Celebrating 25 Years of the Chilterns Chalk Streams Project

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LOW FLOW: RIVER VER CASE STUDYMany of the Chilterns Chalk Streams suffer from low flows and are designatedas over-abstracted by the Environment Agency. Here, John Pritchard, Chairmanof the Ver Valley Society, illustrates the scale of the issue, using the River Ver as an example.Ver masterclass in riverrestoration, 2013A lack of flow is one of the key issues faced by the River Ver, much more regularly now than in the past. It’s nocoincidence that the river was among the first to experience unsustainable levels of abstraction in its valley,in this case to serve the growing new town of Luton. Today, the Ver remains one of the first chalk streams toexperience low flows and dry stretches in periods of low rainfall or extended hot weather. It is undoubtedlythe canary in the coal mine, giving an early indication of what many other chalk streams might expect.When abstraction of the chalk groundwater was at its height, nearly 50 million litres a day were taken forpublic water supply – about 50% of the effective rainfall the catchment receives in an average year.Most would agree that 10% is the maximum amount a chalk stream catchment can sustain without inflictingenvironmental damage. The river was the subject of the Alleviation of Low Flows (ALF) initiative in the 1980safter the river dried, but despite some abstraction reductions, it has yet to regain its former character.Indeed, the Environment Agency’s Environmental Flow Indicator (EFI) estimates that the Ver has a deficit of24 million litres a day.The perennial head of the river has moved downstream about 5km (Markyate to Redbourn) in the past70 years, while in that time abstraction has increased substantially. Rainfall patterns have remained largelythe same. The result is a slow, silty river for much of the time – lacking the healthy biodiversity that might beexpected in a chalk stream.The Ver Valley Society has members who can remember the tresses of water crowfoot billowing in the almostgradient-less Abbey Mill Stream in Verulamium Park – the strength of flow alone encouraging this keystonespecies to thrive.16 | CELEBRATING 25 YEARS OF THE CHILTERNS CHALK STREAMS PROJECT
5040Abstraction in the Ver Valley (million litres per day)(Licensed quantity)47.6 ML/d5040OVERVIEW303020201010001985198019751970196519601955195019451940193519301925192019151910190519001895189018851880187518701865Stonecross Holywell RedbournKensworth LynchBow BridgeFriars WalshMud LaneSir William Halcrow & Partners: Study of Alleviation of Low Flows Resulting from Groundwater Abstraction, Ver Case Study 1988“It was deep and fast flowing with banks of water weed swaying in the current above thegravel riverbed. We saw minnows, shoals of roach, trout and little pike.”Christopher Chapman writing of the 1950sThe Ver is just one of the many rivers that are suffering a similar fate. Our unique chalk streams and pricelesswetlands are disappearing, with most citizens unaware of the consequences of their thirst for water, as theaquifers are drained of their water. Clearly, we all have a part to play in rectifying the situation. We are looking tothe Government, however, to direct water companies to do more: to enforce existing legislation, to play a moreactive role in encouraging consumers to use less and to set the tone that water is a precious commodity to beused sparingly.A sinuous channel arisingfrom the Ver masterclass oneyear on, 2014LOW FLOW: RIVER VER CASE STUDY | 17
Page 1 and 2: CELEBRATING 25 YEARS OF THECHILTERN
Page 3 and 4: FOREWORD2022 marks the 25th anniver
Page 5 and 6: CONTENTSIntroduction 4Milestones of
Page 7 and 8: THE REPORT HAS BEEN SPLIT INTOTHREE
Page 9 and 10: THE TIMELINE ALSOSHOWS HOW THECCSP
Page 11 and 12: 2001First watervole Survey2002Produ
Page 13 and 14: KEYChalk scarp andvale fringesPlate
Page 15 and 16: OVERVIEWChalk streams have not only
Page 17: The reasons for these chemicalfailu
Page 21 and 22: WWF-UK, The Wildlife Trusts, The Ri
Page 23 and 24: OVERVIEWMISBOURNE‘Chalk Streams i
Page 25 and 26: RAISING AWARENESSOF THE NEED FORCON
Page 27 and 28: BEFORE DURING AFTERRIVER RESTORATIO
Page 29 and 30: WATER VOLE SURVEYSACTIVITIESWater v
Page 31 and 32: FESTIVALS, FAMILY EVENTSAND CONFERE
Page 33 and 34: ACTIVITIESProject workand school vi
Page 35 and 36: The earliest river flow records fro
Page 37 and 38: River Chess Smarter WaterCatchmentT
Page 39 and 40: The Ewelme Brook is a small chalkst
Page 41 and 42: The River Gade is under pressurefro
Page 43 and 44: The Hamble Brook is an ephemeralstr
Page 45 and 46: The 3.5 km Hughenden Streamis sprin
Page 47 and 48: The Misbourne is an intriguingchalk
Page 49 and 50: 1. Source of the VerThe embryonic R
Page 51 and 52: The Wye flows 17 km fromWest Wycomb
Page 53 and 54: Scarp slope streamsHorsenden BrookH
Page 55 and 56: For the first time in its history,
Page 57 and 58: WAYS YOU CAN HELPRiverfly monitorin
Page 59 and 60: The River Chess at Sarratt BottomFo

Celebrating 25 Years of the Chilterns Chalk Streams Project

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