Earlier this year, thanks to the huge generosity of Revivel’s members and many others who very kindly donated , we were able to commission the services of John Lawson (a renowned specialist in this field) to conduct a study on the upper Ivel and make recommendations as to how to save our river.
His draft report was discussed in detail at a recent meeting with the Environment Agency (EA) and
Affinity Water. John Lawson and Charles Rangeley-Wilson OBE (author, conservationist, and Chair of
a national chalk streams restoration group) supported RevIvel at the meeting.
If would like to read the redacted report in full please click the link below.
For the highlight of the report the summary is as follows.
Key findings of the draft report:
- With “abstraction as a percentage of recharge” (note 1) at 53%, the upper Ivel is amongst the most over-abstracted chalk streams in the country and, as a result, the river is increasingly dry for long periods
- Historic evidence supports that the water table used to be 3-6m higher. At Black Horse Mill the water used to flow all year round, providing sufficient power to grind corn (note 2). John Lawson concludes that reduction in flows is consistent with increasing abstraction
- Impact of abstraction:
- John Lawson employs the “Chalk Streams First” mathematical model to explain the daily water balance model (note 3). EA representatives have agreed many of the principles behind the model
- Whereas Affinity Water bases its views about the impacts of abstraction, in the area around the boreholes, on 3 “switch off” tests conducted in 2015/16; whereby 1 borehole at a time was switched off for between 10-30 days. Affinity Water’s conclusion was that stopping abstraction resulted in no discernible increase in flow (you might agree with John Lawson when he countered that these switch-off tests might have been too short/ limited in scope to give measurable flow increases?)
Recommendations of the draft report:
- The existing licence of 14.8 Ml/d would need to be reduced to 2.4 Ml/d to achieve the CaBA (note 4) recommendation that abstraction should comprise no more than 10% of the recharge rate, to ensure a healthy chalk stream
- John Lawson suggests an innovative, neat solution to save the upper Ivel.
Please see high level illustration of the proposed solution to save our river:
Benefits of John Lawson’s proposed solution:
1. It does not cost much in terms of new infrastructure i.e. low carbon
2. It does not cost much in terms of water requirements (net 4.5Ml/d)
3. It utilises the emergency storage capacity of the aquifer and could help alleviate drought
conditions locally
4. The upper Ivel could be a test case to save chalk streams nationally
Next steps:
1. John Lawson’s paper is being peer reviewed (note 5)
2. RevIvel will submit/ present the proposed solution to Water Resources East/ Water
Resources South East (WRE/ WRSE) to be included in regional and national plans which
determine water allocation for the rest of the century. It is critical for our voice to be heard
3. Further meetings are planned over the summer with Anglian Water, Affinity Water and the
EA to:
Achieve consensus on the impacts of abstraction
Challenge the EA classification (per The Water Framework Directive) of the flows
and ecological status of the upper Ivel; this is currently “good”, making it hard to
argue that urgent action is needed
Keep pressure on the relevant bodies to adequately take account of the needs of the
upper Ivel
Finally:
If you have any questions or can offer expert help in any of these areas, please contact
media@revivel.org. We would love to hear from you.
This update covers the “John Lawson” work only. A further update will follow about the state of the
river and other actions which RevIvel is undertaking.
Notes:
1. Average abstraction 12.4Ml/d/ average recharge is 23.6Ml/d. Recharge refers to the rate of
replenishment of the aquifer which is largely dependent on autumn and winter rainfall
2. There used to be perennial flows of 5-10Ml/d (millions of litres per day)
3. The CSF model computes the daily aquifer storage within the Upper Ivel catchment by simulating the
water balance of inflows from effective rain and outflows from river flow, underflow and abstraction
4. Note 4: The Catchment Based Approach (CaBA) is an inclusive, civil society-led initiative that works in
partnership with Government, Local Authorities, Water Companies, businesses and more, to maximise
the natural value of our environment
5. Note 5: Peer review: the process by which something proposed (as for research or publication) is
evaluated by a group of experts in the appropriate field. Peer review enhances the credibility of the
manuscript