A detailed history of the river is provided in a book by the late Dr Desmond Hawkins who established the Wilbraham River Preservation Society. By kind permission of his son Pat this is freely available for personal use. To download please click on the link below -
The Wilbraham River is formed by two tributaries; "Little" - arising from springs at the Temple in Great Wilbraham, and "Great" arising from springs near Fulbourn Nature Reserve and in particular Shardelowe's Well at the end of Fleam Dyke. The Wilbraham River forms next to Hawk Mill Farm and flows into Quy Water which passes under the A1303 and the A14. The springs arise from the underlying chalk aquifer and the Wilbraham River is one of many endangered chalk streams in the UK.
The river formed part of a water system of 4 descending levels that powered watermills: 1] Fulbourn Mill (destroyed in the mid-1800s), 2] Hawk Mill (now a farm), 3] Quy Mill (now a hotel) and 4] Lode Mill (a working mill part of NT Anglesey Abbey). The Domesday book records Hawk Mill and it is likely all 4 mills operated through most of the middle ages until the inclosures began around 1800. At this time the improved drainage reduced the water levels making the upper level (and Fulbourn Mill) no longer usable - but the remaining mills struggled on into the early 20th Century when pumped water abstraction for human and agricultural use started at Fleam Dyke and further reduced the water levels.
It is likely that the course of the Little Wilbraham River has been modified over time both to sustain the levels for milling and to ensure field drainage. We know that the Great Wilbraham tributary was effectively abandoned in the mid 1900s and completely diverted into the "Fulbourn New Cut". The old river can still be seen passing under the narrow bridge next to Herring's House as you drive between Fulbourn and Great Wilbraham. It often still contains water in the winter months. Sections of the old river can also be identified in Fulbourn Nature Reserve and also where the river passed under the railway which was built in 1852.
Within living memory the water levels in the rivers were much higher and the local gamekeeper recalls swimming in Hawk Mill Pond along with pike and eels. This is supported by some of the old photographs from the early 20th Century.
Regrettably in recent years the water levels have further reduced and at times in the Autumn the whole river has dried up. This is almost certainly the result of water abstraction from nearby active boreholes of which there are 5 including Fleam Dyke Pumping Station. In the early 1990s in order to allow further abstraction the "Lodes-Granta Groundwater Scheme" was developed to augment flow in the local chalk streams by using boreholes further along the aquifer and pumping the water from the boreholes in pipes to outlets close to the original spring sources. Sadly this scheme has not always been effective - to the detriment of the river flora and fauna. The Environment Agency accept that the scheme has not performed as planned. In many ways this is not surprising as chalk streams are of course flowing on a porous chalk bed and if the surrounding groundwater levels fall then the river water leaks through the bed into the surrounding ground.
In early 2021 there was exceptional rainfall around Cambridge and the WRPS made a video of the river when it was actively flowing along its length. This demonstrates what the river used to be like most of the year - and the WRPS hope to sustain year round flow in the future.