Project Overview
Cain Bio-Engineering completed the construction of a fish pass on the River Lambourn at Bagnor Estate. This reach (Aylott Hatches) of the River Lambourn suffered from three impoundments impassable to fish:
- Aylott Hatches
- Aylott Weir
- Weed rack
In order to improve fish passage, Cain Bio-Engineering was able to successfully eliminate these impounding features by both removing the impounding hatches and weed rack, and creating a rock ramp to manage gradient along the main river channel, allowing fish passage over the concrete Weir. Salmonid habitat quality was improved by dressing the main river and side channel with site-won gravel. Further habitat benefits of this project included the creation of: an area of wet woodland, an online backwater and an offline pond.
Before
View upstream of the impounded Lambourn River. Note slow flows & high sedimentation. 
The existing Aylott Hatches. 
View looking U/S to the existing weir. 
View looking U/S to the existing weir. 
Aerial view of the existing weir & hatch infrastructure.
During
Gravels were excavated from the adjacent floodplain 
The Hatches were removed & bed dressed with site-won gravel 
U/S view prior to weir removal: the weir apron was dressed with boulder rock to create a rock ramp. 
U/S view post weir removal: the rock ramp was dressed with site-won gravel. 
U/S view post weir removal: channel has been narrowed & flow attenuating riffles installed.
After
Hatches have been removed & bed dressed with site-won gravel. 
View looking D/S at the rock ramp 
Aerial view of Aylott Hatches 9 months after completion. 
View looking upstream at the rock ramp, 9 months after completion. 
Extraction of site-won gravel created a new offline pond. 
Newly created wet woodland.
