Alconbury Brook Flood Group Bulletin April 2024

Alconbury Weston Pond: We are delighted that at last work is well underway on the large biodiversity and flood storage pond behind Sallows Farm. Top-soil has been removed and work has started on removing the layers of clay below.

• The archaeology has been signed off, a small number of 5000 y.o. pot sheards were found and are now held by the Cambridgeshire Museum’s Service.

• The pond is designed to take water diverted from a major ditch that runs down Vinegar Hill and previously flooded Hamerton Road. Up to 15,000m3 of water can be diverted into the large pond and then slowly released. The pond will store water from nearly 70 hectares of heavy clay agricultural land.

• It will have a slightly undulating bottom designed to trap sediment and improve water quality.

• When complete the site will include new hedgerow, and wildflowers. The design includes an island wildlife refuge.

• The Flood Group want to thank Anglian Water who have funded the majority of the project. We also want to thank the Baker family who have very kindly allowed us to convert their field into the pond and who have lent massive support throughout.

• In the long term we are interested in monitoring the carbon cost/benefit of constructing the pond.

Deeper Roots Project: Our experiments are intended to see if deeper rooted plants enable the soil to hold more water.

• We are collecting the data from the experiment using a phone ap called Soilmentor. We are delighted that in addition to Cowpasture Farm, 4 other farms are collecting data about soil health using the ap.

• As well as using deeper rooted varieties of plants, we are using recent research to see if plants can be encouraged to produce more roots. To do this we are using soil microbes, and tiny amounts of chemicals that switch-on root growth.

• Our experimental plots have now been sprayed and inoculated with microbial and stimulant additives.

• In order to keep a track of the microbes growing in the soil, we have successfully extracted microbial DNA from the test field. All of the DNA is currently being sequenced to give us a list of all of the microbes, and how much there is of each type. We will be setting out to increase the amount of beneficial microbes in the soil. We have found a way of growing some of these.

• We are also looking at how our plants can make better use of phosphate in the soil. This could mean less pollution in the brook and less fertiliser cost for farmers.

• Our thanks again goes to Cow Pasture Farm, to Natural England who have funded subscriptions to Soilmentor, to farmer partners, to Anglian Water for significant support, to Unium Bioscience who have donated the biostimulant chemicals and provided valuable advice and of course to our volunteers who have collected/processed samples.

Alconbury Flyover: National Highways have sourced funding for the area under the flyover on the left hand side opposite the brook. Their design team are in the process of putting together a plan. The area in the meantime has been cordoned off with barriers to help stop too many vehicles parking there as this has compacted the surface so water does not drain away.

Downstream Collaboration: A group consisting of the  Brampton Holiday Inn, The Racecourse, the Flood Group and others affected by flooding downstream of the villages is meeting for the first time on April 30th , a meeting which will include walking from the Holiday Inn to the River Ouse to look at how flow along that stretch of the brook could be improved. We continue to value the support that the Racecourse and the Hotel give to our other projects.

EA flood alleviation Scheme (FAS): Data from the consultants who are doing the option modelling has started to be sent back to the EA team working on a FAS for the Alconbury’s. There should be a little more news by the AGM (see below). One of many good reasons to attend.

Flood Group AGM 2024. Please attend our AGM at 7.00p.m. on May 31st at the Memorial Hall. We will provide and update on our work over the last year. There will be a chance to ask questions and make suggestions. Look forward to seeing you there!!

Contact us to volunteer at info@alconburybrookfloodgroup.uk

Donate if you can to www.justgiving.com/thealconburybrookfloodgroup