River Tamar

Together, the Tamar, Tavy and Lynher form the Tamar Valley, a designated Area of Outstanding Natural Beauty. The Tamar Valley Area of Outstanding Natural Beauty covers around 195 km² (75 sq mi) around the lower Tamar (below Launceston) and its tributaries the Tavy and the Lynher. It was first proposed in 1963, but was not designated until 1995.[14] The highest point in the AONB is Kit Hill, 334 metres above sea level. The Tamar Discovery Trail is a 35-mile hiking route following the course of the Tamar through the valley.[15]

The tidal river, between Cotehele Quay and Weir Quay, with its mudbanks and reed beds.

The Plymouth Sound and Estuaries are a Special Area of Conservation. Rocky reefs in low salinity estuarine conditions far inland on the Tamar are very unusual and support species such as the hydroid Cordylophora caspia. The Tamar is one of a few estuaries where zonation of rocky habitats (intertidal and subtidal) can be observed along an estuarine gradient.[16]

The Tamar–Tavy Estuary is a Site of Special Scientific Interest (SSSI) covering the tidal estuaries of the River Tamar and the River Tavy. Part of the Tamar estuary also forms the Tamar Estuary Nature Reserve, owned by the Cornwall Wildlife Trust. The site was designated in 1991 for its biodiversity and varying habitats that support a large number of wader and wildfowl species, as well as the special interest of its marine biology. The site supports a nationally important wintering population of avocet and supports species such as black-tailed godwit, Eurasian whimbrel, greenshank, spotted redshank, green sandpiper and golden plover.[17]

Throughout human history the valley has been almost continuously exploited for its rich mineral and metal deposits including silver, tin, lead and arsenic leaving a unique archaeological landscape which forms a significant part of the Cornwall and West Devon Mining Landscape. Remains include wheal or engine houses, deep and open cast mines dating from the Bronze Age through to the medieval and modern era, the export docks at Morwellham Quay were once an international centre of trade in copper, lead and arsenic. The valley, with the stannary town of Tavistock was added to the World Heritage List during the 30th Session of the UNESCO World Heritage Committee in Vilnius, July 2006.[18]

The Environment Agency measures the water quality of the river systems in England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There are several components that are used to determine this, including biological status, which looks at the quantity and varieties of invertebrates, angiosperms and fish. Chemical status, which compares the concentrations of various chemicals against known safe concentrations, is rated good or fail.[19]

Water quality of the River Tamar in 2019:

The most northerly bridge over the river

According to Ordnance Survey mapping, the source of the Tamar is at Woolley Moor, approximately 3.5 mi (5.6 km) from the north Cornish coast, at 50.9184°N 4.4633°W / 50.9184; -4.4633.[27] The location of the spring is a "high windswept plateau largely devoid of farmland, and inhabited by stunted trees and wiry undergrowth."[5] The exact source of the river is difficult to pinpoint, because it arises "from a boggy morass . . . behind a hedge near some willow trees at Woolley Barrows . . . A small square stone culvert drains the first tentative trickle of water away from the bog, through a hedge and into a ditch. From here a pipe carries the water under the highway and the infant river Tamar is on its way to the sea at Plymouth."[7]

The Upper Tamar Lake and Lower Tamar Lake are two small reservoirs on the Tamar's upper course. The Lower Lake was constructed in the 1820s to feed the Bude Canal; it is now a nature reserve. The Upper Lake was constructed in the 1970s and supplies fresh water to the Bude area, as well as having some recreational use.

The east bank of the Tamar was fixed as the border of Cornwall by King Athelstan in the year 936.[28] Several villages north of Launceston, to the west of the Tamar, were transferred to Devon somewhen in the eleventh century; the border was changed to follow the River Ottery westward, rather than the Tamar. The county boundary was restored to the Tamar in 1966, when the civil parishes of North Petherwin and Werrington were transferred from Devon to Cornwall.[29] The Counties (Detached Parts) Act 1844 ensured parishes were entirely within one county. It transferred a part of the Rame Peninsula (on the west side of the Hamoaze) from Devon to Cornwall (namely, parts of the parishes of Maker[30] and St John). The Act also transferred part of the parish of Bridgerule to Devon and part of the parish of North Tamerton to Cornwall — these latter transfers created two of the present-day 'exceptions' to the river boundary.

The modern administrative border between Devon and Cornwall more closely follows the Tamar and Hamoaze than the 'historic' county border (of the 11th to 19th centuries). Only three 'exceptions' to the rule that the border follows the river (from source to sea) currently exist, all of which are upstream of the confluence of the River Deer, in the upper course of the Tamar.[31] Part of the Cornish civil parish of North Tamerton extends east across the river, whilst parts of the Devon civil parishes of Bridgerule and Pancrasweek extend west across the Tamar. Where the border does follow the Tamar, it is defined as being along a line running at the centre of the river — where the river is tidal, it is the centre of the low water channel. This "centre of river" arrangement ends just upstream of the Tamar Bridge at Saltash, downstream of which the counties officially extend only to their respective (tidal) bank's low water mark. The river is dammed at two points of its upper course, forming two reservoirs in place of the natural river: at Upper Tamar Lake the border follows the line of the river as it was prior to the construction of the reservoir (therefore now within the lake), whilst at the older Lower Tamar Lake the border was re-aligned along a (now disused) re-routing of the river to the reservoir's west side, placing the lake in Devon.[32]

Higher New Bridge, near St Stephen by Launceston

The river has 22 road crossings, including some medieval stone bridges. The oldest bridge still extant is at Horsebridge (1437), and the next oldest is Greystone Bridge near Lawhitton — this arched stone bridge was built in 1439. Gunnislake New Bridge was built in 1520 by Sir Piers Edgcumbe, the owner of Cotehele and Mount Edgcumbe. The Gunnislake bridge was a main route into south east Cornwall and the lowest bridge over the Tamar until the Tamar Bridge at Saltash was opened in 1962.

The lower Tamar is spanned also by the Royal Albert Bridge (built 1859), a rail bridge now adjacent to the newer Tamar Bridge. Both of these bridges are between Saltash (known as the 'Gateway to Cornwall') and Plymouth. Further downstream, crossing the Hamoaze, is the Torpoint Ferry — a chain ferry connecting Torpoint to Devonport — and at the most downstream part of the Hamoaze there is also the Cremyll Ferry.

The Calstock Viaduct is another notable structure on the Tamar, being 120 feet (37 m) high with twelve 60-foot (18 m) wide arches, of which three of the piers stand in the river, and was built between 1904 and 1907.

Listed below are all crossings of the River Tamar, in order heading downstream. All cross the county boundary between Devon and Cornwall, except for four that are noted.

High tide at Weir Head — excursion steamer Alexandra, 127 gross tons, 126 feet in length, reversing at the entrance to the Tamar Manure Canal, in 1906.[46]

In 1794 the Tamar Manure Navigation Company was formed to extend navigation inland for a further 30 miles, to Tamerton Bridge in North Tamerton. An Act of Parliament of 1796 authorised the works, with the company empowered to improve and manage navigation on the Tamar from Morwellham Quay upstream to Boat Pool, at Blanchdown (just upstream of Gunnislake), and to construct a canal from there.[47] The project however advanced no further than Gunnislake, with work ceasing in 1808. Barges of up to 30 tons could then proceed as far as Gunnislake New Bridge,[48] bypassing the weir (above Weir Head) via a 500-yard canal to the west of the river. As the only completed work of the original project, this short canal became known as the Tamar Manure (Navigation) Canal. It had one lock allowing vessels to rise from the tidal Tamar to the water level above the weir.[49] A salmon ladder bypassed the lock.[50]

The navigable route along the Tamar and the Manure Canal that was managed by the company (from Morwellham Quay upstream to Blanchdown) was known as the Tamar Manure Navigation and was 3.0 miles (4.8 km) in length.[35] The import of fertilizer (at the time of the construction of the canal all types of which were typically referred to as "manure") and coal and the export of bricks and granite along this short navigation proved profitable for many years.[48] The navigation from Launceston to Tamerton was completed in 1826 as part of a separate project, the Bude Canal.[51] The Tamar Manure Navigation ceased functioning in 1929 and the company was wound up in 1942.[49]

The legend behind the name involves a nymph by the name of Tamara, who lived in the underworld. Tamara wanted to wander freely in the mortal world, against the advice of her parents. One day, wandering in Dartmoor, she happened to meet two giants called Tavy and Torridge (or Tawradge). Both giants became smitten with Tamara and vied for her affections. Tamara led the giants on a dance, but never let them touch her, instead darting out of reach whenever they came too close. Tamara's father, who had been out looking for her, located her just as the giants finally caught up with her near Morwenstow. He flew into a rage and used a spell to put Tavy and Tawradge into a deep sleep. This infuriated Tamara, who subsequently refused to return to the underworld with her father. He became even more enraged and cast a spell on Tamara, turning her into a bubbling spring, which produced the Tamar river and flowed all the way to the sea. Tawradge awoke to find his beloved had become a river; in despair, he sought the advice of a magician, who turned him into a river (the River Torridge and the River Taw) so that he could hope to reunite with Tamara. Tawradge was never able to find and merge with his beloved Tamara, instead turning north toward Bideford and the Bristol Channel and is still said to mourn his love, the Tamar. This legend explains why the River Torridge, which rises only 500 metres from the Tamar, veers away from the Tamar and forms a huge arc, eventually flowing to the North Devon coast. The other giant, Tavy, also awoke in despair and sought the aid of his own father, also a powerful magician. His father turned Tavy into a river as well, and the Tavy set off in search of the Tamar, eventually finding her and merging with her into a wide and beautiful estuary.[5][6][7]