Chalk Streams Working Group

A Chalk River

The Mimram, a Chalk River

Only 14% of rivers nationally are in good ecological health.  The UBO catchment covers a wide area with diverse issues – some rivers are prone to flooding, whilst the headwaters of some chalk streams are dry through over-abstraction.  Water quality issues are pervasive due to differing causes e.g. agricultural and road run off, misconnections etc.    Faced with the vastness of the potential scope, the fact that there are many local and national groups already operating in this space, this small working group has agreed to focus on specific issues which it can influence:

  1. Daylighting can help alleviate surface floods and is beneficial for biodiversity. Aim to work with Local Authorities in Urban Areas
  2. Biodiversity Net Gain (Local Authority Offset Strategy).
  3. Pollution and contaminants: the working group is exploring specific areas in which it can be most impactful
  4. Restoration: the working group is exploring ideas potentially working with the Wildlife Trust/ EA/ Water Companies


Working Group Objectives:

  1. Promote the benefits of daylighting: predominantly through de-culverting which involves opening up buried watercourses and restoring the bed, bank and riparian corridor to more natural conditions. Many urban rivers are hidden underground – ‘daylighting’ them would bring nature back to cities.  An open river will have a higher flood capacity than a culvert, and a slight overflow won’t have the same consequences as a blockage or collapse.
  2. Tie in with Biodiversity Net Gain (riverine application) initiatives and funding.
  3. Agree a practical way forward on urban diffuse pollution/ contaminates/ chemical degradation: contaminant plumes, misconnections, ammonia, also groundwater rebound and sustainable drainage.
  4. Restoration: have input into flagship projects both strategically and opportunistically.

Daylighting: the group is looking closely at initiatives undertaken by the Pix Brook Flood Resilience Innovation Fund Project (ResilienTogether Project), Luton Borough Council, Enfield (the lower Lea) as well as case studies in Sheffield and Bradford (reported in the Environment magazine).  There is potential to use “Luton” as a case study.


Swans in a river

Swans in the Upper Ivel


A  brief summary of some interventions being explored.

“Deliver L/A Offset Strategy through river restoration e.g. one tool of which might be de-culverting (thus linking two of the groups key aims/ policies):

It was agreed that the Ivel might be a good place to start. At the sub-group planning meeting 9 November, the following actions were agreed:

  1. Affinity Water and Five Rivers to lead the planning of the approach working closely with the EA and the working group/ catchment partnership
  2. Project plan and evaluation framework of potential tasks/ deliverables agreed in principle
  • Agree participants and schedule walk of first section (Ivel Springs to Radwell) February 2023
  1. Other areas to focus on include; looking at ownership, modelling of potential impacts, planning to work collaboratively with council representatives and landowners. For example, some riverbanks are deteriorating and washing into the river. Need to engage with local farmers and landowners; might be able to develop a farmer cluster group as elsewhere in the region?”

Water Quality issues: a sub-group is kicking off November 2022 with representatives from Local Authorities, the EA, Anglian Water and the Pix Brook Flood Resilience Innovation Fund Project.  Way forward tbc