The Upper Witham IDB is an English Internal Drainage Board responsible for land drainage and the management of flood risk for an area to the west of the Lincolnshire city of Lincoln, broadly following the valleys of the upper River Witham, the River Till and the course of the Fossdyke Navigation.
History
Land to the west and south of Lincoln was regularly inundated by flood events occurring on the River Trent. The low lands between Torksey and Lincoln would be covered, and flood water would pass through the Lincoln Gap to flow down the course of the modern lower Witham, to reach the sea at Boston, Friskney and Wainfleet Havens. Wheeler suggests that the normal course of the Witham in dryer weather was into Brayford Mere, a large lake to the west of Lincoln, and then westwards, roughly following the course of the Fossdyke Navigation to reach the Trent. To the east of Lincoln, the Langworth River flowed into another mere, located between Washingborough and Chapel Hill, and on to the sea near Boston. The Romans improved the watercourse from Lincoln to the Trent, to make it suitable for navigation, and cut a channel through the high ground in the centre of Lincoln. This continued to Short Ferry, and joined a tidal creek near Chapel Hill.
An Act of Parliament was obtained in 1670, for improvements to the navigation between Boston and the Trent. The preamble stated that there had been a good navigation along this route for centuries, but that both the Witham and the Fossdyke had become clogged with silt. This was the first attempt to put the river system on a commercial footing. The City of Lincoln was to appoint Commissioners, and were given powers to improve the channels or, where necessary, to cut new channels and to build banks, sluices and locks. The Act made provision for the collection of reasonable tolls, in order to fund the work. Another Act of Parliament was passed in 1752, which created the Witham General Commissioners, and divided the area to the east of Lincoln into six drainage districts, the Witham First, Second, Third, Fourth, Fifth and Sixth Districts. At the same time, the civil engineer John Smeaton recommended works to improve the drainage of the area to the west of Lincoln, but these were not carried out at the time.
Two major flood events took place soon afterwards. In 1770, water breached the Fossdyke embankment at Torksey, and land was flooded between the breach and Lincoln. A worse event happened in 1795, when the Trent breached the bank at Spalford. Around of land was flooded, some to a depth of . When the water reached Lincoln, it was constrained by the High Street, which is between above the level of the surrounding land. Houses in the lower part of Saxilby were flooded, and families had to be moved to the upper town, with several of them living in the church until the floods subsided. The villages of Broxholme, Fenton, Hardwick, Hathow, Kettlethorpe, Thorney, and Wigsley were like islands, and could only be reached by boat, while parts of Torksey, Brampton, Fenton and Kettlethorpe were flooded. The flood waters remained for 3 weeks, and it took 80 loads of faggots and over 400 tons of earth to repair the breach in the river wall. Flood risk from the Trent was reduced following further major flooding events in 1824 and 1852, after which the five major 'gaps' along the Trent, at Spalford, Newton, Torksey Lock, Torksey and Marton, were extensively repaired by the Courts of Sewers for Newark and Lincoln.
In 1804 an Act of Parliament was obtained, to authorise the work proposed by Smeaton in 1752. The Act stated that it was For embanking, draining and improving certain Lands in the City of Lincoln and County thereof and in the parishes or townships of Boultham, Skellingthorpe, Saxilby, Broxholme, North Carlton, South Carlton, Burton and Hathow in the County of Lincoln and for inclosing Lands in the said parish of Skellingthorpe. This created two drainage districts, the Lincoln West (North District) Drainage Board, responsible for an area of and the Lincoln West (South District) Drainage Board, responsible for . Again, there was a commercial aspect to the Act, as the drainage districts could raise an annual tax on the owners of lands which benefitted from the drainage and embankment works.