The River Witham is almost entirely in the county of Lincolnshire. It rises south of Grantham close to South Witham, passes through the Lincoln Gap at Lincoln and turns to head towards Boston from whence it flows into The Haven, a tidal arm of The Wash and so into the North Sea.
The Witham has been an important navigation since Roman times. The Romans constructed the Fossdyke from Lincoln to Torksey on the River Trent and thus gave Lincoln access to the east coast via the river whilst the Fossdyke gave access to the Trent and further on to the Humber.
The river is navigable from Lincoln to Boston and once carried commercial traffic. During the 1700's trade flourished and an increasing proportion of goods went by water. The Witham was the main link between Boston and Lincoln, and the means by which the goods shipped to the Port of Boston found their way into, and out of, the county. This water transport was increasing right down to the coming of the railway ion the middle of the 19th century. In an old Lincolnshire directory of 1821 there was advertised a steam packet running every day between Lincoln and Boston for both passengers and goods. It set off from Lincoln at 4 o'clock in the morning (you needed to be an early riser )and set off on the return trip 12 hours later, the fare - 3 shillings (15p).
Commercial traffic on the river has now ceased but has been replaced by pleasure craft catered for with various moorings on the waterways and Marinas at Boston, in Lincoln and on the Fossedyke at Burton Waters and Torksey with at least one other under consideration to the east of Lincoln.