2012 – December Discursions

2012 – December Discursions

‘Tis the season to be jolly and if you care to accentuate the positive, you could join in celebrating the return of the river to Chalfont St Giles – well, sort of.   Thanks largely to closing off some lost flow at Mill House, work clearing obstructions at the dump and behind ArAklowklow kennels, and really energetic group work downstream of the ford the November work party was delighted and excited to bring a small flow to within 20 metres of Pheasant Hill.  Since then, over the past two weeks, there has been an intermittent and variable trickle under the bridge.  While it isn’t much yet, the biggest cause for optimism might be the rate at which this recovery has been achieved compared with three years ago benefitting from the much improved condition of the channel and we can look forward to extending it in the New Year.

That’s all well and good, but what about more robust and sustained improvements you ask. Well, encouragingly, Affinity’s consultants have concluded that a minimum flow of at least 1Ml/d throughout the length of the valley could be achieved by relatively modest, relatively economical recharge at three locations.  These would be just above Amersham, Chalfont St Giles and Chalfont St Peter, where a new borehole would be required.  Our view is that, although stated as a minimum and very welcome, 1Ml/d is not quite enough to provide the amenity and environmental benefit the river needs and the target should be 2 to 2.5 Ml/d as originally suggested in the Halcrow report of 1987.  (Yes, this has been going on for 15 years!).  2.5 Ml/d represents a stream size of 1.5m wide by 0.1 m deep with a water velocity of 0.2 m/s or something like this:



We understand the Environment Agency has similar views to ours regarding quantity but still strongly favours a reduction in abstraction rather than augmentation to generate the flow.  I cannot see how this can be achieved on the scale required at a viable cost or with reasonable certainty but hopefully there is scope for them and Affinity to reach a compromise incorporating the augmentation and a modest reduction in abstraction at Amersham or Chalfont St Giles.  One way or another, a decision is required soon so that, at the latest, the cost of these measures can be included in the Asset Management Plan funding for 2015 – 2020.  Please lobby for this wherever you have an opportunity.

With representatives from the Chiltern Society, including the imminent geologist Haydon Bailey, we met with HS2 Ltd and their consultants to discuss concerns about possible impact of their proposals on flows in the river and the aquifer.  Detailed notes will be added to the website as soon as they are agreed but, overall, it was felt to be a very useful and well conducted meeting during which we became a lot more confident that the potential risks were very well understood and under control.  The possibility of lining the river in the zones under which the tunnel will pass is something we can press for as added security.

Chalfont St Peter Parish Council are considering options for improving the old watersplash site beside the Greyhound.

Over 20 of you have registered for our dinner at The Ivy House next Wednesday evening.  If you would like to join us and haven’t booked yet, our hosts tell me they could take a few more.  If you can join us, let me know as soon as possible.

During the year, we have experienced the end of a devastating drought leading to extraordinarily low groundwater levels,  unusually wet months that helped stabilise and begin to restore the aquifer, some excellent progress within and outside weekend work-days, and benefitted from some wonderful new volunteers whose ages span nine decades!  We look forward to 2013 in good heart and with increasing confidence that, eventually, our goal of routine flow through the valley will be achieved.

On that note, and with sincere thanks for all your support, I’ll close with best wishes to you and yours for Peace and Joy during the festive season.


Leave a Reply

Your email address will not be published.