Alconbury Brook Flood Group (FG) Report November 26th 2022

Alconbury Brook Flood Alleviation Scheme.

• A meeting took place last week with EA about the Flood Alleviation Scheme (‘the options’). These are regular scheduled meetings.

• Visit to Barford Reservoirs discussed (see below)

• Survey team had started work from the Old Bridge Hotel, Huntingdon to Hamerton.

• Discussion about estimating scheme benefit without accurate data. FG is currently collecting lived data of accurate flood depths in the 78 properties which flooded indoors in 2020.

• Positive discussion.

Barford Reservoir

• FG invited to look at Barford Reservoirs by IDB operations manager and later by farmer who owns lad adjacent to both dams.

• Two 5m high bunds with culverts in different watercourses possibly similar in design to Option 5 at Alconbury Weston

• Built 2007 for approx. £500,000 each. Funding from a variety of sources including Defra 45%

• Reservoir so regular engineering inspection. Structure very simple, soil netted grass bank with embedded curb stones

• Spoil from another project close by incorporated into the bunds

• Great Barford flooding frequency and number of properties affected similar to Alconbury’s.

• Took less than a fortnight to construct each dam!

• Alconbury version 1m higher and somewhat larger storage capacity given shape of upstream valley.

• Using local contractors to reduce cost and funding arrangements discussed with EA FAS team

Many thanks to IDB Phil Lovesey and landowner Gary Davison

40 Ponds/NFM Two more NFM projects now completed this month. (left Black Lodge Pond by FG and FWAG and right Winwick new brook meanders, ponds and leaky dams by EA and FWAG) Black Lodge filling and emptying nicely in last few days. Winwick project significant project on 250m of brook upstream) FG

Thanks Lucy Jenkins FWAG and Karen Paterson EA)

Next two ponds are in planning process. AW-Philip Baker’s pond planning application submitted, Buckworth Brook scrape application with planning consultant.

Survey Community interaction with survey team revealed that they have been commissioned to do 100m intervals. We have suggested to EA that this may miss key bottlenecks and pinch points, and that these are important when improving the current models. Suggestions have been made to some additional cross sections that could be surveyed.

Sensor projects FG believes that accurate information about rainfall, soil moisture and flow is crucial to understanding the brook and measuring outcomes of interventions. FG has met with cthings and CCC to look at how we could integrate our sensors with their 3G data communication system. Very positive response. Visit planned to cthings HQ to develop technical side. Bid in to ‘entrade’ for £7500 towards sensors and nodes. FG is monitoring soil moisture and flow on a regular basis.