Ptolemy's
Geography (2nd century AD) described a river mouth called Αργιτα (
Argita, "shining"), referring to the Bann. The Lower Bann provides the only outlet for Lough Neagh, the largest freshwater lake in the British Isles, which is fed by six major rivers, including the Upper Bann. The ability of the lough to absorb large quantities of flood water is limited, and consequently, the areas around the lough are prone to flooding. The Lower Bann encountered a large shoal of rock at Portna, which reduced the effectiveness of the outflow, and in 1738,
Francis Hutchinson, the
Bishop of Down and Connor petitioned the Irish Parliament to do something about the shoals, and hence the annual flooding that affected his people. Although Parliament responded encouragingly, no actual work was done, and the problem remained. In 1822, the Scottish engineer
Alexander Nimmo proposed a radical solution. The
Newry Canal provided a route southwards from Lough Neagh to
Carlingford Lough, but it rose to a summit and then descended again. His proposal was to lower the summit level so that it was below the level of Lough Neagh, remove all the locks, and so provide a second outlet to the sea. Not only would it solve the problems of flooding, but it would also solve the inadequate water supply for the canal, eliminate lock maintenance, and could generate around 2,200 kW as the water would still have to fall by . The plan was a little too ambitious and failed to win support. The
Board of Works were authorised by the
Drainage (Ireland) Act 1842 (
5 & 6 Vict. c. 89) to carry out works in the Lough Neagh basin, which would improve navigation, drainage and milling. A series of public meetings were held, and a survey was made of the Lower Bann. The Board of Works then instructed their own engineer to carry out a survey. John McMahon estimated that it would cost £183,775 to improve the Lower Bann from Lough Neagh to the sea, and that the navigation works accounted for less than half of this, with the drainage works making up the rest. Removal of the Portna shoal would reduce the level of the lake surface by some . The plan was well received, and work began in 1847. Charles Ottley acted as chief engineer but found difficulty in recruiting a labour force. The number of men looking for work had been reduced by famine and emigration, and the railways were competing for workers. The project took eleven years to complete. A double-chambered lock was constructed at Portna, where the shoal was removed, and four other locks were needed to negotiate the difference in levels. Quays and swing bridges were erected, and various alterations had to be made around Lough Neagh to cope with the drop in the surface level. The final lock on the
Lagan Canal, the
Coalisland Canal and the
Ulster Canal had to be rebuilt with a lower cill and deeper lock gates, and the
River Blackwater had to be made deeper and wider. The cost of the project overran by £50,000 and the government was asked to make up the shortfall. The Upper Bann Navigation included the River Bann between its junction with the Newry Canal at Whitecoat Point and Lough Neagh, a route across Lough Neagh to the mouth of the Blackwater, and the lower of the Blackwater as far as
Blackwatertown. This was one of four works of navigation part funded by the Treasury during the famine years in Ireland. The other three were the Ballinamore-Ballyconnell Canal linking Lough Erne to the river Shannon across County Leitrim; Loughs Corrib, Mask and Carra in counties Galway and Mayo; and Lough Oughter and Lough Gowna in County Cavan. The Upper Bann Navigation was the only one completed to its full design extent. The final award for this scheme was made on 13 April 1859. The finished scheme was not well received by the counties through which it ran. As originally conceived, revenue from tolls and water power on the Lower Bann would finance maintenance work on the Upper Bann. Instead, three separate trusts were set up. These were the Upper Bann Navigation Trust, the Lower Bann Navigation Trust and the Lough Neagh Drainage Trust. The adjoining counties appointed representatives to each and also financed their continued operation. Those to the south of the lake had to contribute towards the drainage and navigation works which had been completed, and also find £800 per year for ongoing maintenance, with no source of income to cover it.
Coleraine was expanded as a port, but even the Lower Bann did not generate the expected revenue, and the adjoining counties had to finance an annual deficit of around £400. A passenger service between Coleraine and Toomebridge was started in 1863, but the increased flow on the river made travel upstream difficult, and the service was abandoned. Like so many schemes that tried to combine drainage and navigation, this one did neither particularly well. Flooding around the southern shores of Lough Neagh continued to be a problem, and in 1882 the chairman of
Portadown Town Commissioners suggested that Alexander Nimmo's scheme should be revived. The Upper Bann would be made much deeper near the lough, so that its flow could be reversed, and the amount of water entering the lough reduced correspondingly. The proposal was no better received than when Nimmo had originally made it. Both the Monck Commission, which sat in the early 1880s, and an enquiry into the Board of Works held in 1887, suggested that for the benefit of flood relief, the navigation should be abandoned, and that the three Trusts were counter-productive. No action was taken, and when the President of the
Institution of Civil Engineers, Sir
Alexander Binnie, was asked for his advice in 1906, he came to a similar conclusion. He suggested that a canalised river, which in winter had a flow of between was never going to succeed. Again his advice was ignored, as the navigation works were still relatively new. The counties continued to fund the annual deficit. A proposal to build a
hydro-electric scheme across the Lower Bann in 1925 came to nothing, and four years later, the Lough Neagh Drainage Trust and the Lower Bann Navigation Trust were disbanded, with the Ministry of Finance assuming responsibility for the river. The counties contributing to the Upper Bann Navigation Trust appealed for that to be disbanded too, but the appeal was refused and they had to continue funding it. Some improvements to weirs were made by the Ministry of Finance, and there was some traffic, consisting mostly of sand dredged from Lough Neagh and used by brickworks. Finally, in 1954, responsibility for the Upper Bann was transferred to the Ministry of Commerce, the Trust was disbanded, and the navigation was abandoned. The Lower Bann has seen an increase in use by pleasure craft, and now supports four
marinas, two at Coleraine, one at Drumaheglis and one at
Portglenone. ==See also==