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56-694: The Warragamba River , a river that is part of the Hawkesbury - Nepean catchment, is located in the Macarthur region of New South Wales , Australia . Formed through the confluence of the Coxs River and two minor tributaries , Warragamba River rises within Lake Burragorang and is the river on which Warragamba Dam is established, creating a large reservoir with total capacity of 2,031 gigalitres (7.17 × 10 cu ft), that forms

112-424: A lake , bay or ocean but joins another river (a parent river). Sometimes also called a branch or fork. A distributary , or a distributary channel , is a stream that branches off and flows away from a main stream channel, and the phenomenon is known as river bifurcation . Distributaries are common features of river deltas , and are often found where a valleyed stream enters wide flatlands or approaches

168-403: A bed armor layer, and other depositional features, plus well defined banks due to bank erosion, are good identifiers when assessing for perennial streams. Particle size will help identify a perennial stream. Perennial streams cut through the soil profile, which removes fine and small particles. By assessing areas for relatively coarse material left behind in the stream bed and finer sediments along

224-658: A continuous aquatic habitat until they reach maturity. Crayfish and other crustaceans , snails , bivalves (clams), and aquatic worms also indicate the stream is perennial. These require a persistent aquatic environment for survival. Fish and amphibians are secondary indicators in assessment of a perennial stream because some fish and amphibians can inhabit areas without persistent water regime. When assessing for fish, all available habitat should be assessed: pools, riffles, root clumps and other obstructions. Fish will seek cover if alerted to human presence, but should be easily observed in perennial streams. Amphibians also indicate

280-470: A continuous or intermittent stream. The same non-perennial channel might change characteristics from intermittent to ephemeral over its course. Washes can fill up quickly during rains, and there may be a sudden torrent of water after a thunderstorm begins upstream, such as during monsoonal conditions. In the United States, an intermittent or seasonal stream is one that only flows for part of

336-422: A drainage network. Although each tributary has its own source, international practice is to take the source farthest from the river mouth as the source of the entire river system, from which the most extended length of the river measured as the starting point is taken as the length of the whole river system, and that furthest starting point is conventionally taken as the source of the whole river system. For example,

392-540: A major part of the water supply to greater metropolitan Sydney . The river descends 96 metres (315 ft), the majority of which is over the dam spillway , and then flows north into the Nepean River , north of the village of Warragamba , a course of approximately 18 kilometres (11 mi). Prior to the creation of Lake Burragorang, the Warragamba River would have been formed by the confluences of

448-404: A path into mines or other underground chambers. According to official U.S. definitions, the channels of intermittent streams are well-defined, as opposed to ephemeral streams, which may or may not have a defined channel, and rely mainly on storm runoff, as their aquatic bed is above the water table . An ephemeral stream does not have the biological, hydrological, and physical characteristics of

504-412: A perennial stream and include tadpoles , frogs , salamanders , and newts . These amphibians can be found in stream channels, along stream banks, and even under rocks. Frogs and tadpoles usually inhabit shallow and slow moving waters near the sides of stream banks. Frogs will typically jump into water when alerted to human presence. Well defined river beds composed of riffles, pools, runs, gravel bars,

560-483: A perennial stream, fine sediment may cling to riparian plant stems and tree trunks. Organic debris drift lines or piles may be found within the active overbank area after recent high flow. Streams, headwaters, and streams flowing only part of the year provide many benefits upstream and downstream. They defend against floods, remove contaminants, recycle nutrients that are potentially dangerous as well as provide food and habitat for many forms of fish. Such streams also play

616-655: A river can be crossed". Although today brod in the Serbo-Croatian means 'ship', Slavonski Brod in Croatia, as well as Makedonski Brod in North Macedonia and other place names containing Brod in Slavic countries, where brod is still the word for 'ford', are named after fords. In historic times, positioning an army in large units close to a river was thought best for direct defense as well as to attack

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672-406: A slow-moving wetted channel or stagnant area. This is evidence that iron-oxidizing bacteria are present, indicating persistent expression of oxygen-depleted ground water. In a forested area, leaf and needle litter in the stream channel is an additional indicator. Accumulation of leaf litter does not occur in perennial streams since such material is continuously flushed. In the adjacent overbank of

728-486: A stream as intermittent, "showing interruptions in time or space". Generally, streams that flow only during and immediately after precipitation are termed ephemeral . There is no clear demarcation between surface runoff and an ephemeral stream, and some ephemeral streams can be classed as intermittent—flow all but disappearing in the normal course of seasons but ample flow (backups) restoring stream presence — such circumstances are documented when stream beds have opened up

784-424: A stream is a critical factor in determining its character and is entirely determined by its base level of erosion. The base level of erosion is the point at which the stream either enters the ocean, a lake or pond, or enters a stretch in which it has a much lower gradient, and may be specifically applied to any particular stretch of a stream. In geological terms, the stream will erode down through its bed to achieve

840-574: A stream is controlled by three inputs – surface runoff (from precipitation or meltwater ), daylighted subterranean water , and surfaced groundwater ( spring water ). The surface and subterranean water are highly variable between periods of rainfall. Groundwater, on the other hand, has a relatively constant input and is controlled more by long-term patterns of precipitation. The stream encompasses surface, subsurface and groundwater fluxes that respond to geological, geomorphological, hydrological and biotic controls. Streams are important as conduits in

896-524: A thin layer called sheet wash, combined with a network of tiny rills, which together form the sheet runoff; when this water is focused in a channel, a stream is born. Some rivers and streams may begin from lakes or ponds. Freshwater's primary sources are precipitation and mountain snowmelt. However, rivers typically originate in the highlands, and are slowly created by the erosion of mountain snowmelt into lakes or rivers. Rivers usually flow from their source topographically, and erode as they pass until they reach

952-627: A vital role in preserving our drinking water quality and supply, ensuring a steady flow of water to surface waters and helping to restore deep aquifers. The extent of land basin drained by a stream is termed its drainage basin (also known in North America as the watershed and, in British English, as a catchment). A basin may also be composed of smaller basins. For instance, the Continental Divide in North America divides

1008-414: Is a large natural stream that is much wider and deeper than a creek and not easily fordable, and may be a navigable waterway . The linear channel between the parallel ridges or bars on a shoreline beach or river floodplain, or between a bar and the shore. Also called a swale . A tributary is a contributory stream to a larger stream, or a stream which does not reach a static body of water such as

1064-441: Is known as surface hydrology and is a core element of environmental geography . A brook is a stream smaller than a creek, especially one that is fed by a spring or seep . It is usually small and easily forded . A brook is characterised by its shallowness. A creek ( / k r iː k / ) or crick ( / k r ɪ k / ): In hydrography, gut is a small creek; this is seen in proper names in eastern North America from

1120-414: Is low but may be treated as a ford when the river is high and water covers the crossing. The word ford is both a noun (describing the water crossing itself) and a verb (describing the act of crossing a ford). A ford is a much cheaper form of river crossing than a bridge , and it can transport much more weight than a bridge, but it may become impassable after heavy rain or during flood conditions. A ford

1176-425: Is sometimes termed a "young" or "immature" stream, and the later state a "mature" or "old" stream. Meanders are looping changes of direction of a stream caused by the erosion and deposition of bank materials. These are typically serpentine in form. Typically, over time the meanders gradually migrate downstream. If some resistant material slows or stops the downstream movement of a meander, a stream may erode through

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1232-445: Is therefore normally only suitable for very minor roads (and for paths intended for walkers and horse riders etc.). Most modern fords are usually shallow enough to be crossed by cars and other wheeled or tracked vehicles (a process known as "fording"). Fords may be accompanied by stepping stones for pedestrians. The United Kingdom has more than 2,000 fords, and most of them do not have any way of stopping vehicles from crossing when

1288-456: Is usually called a creek and marked on topographic maps with a solid blue line. There are five generic classifications: "Macroinvertebrate" refers to easily seen invertebrates , larger than 0.5 mm, found in stream and river bottoms. Macroinvertebrates are larval stages of most aquatic insects and their presence is a good indicator that the stream is perennial. Larvae of caddisflies , mayflies , stoneflies , and damselflies require

1344-757: The Dutch voorde (as in Vilvoorde , Coevorden , Zandvoort , or Amersfoort ) are cognates with the same meaning, all deriving from Proto-Indo-European *pértus 'crossing'. This is the source of Brythonic and Gaulish ritus (modern Welsh rhyd ; the Welsh name of Oxford is Rhydychen "ford of oxen"), which underlies such names as Chambord (from Gaulish *Camboritum "ford at the bend") and Niort ( Novioritum "new ford"). Towns such as Maastricht , Dordrecht , and Utrecht also formed at fords. The endings tricht , drecht , and trecht are derived from

1400-587: The Latin word traiectum , meaning "crossing". Thus the name Utrecht, originally the Roman fort of Traiectum , is derived from "Uut Trecht", meaning "downstream crossing". The Afrikaans form was taken into South African English as drift and led to place names like Rorke's Drift and Velddrift . Similarly, in Slavic languages , the word brod comes from the linguistic root that means "river-crossing" or "place where

1456-654: The River Amman ); Stafford , the county town of Staffordshire ('ford by a staithe ', or 'ford by the landing place'), Staffort crossing the river Pfinz ; and Stratford (a ford on a Roman street ). Similarly, the German word Furt (as in Frankfurt , the ford of the Franks ; Ochsenfurt , synonymous to Oxford; Schweinfurt , a ford where swine crossed the river; and Klagenfurt , literally "ford of complaints") and

1512-691: The Tombigbee River basin. Continuing in this vein, a component of the Mississippi River basin is the Ohio River basin, which in turn includes the Kentucky River basin, and so forth. Stream crossings are where streams are crossed by roads , pipelines , railways , or any other thing which might restrict the flow of the stream in ordinary or flood conditions. Any structure over or in a stream which results in limitations on

1568-910: The United Kingdom . Examples are at Brockenhurst in Hampshire , Wookey in Somerset , and Swinbrook in Oxfordshire . Some of these are being replaced by bridges as these are a more reliable form of crossing in adverse weather conditions. Some very spectacular watersplashes can be found in diverse locations. Australia has the Gulf Savannah , and others may be found in Canada , Italy , South Africa , and Finland . They are also found on some Tennessee backroads, where they are referred to as "underwater bridges". In Israel and part of

1624-713: The coastal plains around a lake or an ocean . They can also occur inland, on alluvial fans , or where a tributary stream bifurcates as it nears its confluence with a larger stream. Common terms for individual river distributaries in English-speaking countries are arm and channel . There are a number of regional names for a stream. A stream's source depends on the surrounding landscape and its function within larger river networks. While perennial and intermittent streams are typically supplied by smaller upstream waters and groundwater, headwater and ephemeral streams often derive most of their water from precipitation in

1680-480: The velocity of the stream. A perennial stream is one which flows continuously all year. Some perennial streams may only have continuous flow in segments of its stream bed year round during years of normal rainfall. Blue-line streams are perennial streams and are marked on topographic maps with a solid blue line. The word "perennial" from the 1640s, meaning "evergreen," is established in Latin perennis, keeping

1736-416: The water cycle , instruments in groundwater recharge , and corridors for fish and wildlife migration. The biological habitat in the immediate vicinity of a stream is called a riparian zone . Given the status of the ongoing Holocene extinction , streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity . The study of streams and waterways in general

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1792-677: The British areas under the mandate a low water crossing or watersplash had been known as the "Irish bridge" in reference to the Anglo–Irish war . The names of many towns and villages are derived from the word 'ford'. Examples include Oxford (a ford where oxen crossed the river: see the Coat of arms of Oxford ); Hertford , the county town of Hertfordshire (the ford where harts cross or "deer crossing"); Brantford , (the ford where Joseph Brant Forded The Grand River ); Ammanford (a ford on

1848-605: The Coxs, Nattai , and Wollondilly rivers in the Burragorang Valley . Downstream, the river flowed through a gorge that varied in width from 300 metres (980 ft) to 600 metres (2,000 ft), and was 100 metres (330 ft) in depth. It was this configuration which allowed a relatively short but high dam wall in the gorge to impound a large quantity of water. Today, the Burragorang Valley and most of

1904-840: The Mid-Atlantic states (for instance, The Gut in Pennsylvania, Ash Gut in Delaware, and other streams) down into the Caribbean (for instance, Guinea Gut , Fish Bay Gut , Cob Gut , Battery Gut and other rivers and streams in the United States Virgin Islands , in Jamaica (Sandy Gut, Bens Gut River, White Gut River), and in many streams and creeks of the Dutch Caribbean ). A river

1960-867: The Warragamba River is submerged beneath the lake, and the remaining section of the river flows only the 3.5 kilometres (2.2 mi) north-east from the Warragamba Dam spillway to its confluence with the Nepean River. The area surrounding Warragamba River is managed by Sydney Catchment Authority under the Sydney Water Catchment Management Act, 1998 (NSW) that defines special zones and places restrictions and controls on land use, development and access in order to safeguard potable water . 33°52′S 150°37′E  /  33.867°S 150.617°E  / -33.867; 150.617 Perennial stream The flow of

2016-533: The atmosphere either by evaporation from soil and water bodies, or by plant evapotranspiration. By infiltration some of the water sinks into the earth and becomes groundwater, much of which eventually enters streams. Most precipitated water is partially bottled up by evaporation or freezing in snow fields and glaciers. The majority of the water flows as a runoff from the ground; the proportion of this varies depending on several factors, such as climate, temperature, vegetation, types of rock, and relief. This runoff begins as

2072-525: The base level of erosion throughout its course. If this base level is low, then the stream will rapidly cut through underlying strata and have a steep gradient, and if the base level is relatively high, then the stream will form a flood plain and meander. Typically, streams are said to have a particular elevation profile , beginning with steep gradients, no flood plain, and little shifting of channels, eventually evolving into streams with low gradients, wide flood plains, and extensive meanders. The initial stage

2128-597: The base stage of erosion. The scientists have offered a way based on data to define the origin of the lake. A classified sample was the one measured by the Chinese researchers from the University of Chinese Academy of Sciences. As an essential symbol of the river formation environment, the river source needs an objective and straightforward and effective method of judging . A calculation model of river source catchment area based on critical support flow (CSD) proposed, and

2184-707: The flow is reduced to a trickle or less. Typically torrents have Apennine rather than Alpine sources, and in the summer they are fed by little precipitation and no melting snow. In this case the maximum discharge will be during the spring and autumn. An intermittent stream can also be called a winterbourne in Britain, a wadi in the Arabic -speaking world or torrente or rambla (this last one from arabic origin) in Spain and Latin America. In Australia, an intermittent stream

2240-447: The form of rain and snow. Most of this precipitated water re-enters the atmosphere by evaporation from soil and water bodies, or by the evapotranspiration of plants. Some of the water proceeds to sink into the earth by infiltration and becomes groundwater, much of which eventually enters streams. Some precipitated water is temporarily locked up in snow fields and glaciers , to be released later by evaporation or melting. The rest of

2296-532: The lake has significant feeder rivers. The Kagera River, which flows into Lake Victoria near Bukoba's Tanzanian town , is the longest feeder, though sources do not agree on which is the Kagera's longest tributary and therefore the Nile's most remote source itself. To qualify as a stream, a body of water must be either recurring or perennial. Recurring (intermittent) streams have water in the channel for at least part of

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2352-683: The mainly easterly-draining Atlantic Ocean and Arctic Ocean basins from the largely westerly-flowing Pacific Ocean basin. The Atlantic Ocean basin, however, may be further subdivided into the Atlantic Ocean and Gulf of Mexico drainages. (This delineation is termed the Eastern Continental Divide .) Similarly, the Gulf of Mexico basin may be divided into the Mississippi River basin and several smaller basins, such as

2408-412: The meaning as "everlasting all year round," per "over" plus annus "year." This has been proved since the 1670s by the "living years" in the sense of botany. The metaphorical sense of "enduring, eternal" originates from 1750. They are related to "perennial." See biennial for shifts in vowels. Perennial streams have one or more of these characteristics: Absence of such characteristics supports classifying

2464-424: The movement of fish or other ecological elements may be an issue. Ford (crossing) A ford is a shallow place with good footing where a river or stream may be crossed by wading, or inside a vehicle getting its wheels wet. A ford may occur naturally or be constructed. Fords may be impassable during high water. A low-water crossing is a low bridge that allows crossing over a river or stream when water

2520-453: The neck between two legs of a meander to become temporarily straighter, leaving behind an arc-shaped body of water termed an oxbow lake or bayou . A flood may also cause a meander to be cut through in this way. The stream load is defined as the solid matter carried by a stream. Streams can carry sediment, or alluvium. The amount of load it can carry (capacity) as well as the largest object it can carry (competence) are both dependent on

2576-596: The origin of the Nile River is the confluence of the White Nile and the Blue Nile, but the source of the whole river system is in its upper reaches. If there is no specific designation, "length of the Nile" refers to the "river length of the Nile system", rather than to the length of the Nile river from the point where it is formed by a confluence of tributaries. The Nile's source is often cited as Lake Victoria, but

2632-469: The relationship between CSA and CSD with a minimum catchment area established. Using the model for comparison in two basins in Tibet (Helongqu and Niyang River White Water), the results show that the critical support flow (Qc) of the housing dragon song is 0.0028 m /s. At the same time, the white water curvature is 0.0085 m /s. Besides, the critical support flow can vary with hydrologic climate conditions, and

2688-425: The side of the stream or within the floodplain will be a good indicator of persistent water regime. A perennial stream can be identified 48 hours after a storm. Direct storm runoff usually has ceased at this point. If a stream is still flowing and contributing inflow is not observed above the channel, the observed water is likely baseflow. Another perennial stream indication is an abundance of red rust material in

2744-655: The vital support flow Qc in wet areas (white water) is larger than in semi-arid regions (heap slot). The proposed critical support flow (CSD) concept and model method can be used to determine the hydrographic indicators of river sources in complex geographical areas, and it can also reflect the impact of hydrologic climate change on river recharge in different regions. The source of a river or stream (its point of origin) can consist of lakes, swamps, springs, or glaciers. A typical river has several tributaries; each of these may be made up of several other smaller tributaries, so that together this stream and all its tributaries are called

2800-512: The water flows off the land as runoff, the proportion of which varies according to many factors, such as wind, humidity, vegetation, rock types, and relief. This runoff starts as a thin film called sheet wash, combined with a network of tiny rills, together constituting sheet runoff; when this water is concentrated in a channel, a stream has its birth. Some creeks may start from ponds or lakes. The streams typically derive most of their water from rain and snow precipitation. Most of this water re-enters

2856-432: The water is shallow enough, but the material on the riverbed will not support heavy vehicles, fords are sometimes improved by building a submerged concrete floor. In such cases, a curb (kerb) is often placed on the downstream side to prevent vehicles from slipping off, as the growth of algae will often make the slab very slippery. Fords may be also equipped with a post indicating the water depth, so that users may know if

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2912-615: The water is too deep to attempt to cross. Some have an adjacent footbridge so that pedestrians may cross dryshod. Fords were sometimes the only way to cross, such as at the Milkhouse at Rock Creek in Washington, DC, but the regular use of this ford has been superseded by bridges. The crossing remained for "adventurous" drivers until 1996 when the National Park Service closed the ford to cars. A road running below

2968-459: The water level of a stream or river is often known as a "watersplash". It is a common name for a ford or stretch of wet road in some areas, and is sometimes also used to describe tidal crossings. They have become a common feature in rallying courses. Some enthusiasts seek out and drive through these water features, recording details (such as wave created, position, and access) on dedicated websites. There are many old fords known as watersplashes in

3024-531: The water makes them impassable. According to The AA , many flood-related vehicle breakdowns are at fords. In New Zealand , fords are a normal part of roads, including, until 2010, along State Highway 1 on the South Island 's east coast. In dry weather, drivers become aware of a ford by crunching across outwash detritus on the roadway. A Bailey bridge may be built off the mainline of the road to carry emergency traffic during high water. At places where

3080-521: The year and is marked on topographic maps with a line of blue dashes and dots. A wash , desert wash, or arroyo is normally a dry streambed in the deserts of the American Southwest , which flows after sufficient rainfall. In Italy, an intermittent stream is termed a torrent ( Italian : torrente ). In full flood the stream may or may not be "torrential" in the dramatic sense of the word, but there will be one or more seasons in which

3136-402: The year. A stream of the first order is a stream which does not have any other recurring or perennial stream feeding into it. When two first-order streams come together, they form a second-order stream. When two second-order streams come together, they form a third-order stream. Streams of lower order joining a higher order stream do not change the order of the higher stream. The gradient of

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