After leaving Cambridge, it flows north and east before joining the River Great Ouse to the south of Ely, at Pope's Corner.
The total distance from Cambridge to the sea is about 40 mi (64 km) and is navigable for punts, small boats, and rowing craft.
The Great Ouse also connects to England's canal system via the Middle Level Navigations and the River Nene.
In total, the Cam runs for around 69 kilometres (43 mi) from its furthest source (near Debden in Essex) to its confluence with the Great Ouse.
[3] Navigation on the lowest section of the Cam, below and including Bottisham Lock,map 2 is the responsibility of the Environment Agency.
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 endmap 8 of Jesus Greenmap 6) between 1 April and 30 September, when the middle and upper river are open only to manually propelled craft.
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.
At this point its course turns east and from here until it merges with the Granta it forms the parish boundary between a succession of villages, though until it reaches Barrington it remains at a distance of around a kilometre from any settlement of any size.
[2] Just after flowing under the Roman Ermine Street, it crosses the avenue of Wimpole Hall and a few kilometres later it receives the waters of the minor River Mel that runs through Meldreth.
A couple of miles later it forms a picturesque addition to views of the stately home as it flows past the front of Audley End House, and is also joined by the stream known as Fulfen Slade.
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.
River Cam is referred to as "Camus, reverend Sire" in line 103 of John Milton's pastoral elegy Lycidas.
[9] The Cam below Bottisham Sluice may still hold burbot, a fish thought to be extinct in English waters since the early 1970s.
There is a public slipway next to the garden of the Green Dragon pub in Water Street, Chesterton.map 4 This is occasionally used for launching small boats.
Powered boats may navigate as far upstream as La Mimosa restaurant (next to Jesus Green) all year round, and as far as the Mill Pool between 1 October and 31 March.
[16] Swimming on the upper river is popular in the summer, and people bathe at Grantchester Meadows all year round.
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.
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.
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.
3. c. ccxiv), was obtained on 21 July 1813[18] which allowed the Conservators to alter the tolls and charge penalties, while the South Level Act 1827 (7 & 8 Geo.
The Environment Agency is responsible for managing water levels and issuing flood warnings for the entire river.