Lock (water navigation) in the context of "Soo Locks"

A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is especially noticeable at the place rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard crystalline basement rock, and the coastal plain is softer sedimentary rock. A fall line often will recede upstream as a river cuts out the uphill dense material, forming "c"-shaped waterfalls and exposing bedrock shoals. Due to these features, riverboats typically cannot travel any further inland without portaging, unless locks are built. The rapid change of elevation of the water and resulting energy release make the fall line a good location for water mills, grist mills, and sawmills. Seeking a head of navigation with a ready supply of water power, people have long made settlements where rivers cross a fall line.

The Corinth Canal (Greek: Διώρυγα της Κορίνθου, romanized: Dioryga tis Korinthou) is a canal in Greece that connects the Gulf of Corinth in the Ionian Sea with the Saronic Gulf in the Aegean Sea. Completed in 1893, it cuts through the narrow Isthmus of Corinth and separates the Peloponnese peninsula from the Greek mainland. The canal was dug through the Isthmus at sea level and has no locks. It is 6.4 kilometres (4 miles) in length and at 24.6 metres (80.7 feet) wide at sea level is impassable for many modern ships. It is currently of little economic importance and is mainly a tourist attraction.

The Corinth canal concept originated with Periander of Corinth in the 7th century BC. Daunted by its enormity, he chose to implement the Diolkos, a land trackway for transporting ships, instead. Construction of a canal finally began under Roman Emperor Nero in 67 AD, using Jewish prisoners captured during the First Jewish–Roman War. However, the project ceased shortly after his death. In subsequent centuries, the idea intrigued figures like Herodes Atticus in the second century and, following their conquest of the Peloponnese in 1687, the Venetians. Despite their interest, neither of them undertook the construction.

The Great Lakes Waterway (GLW) is a system of natural channels and artificial locks and canals that enable navigation between the North American Great Lakes. Although all of the lakes are naturally connected as a chain, water travel between the lakes was impeded for centuries by obstacles such as Niagara Falls and the rapids of the St. Marys River.

Its principal civil engineering works are the Welland Canal between Lakes Ontario and Erie, and the Soo Locks between Huron and Superior. Dredged channels were constructed in the St. Marys River, the Detroit River, Lake St. Clair and the St. Clair River between Huron and Erie. Usually, one or more U.S. Coast Guard icebreakers help keep the water passage open for part of the fall and early winter, although shipping usually ceases for two to three months thereafter. The St. Lawrence Seaway allows navigable shipping from the GLW to the Atlantic Ocean, while the Illinois Waterway extends commercial shipping to the Mississippi River and the Gulf of Mexico. The Great Lakes Waterway is co-administered by the governments of Canada and the United States.

9°7′12″N 79°45′0″W / 9.12000°N 79.75000°W / 9.12000; -79.75000

The Panama Canal (Spanish: Canal de Panamá) is an artificial 82-kilometer (51-mile) waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a conduit for maritime trade between the Atlantic Ocean and the Pacific Ocean. Locks at each end lift ships up to Gatun Lake, an artificial fresh water lake 26 meters (85 ft) above sea level, created by damming the Chagres River and Lake Alajuela to reduce the amount of excavation work required for the canal. Locks then lower the ships at the other end. An average of 200,000,000 litres (52 million US gallons) of fresh water is used in a single passing of a ship. The canal is threatened by low water levels during droughts.

The Dnieper Hydroelectric Station (Ukrainian: ДніпроГЕС, romanized: DniproHES), also known as the Dnipro Dam, is a hydroelectric power station in the city of Zaporizhzhia, Ukraine. Operated by Ukrhydroenergo, it is the fifth and largest station in the Dnieper reservoir cascade, a series of hydroelectric stations on the Dnieper river that supply power to the Donets–Kryvyi Rih industrial region. Its dam has a length of 760 metres (2,490 ft), a height of 60 metres (200 ft).

The dam elevates the Dnieper river by 37.5 metres (123 ft) and maintains the water level of the Dnieper Reservoir, which has a volume of 3.3 km and stretches 129 kilometres (80 mi) upstream to the nearby city of Dnipro. The reservoir's two shipping canals—the disused original one with three staircase locks and a newer one with one staircase lock—allow ships to bypass the dam at its eastern end and sail upstream as far as the Pripyat River. A highway on the dam and bridge over the shipping canals enable vehicles to cross the Dnieper.

A sluice (/slus/ SLOOS) is a water channel containing a sluice gate, a type of lock to manage the water flow and water level. There are various types of sluice gates, including flap sluice gates and fan gates.

Sluices are used for channeling water toward a water mill, including for transporting logs from steep hillsides. Different terms are used regionally for sluices; the terms sluice, sluice gate, knife gate, and slide gate are used interchangeably in the water and wastewater control industry.

The caisson lock is a type of canal lock in which a narrowboat is floated into a sealed watertight box and raised or lowered between two different canal water levels. It was invented in the late 18th century as a solution to the problem posed by the excessive demand for water when conventional locks were used to raise and lower canal boats through large height differences. Such locks, each of which would only raise and lower boats through small height differences of a few feet, would not suffice when large height differences had to be tackled nor when water was in short supply. The caisson (or caisoon) was thought to be one solution, although it transpired that the technology of the day was not capable of achieving this type of construction economically.

It was designed primarily as a water-saving measure, and also was an attempt to minimise construction costs compared with other engineering solutions of the time. In use, it was capable of replacing up to seven conventional locks. Another benefit was increased speed of boat descent/ascent.

St John's Lock, below the town of Lechlade, Gloucestershire, is the furthest upstream lock on the River Thames in England. The name of the lock derives from a priory that was established nearby in 1250, but which no longer exists. The lock was built of stone in 1790 by the Thames Navigation Commission.

The main weir is downstream, just below St John's Bridge, where the River Cole and the River Leach join the Thames on opposite banks.