112-671: The Louth Navigation was a canalisation of the River Lud . It ran for 11 miles (18 km) from Louth in Lincolnshire , England, to Tetney Haven , at the mouth of the Humber . It was authorised by act of Parliament in 1763 and completed in 1770, under the supervision of the engineer John Grundy Jr. and then by James Hoggard. Eight locks were required to overcome the difference in altitude, six of which were constructed with sides consisting of four bays. The act did not provide
224-598: A bill , as opposition in Parliament could be difficult to counter. In August, Smeaton reviewed Grundy's plans, which was for a river navigation. Cuts would be made to straighten the River Lud, and a sea sluice and lock would be provided where the river joined the Humber . The length would be a little over 11 miles (18 km), and nine locks would be required along its course together with several bridges. Costs for different sizes of canal were provided, from £15,590 for
336-444: A current to transport materials varies with its velocity , so that torrents with a rapid fall near the sources of rivers can carry down rocks, boulders and large stones , which are by degrees ground by attrition in their onward course into slate , gravel , sand and silt , simultaneously with the gradual reduction in fall, and, consequently, in the transporting force of the current. Accordingly, under ordinary conditions, most of
448-399: A lock has to be provided alongside the weir, or in a side channel, to provide for the passage of vessels. A river is thereby converted into a succession of fairly level reaches rising in steps up-stream, providing still-water navigation comparable to a canal; but it differs from a canal in the introduction of weirs for keeping up the water-level, in the provision for the regular discharge of
560-483: A watershed (called a "divide" in North America) over which rainfall flows down towards the river traversing the lowest part of the valley, whereas the rain falling on the far slope of the watershed flows away to another river draining an adjacent basin. River basins vary in extent according to the configuration of the country, ranging from the insignificant drainage areas of streams rising on high ground very near
672-457: A 36-inch (914 mm) pipeline from the Great Eau. The pumping station is located at Cloves Bridge, to the east of Saltfleetby All Saints, and the 6.8-mile (11 km) pipeline empties into the canal below the site of Outfen Lock. To protect the drinking water supply from contamination by salt water entering the canal through the outfall sluice, the original Tetney Lock has been replaced by
784-474: A canal. The first 5 miles (8 km) from Tetney Haven to Fire Beacon Lane were opened in May 1767. Hogard then took over from Grundy as Chief Engineer, at a salary of £140 per year, and began the construction of the final section including seven locks. Additional subscriptions had to be found to fund the work, but the navigation reached Riverhead basin at Louth, and a formal opening was held in May 1770. The total cost
896-534: A cold season, extending from May to October and from November to April in the Northern hemisphere respectively; the rivers are low and moderate floods are of rare occurrence during the warm period, and the rivers are high and subject to occasional heavy floods after a considerable rainfall during the cold period in most years. The only exceptions are rivers which have their sources amongst mountains clad with perpetual snow and are fed by glaciers ; their floods occur in
1008-520: A heavily built hull. The wooden keels being built at the beginning of the 20th century had steel keelsons and iron knees. Iron-hulled keels were built in the latter part of the 19th century and steel hulls into the 20th century. The result of this was that in the closing years of working keels, wooden, iron and steel hulled vessels could be found working alongside each other. In the 20th century, steam and diesel engines replaced sail, with grants available to convert sailing vessels to mechanical power before
1120-469: A huge pair of leeboards , since the structural keel protruded below the flat bottom of the hull by only a few inches. A topsail was used when they were navigating the canals and rivers, but not usually when they were on the Humber estuary. The dimensions of these craft were influenced by the gauge, or width, of inland waterways created or modernised during that period. In comparison to the widespread use of
1232-399: A moderate fall and a fair discharge at their lowest stage, for with a large fall the current presents a great impediment to up-stream navigation, and there are generally great variations in water level, and when the discharge becomes very small in the dry season. It is impossible to maintain a sufficient depth of water in the low-water channel. The possibility to secure uniformity of depth in
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#17327867378191344-469: A net effect of flood control in one area coming at the expense of greatly aggravated flooding in another. In addition, studies have shown that stream channelization results in declines of river fish populations. A 1971 study of the Chariton River in northern Missouri , United States, found that the channelized section of the river contained only 13 species of fish, whereas the natural segment of
1456-436: A north-easterly direction. At the end are two Grade II listed warehouses. To the west is Navigation Warehouse, a rectangular building with five bays and three storeys, constructed of red brick with a pantile roof. It is little altered from when it was built in 1790. It was used to store grain and wool, which was then shipped down the navigation. It was largely open-plan, but has since been converted into offices, although most of
1568-405: A physical alteration, and maintain public safety. The size of rivers above any tidal limit and their average freshwater discharge are proportionate to the extent of their basins and the amount of rain which, after falling over these basins, reaches the river channels in the bottom of the valleys, by which it is conveyed to the sea. The basin of a river is the expanse of country bounded by
1680-477: A red-brick building, dating from around 1800, with hipped pantile roofs. The main section has three storeys, and there is a two storey office range. Adjacent to the mill was the works of the Louth Gaslight Company, which were built in 1826. Baines erected a stone to define the boundary between his land and that of the gaslight company in 1878, following a dispute over encroachment. Soon the site of
1792-479: A river bed furnishes a simple and efficient means of increasing the discharging capacity of its channel. Such removals will consequently lower the height of floods upstream. Every impediment to the flow, in proportion to its extent, raises the level of the river above it so as to produce the additional artificial fall necessary to convey the flow through the restricted channel, thereby reducing the total available fall. Human intervention sometimes inadvertently modifies
1904-407: A river by lowering the shoals obstructing the channel depends on the nature of the shoals. A soft shoal in the bed of a river is due to deposit from a diminution in velocity of flow, produced by a reduction in fall and by a widening of the channel, or to a loss in concentration of the scour of the main current in passing over from one concave bank to the next on the opposite side. The lowering of such
2016-421: A routine basis. One major reason is to reduce natural erosion ; as a natural waterway curves back and forth, it usually deposits sand and gravel on the inside of the corners where the water flows slowly, and cuts sand, gravel, subsoil , and precious topsoil from the outside corners where it flows rapidly due to a change in direction. Unlike sand and gravel, the topsoil that is eroded does not get deposited on
2128-582: A ship built using a longitudinal strengthening beam (keel) together with a single mast and square rigging. The remains of keels from the 13th century have been excavated, and the keel is identified as a specific class of vessel in the Tudor records kept by the Corporation of York. Early keels were designed to work in waterways which were only 3.5 feet (1.1 m) deep, but could still carry 40 to 50 tonnes of cargo. Such boats were clinker-built, meaning that
2240-476: A shoal by dredging merely effects a temporary deepening, for it soon forms again from the causes which produced it. The removal, moreover, of the rocky obstructions at rapids, though increasing the depth and equalizing the flow at these places, produces a lowering of the river above the rapids by facilitating the efflux, which may result in the appearance of fresh shoals at the low stage of the river. Where, however, narrow rocky reefs or other hard shoals stretch across
2352-445: A sluice with rising sector gates. The final section is now protected from high sea levels by an outfall sluice at Tetney Haven, with two sets of pointed doors. Download coordinates as: [REDACTED] Media related to Louth Navigation at Wikimedia Commons 53°27′10″N 0°02′11″E / 53.4527°N 0.0363°E / 53.4527; 0.0363 River engineering#Canalization of rivers River engineering
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#17327867378192464-401: A stream channelization project in one place must be offset by the creation of new wetlands in another, a process known as "mitigation." The major agency involved in the enforcement of this policy is the same Army Corps of Engineers, which for many years was the primary promoter of wide-scale channelization. Often, in the instances where channelization is permitted, boulders may be installed in
2576-493: A stream may be undertaken for several reasons. One is to make a stream more suitable for navigation or for navigation by larger vessels with deep draughts. Another is to restrict water to a certain area of a stream's natural bottom lands so that the bulk of such lands can be made available for agriculture. A third reason is flood control, with the idea of giving a stream a sufficiently large and deep channel so that flooding beyond those limits will be minimal or nonexistent, at least on
2688-479: A stream once it has been dredged is extremely slow, with many streams showing no significant recovery 30 to 40 years after the date of channelization. For the reasons cited above, in recent years stream channelization has been greatly curtailed in the U.S., and in some instances even partially reversed. In 1990 the United States Government published a " no net loss of wetlands" policy, whereby
2800-409: A tilting weir. This is controlled automatically, and maintains a difference in level between its upstream and downstream sides. The difference is between 6 and 8 inches (15 and 20 cm) in winter, rising to between 16 and 18 inches (40 and 45 cm) in summer. The Louth Navigation Trust was formed in 1986 as a registered charity, with the primary aim of preservation, conservation and restoration of
2912-475: A twentieth century concrete bridge, which carries a minor road over the lock chamber. Nearby are the Grade I listed ruins of Louth Abbey, a Cistercian abbey dating from 1139. Willows Lock is also reasonably well preserved, and is of a similar construction to Ticklepenny Lock, as is Salter Fen Lock, although it differs in having a large opening which acts as an overflow in the south-eastern side. Sandwiched between
3024-592: A two barge canal to £10,884 for a canal suitable for lighters drawing 2 feet (0.61 m). The committee asked Grundy to accompany them to Lincoln Races , where they would show the plans to the noblemen and gentlemen. This produced a favourable response, and with little local opposition, the pace of the project slowed. The reports were printed in September 1761, and the bill was submitted to Parliament on 6 December 1762. The canal obtained its act of Parliament on 24 March 1763, but contained no proper provision for raising
3136-421: A very variable flow, and end as gently flowing rivers with a comparatively regular discharge. The irregular flow of rivers throughout their course forms one of the main difficulties in devising works for mitigating inundations or for increasing the navigable capabilities of rivers. In tropical countries subject to periodical rains, the rivers are in flood during the rainy season and have hardly any flow during
3248-399: Is a discipline of civil engineering which studies human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the water resources , to protect against flooding , or to make passage along or across rivers easier. Since
3360-408: Is generally referred to as canalization . Reducing the length of the channel by substituting straight cuts for a winding course is the only way in which the effective fall can be increased. This involves some loss of capacity in the channel as a whole, and in the case of a large river with a considerable flow it is very difficult to maintain a straight cut owing to the tendency of the current to erode
3472-418: Is in water throughout its length and has not been in-filled or built over as it is important for drainage of the surrounding land. Several formerly movable bridges have since been replaced with fixed bridges. The eight locks are in varying states of repair; two have been obliterated, while Alvingham lock is the best surviving example. The navigation begins at a large basin near the centre of Louth, which runs in
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3584-486: Is liable to be stopped during the descent of high floods, which in many cases rise above the locks; and it is necessarily arrested in cold climates on all rivers by long, severe frosts, and especially by ice. Many small rivers, like the Thames above its tidal limit, have been rendered navigable by canalization, and several fairly large rivers have thereby provided a good depth for vessels for considerable distances inland. Thus
3696-465: Is licensed to be abstracted for spray irrigation of crops. Large volumes are also pumped from a feeder into Covenham Reservoir, from which it is treated and fed into the public water supply. Water from the Waithe Dike supplements this, and effectively flows upstream along the canal. In summer months, the available supply is not always sufficient to meet the demand, and additional water is pumped along
3808-431: Is not clear that it was carried out, since George Chaplin, the son of Thomas, paid for the navigation to be made wider and deeper in 1811, and spent another £400 on repairs in 1814. There are no records of actual tolls, but estimates suggest that they rose from around £2,000 in the 1770s to £5,000 in the 1820s. Interest payments were £1,375 per year, and Chaplin argued that it had only become a profitable enterprise for him in
3920-468: Is not known which of the engineers involved in the construction designed the locks, which are rare in Britain. The two other locks had conventional straight walls. The locks were not built to a standard size, varying in length between 86 and 100 feet (26 and 30 m) and in width between 15.25 and 19 feet (4.65 and 5.79 m), although all had a depth of 5.33 feet (1.62 m) over the sill, to cater for
4032-440: Is provided for the discharge of the river as soon as it overflows its banks, while leaving the natural channel unaltered for the ordinary flow. Low embankments may be sufficient where only exceptional summer floods have to be excluded from meadows. Occasionally the embankments are raised high enough to retain the floods during most years, while provision is made for the escape of the rare, exceptionally high floods at special places in
4144-512: Is the case with the smaller river. The fall available in a section of a river approximately corresponds to the slope of the country it traverses; as rivers rise close to the highest part of their basins, generally in hilly regions, their fall is rapid near their source and gradually diminishes, with occasional irregularities, until, in traversing plains along the latter part of their course, their fall usually becomes quite gentle. Accordingly, in large basins, rivers in most cases begin as torrents with
4256-739: The East Lincolnshire Railway (Louth Navigation Purchase) Act 1847 ( 10 & 11 Vict. c. cxiii) which allowed them to purchase the lease of the Louth Navigation, and later the same year, the Great Northern Railway Company (GNR) obtained another act of Parliament allowing them to purchase or lease the East Lincolnshire Railway and Canal. They held it for the remaining 29 years, as a tactical move to prevent opposition from
4368-617: The Rhine , the Danube and the Mississippi . River engineering works are only required to prevent changes in the course of the stream, to regulate its depth, and especially to fix the low-water channel and concentrate the flow in it, so as to increase as far as practicable the navigable depth at the lowest stage of the water level. Engineering works to increase the navigability of rivers can only be advantageously undertaken in large rivers with
4480-603: The Second World War . All of the sailing keels had gone by 1949, but one has been preserved and returned to sail by the Humber Keel and Sloop Preservation Society. The sailing rig consisted of a single mast on which was set a square mainsail and a topsail. The mast was stepped on a post called a lutchet, which went from the top of the keelson to deck level, where it provided a socket for the mast to sit in. The mast could be lowered and raised by one person operating
4592-469: The Yuan Dynasty and Ancient Roman times, rivers have been used as a source of hydropower . From the late 20th century, the practice of river engineering has responded to environmental concerns broader than immediate human benefit. Some river engineering projects have focused exclusively on the restoration or protection of natural characteristics and habitats . Hydromodification encompasses
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4704-405: The church of St Mary , once the chapel for a Gilbertine Priory, which dates from the eleventh to fourteenth centuries. It was the parish church for North Cockerington , and is Grade I listed. In the same churchyard is the parish church of St Adelwold, also Grade I listed, and built in the 13th, 15th and 16th centuries. The churches separate Alvingham Water Mill from the canal. The present building
4816-485: The keels and sloops that used the navigation. The act of Parliament allowed the commissioners to lease the tolls for periods of up to seven years, and the first lease was granted to Charles Chaplin, one of the commissioners who held ten shares, in January 1770. He agreed to pay a rent of 4 per cent per year to the other shareholders, and to contribute a maximum of £500 per year towards maintenance costs. If more than £500
4928-573: The 1820s. Users of the canal felt that the tolls, which had not altered since 1770, were too high, as the volume of traffic using the navigation had increased. To rectify the situation, a new act of Parliament, the Louth Navigation Act 1828 ( 9 Geo. 4 . c. xxx) was obtained in 1828, which reduced the tolls and formalised the 99-year lease of 1777. In 1847, the East Lincolnshire Railway Company obtained
5040-461: The Army Corps with EPA participation. Rivers whose discharge is liable to become quite small at their low stage, or which have a somewhat large fall, as is usual in the upper part of rivers, cannot be given an adequate depth for navigation purely by works which regulate the flow; their ordinary summer level has to be raised by impounding the flow with weirs at intervals across the channel, while
5152-514: The Po River, taken in 1874 and 1901, show that its bed was materially raised during this period from the confluence of the Ticino to below Caranella , despite the clearance of sediment effected by the rush through breaches. Therefore, the completion of the embankments, together with their raising, would only eventually aggravate the injuries of the inundations they have been designed to prevent, as
5264-425: The act did not authorise such an action. He collected the tolls but failed to maintain the navigation. When complaints were received, a new act of Parliament was obtained in 1828 to alter the tolls and legalise Chaplin's long lease. The lease was transferred to two railway companies in 1847, and reverted to the commissioners in 1876. The operation was a moderate success until the beginning of the 20th century, when there
5376-530: The banks and form again a sinuous channel. Even if the cut is preserved by protecting the banks, it is liable to produce changes shoals and raise the flood-level in the channel just below its termination. Nevertheless, where the available fall is exceptionally small, as in land originally reclaimed from the sea, such as the English Fenlands , and where, in consequence, the drainage is in a great measure artificial, straight channels have been formed for
5488-411: The barges, rather than them sailing along the navigation. To prevent the boats grounding, the water levels had been raised, preventing natural drainage from the surrounding land and causing flooding. Chaplin was ordered to carry out repairs but failed to do so, and died soon afterwards. His son Thomas took over, and tried to negotiate an end to the lease. On paper, this appears to have been accepted, but it
5600-460: The basin. Initially, the commercial community around Riverhead was separate from the main centre of population in Louth, but after the coming of the railway, ribbon development resulted in the two areas being connected. Six of the eight locks were built in an unusual way with the sides of the lock chambers consisting of four elliptical bays, to help them resist soil movement in the surrounding ground. It
5712-592: The bed of the new channel so that water velocity is slowed, and channels may be deliberately curved as well. In 1990 the U.S. Congress gave the Army Corps a specific mandate to include environmental protection in its mission, and in 1996 it authorized the Corps to undertake restoration projects. The U.S. Clean Water Act regulates certain aspects of channelization by requiring non-Federal entities (i.e. state and local governments, private parties) to obtain permits for dredging and filling operations. Permits are issued by
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#17327867378195824-406: The bottom of a river and present obstacles to the erosion by the current of the soft materials forming the bed of the river above and below, their removal may result in permanent improvement by enabling the river to deepen its bed by natural scour. The capability of a river to provide a waterway for navigation during the summer or throughout the dry season depends on the depth that can be secured in
5936-455: The canal a little further downstream. This is only possible because of the lowered water levels in the canal. Before closure to navigation, there was another inverted syphon under the canal, which returned the water to the River Lud, but this has been blocked up and abandoned. At High Bridge, the canal turns to the north, and the River Lud continues to the north-east as the Old Eau. Outfen Lock
6048-506: The canal and of the buildings associated with it, including the lock structures. They have carried out several projects, using voluntary labour, which have included maintenance of Ticklepenny lock and clearance work on the towpath. They are based at the Navigation Warehouse at Riverhead, Louth, which they helped to restore to a high standard in 1998/9, in partnership with Groundwork Lincolnshire. The towpath may be walked along
6160-436: The canal and the River Lud is a sewage treatment plant. The treated effluent is discharged into the canal below the lock site. Beyond the works are Alvingham Fisheries, and then a bridge which carries Lock Road over the canal. Alvingham Lock has two semi-circular drain openings in its western wall, and an inverted syphon carries water from the River Lud under the lock, to feed the mill pond for Alvingham Mill. The canal then passes
6272-525: The canal are owned and operated by the Lindsey Marsh Internal Drainage Board . The canal continues past Canal Farm and under Fen Bridge. On the east bank is a nineteenth century nine-bayed warehouse with three storeys and an attic. Biergate East and West pumping stations are situated near Covenham Reservoir , constructed in the 1960s to supply drinking water. The works to treat the water is near Fire Beacon Farm and bridge,
6384-550: The canal by gravity. Most of the flow from the River Lud is fed into the canal, and the Environment Agency maintain a tilting weir at the site of the original Top Lock. This controls water levels in the Riverhead Basin, and also includes a gauging station which measures the flow along the canal. The water is used for three main purposes. Some water is fed back into the River Lud to maintain its ecology. Some
6496-402: The canal. In 1924, the county council and the rural district council agreed to take over maintenance of the bridges. The final annual general meeting took place on 5 September 1924, and the assets of the navigation were sold on 8 October. The sale raised £6,240, of which £1,500 had to be paid to the councils towards the bridge works. The remainder was distributed to the shareholders in 1927. With
6608-404: The canalized Seine has secured a navigable depth of 10 1 ⁄ 2 feet (3.2 metres) from its tidal limit up to Paris, a distance of 135 miles, and a depth of 6 3 ⁄ 4 feet (2.06 metres) up to Montereau, 62 miles higher up. As rivers flow onward towards the sea, they experience a considerable diminution in their fall, and a progressive increase in the basin which they drain, owing to
6720-403: The capital needed to build the canal. Money could only be borrowed against the expected tolls, and this caused difficulties. On 30 May, the commissioners tried to find someone willing to lend £14,000, in return for all the tolls. A year later, they tried to raise £12,000 in transferable shares of £100 each, but the uptake was slow. By 13 February 1765, the full amount had been subscribed, and Grundy
6832-480: The channel at the low stage by low-dipping cross dikes extending from the river banks down the slope and pointing slightly up-stream so as to direct the water flowing over them into a central channel. The needs of navigation may also require that a stable, continuous, navigable channel is prolonged from the navigable river to deep water at the mouth of the estuary . The interaction of river flow and tide needs to be modeled by computer or using scale models, moulded to
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#17327867378196944-496: The channel at the lowest stage. The problem in the dry season is the small discharge and deficiency in scour during this period. A typical solution is to restrict the width of the low-water channel, concentrate all of the flow in it, and also to fix its position so that it is scoured out every year by the floods which follow the deepest part of the bed along the line of the strongest current. This can be effected by closing subsidiary low-water channels with dikes across them, and narrowing
7056-449: The channelization of Florida's Kissimmee River has been cited as a cause contributing to the loss of wetlands. This straightening causes the streams to flow more rapidly, which can, in some instances, vastly increase soil erosion. It can also increase flooding downstream from the channelized area, as larger volumes of water traveling more rapidly than normal can reach choke points over a shorter period of time than they otherwise would, with
7168-433: The coast and flowing straight down into the sea, up to immense tracts of great continents, where rivers rising on the slopes of mountain ranges far inland have to traverse vast stretches of valleys and plains before reaching the ocean. The size of the largest river basin of any country depends on the extent of the continent in which it is situated, its position in relation to the hilly regions in which rivers generally arise and
7280-416: The compulsory raising of their gates for the passage of floods, the removal of fish traps , which are frequently blocked up by leaves and floating rubbish, reduction in the number and width of bridge piers when rebuilt, and the substitution of movable weirs for solid weirs. By installing gauges in a fairly large river and its tributaries at suitable points, and keeping continuous records for some time of
7392-430: The configuration of the estuary under consideration and reproducing in miniature the tidal ebb and flow and fresh-water discharge over a bed of very fine sand, in which various lines of training walls can be successively inserted. The models should be capable of furnishing valuable indications of the respective effects and comparative merits of the different schemes proposed for works. Humber Keel The Humber keel
7504-406: The course or characteristics of a river, for example by introducing obstructions such as mining refuse, sluice gates for mills, fish-traps, unduly wide piers for bridges and solid weirs . By impeding flow these measures can raise the flood-level upstream. Regulations for the management of rivers may include stringent prohibitions with regard to pollution , requirements for enlarging sluice-ways and
7616-825: The danger of flooding downstream. In the Midwestern United States and the Southern United States the term for this measure is channelization. Much of it was done under the auspices or overall direction of the United States Army Corps of Engineers . One of the most heavily channelized areas in the United States is West Tennessee , where every major stream with one exception (the Hatchie River ) has been partially or completely channelized. Channelization of
7728-687: The demise of navigation and the decay of the lock structures, water levels are considerably lower than they once were. The whole of the canal, together with parts of the old channel of the River Lud, the Black Dike, the Poulton Drain and the Waithe Dike, which feed into the Mother Drain before it joins the canal, are designated as main rivers , and are the responsibility of the Environment Agency . The land drainage functions for
7840-410: The embankments, where the scour of the issuing current is guarded against, and the inundation of the neighboring land is least injurious. In this manner, the increased cost of embankments raised above the highest flood-level of rare occurrence is avoided, as is the danger of breaches in the banks from an unusually high flood-rise and rapid flow, with their disastrous effects. A most serious objection to
7952-444: The engineer John Grundy Jr. to survey a route. He suggested a route from Louth to Tetney Haven, and on 28 January 1760, subscriptions were invited to pay for a full survey and an act of Parliament . The fund soon reached £850, and on 18 February 1760 the town clerk approached John Smeaton to carry out the survey. Smeaton advised caution, suggesting that they obtained the consent of as many landowners as possible before proceeding with
8064-466: The escape of floods from the raised river must occur sooner or later. In the UK, problems of flooding of domestic properties around the turn of the 21st century have been blamed on inadequate planning controls which have permitted development on floodplains. This exposes the properties on the floodplain to flood, and the substitution of concrete for natural strata speeds the run-off of water, which increases
8176-561: The existing leaseholders. When the lease came to an end, the General Manager of the GNR reported that they had kept the tolls as high as was legally possible, but suggested that they refrain from renewing the lease. The commissioners were unable to find anyone wanting to bid for the tolls, and collected them themselves until a bidder was found three months later. Although the tolls were lower than they had been under railway ownership, income
8288-545: The expenditure involved where significant assets (such as a town) are under threat. Additionally, even when successful, such floodworks may simply move the problem further downstream and threaten some other town. Recent floodworks in Europe have included restoration of natural floodplains and winding courses, so that floodwater is held back and released more slowly. The removal of obstructions, natural or artificial (e.g., trunks of trees, boulders and accumulations of gravel) from
8400-430: The formation of continuous, high embankments along rivers bringing down considerable quantities of detritus, especially near a place where their fall has been abruptly reduced by descending from mountain slopes onto alluvial plains, is the danger of their bed being raised by deposit, producing a rise in the flood-level, and necessitating a raising of the embankments if inundations are to be prevented. Longitudinal sections of
8512-403: The heights of the water at the various stations, the rise of the floods in the different tributaries, the periods they take in passing down to definite stations on the main river, and the influence they severally exercise on the height of the floods at these places, can be ascertained. With the help of these records, and by observing the times and heights of the maximum rise of a particular flood at
8624-400: The impending inundation. Where portions of a riverside town are situated below the maximum flood-level, or when it is important to protect land adjoining a river from inundations, the overflow of the river must be diverted into a flood-dam or confined within continuous embankments on both sides. By placing these embankments somewhat back from the margin of the river-bed, a wide flood-channel
8736-406: The inland waterway network that the keel was intended to work on, having the maximum size hull that could get through the locks on their intended routes. They had strongly built hulls with a bluff bow and a flat bottom. The after part of the hull, in the region of the structural keel, was shaped to give a slightly concave run so that water flowed efficiently past the sternpost and the rudder. Wood
8848-402: The inside of the next corner of the river. It simply washes away. Channelization has several predictable and negative effects. One of them is loss of wetlands . Wetlands are an excellent habitat for many forms of wildlife, and additionally serve as a "filter" for much of the world's surface fresh water. Another is the fact that channelized streams are almost invariably straightened. For example,
8960-572: The late 20th century, the river engineering discipline has been more focused on repairing hydromodified degradations and accounting for potential systematic response to planned alterations by considering fluvial geomorphology . Fluvial geomorphology is the study of how rivers change their form over time. Fluvial geomorphology is the cumulation of a number of sciences including open channel hydraulics , sediment transport , hydrology , physical geology, and riparian ecology. River engineering practitioners attempt to understand fluvial geomorphology, implement
9072-410: The level of the main yard) and then to the foot of the sail. This would lift the sail up to the yard and take the wind out of it. One advantage of the design was the ability to sail very close to the wind, which was essential on the narrow waterways on which they plied. They were also very manoeuvrable, and a single person could handle one on narrow and quiet waters. Lateral resistance was provided by
9184-589: The low stage of the Saône flowing into the Rhone at Lyon, which has its floods in the winter when the Arve, on the contrary, is low. Another serious obstacle encountered in river engineering consists in the large quantity of detritus they bring down in flood-time, derived mainly from the disintegration of the surface layers of the hills and slopes in the upper parts of the valleys by glaciers, frost and rain. The power of
9296-656: The low-lying land surrounding the lower reaches of the canal are the responsibility of the Lindsey Marsh Internal Drainage Board (IDB). This was formed in November 2000, when the Louth IDB, the Alford IDB, and the Skegness District IDB amalgamated. The Lindsey Marsh IDB maintains five pumping stations which pump into the canal, and because of the lower water levels, a number of drains which discharge into
9408-548: The materials brought down from the high lands by torrential water courses are carried forward by the main river to the sea, or partially strewn over flat alluvial plains during floods; the size of the materials forming the bed of the river or borne along by the stream is gradually reduced on proceeding seawards, so that in the Po River in Italy, for instance, pebbles and gravel are found for about 140 miles below Turin , sand along
9520-448: The next 100 miles, and silt and mud in the last 110 miles (176 km). Improvements can be divided into those that are aimed at improving the flow of the river, particularly in flood conditions, and those that aim to hold back the flow, primarily for navigation purposes, although power generation is often an important factor. The former is known in the US as channelization and the latter
9632-407: The normal provisions for raising capital for the construction, as finance could only be obtained by leasing of the tolls. When completed, the commissioners leased the tolls to Charles Chaplin, who held ten shares and was also a commissioner, for an initial period of seven years. When the lease was due for renewal, no other takers were found, and Chaplin was granted a 99-year lease, despite the fact that
9744-461: The original features are still visible. To the east is Jackson's Warehouse, with ten bays, two storeys and an attic. It was converted into a dwelling in 2003, which resulted in minor changes to the doors and windows, but the open-plan interior has been retained. The two buildings are complemented by the Woolpack Inn, also Grade II listed. Baines Flour Mill, which supplied water to the basin, is
9856-466: The planks overlapped one another, but this gradually gave way to carvel construction, where the planks join edge to edge. First the bottom of the hull was carvel-built, with the sides still clinker-built, and then the whole boat used the newer method. Humber keels were constructed to a variety of sizes, between 57 and 68 feet (17 and 21 m) long and between 14.5 and 16.5 feet (4.4 and 5.0 m) wide. These different sizes were dictated by which part of
9968-409: The rest of the year, while in temperate regions, where the rainfall is more evenly distributed throughout the year, evaporation causes the available rainfall to be much less in hot summer weather than in the winter months, so that the rivers fall to their low stage in the summer and are very liable to be in flood in the winter. In fact, with a temperate climate, the year may be divided into a warm and
10080-450: The river at the weirs, and in the two sills of the locks being laid at the same level instead of the upper sill being raised above the lower one to the extent of the rise at the lock, as usual on canals. Canalization secures a definite available depth for navigation; and the discharge of the river generally is amply sufficient for maintaining the impounded water level, as well as providing the necessary water for locking. Navigation, however,
10192-428: The rivers. Because of the perceived value in protecting these fertile, low-lying lands from inundation, additional straight channels have also been provided for the discharge of rainfall, known as drains in the fens. Even extensive modification of the course of a river combined with an enlargement of its channel often produces only a limited reduction in flood damage. Consequently, such floodworks are only commensurate with
10304-414: The sea into which they flow, and the distance between the source and the outlet into the sea of the river draining it. The rate of flow of rivers depends mainly upon their fall, also known as the gradient or slope. When two rivers of different sizes have the same fall, the larger river has the quicker flow, as its retardation by friction against its bed and banks is less in proportion to its volume than
10416-438: The stations on the various tributaries, the time of arrival and height of the top of the flood at any station on the main river can be predicted with remarkable accuracy two or more days beforehand. By communicating these particulars about a high flood to places on the lower river, weir-keepers are enabled to fully open the movable weirs beforehand to permit the passage of the flood, and riparian inhabitants receive timely warning of
10528-423: The stream was home to 21 species of fish. The biomass of fish able to be caught in the dredged segments of the river was 80 percent less than in the natural parts of the same stream. This loss of fish diversity and abundance is thought to occur because of reduction in habitat, elimination of riffles and pools, greater fluctuation of stream levels and water temperature, and shifting substrates. The rate of recovery for
10640-417: The subscribers. Clearly, the 99-year lease was not authorised by the enabling act, but nobody challenged its legality for over 50 years. Chaplin was not thorough in carrying out his side of the bargain and had to be reminded that he had not been paying the interest in 1782 and again in 1788. There were problems with water levels in 1792. A lack of maintenance had resulted in silting, and horses were used to tow
10752-411: The successive influx of their various tributaries. Thus, their current gradually becomes more gentle and their discharge larger in volume and less subject to abrupt variations; and, consequently, they become more suitable for navigation. Eventually, large rivers, under favorable conditions, often furnish important natural highways for inland navigation in the lower portion of their course, as, for instance,
10864-562: The summer from the melting of snow and ice, as exemplified by the Rhône above the Lake of Geneva , and the Arve which joins it below. But even these rivers are liable to have their flow modified by the influx of tributaries subject to different conditions, so that the Rhone below Lyon has a more uniform discharge than most rivers, as the summer floods of the Arve are counteracted to a great extent by
10976-610: The supply, effectively flowing upstream along the canal, and when required, additional water is pumped into the canal along a pipeline from the Great Eau. Despite being separated from the sea by a low coastal plain, which made contact with the wider world difficult, by the 18th century Louth had become a prosperous market town with a forward-looking town corporation. Realising that a link to the North Sea would provide opportunities for trade and expansion, in October 1756 they commissioned
11088-574: The systematic response to alterations to riverine and non-riverine water bodies such as coastal waters ( estuaries and bays ) and lakes. The U.S. Environmental Protection Agency (EPA) has defined hydromodification as the "alteration of the hydrologic characteristics of coastal and non-coastal waters, which in turn could cause degradation of water resources." River engineering has often resulted in unintended systematic responses, such as reduced habitat for fish and wildlife, and alterations of water temperature and sediment transport patterns. Beginning in
11200-504: The temporary terminus of the opened waterway during construction. Fulstow East and West pumping stations are close to Heelgate Farm. The only major road to cross the canal is the A1031, which does so at Thoresby Bridge. By the bridge is another surviving warehouse, built in 1821 with seven bays and three storeys, and Thoresby Bridge pumping station. The final straight sided lock was at Tetney , but nothing remains of it. It has been replaced by
11312-409: The top lock is reached. This has been replaced by a tilting weir, which controls water levels in the basin. Keddington , where much of the parish church dates from the twelfth and fourteenth centuries, was the site of Keddington Church Lock, although little of it remains. Ticklepenny Lock is better preserved, with four concave sections separated by timber posts. The third section is partially hidden by
11424-595: The whole length of the canal, parts of which are in shallow water. The trust are engaged in a scheme to restore the full length of the canal by 2020. To assist in this, a feasibility study was commissioned in September 2004, and was carried out by Faber Maunsell. The costs of the study were shared by the trust, Louth Town Council, Lincolnshire County Council , the Inland Waterways Association , East Lindsey District Council, and Anglian Water . The Louth Navigation, unlike many other disused canals,
11536-414: The winch in the bows. This allowed the keel to go under low bridges. The square sails were carried on yards which were hoisted from the deck when sails were set. In stronger winds, the yards would be hoisted with the sails furled to them with light yarn that would be broken when the sheets were pulled. The mainsail could be doused by hauling on the slabline – a rope from the deck, up to the hounds (the mast at
11648-506: Was a rapid decline in income, and the canal formally closed in 1924. Because the canal was also a land drainage channel, it was not subject to infilling, and is now a designated main river , managed by the Environment Agency that drains the surrounding land managed by the Lindsey Marsh Internal Drainage Board . It is as a feeder for Covenham Reservoir , from which treated water enters the public water supply. Water from Waithe Dike supplements
11760-667: Was a type of single-masted, square-rigged sailing craft used for inshore and inland cargo transport around Hull and the Humber Estuary , in the United Kingdom , particularly through the late 19th and early 20th centuries. The square sail arrangement of the Humber keel is most probably a descendant of the Saxon ship of the fifth century AD. The term "keel" is derived from the Anglo-Saxon word "ceol", which referred to
11872-429: Was constructed in 1782 by John Maddison, with extensions in 1900, and it was restored in 1972. Most of the machinery, including an 11-foot (3.4 m) diameter breast shot water wheel , dates from 1782, and was in regular use following restoration. The building replaced an earlier structure, as a water mill is known to have existed on the site since 1155. Water from the mill stream flows into Westfield Drain and returns to
11984-472: Was engaged as Chief Engineer at a salary of £300 per year. He employed James Hogard as resident engineer, and work began in March. By mid-1767, the outfall sluice and lock at Tetney Haven had been completed, as had the first 7 miles (11 km) of cut. The cut was of sufficient depth that water levels were around 2 feet (0.6 m) below the land surface, so that the navigation could act as a land drain as well as
12096-402: Was needed, the commissioners were to supply any additional amounts. Although Chaplin had an option to renew the lease after 7 years, he did not do so, and no other takers could be found. The commissioners then negotiated with Chaplin, and revised terms were agreed. In return for a 99-year lease, he would fund all repairs, pay the salaries of the officers of the canal, and pay 5 per cent interest to
12208-416: Was one of the locks constructed with straight sides. The western wall has collapsed, but the eastern wall survives. The surrounding countryside is very flat and low lying, being crossed by numerous drainage ditches. The Black Dike enters the channel from the west. Water from Austen Fen is pumped into the canal by Austen Fen East and West pumping stations. These, and the other pumping stations that discharge into
12320-664: Was satisfactory into the early 1900s. The early years of the 20th century saw a rapid decline in the use of the canal and the First World War killed what traffic was left. Income for 1916 was only £66. The final blow was the devastation caused by the Louth flood of 1920 to the Riverhead area, the terminus of the canal. The commissioners applied to the Minister of Transport, asking to be relieved of their liability to maintain
12432-447: Was used as the construction material for much of the keel's history. Clinker construction was the norm until the middle of the 19th century, when carvel construction was gradually introduced. Some were built with carvel bottoms and clinker sides. Typically, oak and elm were used for the planking and the timbers, with a keelson (which was a major structural member) possibly of pitch pine, if not, of oak. Timber dimensions were generous, giving
12544-414: Was £27,500. At Louth, the River Lud was diverted from its original course to the north of the Riverhead basin, and followed a new course along its south side. It supplied Bain's Water Mill, from which water discharged into the basin to maintain its level. When the mill was not in use, water levels were topped up through a 4-foot (1.2 m) diameter culvert, which passed under a stables and granary to reach
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