Sluice in the context of "Floodgate"

The Romans constructed aqueducts throughout their Republic and later Empire, to bring water from outside sources into cities and towns. Aqueduct water supplied public baths, latrines, fountains, and private households; it also supported mining operations, milling, farms, and gardens.

Aqueducts moved water through gravity alone, along a slight overall downward gradient within conduits of stone, brick, concrete or lead; the steeper the gradient, the faster the flow. Most conduits were buried beneath the ground and followed the contours of the terrain; obstructing peaks were circumvented or, less often, tunneled through. Where valleys or lowlands intervened, the conduit was carried on bridgework, or its contents fed into high-pressure lead, ceramic, or stone pipes and siphoned across. Most aqueduct systems included sedimentation tanks, which helped to reduce any water-borne debris. Sluices, castella aquae (distribution tanks) and stopcocks regulated the supply to individual destinations, and fresh overflow water could be temporarily stored in cisterns.

A moat is a deep, broad ditch dug around a castle, fortification, building, or town, historically to provide it with a preliminary line of defence. Moats can be dry or filled with water. In some places, moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices. In older fortifications, such as hillforts, they are usually referred to simply as ditches, although the function is similar. In later periods, moats or water defences may be largely ornamental. They could also act as a sewer.

A polder (Dutch pronunciation: [ˈpɔldər] ) is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes. The three types of polder are:

1. Land reclaimed from a body of water, such as a lake or the seabed
2. Flood plains separated from the sea or river by a dike
3. Marshes separated from the surrounding water by a dike and subsequently drained; these are also known as koogs, especially in Germany

The ground level in drained marshes subsides over time. All polders will eventually be below the surrounding water level some or all of the time. Water enters the low-lying polder through infiltration and water pressure of groundwater, or rainfall, or transport of water by rivers and canals. This usually means that the polder has an excess of water, which is pumped out or drained by opening sluices at low tide. Care must be taken not to set the internal water level too low. Polder land made up of peat (former marshland) will sink in relation to its previous level, because of peat decomposing when exposed to oxygen from the air.

The Afsluitdijk (Dutch: [ˈɑfslœydɛik] ; West Frisian: Ofslútdyk [ˈɔfslyːdik]; "closure dyke") is a major dam and causeway in the Netherlands. It was constructed between 1927 and 1932 and runs from Den Oever in North Holland province to the village of Zurich in Friesland province, over a length of 32 kilometres (20 mi) and a width of 90 metres (300 ft), at an initial height above Amsterdam Ordnance Datum of between 6.7 metres (22 ft) along the section at Friesland, and 7.4 metres (24 ft) where it crosses the deep channel of the Vlieter. The height at the greater sea depths west of Friesland was required to be a minimum of 7 metres everywhere when originally constructed.

Increases to the height of the Afsluitdijk have been made several times since 1958 as part of regular maintenance since the deadly North Sea Flood of 1953. The section between the Stevinsluizen and Lorentzsluizen sluice complexes was raised to 7.8 metres. Major upgrade works commenced in 2019, with one of the design conditions being that only limited wave overtopping during the design storm condition be permitted. The design proposed by the successful contractor to meet this criterion will see a further increase in the height of the dam, by approximately 2 metres.

The Unterelbe (German pronunciation: [ˈʊntɐˌʔɛlbə] ) or, in English usually the Lower Elbe, refers to the lower reaches of the river Elbe in Germany influenced by the tides.

It starts at kilometre 586, at the sluice of Geesthacht, where the Elbe forms the border between Lower Saxony and Schleswig-Holstein. It continues downstream, then forming the border between Lower Saxony and Hamburg, before fully entering Hamburg territory. In Hamburg the Unterelbe forms two anabranches, Norderelbe and Süderelbe, the latter now partially a cut-off meander. Where Norderelbe and Süderelbe used to reunite, at kilometre 634 there is a bay called the Mühlenberger Loch [de; nds]. This marks the beginning of the section of the Unterelbe which called the Niederelbe. After leaving Hamburg it forms the border between Lower Saxony and Schleswig-Holstein, again. The end it defined by the Kugelbake in Cuxhaven at kilometre 727.73. It continues further into the Wadden Sea as the Außenelbe, where it passes the Hamburg islands Scharhörn and Nigehörn.

A tide mill is a water mill driven by tidal rise and fall. A dam with a sluice is created across a suitable tidal inlet, or a section of river estuary is made into a reservoir. As the tide comes in, it enters the mill pond through a one-way gate, and this gate closes automatically when the tide begins to fall. When the tide is low enough, the stored water can be released to turn a water wheel.

Tide mills are usually situated in river estuaries, away from the effects of waves but close enough to the sea to have a reasonable tidal range. Cultures that built such mills have existed since the Middle Ages, and some may date back to the Roman period.

59°19′16.2″N 18°4′21.5″E / 59.321167°N 18.072639°E / 59.321167; 18.072639

Slussen (transl. The Sluice) is an area in Stockholm, Sweden, located at the northern edge of Södermalm, adjacent to Gamla stan. It is known for its locks system between Lake Mälaren and the Baltic Sea, as well as its historic role as a major transport interchange. The Slussen area includes the Slussen metro station and Saltsjöbanan terminus, and a bus terminal.

Eriocheir sinensis, the Chinese mitten crab (simplified Chinese: 大闸蟹; traditional Chinese: 大閘蟹; pinyin: dàzháxiè; Jyutping: daai6 zaap6 haai5; Shanghainese: du-zaq-ha, lit. "big sluice crab"; Korean: 참게) or Shanghai hairy crab (上海毛蟹, p Shànghǎi máoxiè), is a medium-sized burrowing crab that is named for its furry claws, which resemble mittens. It is native to rivers, estuaries, and other coastal habitats of East Asia; from Korea in the north to Fujian in the south. It has also been introduced to Europe and North America, where it is considered an invasive species. The species features on the list of invasive alien species of Union concern. This means that the import of the species and trade in the species is forbidden in the whole of the European Union.