There has been flow through CStP on 1st August in just 15 of the last 35 years. Yet today, almost unbelievably after this summer, Misbourne is still flowing from Deep Mill Pond to the Colne. As noted before I think this comparison with 30 years ago, is due largely to reductions in upstream abstractions by Affinity Water and Thames Water. 👍 These reductions were doggedly campaigned for by Vic Wotton and others of the Chiltern Society, and later joined by many other voices. (If interested, I can provide an electronic copy of Vic’s 1987 book “To Rescue a River” in return for a donation to the Chiltern Society).Nevertheless, the upward trend on the graph below has dipped very slightly in the month reflecting the exceptionally dry July, and indeed generally below average rainfall for some time. We need the winter recharge to tell whether the theory above can be sustained, whether climate change is overtaking it, or otherwise. Said recharge will need significant rain in the months ahead as the EA tell us that the soil/moisture deficit locally is a record high of more than 126mm – i.e. roughly and approximately we need getting on for 150mm (6”) effective rain before the aquifer starts to refill. (“Effective” = settles into the ground net of evaporation, plant take-up, run-off etc).Orange balsam has also arrived in alarming quantities – far more through Chalfont St Peter particularly than I have ever seen before. For many years the popular view has been that this particular INNS (Invasive Non-Natural Species) was of low concern and unlikely to pose a threat. However, various river groups around the country and our own Trish Mallet have drawn attention to its spread and we must recognise we now have a problem on our hands. Even the new Misbourne Nature Reserve has extensive stands which we know are not the result of careless work allowing seeds to float downstream. Many thanks to Trish and all those who have cleared significant lengths of riverbank to date but it remains “work-in-progress”.Another recent arrival was the unauthorised development of a quad-bike circuit beside and across a particularly attractive, peaceful and ecologically rich reach. 😡 Work involved a bulldozer, digger, and quad bikes in the river and devastation of the river banks for maybe 250 yards. The responsible party is identified and Environment Agency and Affinity Water Restoration Team are on the case so we trust appropriate action will follow.The Chilterns Chalk Streams Project (CCSP), through Mending the Misbourne, is working with CABI to identify release sites for the Pennywort Weevil (Listronotus elongatus) a small, rice-sized insect from South America, where it naturally feeds on floating pennywort. Weevils are already active at 3 sites on the Misbourne but need time to become established: if the weed is physically removed they have nothing to eat and will not be able to sustain themselves to help in the long term. A patch of American Skunk Cabbage at Denham is to be professionally removed. CCSP are also looking at various improvement projects and we hope to have news to share soon.There were several productive work parties in the period – 2 clearing between Arklow Kennels and Bottom House Farm Lane plus one in Amersham with another near Amersham By-pass bridge, and others removing balsam in the Missendens, by Quarrendon Mill and in CStP. As always, everyone taking part found the time spent was fun and satisfying – (we also saw several shoals of little fish!) – but turnouts recently have been surprisingly low – extra-hot weather maybe?, holiday season? Insufficient clarity re dates? I don’t know, but would welcome your suggestions. This month we will be finishing Arklow to Bottom House, re-visiting the leat between Gorilla and Mill Lane and, numbers permitting checking the sheepfields d/s of CStG as well as continuing balsam removal. With these in mind, please let me know which dates suit you and I will send “orders of the day” to you just before. Work party dates: Wednesday 26 August morning or afternoon; Saturday 29th August morning, Wednesday 2nd September morning, Saturday 5th September morning.Other dates and info will no doubt appear on our lively WhatsApp group. Please let me know if you would like to join. Also note that our expanding citizen science work with Chiltern Chalkstreams Project “Mending the Misbourne” team always needs resources. Activities include Riverfly surveys, flow measurement, water quality and temperature studies, watervole surveys, physical surveys and more. In passing, we celebrate the results of the latest RiverFly survey at Bottom House Farm where a “full house” of the indicator species was recorded for the first time since the work by HS2 in 2020.Our next “not-a-meeting” – informal gathering to chat over all things “Misbourne” or other – will be from 7.15pm on Monday 14th September at Chalfont St Peter Sports Club, SL9 0QA. All Very Welcome! (What3words address = “robots.lime.inform”).Some of Chalfont St Peter’s orange balsam – it does come out with roots very easily!
Getting stuck in removing debris at Amersham with welcome help from “BJ” of the Tesco team.Quad bike circuit: Not welcome at what was one of the most beautiful reaches of the Misbourne!We are certainly now enjoying flow through the Chalfonts for more of the time than we used to
