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32-521: The Zwanenburgwal flows from the Sint Antoniessluis sluice gate (between the streets Sint Antoniesbreestraat and Jodenbreestraat ) to the Amstel river. The canal was originally named Verversgracht ("dyers' canal"), after the textile industry that once dominated this part of town. Dyed textiles were hung to dry along the canal. Waterlooplein , a market-square popular among city visitors, sits along

64-633: A dike along the eastern edge of the city, was breached to construct a sluice gate, the Sint Antoniessluis. The inner section came to be known as the Zwanenburgwal and the outer section, beyond the sluice gate, became known as the Oude Schans . During construction of the canal, a part of the Amstel river was reclaimed to form two new neighborhoods, Zwanenburg (west of the Zwanenburgwal) and Vlooienburg (east of

96-424: A change in the height of the river level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. There is no single definition as to what constitutes a weir. Weir can also refer to the skimmer found in most in-ground swimming pools, which controls

128-482: A negative effect on fish species that migrate as part of their breeding cycle (e.g., salmonids ), but it also can be useful as a method of preventing invasive species moving upstream. For example, weirs in the Great Lakes region have helped to prevent invasive sea lamprey from colonising farther upstream. Mill ponds are created by a weir that impounds water that then flows over the structure. The energy created by

160-415: A range of biota , including poor swimmers. Even though the water around weirs can often appear relatively calm, they can be extremely dangerous places to boat, swim, or wade, as the circulation patterns on the downstream side—typically called a hydraulic jump —can submerge a person indefinitely. This phenomenon is so well known to canoeists, kayakers, and others who spend time on rivers that they even have

192-426: A river sluice used in gold prospecting or fossicking . A mill race , leet , flume , penstock or lade is a sluice channeling water toward a water mill . The terms sluice , sluice gate , knife gate , and slide gate are used interchangeably in the water and wastewater control industry. "Sluice gate" refers to a movable gate allowing water to flow under it. When a sluice is lowered, water may spill over

224-416: A rueful name for weirs: "drowning machines". The Ohio DNR recommends that a victim should "tuck the chin down, draw the knees up to the chest with arms wrapped around them. Hopefully, conditions will be such that the current will push the victim along the bed of the river until swept beyond the boil line and released by the hydraulic." The Pennsylvania State Police also recommends to victims, "curl up, dive to

256-449: A weir is broad-crested for much of its length, but has a section where the weir stops or is 'open' so that small boats and fish can traverse the structure. A notch weir is any weir where the physical barrier is significantly higher than the water level except for a specific notch (often V-shaped) cut into the panel. At times of normal flow all the water must pass through the notch, simplifying flow volume calculations, and at times of flood

288-512: A winter activity for men who spent summers working on farms. Where there were freezing nights, water might be applied to logging sluices every night so a fresh coating of slippery ice would reduce friction of logs placed in the sluice the following morning. Sluice boxes are often used in the recovery of black sands , gold , and other minerals from placer deposits during placer mining operations. They may be small-scale, as used in prospecting , or much larger, as in commercial operations, where

320-405: Is a flat-crested structure, where the water passes over a crest that covers much or all of the channel width. This is one of the most common types of weir found worldwide. A compound weir is any weir that comprises several different designs into one structure. They are commonly seen in locations where a river has multiple users who may need to bypass the structure. A common design would be one where

352-473: Is a generic relationship and specific calculations are available for the many different types of weir. Flow measurement weirs must be well maintained if they are to remain accurate. The flow over a V-notch weir (in ft /s) is given by the Kindsvater–Shen equation: where As weirs are a physical barrier, they can impede the longitudinal movement of fish and other animals up and down a river. This can have

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384-542: The Somerset Levels , sluice gates are known as clyse or clyce. Most of the inhabitants of Guyana refer to sluices as kokers. The Sinhala people in Sri Lanka, who had an ancient civilization based on harvested rain water, refer to sluices as Horovuwa. Weir A weir / w ɪər / or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in

416-616: The Zwanenburgwal. The combined city hall and opera house structure, the Stopera , lies at the intersection of the Zwanenburgwal and the river Amstel. Also on this corner lies the Joods Verzetsmonument, a monument to the Jewish resistance during World War II , where a ceremony in remembrance of the Kristallnacht massacre is held each year. Well-known inhabitants of the Zwanenburgwal include

448-577: The adjacent house, now the Rembrandthuis museum. Rembrandt was able to leave his house via an exit onto the Zwanenburgwal, running underneath the adjacent corner house, which enabled him to move the giant canvas of the Night Watch out of his studio. The Zwanenburgwal was originally an arm of the Amstel delta which was dug into a canal at the start of the 17th Century. In 1602 the Sint Antoniesdijk,

480-502: The bottom, and swim or crawl downstream". As the hydraulic jump entrains air, the buoyancy of the water between the dam and boil line will be reduced by upward of 30%, and if a victim is unable to float, escape at the base of the dam may be the only option for survival. There are many different types of weirs and they can vary from a simple stone structure that is barely noticeable, to elaborate and very large structures that require extensive management and maintenance. A broad-crested weir

512-552: The canal). With the arrival in Amsterdam of large numbers of Jews from all over Europe in the late 16th and early 17th Century, the Zwanenburgwal became part of the Jewish neighborhood of Amsterdam. A synagogue was located on the Zwanenburgwal until 1936. During World War II, the neighborhood was emptied of its residents as most were deported to the Nazi concentration camps . The deserted houses were used for firewood and left derelict. After

544-501: The change in height of the water can then be used to power waterwheels and power sawmills, grinding wheels, and other equipment. Weirs are commonly used to control the flow rates of rivers during periods of high discharge. Sluice gates (or in some cases the height of the weir crest) can be altered to increase or decrease the volume of water flowing downstream. Weirs for this purpose are commonly found upstream of towns and villages and can either be automated or manually operated. By slowing

576-505: The crest of an overflow spillway on a large dam may therefore be referred to as a weir. Weirs can vary in size both horizontally and vertically, with the smallest being only a few centimetres in height whilst the largest may be many metres tall and hundreds of metres long. Some common weir purposes are outlined below. Weirs allow hydrologists and engineers a simple method of measuring the volumetric flow rate in small to medium-sized streams/rivers or in industrial discharge locations. Since

608-414: The design of a weir that ensure that fish can bypass the barriers and access upstream habitats. Unlike dams, weirs do not usually prevent downstream fish migration (as water flows over the top and allows fish to bypass the structure in that water), although they can create flow conditions that injure juvenile fish. Recent studies suggest that navigation locks have also potential to provide increased access for

640-461: The flow in open channels. Vertical rising sluice gates are the most common in open channels and can operate under two flow regimes: free flow and submerged flow. The most important depths in designing of sluice gates are: In the mountains of the United States, sluices transported logs from steep hillsides to downslope sawmill ponds or yarding areas. Nineteenth-century logging was traditionally

672-413: The flow of water pulled into the filtering system. The word likely originated from Middle English were , Old English wer , a derivative of the root of the verb werian, meaning "to defend, dam". The German cognate is Wehr , which means the same as English weir. Commonly, weirs are used to prevent flooding , measure water discharge, and help render rivers more navigable by boat. In some locations,

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704-431: The following painters: Rembrandt , Karel Appel , Nicolaes Eliasz. Pickenoy , Salomon Meijer , and Cornelis van der Voort , the philosopher Baruch de Spinoza , the architect Michel de Klerk , the writer Arend Fokke Simonsz , and the communist leader Paul de Groot . From 1631 to 1635, Rembrandt lived and worked at the home of Hendrick van Uylenburgh at the corner of Zwanenburgwal and Jodenbreestraat. In 1639 he bought

736-602: The geometry of the top of the weir is known and all water flows over the weir, the depth of water behind the weir can be converted to a rate of flow. However, this can only be achieved in locations where all water flows over the top of the weir crest (as opposed to around the sides or through conduits or sluices) and at locations where the water that flows over the crest is carried away from the structure. If these conditions are not met, it can make flow measurement complicated, inaccurate, or even impossible. The discharge calculation can be summarised as where However, this calculation

768-407: The material is sometimes screened using a trommel , screening plant or sieve. Traditional sluices have transverse riffles over a carpet or rubber matting, which trap the heavy minerals, gemstones, and other valuable minerals. Since the early 2000s more miners and prospectors are relying on more modern and effective matting systems. The result is a concentrate which requires additional processing. In

800-423: The maximum height a species can jump or creates flow conditions that cannot be bypassed (e.g., due to excessive water velocity) effectively limits the maximum point upstream that fish can migrate. In some cases this can mean that huge lengths of breeding habitat are lost, and over time this can have a significant impact on fish populations. In many countries, it is now a legal requirement to build fish ladders into

832-413: The rate at which water moves downstream even slightly, a disproportionate effect can be had on the likelihood of flooding. On larger rivers, a weir can also alter the flow characteristics of the waterway to the point that vessels are able to navigate areas previously inaccessible due to extreme currents or eddies . Many larger weirs will have construction features that allow boats and river users to "shoot

864-427: The river bottom) that reduces the water oxygen content and smothers invertebrate habitat and fish spawning sites. The oxygen content typically returns to normal once water has passed over the weir crest (although it can be hyper-oxygenated), although increased river velocity can scour the river bed causing erosion and habitat loss. Weirs can have a significant effect on fish migration . Any weir that exceeds either

896-410: The terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. Usually, a dam is designed specifically to impound water behind a wall, whilst a weir is designed to alter the river flow characteristics. A common distinction between dams and weirs is that water flows over the top (crest) of a weir or underneath it for at least some of its length. Accordingly,

928-440: The top, in which case the gate operates as a weir . Usually, a mechanism drives the sluice up or down. This may be a simple, hand-operated, chain pulled/lowered, worm drive or rack-and-pinion drive , or it may be electrically or hydraulically powered. A flap sluice, however, operates automatically, without external intervention or inputs. Sluice gates are one of the most common hydraulic structures used to control or measure

960-534: The war, the Vlooienburg district was demolished to make way for a new city hall, which however was not built until the 1980s. 52°22′07″N 4°53′59″E  /  52.36861°N 4.89972°E  / 52.36861; 4.89972 Sluice gate A sluice ( / s l u s / SLOOS ) is a water channel containing a sluice gate , a type of lock to manage the water flow and water level. It can also be an open channel which processes material, such as

992-515: The water level can rise and submerge the weir without any alterations made to the structure. A polynomial weir is a weir that has a geometry defined by a polynomial equation of any order n . In practice, most weirs are low-order polynomial weirs. The standard rectangular weir is, for example, a polynomial weir of order zero. The triangular (V-notch) and trapezoidal weirs are of order one. High-order polynomial weirs are providing wider range of Head-Discharge relationships, and hence better control of

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1024-540: The weir" and navigate by passing up or down stream without having to exit the river. Weirs constructed for this purpose are especially common on the River Thames , and most are situated near each of the river's 45 locks . Because a weir impounds water behind it and alters the flow regime of the river, it can have an effect on the local ecology . Typically, the reduced river velocity upstream can lead to increased siltation (deposition of fine particles of silt and clay on

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