River Cam

The original name of the river was the Granta and (unusually) its present name derives from the city of Cambridge (Old English: Grantebrycge) rather than the other way around: After the city's present name developed in Middle English, the river's name was backformed to match. This was not universally applied, however, and the upper stretch of the river continues to be informally known as the Granta. It has been said[1] that the river is the "Granta" above the Silver Street Bridge^{map 11} (in Cambridge) and the "Cam" below it. The Rhee tributary is also formally known as the Cam,[2] and the Granta has a tributary on its upper stretch also known as the Granta.

The Cam has no connection with the much smaller River Cam in Gloucestershire.

A Caius eight on the lower river about to be "bumped" by 1st & 3rd Trinity during the May Bumps rowing races 2005

An organisation called the Conservators of the River Cam was formed in 1702, charged with keeping the river navigable. The Conservators are responsible for the two locks in and north east of Cambridge: Jesus Lock^{map 7} and Baits Bite Lock.^{map 3} The stretch north (downstream) of Jesus Lock is sometimes called the lower river.

The River Cam flowing past Stourbridge Common

The stretch between Jesus Lock and Baits Bite Lock is much used for rowing. There are also many residential boats on this stretch, their occupants forming a community who call themselves the Camboaters.[3]

Navigation on the lowest section of the Cam, below and including Bottisham Lock,^{map 2} is the responsibility of the Environment Agency.[4]

The Backs: King's College chapel and Clare College

The stretch above Jesus Lock is sometimes known as the middle river (with the section above the Mill Pond being referred to as the upper river).[5] Between Jesus Lock and the Mill Pond,^{map 12} it passes through the Backs^{map 10} below the walls of many of the colleges. This is the section of river most popular with tourists, with its picture-postcard views of elegant bridges, green lawns and graceful willows. This stretch also has the unusual feature of the remains of a submerged towpath: the riverside colleges did not permit barge horses on the Backs, so the beasts waded up the Cam to the mill pulling their loads behind them.

Access for mechanically powered boats is prohibited above 'La Mimosa' Pub (at the upstream end^{map 8} of Jesus Green^{map 6}) between 1 April and 30 September, when the middle and upper river are open only to manually propelled craft. The most common of these are the flat-bottomed punts.

Between 1 October and 31 March powered boats are allowed as far as Mill Pool, but few people take advantage of this, as there are very few public mooring places along the Backs, and the river is too narrow and the bridges too low to afford easy passing or turning for many boats.

A punt being pulled up rollers on the slipway between the upper and lower levels of the River Cam near the Mill Pool.

Punts and canoes can be manhandled around the weir above the Mill Pool by means of the rollers, a slipway from lower to upper level. From the Mill Pool and its weir, the river can be followed upstream through Grantchester meadows to the village of Grantchester^{map 14} and Byron's Pool,^{map 15} where it is fed by many streams.

The two principal tributaries of the Cam are the Granta and the Rhee, though both are also known as the Cam.[2]

"The Reeve's Tale" from Geoffrey Chaucer's Canterbury Tales begins:

At Trumpyngtoun, nat fer fro Cantebrigge,
Ther gooth a brook, and over that a brigge,
Upon the whiche brook ther stant a melle;
And this is verray sooth that I yow telle:
A millere was ther dwellynge many a day.

The mill formerly stood by Brasley Bridge on Grantchester Road. The mill pond is extant and the foundations of the mill can be seen when the water is low.[7]

Byron's Pool is named after the poet, Lord Byron, who is reputed to have swum there. It was certainly a bathing place for Rupert Brooke and the Cambridge neo-Pagans. Brooke used to canoe from Cambridge to lodgings in Grantchester, which included the Old Vicarage. His homesick poem of 1912 evokes the river:

Oh! there the chestnuts, summer through,

Beside the river make for you

A tunnel of green gloom, and sleep

Deeply above; and green and deep

The stream mysterious glides beneath,

Green as a dream and deep as death.

...

To smell the thrilling-sweet and rotten

Unforgettable, unforgotten

River-smell, and hear the breeze

Sobbing in the little trees.

Say, do the elm-clumps greatly stand

Still guardians of that holy land?

The chestnuts shade, in reverend dream,

The yet unacademic stream?

—"The Old Vicarage, Grantchester", Collected Poems (1916)[8]

One of Brooke's contemporaries, Gwen Darwin, later Raverat, grew up in the old mill by the Mill Pond. Her book, Period Piece, is a memoir of a childhood messing about on the river. The mill house is now part of Darwin College.

Darwin College seen across the Mill Pond

Children's author Philippa Pearce, who lived in Great Shelford until her death in December 2006, featured the Cam in her books, most notably Minnow on the Say. The river is renamed the River Say, with Great and Little Shelford becoming Great and Little Barley, and Cambridge becoming "Castleford" (not to be confused with the real town of the same name in West Yorkshire).

River Cam is referred to as "Camus, reverend Sire" in line 103 of John Milton's pastoral elegy Lycidas. Edward King, in whose memory the elegy was composed, was a fellow student at Cambridge.

Mathematical Bridge connects Queens’ College with the President's Lodge at Cambridge.

The confluence of the Cam (left) and the Great Ouse at Pope's Corner

Like many rivers, the Cam is extensively used for several forms of recreational activity. These include angling, swimming and various kinds of boating.

Some participants of the annual cardboard boat race on Suicide Sunday 2012.

Swimming

Swimming in the River Cam near Grantchester Meadows

The local swimming club's annual swim from the Mill pond to Jesus Green was cancelled for some years in the past because of higher pollution levels.

Swimming on the upper river is popular in the summer, and people bathe at Grantchester Meadows all year round. Hardy bathers take part in the New Year's Day swim.

River Cam
River Great Ouse (to Denver) Popes Corner Popes Corner Marina  B1514  Dimmock's Cote bridge Pumping Station Upware Marina Reach Lode and lock Tiptree Marina Swaffham Lode and lock Shrubb's Wharf Bottisham Lode Bottisham lock and sluice London & Cambridge Junction Canal (never built) Clayhithe Road bridge Baits Bite Lock and weir  A14  Abbey Chesterton Bridge Fen line Green Dragon Bridge Riverside Bridge  A1134  Elizabeth Way Bridge Cutter Ferry Bridge Fort St. George bridge Victoria Avenue Bridge Jesus Lock Footbridge Jesus Lock and weir Magdalene Bridge Bridge of Sighs (Cambridge) Kitchen Bridge Trinity College Bridge Garret Hostel Bridge Clare Bridge King's College Bridge Mathematical Bridge Silver Street Mill pool and weir Punt rollers Darwin College Bridges Crusoe Bridge  A1134  Fen Causeway Footbridge (left) and Sheep's Green Bridge Brasley Bridge Weir Byron's Pool  M11  Bourn Brook River Cam or Granta River Cam or Rhee from source (Ashwell Springs)

Cambridge had been an inland port due to its location on the River Cam prior to the draining of the Fens. As the university colleges rose in importance, the course of the river through the town, known as the Backs, was moved further to the east to accommodate their new buildings. A report conducted in 1618 by Richard Atkyns highlighted the problems caused by sandbanks above Clayhithe and watermills obstructing navigation. An order made by the parliamentary Committee of the Association in 1643 regulated use of the river for trade, but the biggest change was the construction of Denver Sluice on the River Great Ouse, which reduced river levels on the lower river as tidal waters were excluded from the Ouse. Both the university and the Corporation of Cambridge complained to parliament in 1697 that the trade route to the town from King's Lynn had been severely impaired.[17]

In 1699, the Corporation sought to obtain an Act of Parliament which would allow them to improve the river from Clayhithe to Queens Mill at Cambridge.[17] This was obtained on 27 February 1702[18] and created the Conservators of the River Cam, a legal body with authority to charge tolls for use of the river, which ranged from four shillings (20p) a ton for wine to one penny (0.4p) per person for passengers. The Conservators, of which there were a maximum of eleven, had powers to mortgage the tolls, in order to raise capital for improvements to the river immediately. This they did, and built sluices at Jesus Green, Chesterton, Baits Bite and Clayhithe. Most of the tolls were collected at Clayhithe.[17]

Prior to 1722, Denver sluice had been destroyed, and although Cambridge Corporation opposed its reconstruction, it was rebuilt by 1750. The river entered a period of steady profitability, with toll receipts rising from £432 in 1752 to over £1,000 by 1803. In 1835 they peaked at £1,995, and then declined slightly until 1846. The Convervators also raised some revenue from rents on the public houses which they owned adjacent to each of the sluices.[17] Another Act of Parliament was obtained on 21 July 1813[18] which allowed the Conservators to alter the tolls and charge penalties, while the South Level Act of 1827 created Commissioners who had responsibility for the river below Bottisham. This act also appointed the vice-chancellor of the university and the mayor as navigation commissioners. The Conservators built locks at Baits Bite and Bottisham, and removed the sluice at Chesterton.[17]

The river was sufficiently profitable that the Conservators were able to contribute £400 towards the cost of rebuilding the Great Bridge, now called the Magdalene Bridge,^{map 9} in 1823, and a further £300 for the rebuilding of the Small Bridge, now Silver Street Bridge, in 1841. A year later they constructed a house at Clayhithe, which cost £880, and included a large room for meetings and banquets. Just three years later the Eastern Counties Railway reached Cambridge, and the navigation declined rapidly. Receipts dropped from £1,393 in 1846 to £367 in 1850, and were just £99 in 1898. Most commercial carrying on the river had stopped by World War I, although Banhams operated two steam tugs and three barges until the late 1930s, carrying gas water from Cambridge Gasworks to King's Lynn, where it was used in the manufacture of fertiliser. The last recorded passenger services had ceased nearly 100 years earlier, in 1839 and were started again in 2008 with the passenger vessel moored on Jesus Green.[17]

Traffic using the river today consists of private cruisers making the journey to Jesus Lock, with the section above Baits Bite lock regularly in use by the University rowing clubs, both for practice and for races. Motorised craft can navigate along the Backs in winter, but headroom is severely restricted. The Conservators of the River Cam now have an office in the former lock-keepers cottage at Baits Bite, while the house at Clayhithe is now the residence of the foreman of the Conservators. The Conservators are still responsible for the river above Bottisham lock, while the lower river has been managed by the Environment Agency since its creation in 1995.[15]

The three locks are all of different sizes. Bottisham and Baits Bite locks are both fully automated, with a vertical guillotine gate at the upstream end and traditional mitre gates at the downstream end. Jesus lock is manually operated, and has mitre gates at both ends. Boat sizes are restricted to 96.8 ft (29.5 m) by the length of Bottisham lock, and to 14 ft (4.3 m) by the width of Baits Bite lock. Jesus lock is only 9.7 ft (3.0 m) wide.[19] The navigable lodes of Reach, Swaffham Bulbeck and Bottisham, the last of which is no longer navigable, can be reached from the River Cam.

The Cam (left) flooding parts of Stourbridge Common (right), 23 October 2001. Looking east from Green Dragon Bridge.

The Cam is normally a placid river but flooding does occasionally happen. The most recent serious floods were in 2001, first in February and again on 22–23 October.[20] Further serious flooding occurred in February 2009.

The Environment Agency is responsible for managing water levels and issuing flood warnings for the entire river.

• Franz X. Bogner & Stephen P. Tomkins: The Cam. An Aerial Portrait of the Cambridge River. Laber Foundation, 2015. ISBN 978-0-9932642-0-7 (http://www.cambridgeriver.info/).

• List of bridges in Cambridge
• Jesus Green Swimming Pool
• List of rivers of the United Kingdom

Wikimedia Commons has media related to River Cam.

• Conservators of the River Cam
• First and Third Trinity Boat Club guide to the Cam
• Cambridge Fish Preservation and Angling Society
• History of the River Cam (on the Camboaters website)