RIVER HISTORY – The River Cam – 180,000 BC to today!
If you are on Jesus Green and walk alongside the river to Jesus Green Swimming Pool (Lido). Stand with your back outside the entrance of the pool and look at the river. Hundreds of thousands of years ago you would have been standing (or swimming!) in a large river that flowing straight across (at right angles to) the path of the current river. A buried channel between around 40ft (12 metres) deep full of gravel, sand and mud runs beneath Jesus College, under Jesus Green and carries on straight past the old site of the Cambridge City football ground (just off Milton Road) and then northwards to the Histon Road Allotments. The site of the old football ground was know as Swan’s Pit; a quarry that produced the sand and gravel from which much of north Cambridge is built. Remains of cold tolerant animals such as giant deer, mammoth, woolly rhino and horse were found here in deposits that have been dated to around 180,000 years ago. At Histon Road Allotments the same channel contains ancient floodplain deposits of the River Cam from 120,000 years ago. This was the last time that the earth was as warm as it is currently. At that time the landscape would have looked very different, with dense woodland cloaking the surrounding hills, and hippos and elephants grazing where the houses and shops are now.
So it seems that there was another route of the River Cam. But how come the river seems to have changed its course and is completely different to the river we see today?
At some time during the last Ice Age, perhaps 50,000 years ago, the River Cam was literally captured by another river, and changed course. At the time of the last interglacial (brief period of warmth) the River Cam had been a tributary of the river Great Ouse, joining it somewhere near Over on the Ouse Valley. A huge flood combined with the destruction of the valley side by intense freezing and thawing allowed the river to adopt a new course further to the east. It appears that the River Cam settled into this new course only to be diverted further to the east by another huge flood which may have happened about 14,000 years ago, which left the river in its current course flowing to the east of Ely.
Without the river the City of Cambridge would have grown quite differently
The current River Cam has been navigable since Roman times. Mentions of it were made throughout the Middle Ages including the types of cargo carried – corn being the main export with building materials coming in to serve the growing university town of Cambridge. Before the 1200’s, the navigable river ran from the centre of Cambridge in a northerly direction to Ely. Further north it met the River Great Ouse and the combined waters became the Wellstream, heading northwest to Wisbech and then into the sea.
The River Cam now runs just over 14 miles, from Cambridge to the junction with the River Great Ouse at Popes Corner. At regular times throughout the year, regattas and races an other events affect much of the river between Baits Bite Lock and the Victoria Road Bridge.
Rowing Event on the River Cam
