Brackish water, also sometimes termed brack water, is water occurring in a natural environment having more salinity than freshwater, but not as much as seawater. It may result from mixing seawater with fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak". Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 miles (346 km), it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.
The history of lightvessels in the United Kingdom goes back over 250 years. This page also gives a list of lightvessel stations within the United Kingdom, the Channel Islands and Gibraltar.
The Isle of Sheppey is an island off the northern coast of Kent, England, neighbouring the Thames Estuary, centred 42 miles (68 km) from central London. It has an area of 36 square miles (93 km2). The island forms part of the local government district of Swale. Sheppey is derived from Old English Sceapig, meaning "Sheep Island".
Poole Harbour is a large natural harbour in Dorset, southern England, with the town of Poole on its shores. The harbour is a drowned valley (ria) formed at the end of the last ice age and is the estuary of several rivers, the largest being the Frome. The harbour has a long history of human settlement stretching to pre-Roman times. The harbour is extremely shallow, with one main dredged channel through the harbour, from the mouth to Holes Bay.
The Port of London Authority (PLA) is a self-funding public trust established on 31 March 1909 in accordance with the Port of London Act 1908 to govern the Port of London. Its responsibility extends over the Tideway of the River Thames and its continuation. It maintains and supervises navigation, and protects the river's environment.
Queenborough is a small town on the Isle of Sheppey in the Swale borough of Kent in South East England.
Isle of Grain is a village and the easternmost point of the Hoo Peninsula within the district of Medway in Kent. No longer an island and now forming part of the peninsula, the area is almost all marshland and is a major habitat for diverse wetland birds. The village constitutes a civil parish, which at the 2011 census had a population of 1,648, a net decrease of 83 people in 10 years.
A tidal island is a piece of land that is connected to the mainland by a natural or man-made causeway that is exposed at low tide and submerged at high tide. Because of the mystique surrounding tidal islands, many of them have been sites of religious worship, such as Mont-Saint-Michel with its Benedictine Abbey. Tidal islands are also commonly the sites of fortresses because of their natural fortifications.
The Swale is a tidal channel of the Thames estuary that separates the Isle of Sheppey from the rest of Kent. On its banks is a 6,509.4-hectare (16,085-acre) biological Site of Special Scientific Interest which stretches from Sittingbourne to Whitstable in Kent. It is also a Ramsar internationally important wetland site and a Special Protection Area under the European Union Directive on the Conservation of Wild Birds. Parts of it are a Nature Conservation Review site, Grade I, National Nature Reserves, a Kent Wildlife Trust nature reserve and a Local Nature Reserve.
The Nore is a sandbank at the mouth of the Thames Estuary, England. It marks the point where the River Thames meets the North Sea, roughly halfway between Havengore Creek in Essex and Warden Point on the Isle of Sheppey in Kent.
The Tideway is that part of the River Thames in England which is subject to tides. This stretch of water is downstream from Teddington Lock. The Tideway includes the Thames Estuary, the Thames Gateway and the Pool of London.
Chiswick Eyot is a 3.266-acre (1.3 ha) narrow, uninhabited ait in the River Thames. It is a tree- and reed-covered rise on the Tideway by Chiswick, in the Borough of Hounslow, London, England and is overlooked by St Nicholas Church, Chiswick, the Mall of Hammersmith and by some of the Barnes riverside on the far bank. Excluding tidal mudflats and sandbanks, it is the most downstream island purely on the Thames itself.
The River Roach is a river that flows entirely through the English county of Essex. It is one of four main streams that originate in the Rayleigh Hills to the west, and flow east. They then flow towards the centre of the Rochford Basin, a circular feature which may have been caused by an asteroid impact in the Late Oligocene or Early Miocene periods. To the east of Rochford, the river becomes tidal, and is governed by the Crouch Harbour Authority. It joins the River Crouch between Wallasea Island and Foulness Island. To the west of Rochford, there is some doubt as to which of the four streams is officially the Roach.
Grazing marsh is a British Isles term for flat, marshy grassland in polders. It consists of large grass fields separated by fresh or brackish ditches, and is often important for its wildlife.
The Black Deep is a channel which forms the most important of the three main permanent shipping routes past the shoals in the North Sea and outer Thames Estuary, the others being the Barrow Deep and Princes Channel.
The geology of Kent in southeast England largely consists of a succession of northward dipping late Mesozoic and Cenozoic sedimentary rocks overlain by a suite of unconsolidated deposits of more recent origin.
Deadman's Island is a small island in the estuary of the River Medway in Kent, United Kingdom close to where The Swale flows into the Medway. It is a flat, raised area of marshland around 1,200 metres (3,900 ft) long and 200 metres (660 ft) wide among the tidal sand banks on the southern side of the estuary and separated from the British mainland of Chetney Marshes by a narrow channel known as Shepherd's Creek. The town of Queenborough lies around one kilometre (0.62 mi) to the east across the West Swale channel. The island is crossed by several narrow tidal channels that mean that at high tide the island is separated into several smaller islands.
The Swin is a passage in the Thames estuary between Maplin Sands, Foulness Sand and Gunfleet Sand to the north and the Barrow and Sunk sand ridges to the south. The Swin was used by barges and leisure craft from the Essex rivers, and coasters and colliers from the north east.
George Smeed is a Thames barge built in 1882 by Smeed Dean & Co. Ltd. in Murston.
