Alconbury Brook Flood Group Bulletin July 2024

Alderman’s Pond/Alconbury Weston Pond: The last week has seen finishing touches including further removal of spoil and the restoration of the banks prior to sowing with deep rooted wild flowers, and native hedging. We have added a connection to another ditch so that the pond now collects rainwater run-off from over 100ha. Additional inlet and outlet culverts have been added. The inlet dam is also complete. Final touches such as a lifebuoy, safety signage, and an interpretation board to help users of the nearby footpath to understand how the pond works both for flood mitigation and wildlife habitat.

We were very pleased to host a visit by members of the Regional Flood and Coast Committee. The main function of the committee is to advise the Environment Agency on the use of funds to prevent flooding and coastal erosion. From our point of view, the visit was an opportunity to demonstrate how we as a group are serious and  can competently provide excellent value and benefit. In addition the scale of flood management interventions in an impermeable catchment generating 4 million cubic metres (December 2020) of run-off in a few hours need to be BIG!

We have applied to the Huntingdonshire Futures grant scheme for restorative planting which will provide an environmental benefit, a volunteering opportunity and contribute to the flood mitigation provided by the site. (Fingers crossed).

Vinegar Hill east. It seems unlikely, given the advice we have received, that there will be archaeological or planning complications for this project since we plan to restore the ridge and furrow structures and restore the pond to it’s original dimensions. We now have concept drawings ready to present to the landowner and hope that given their permission work will be able to take place in the spring.

Vinegar Hill rainwater capture gardens: We are pleased to say that Chelsey and Jared from our construction partners Silver Fern have completed their Streetworks training which means that we can now apply for the necessary permit for work to occur. The permitting is time consuming so it seems likely that work will be delayed until late autumn at the earliest.

New experiments: Cowpasture Farm have drilled another special deep rooted seed mix for us. This time ‘winter wild bird’ mix which is found in corners of many of the catchment farms. The objectives are much the same: to find if we can increase soil porosity and yield at the same time along with other measures.

Our Herbal Ley experiment at Cowpasture Farm  has now been cut. We are in the process of analysing stacks of data. One thing that stands out is that where the soil is compacted, yields are smaller both above and below ground.  The same small scale version of the experiment at Alconbury Allotments is demonstrating porosity differences between treatments.

We are also looking at the widespread problem of leatherjackets which are the root eating larvae (not helpful if you want deep rooted plants). We will be trying a type of bacteria which attacks the larvae as a means of control. Our DNA works shows the bacteria are already there but only in small quantities.

Following our collaboration on sediment, Rothampsted Research (RR) have applied for £1.9 million to continue the work. In this catchment there is evidence that top-soil is being washed away. The RR bid if successful will include opportunities for some farmers in our cluster to have demonstration sediment capture approaches constructed on their land.

The microplastics trap funded by Mott Macdonald is now installed thanks to hard work by volunteers. Apart from checking that it’s still there, it will be several months before the trap contents in analysed.

Thank you to everyone who visited our stall at the village fete and the wonderful volunteers who spent the afternoon talking non-stop, answering questions, and signing up new volunteers. (We look forward to working with you soon).

Our new rain gauges are working well. As can be seen here the beginning of July was pretty wet. If the same amount of rain had fallen on saturated soil we would have seen a very full brook.

Contact us to volunteer at info@alconburybrookfloodgroup.uk