Aerial image of Chi-Chi Gorge, downstream from Chi-Chi Falls, Upper Mazaruni River, Upper Mazaruni District, Guyana, South America

River Tamar, Tamar Valley, Tasmania, Australia, Pacific

Aerial image of the Upper Mazaruni River, downstream from Kamarang, Guyana, South America

Indus River at Skardu looking downstream, Mount Marshakala, 5150m, Mashabrum Range, Karakorams, Baltistan, Pakistan, Asia

Man walking along the irrigation canals (Falaj) to supply the palm grove downstream from the Village of Misfat (or Misfah) Al Abriyeen in Jebel Akhdar, Sultanate of Oman, Arabian Peninsula, Middle East

Men guiding large bamboo raft downstream with oars, past sandspit in the Brahmaputra River, Assam, India, Asia

Sof Omar cave, exit into the downstream gorge, Southern Highlands, Ethiopia, Africa

Female mute swan, Cygnus olor, and her cygnet in Southrop in the Cotswolds, Gloucestershire, UK

Female mute swan, Cygnus olor, and her cygnet in Southrop in the Cotswolds, Gloucestershire, UK

Male mute swan, Cygnus olor, known as a cob, in Southrop in the Cotswolds, Gloucestershire, UK

Female mute swan, Cygnus olor, and her cygnet in Southrop in the Cotswolds, Gloucestershire, UK

Female mallard duck with new ducklings, Anas platyrhynchos, on a stream in springtime at Swinbrook, the Cotswolds, UK

Sof Omar cave, downstream maze, daylight in through multiple entrances, Southern Highlands, Ethiopia, Africa

Part of the $300 million, 230 megawatt San Francisco hydroelectric project that extends the existing Agoyan power station in the Rio Pastaza valley, downstream of Banos, Ambato Province, Central Highlands, Ecuador, South America

Part of the $300 million, 230 megawatt San Francisco hydroelectric project that extends the existing Agoyan power station in the Rio Pastaza valley, downstream of Banos, Ambato Province, Central Highlands, Ecuador, South America

A fishing boat on Lake Athabasca in Fort Chipewyan, a First Nation community downstream of the tar sands industry, Alberta, Canada, North America

A fish caught in Lake Athabasca by Robert Grandjamber, who lives in Fort Chipewyan, a First Nation community downstream of the tar sands industry, Alberta, Canada, North America

A fish caught in Lake Athabasca by Robert Grandjamber, who lives in Fort Chipewyan, a First Nation community downstream of the tar sands industry, Alberta, Canada, North America

The November 2009 floods eroded the banks of the River Derwent, downstream of Cockermouth, revealing and damaging this pipeline, Cumbria, England, United Kingdom, Europe

Flood debris from the November 2009 floods on the banks of the River Derwent, downstream of Cockermouth, Cumbria England, United Kingdom, Europe

Flood debris from the November 2009 floods on the banks of the River Derwent, downstream of Cockermouth, Cumbria England, United Kingdom, Europe

A van washed away during the November 2009 floods in the River Derwent, downstream of Cockermouth, Cumbria, England, United Kingdom, Europe

Hambleden Mill downstream of Henley-on-Thames, Oxfordshire, England, United Kingdom, Europe

Flooded meadow by Thames downstream of Henley-on-Thames, Oxfordshire, England, United Kingdom, Europe

River Thames downstream of Henley-on-Thames, Oxfordshire, England, United Kingdom

Iron Gate, Portile de Fier, gorge of river danube through the southern carpathian Mountains, a national park on the serbian and romanian side of the river. A dam downstream of the gorge holds also the same name Iron Gate and has created an artifical lake of about 130 km length, reaching nearly upstream to Beograd. The castle of Trikule is now submerged in the artificial lake, Europe, Eastern Europe, Romania

A ganchero was a person dedicated to a craft of assisting in the transport of a large quantity of loose logs floating downstream. by the river Tagus.

A ganchero was a person dedicated to a craft of assisting in the transport of a large quantity of loose logs floating downstream. by the river Tagus.

A ganchero was a person dedicated to a craft of assisting in the transport of a large quantity of loose logs floating downstream. by the river Tagus.

A ganchero was a person dedicated to a craft of assisting in the transport of a large quantity of loose logs floating downstream. by the river Tagus.

Rubber rafts row downstream during a whitewater rafting trip in Western China.

A Female Sockeye Salmon (Oncorhynchus Nerka) Uses Her Anal Fin To Probe Her Redd While A Jack Is Positioned Downstream. Underwater View In An Alaskan Stream During The Summer.