A fascinating article written by Dr Shirley Wittering and first published in 2001 describes the swollen water courses and additional standing water in Thriplow as a result of the very wet winter 2000/2001, and compares the water map of February 2001 with the water map compiled in 1840 at the time of Enclosure. You can read it here.
All of the water that flows out of Thriplow eventually enters the Hoffer Brook. There are two main upstream reaches which join downstream of Newton before feeding into the Rhee (shown as the Cam on some maps).
The two reaches are:
- A stream flows under School Lane fed by springs in central Thriplow to the Thriplow Meadows SSSI and then flows alongside Brook Road. As part of the Enclosure Award the Commissioners confirmed six public drains in Thriplow. This was one of them. Possibly it was the engineering work that they ordered, resulting in the water flowing under rather than over the road, that led to it losing its original name of Gutter Lane.
- A stream arises near to Heathfield, augmented notably from springs at Little Nine Wells in Squires Plantation (where there is another SSSI called Thriplow Peat Holes).
The Hoffer Brook is an example of a rare type of stream, namely a chalk stream – one that emerges from an underground chalk aquifer. This is most evident at Little Nine Wells, where the water runs clear over a short section of chalk. There are only about 200 chalk streams in the world, and most of them are in the southern half of England.
Unfortunately the Hoffer Brook has been known to suffer from low flows for many years. Restoration work has been attempted in the lower reaches – see https://www.wildlifebcn.org/sites/default/files/2018-05/hofferbrookreport.pdf
Currently two members of the Society are monitoring flow near Thriplow on a weekly basis to provide information that might attract funding for further restoration work. Please contact the Archivist Dr Shirley Wittering via the email on the Home Page if you are interested in volunteering to help.