Barrage (dam) in the context of "Degania Dam"

The Kerala backwaters are a network of brackish lagoons and canals running parallel to the Arabian Sea along the Malabar coast of Kerala state in south-western India. It also includes interconnected lakes, rivers, and inlets, a labyrinthine system formed by more than 900 km (560 mi) of waterways, and sometimes compared to bayous. The network includes five large lakes linked by canals, both man made and natural, fed by 38 rivers, and extending virtually half the length of the Kerala state. The backwaters were formed by the action of waves and shore currents creating low barrier islands across the mouths of the many rivers flowing down from the Western Ghats range. In the midst of this landscape there are a number of towns and cities, which serve as the start and end points of backwater cruises. There are 34 backwaters in Kerala. Out of it, 27 are located either closer to Arabian Sea or parallel to the sea. The remaining 7 are inland navigation routes.

The backwaters have a unique ecosystem: Freshwater from the rivers meets the seawater from the Arabian Sea. A barrage has been built near Thanneermukkom, so salt water from the sea is prevented from entering the deep inside, keeping the fresh water intact. Such fresh water is extensively used for irrigation purposes. Many unique species of aquatic life including crabs, frogs and mudskippers, water birds such as terns, kingfishers, darters and cormorants, and animals such as otters and turtles live in and along the backwaters. Palm trees, pandanus shrubs, various leafy plants, and bushes grow alongside the backwaters, providing a green hue to the surrounding landscape.

The Godavari (IAST: Godāvarī, IPA: [ɡoːd̪ɑːʋɐɾiː]) is India's second longest river after the Ganges River, and drains the third largest basin in India, covering about 10% of the total geographical area. Its source is in Trimbakeshwar, Nashik, Maharashtra. It flows east for 1,465 kilometres (910 mi), draining the states of Maharashtra (48.6%), Telangana (18.8%), Andhra Pradesh (4.5%), Chhattisgarh (10.9%) and Odisha (5.7%). The river ultimately empties into the Bay of Bengal through an extensive network of distributaries. Its 312,812 km (120,777 sq mi) drainage basin is one of the largest in the Indian subcontinent, with only the Ganga and Indus rivers having a larger drainage basin. In terms of length, catchment area and discharge, the Godavari is the largest in peninsular India, and had been dubbed as the Dakshina Ganga (Southern Ganges).

The river has been revered in Hindu scriptures for many millennia and continues to harbour and nourish a rich cultural heritage. In the past few decades, the river has been barricaded by several barrages and dams, keeping a head of water (depth) which lowers evaporation. Its broad river delta houses 729 persons/km – nearly twice the Indian average population density and has a substantial risk of flooding, which in lower parts would be exacerbated if the global sea level were to rise.

Headworks is a civil engineering term for any structure at the head or diversion point of a waterway. It is smaller than a barrage and is used to divert water from a river into a canal or from a large canal into a smaller canal.

An example is the Horseshoe Falls at the start of the Llangollen Canal.

The Hindiya Barrage is a barrage on the Euphrates south of the town of Musayyib in Babil Governorate of Iraq. Located north of the Al-Hindiya District, it was designed by British civil engineer William Willcocks in response to the silting up of the Hillah branch of the Euphrates. Construction of the dam, with a length of over 250 metres (820 ft), lasted between 1911 and 1913. Between 1984 and 1989, a new dam was built several kilometres upstream as a replacement for the Hindiya Barrage.

South Asian river dolphins are toothed whales in the genus Platanista, which inhabit the waterways of the Indian subcontinent. They were historically considered to be one species (P. gangetica) with the Ganges river dolphin and the Indus river dolphin being subspecies (P. g. gangetica and P. g. minor respectively). Genetic and morphological evidence led to their being described as separate species in 2021. The Ganges and Indus river dolphins are estimated to have diverged 550,000 years ago. They are the only living members of the family Platanistidae and the superfamily Platanistoidea. Fossils of ancient relatives date to the late Oligocene.

South Asian river dolphins are small but stocky cetaceans with long snouts or rostra, broad flippers, and small dorsal fins. They have several unusual features. Living in murky river waters, they have eyes that are tiny and lensless; the dolphins rely instead on echolocation for navigation. The skull has large crests over the melon, which help direct their echolocation signals. These dolphins prey mainly on fish and shrimp and hunt them throughout the water column. They are active through the day and are sighted in small groups. Both species are listed as endangered by the IUCN Red List of mammals. Major threats include dams, barrages, fishing nets, and both chemical and acoustic pollution.