Witham Navigable Drains

Witham Navigable Drains
Cowbridge Aqueduct carries the Stonebridge Drain over the Cowbridge Drain
Specifications
Maximum boat length	70 ft 0 in (21.34 m)
Maximum boat beam	10 ft 0 in (3.05 m)
Locks	2 (3 other locks are defunct)
Status	Navigable in summer
Navigation authority	Witham Fourth District IDB
History
Original owner	Witham Fourth Drainage District
Principal engineer	various
Date of act	1801
Date of first use	1780s
Geography
Start point	Anton's Gowt, Boston
End point	various

The Witham Navigable Drains are located in Lincolnshire, England, and are part of a much larger drainage system managed by the Witham Fourth District Internal Drainage Board. The Witham Fourth District comprises the East Fen and West Fen, to the north of Boston, which together cover an area of 97 square miles (250 km²). In total there are over 438 miles (705 km) of drainage ditches, of which under 60 miles (97 km) are navigable. Navigation is normally only possible in the summer months, as the drains are maintained at a lower level in winter, and are subject to sudden changes in level as a result of their primary drainage function, which can leave boats stranded. Access to the drains is from the River Witham at Anton's Gowt Lock.

The area is bounded by the

Most of the fens were extra-parochial, consisting of a huge common, on which people from the surrounding villages had grazing rights. These could only be exercised in summer, as prior to drainage works being carried out, the East Fen drained northwards to the Steeping River, and during the winter months, most of that river discharged into the fen, causing widespread flooding.^[5]

The area has been subject to flooding for centuries, both from the rivers and from the sea. While there is evidence for occupation of the region by Romans, Saxons, Danes and Normans, the first references to flood defences occur in the 11th and 12th centuries, when monks built a sea bank to hold back tides from their agricultural land. A sluice was constructed in 1142 on the River Witham to improve it for navigation, and

United Kingdom legislation

Witham Drainage Act 1762
Act of Parliament
2 Geo. 3. c. 32
Dates
Royal assent	2 June 1762

v t e Witham Navigable Drains
Legend
East Fen Catchwater Drain B1183 Revesby Bridge Hagnaby Lock (no gates) Thorpe Drain New Bolingbroke Drain Bell Water Drain Fodder Dyke West Fen Catchwater Drain A16 Bar Bridge Medlam Drain Lade Bank Pumping Stn (former lock) B1192 Hough Bridge Railway bridge West Fen Drain B1183/4 Bridges Castle Dyke Newham Drain Hobhole Drain Stonebridge Drain Frith Bank Drain Anton's Gowt + Cowbridge Locks East Fen Lock (filled in) River Witham Cowbridge Drain Railway bridges Grand Sluice A16 Road Bridges Boston Maud Foster Drain and sluice Black Sluice Lock SF-FD Hobhole sluice Hobhole Drain and pumping stn The Haven

As the drains became wider and more extensive, there were proposals to use them for navigation, and a lock at Anton's Gowt was first suggested in 1779. Funds were not available at the time, and so land doors were built so that boats could access the drains until the lock was completed in 1813.^[11]

In 1784, Mill Drain was enlarged, with the intention of using it to drain parts of the East Fen, but this action was stopped by

The construction of Hobhole sluice was the first time that a steam engine is known to have been used in connection with Fens drainage. In order to keep the foundations for the sluice free from water, they were pumped out by a Boulton & Watt steam engine, rated at 6 hp (4.5 kW). The machine lasted until at least 1814, just three years before the first permanent steam pumping station was built at Sutton St. Edmund in South Holland.^[14] There is a small drain that runs eastwards from the Medlam Drain to New Bolingbroke. This was probably built by John Parkingson in the early 19th century, to provide canal access to the village which he hoped would become a market town.^[15]

The Fourth District was extended in 1818, following another report by Rennie on the lower reaches of the Steeping River. An act of Parliament^[

In 1956, work started on a new outfall for the Hobhole drain, to the south-east of the old sluices. A pumping station containing three Allen diesel engines was built, each driving a 88-inch (220 cm) pump. The station could discharge 800 tons per minute (1175 Mld) when all three pumps were running.[19] Once the station was complete, the old sluice was blocked off. Further improvements to the drainage of the area occurred in the next few years, with a pumping station being built at Wrangle Horseshoe, at the eastern edge of the district, in 1959, and the first electric pump being installed at Lade Bank pumping station in 1963.^[6] The electric motor drove a 36-inch (91 cm) pump.^[17] Two new pumping stations at Leverton and Benington were completed in 1976, again on the eastern edge and pumping directly into The Wash. The pumping station at Thorpe Culvert was managed by the Anglian Water Authority, but a replacement in 1983 was partly funded by the Fourth District. The Hobhole pumping station was modified in 1988, when the old sluice channel was reopened and the sluices were fitted with four 33-inch (84 cm) submersible electric pumps, manufactured by Flygt.^[19] The number of electric pumps at Lade Bank was increased to three in 1990. These schemes resulted in the Fourth District being awarded a Borough of Boston Civic Design Award for the way in which the buildings were renovated.^[6]

Historically, the drains were used for importing coal to the fens and exporting agricultural produce. They are now only used for pleasure cruising; this is restricted to the summer months, for between October and April, the water levels are maintained at a low level, so that there is scope to deal with high volumes of rainfall. Consequently, there is insufficient depth for navigation, and operation of the sluices can cause rapid changes in water level. Between April and October, their function is to provide irrigation water for agriculture, and so they are maintained at a higher level, although changes in level can still occur at short notice.^[20]

Anton's Gowt lock is 75 by 18 feet (22.9 by 5.5 m), but although a boat of this size could pass through it, most of the drains are inaccessible to such large craft. The only other working lock is at Cowbridge, which is 70 by 10 feet (21.3 by 3.0 m), and gives access to the Maud Foster drain, enabling boats to visit the centre of Boston. From Cowbridge Lock it is also possible to visit the Lincolnshire Wolds, using the Stonebridge Drain and the East Fen and West Fen Catchwater Drains.^[21]

It used to be possible to navigate Cowbridge Drain and Hobhole Drain, but they are isolated from the rest of the system by the derelict East Fen Lock.^[22] Restoration of this lock was proposed by the Lincolnshire Branch of the Inland Waterways Association in 1975,^[23] who sought to encourage use of the drains by offering a plaque to boats that used Cowbridge Lock,^[24] but no progress has been made with this, and the lock has been infilled.^[25] Hagnaby Lock, near the top of the West Fen Catchwater Drain has no gates, but it is usually possible to pass straight through, while the lock which bypassed Lade Bank pumping station on the Hobhole Drain has been converted to a sluice.^[20]

In addition to sudden changes in water levels, there are a number of very low bridges with an air draft of less than 6 feet (1.8 m), which can cause problems if the water levels rise a little,^[20] and there are often no turning places at the end of the drains. Cruising can be hazardous due to weed growth, which forms a dense blanket in some channels, but a drain that was formerly virtually un-navigable may suddenly be cleared to improve its drainage performance and become navigable again.^[26] One unexpected possibility of cruising the drains is to visit New York,^[20] a hamlet just to the north of Hough Bridge on the West Fen Drain.

The relative isolation of much of the Witham Navigable Drains has resulted in many of the structures which were built as part of Rennie's upgrade in the early 1800s surviving. Because of their historic interest, they have been added to the listed structures register, and are

On the Cowbridge Drain, Baker's Bridge is another 3-arched bridge, which is listed with the adjacent sluice,[34] while Mastin's Bridge is a single-span structure.^[35] On the Maud Foster Drain, Rawson's Bridge is an original single-span bridge, but further south, Bargate Bridge carries the A16 road over the drain in the centre of Boston. In order to accommodate additional traffic, the Department of Transport demolished the south side of the bridge in 1972, and widened the carriageway. A new south face was then constructed, using the original materials and to the same design.^[36] Two footbridges survive, built of cast iron in 1811 by the Butterley Works. The works was established in 1790 by Benjamin Outram at Ripley, Derbyshire. One is the Hospital Bridge in Boston,^[37] while the second is near Cowbridge Lock. Both carry the text "CAST AT BUTTERLEY 1811" stamped into the girders, and are supported by gritstone piers.^[38] Vauxhall Bridge, a third example of the type, was replaced by a road bridge in 1924.^[39] At the south end of the drain, Maud Foster sluice survives largely in original condition, although some alterations were made in the twentieth century. It consists of three elliptical arches, with gates made of timber and iron bindings. They are raised and lowered by pulleys mounted on an overhead gantry.^[40] The entrance lock at Anton's Gowt is also listed. It was altered in 1848 when the Great Northern Railway Lincolnshire loop line crossed the northern end of the lock.^[41]

Nunn's Bridge is the first bridge to cross the Hobhole Drain to the north of Hobhole Sluice. It has a span of 72 feet (22 m), and when erected in 1948 was the first pre-stressed concrete bridge cast in situ in Britain. L G Mouchel and Partners were the designers, and the work was carried out using labour from the Fourth District IDB, overseen by G E Buchner.^[42]

The Environment Agency measure the water quality of the river systems in England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There are several components that are used to determine this, including biological status, which looks at the quantity and varieties of

The water quality in the river has deteriorated since 2014, when it was rated good for ecological status. In 2015 it was rated moderate and is now rated bad. The main reason for this is that the drains are artificial, with the land drainage functions and flow having a detrimental effect on fish populations. Like most rivers in the UK, the chemical status changed from good to fail in 2019, due to the presence of polybrominated diphenyl ethers (PBDE), perfluorooctane sulphonate (PFOS) and mercury compounds, none of which had previously been included in the assessment.[45]

• Canals of the United Kingdom
• History of the British canal system
• Witham First District IDB
• Witham Third District IDB
• Upper Witham IDB

Media related to Witham Navigable Drains at Wikimedia Commons