Environment

The River Lambourn – January 2019 update (with a sweepstake…)
Dredging update

As reported here last month, there were alleged incidents in late November and early December involving dredging the river bed in East Garston without permission. Penny Post has learned that representatives from the Environment Agency visited the site most recently on 9 January to assess the extent and nature of the restitution work required. We also understand that this work will start some time after 16 January. This will be carried out by, or the very least closely supervised by, the EA. We shall be asking the EA for a comment after this date and will add any response to this post.

The river flow

January is a month for many things including diets, resolutions, thermal underwear and tax returns. If you live in the upper reaches of the River Lambourn it’s also the time we start wondering when our chalk stream will return…

As all local residents know, the section of the River Lambourn from its source down to Maiden Court Farm (between East Garston and Shefford) is seasonal winterboure and generally tends to be dry between August and early January. This can vary depending on the level of the water table; the river is fed by springs from the underground chalk aquifer which in turn is fed by rainwater. Depending on rainfall, the river sometimes flows continuously for over a year and sometimes the river is dry for over a year.

Looking at the chart of the river flow between 1964 and 1999 in the book East Garston Past and Present the river is usually flowing between January and May and usually dry in September and October. Even this can’t be guaranteed. Between late July 1990 and mid November 1992 it didn’t flow at all but then did so without a break until early September 1994. Another odd period was 1975-76. The river dried up in July 1975 and stayed dry for the next 18 months. However, despite the notoriously hot summer that year, the flow began again in early January as if nothing odd had happened. This may (or may not) be an omen for this year.

I spoke to Mark Brock from East Garston who is the Parish Council’s appointed Flood Warden. One of his tasks is to take measurements from various boreholes and report the findings to Thames Water, the Environment Agency and West Berkshire Council. “When the river will start flowing again will depend very much on the rainfall pattern over the next few months,” he explained.. “Groundwater levels are low for this time of year but a prolonged period of heavy rainfall could result in groundwater levels rising rapidly, though currently there is little or no rain in the forecast.”

On top of the unpredictable amount of rainfall, there is also the issue of how heavy it is, as heavy rainfall is less beneficial to the water table than lighter rain because after a downpour much of it will run off. And when it rains is also an issue as rain that falls in the summer is more likely to be soaked up by vegetation or lost to evaporation. On top of this, the chalk sub-strata is constantly changing which effects the amount of water that can be retained in any one part of it.

All in all, predicting the river flow is a bit of a dark art.

East Garston River Sweepstake

However, we’re not going to let that stop us trying. Our neighbour Hilary Reem, who’s lived, and tended a garden, next to the river for over 60 years, told us the other day that she felt it would be flowing again on 1 March. Defining what ‘flowing’ means is open to some debate as the various springs start at different times and there’s a period when the river might flow gently for 100 yards and then stop for another 100. However, we’ll take up her challenge and will define ‘flowing’ as when the river is clearly flowing as far as one can see on both sides of the bridge by the war memorial in East Garston.

Before casting my vote, I thought I’d seek some expert advice. What did Mark think about 1 March? “Not sure,” he said. “I think it’s unlikely unless we get some persistent and heavy rain in the next month. My readings show the water levels have been falling since May and still haven’t levelled off. If it stays dry it’s quite possible it won’t flow at all this year.” I asked him if he’d like to predict a date and he said he’d have another look at the figures and get back to me.

So, science and instinct, not for the first time, are in disagreement. Penny has gone for 15 March while I – with my natural pessimist’s supposition of apocalyptic weather just round the corner at any time of the year – have opted for 25 February.

How to Enter

So – have a guess yourself. Please send an email with your predicted date (and year) to competitions@pennypost.org.uk with the subject ‘River Lambourn’. You can nominate a date in 2020 or beyond if you want. Whenever the river next comes back, the person whose guess was the closest will win a £10 voucher for use in the East Garston Social Club – many thanks to Raymond Baker for donating the prize.

If two or more people are equally close we’ll toss a coin or similar. Only the first entry from any one email address will be accepted and no entry will be accepted if sent to us on the actual day the river re-starts. Penny’s decision (in this as in so much else) will be final. So, get your divining rods out and place your bets now…

Tidying the river

While the Lambourn is dry, it’s a good time for any river-fronting residents to clear any rubbish on the bed (though the recent village clean-up day should have dealt with most of it). We strongly advise against doing anything more invasive than this unless you’ve first had a look at this article and perhaps contacted some of the organisations or sources of advice it refers to. And don’t do any dredging.

When the river does return

This is an almost magical experience, often spanning a week or so, and one of the great delights of living on this remarkable and almost unique little river. Click here to see a stop-action video Penny made charting is return in March 2017.

A search for ‘River Lambourn’ on this website will take you to a number of other related articles.

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