Weir in the context of "Dam failure"

Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and runoff. Flood management methods can be either of the structural type (i.e. flood control) and of the non-structural type. Structural methods hold back floodwaters physically, while non-structural methods do not. Building hard infrastructure to prevent flooding, such as flood walls, is effective at managing flooding. However, it is best practice within landscape engineering to rely more on soft infrastructure and natural systems, such as marshes and flood plains, for handling the increase in water.

Flood management can include flood risk management, which focuses on measures to reduce risk, vulnerability and exposure to flood disasters and providing risk analysis through, for example, flood risk assessment. Flood mitigation is a related but separate concept describing a broader set of strategies taken to reduce flood risk and potential impact while improving resilience against flood events.

Lake Tana (Amharic: ጣና ሐይቅ, romanized: T’ana ḥāyik’i; previously transcribed Tsana) is the largest lake in Ethiopia and a source of the Blue Nile. Located in Amhara Region in the north-western Ethiopian Highlands, the lake is approximately 84 kilometres (52 miles) long and 66 kilometres (41 miles) wide, with a maximum depth of 15 metres (49 feet), and an elevation of 1,788 metres (5,866 feet). Lake Tana is fed by the Gilgel Abay, Reb and Gumara rivers. Its surface area ranges from 3,000 to 3,500 square kilometres (1,200 to 1,400 square miles), depending on season and rainfall. The lake level has been regulated since the construction of the control weir where the lake discharges into the Blue Nile. This controls the flow to the Blue Nile Falls (Tis Abbai) and hydro-power station.

In 2015, the Lake Tana region was nominated as a UNESCO Biosphere Reserve recognizing its national and international natural and cultural importance.

A whirlpool is a body of rotating water produced by opposing currents or a current running into an obstacle. Small whirlpools form when a bath or a sink is draining. More powerful ones formed in seas or oceans may be called maelstroms (/ˈmeɪlstrɒm, -rəm/ MAYL-strom, -⁠strəm). Vortex is the proper term for a whirlpool that has a downdraft.

In narrow ocean straits with fast flowing water, whirlpools are often caused by tides. Many stories tell of ships being sucked into a maelstrom, although only smaller craft are actually in danger. Smaller whirlpools appear at river rapids and can be observed downstream of artificial structures such as weirs and dams. Large cataracts, such as Niagara Falls, produce strong whirlpools.

The Ottu barrage, sometimes spelled as the Otu barrage and also known as Ottu Head, is a masonry weir on the Ghaggar-Hakra River in Sirsa, Haryana state of India that creates a large water reservoir out of the formerly-small Dhanur lake, located near the village of Ottu, which is about 8 miles from Sirsa City in Haryana, India. It is a feeder for the two Ghaggar canals (the Northern Ghaggar canal and the Southern Ghaggar canal) that carry irrigation water to northern Haryana state. In 2002, a new tourist complex was inaugurated at the barrage, and it was given the honorary name of "Chaudhary Devi Lal Weir" to commemorate the former Chief Minister of Haryana state, Chaudhary Devi Lal. The Dhanur lake reservoir is now often referred to simply as the Ottu reservoir.

The Kansas River, also known as the Kaw, is a meandering river in northeastern Kansas in the United States. It is potentially the southwestern most part of the Missouri River drainage, which is sometimes in turn the northwesternmost portion of the extensive Mississippi River drainage. Its two names both come from the Kanza (Kaw) people who once inhabited the area; Kansas was one of the anglicizations of the French transcription Cansez (IPA: [kɑ̃ze]) of the original kką:ze. The city of Kansas City, Missouri, was named for the river, as was later the state of Kansas.

The river valley averages 2.6 miles (4.2 km) in width, with the widest points being between Wamego and Rossville, where it is up to 4 miles (6.4 km) wide, then narrowing to 1 mile (1.6 km) or less in places below Eudora and De Soto. Much of the river's watershed is dammed for flood control, but the Kansas River is generally free-flowing and has only minor obstructions, including diversion weirs and one low-impact hydroelectric dam.

The Mount Crosby Weir is a heritage-listed weir on the Brisbane River at Mount Crosby and Chuwar, both in City of Brisbane, Queensland, Australia. The project was instigated by John Petrie at the end of the 19th century. The town of Brisbane was expanding and seeking more reliable sources of drinking water than Enoggera Dam and Gold Creek Dam could provide. In conjunction with the Mount Crosby Pumping Station, it was listed on the Queensland Heritage Register on 25 October 2019.