navigation Company, as almost no trade passed between the two. This was not helped by the fact that the locks on the Ulster Canal were narrower, and the depth over the cills was less, so that Lagan boats could not work the canal, and goods had to be transshipped. Although the Board of Public Works controlled the Ulster Canal, and had spent £20,000 on it since they took control in 1865, no additional traffic had been generated. Between 1878 and 1880, the Lagan Canal built five boats which could work through both canals. The Lagan Canal was persuaded to take over the Ulster Canal and the Coalisland Canal or Tyrone Navigation in 1888. Although they spent a great deal on improvements, the additional canals remained in a poor state and continued to make a loss. The Lagan itself was maintained well, and traffic rose from 153,000 tons in 1893 to 170,000 tons in 1898.
Lagan Canal