A levee, dike, dyke, embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastlines.
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in 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.
The Coquitlam River is a tributary of the Fraser River in the Canadian province of British Columbia. The river's name comes from the word Kʷikʷəƛ̓əm which translates to "Red fish up the river". The name is a reference to a sockeye salmon species that once occupied the river's waters.
Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination.
Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge system. Since most of these devices operate by controlling the water surface elevation being stored or routed, they are also known as crest gates. In the case of flood bypass systems, floodgates sometimes are also used to lower the water levels in a main river or canal channels by allowing more water to flow into a flood bypass or detention basin when the main river or canal is approaching a flood stage.
Surface runoff is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is saturated by water to its full capacity, and the rain arrives more quickly than the soil can absorb it. Surface runoff often occurs because impervious areas do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or man-made processes. Surface runoff is a major component of the water cycle. It is the primary agent of soil erosion by water. The land area producing runoff that drains to a common point is called a drainage basin.
Streamflow, or channel runoff, is the flow of water in streams and other channels, and is a major element of the water cycle. It is one component of the movement of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel.
A beaver dam or beaver impoundment is a dam built by beavers to create a pond which protects against predators such as coyotes, wolves and bears, and holds their food during winter. These structures modify the natural environment in such a way that the overall ecosystem builds upon the change, making beavers a keystone species and ecosystem engineers. They build prolifically at night, carrying mud and stones with their forepaws and timber between their teeth.
The environmental impact of reservoirs comes under ever-increasing scrutiny as the global demand for water and energy increases and the number and size of reservoirs increases.
A drop structure, also known as a grade control, sill, or weir, is a manmade structure, typically small and built on minor streams, or as part of a dam's spillway, to pass water to a lower elevation while controlling the energy and velocity of the water as it passes over. Unlike most dams, drop structures are usually not built for water impoundment, diversion or raising the water level. Mostly built on watercourses with steep gradients, they serve other purposes such as water oxygenation and erosion prevention.
A riparian buffer or stream buffer is a vegetated area near a stream, usually forested, which helps shade and partially protect the stream from the impact of adjacent land uses. It plays a key role in increasing water quality in associated streams, rivers, and lakes, thus providing environmental benefits. With the decline of many aquatic ecosystems due to agriculture, riparian buffers have become a very common conservation practice aimed at increasing water quality and reducing pollution.
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague.
Freshwater biology is the scientific biological study of freshwater ecosystems and is a branch of limnology. This field seeks to understand the relationships between living organisms in their physical environment. These physical environments may include rivers, lakes, streams, ponds, lakes, reservoirs, or wetlands. Knowledge from this discipline is also widely used in industrial processes to make use of biological processes involved with sewage treatment and water purification. Water presence and flow is an essential aspect to species distribution and influences when and where species interact in freshwater environments.
Flood control methods are used to reduce or prevent the detrimental effects of flood waters. Flood relief methods are used to reduce the effects of flood waters or high water levels. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and runoff. Though building hard infrastructure to prevent flooding, such as flood walls, can be effective at managing flooding, increased best practice within landscape engineering is to rely more on soft infrastructure and natural systems, such as marshes and flood plains, for handling the increase in water. For flooding on coasts, coastal management practices have to not only handle changes water flow, but also natural processes like tides.
A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity. Check dams themselves are not a type of new technology; rather, they are an ancient technique dating from the second century A.D. Check dams are typically, though not always, implemented in a system of several dams situated at regular intervals across the area of interest.
The environmental effects of irrigation relate to the changes in quantity and quality of soil and water as a result of irrigation and the subsequent effects on natural and social conditions in river basins and downstream of an irrigation scheme. The effects stem from the altered hydrological conditions caused by the installation and operation of the irrigation scheme.
An alluvial river is one in which the bed and banks are made up of mobile sediment and/or soil. Alluvial rivers are self-formed, meaning that their channels are shaped by the magnitude and frequency of the floods that they experience, and the ability of these floods to erode, deposit, and transport sediment. For this reason, alluvial rivers can assume a number of forms based on the properties of their banks; the flows they experience; the local riparian ecology; and the amount, size, and type of sediment that they carry.
Matilija Dam is a concrete arch dam in Ventura County, California, completed in 1947. Designed for water storage and flood control, it impounds Matilija Creek to create the Matilija Reservoir in the Los Padres National Forest, south of the Matilija Wilderness and north of Ojai.
Clifton, Rawcliffe and Poppleton ings are temporary storage area for water that flows down the River Ouse in York, England.
Pickering Beck is a river that runs for over 18 miles (29 km) from its source in the North York Moors National Park through the town of Pickering and on to its confluence with Costa Beck at Kirby Misperton. It is a meandering river that is fed by numerous named and unnamed becks and streams which flow over sandstone and limestone beds and an alluvia of sand, clay silt and gravel. The beck is known for flooding and in recent times has been a beneficiary of funding and experimental flood protection schemes.
