Minutes of supported Severn Thames transfer water resources option – Lake Vyrnwymeeting

10:30-14.30Tuesday4thApril2017.

Severn Trent Shelton offices, Shrewsbury, Shropshire SY3 8BJ

Attendees:

Pat Spain (PS), Severn Trent

Sarah Clark (SC) Severn, Trent

William Mackveley (WM), Severn Trent

Liz Franks (LF), Severn Trent

Steve Tuck (ST), Thames Water

Chris Lambert (CL), Thames Water

Afzal Ginwalla (AG), Thames Water

Martin Ferreira (MF), Ricardo

Mark Smith (MS), United Utilities

Bill Hume-Smith (BHS), Mott MacDonald

Stuart Hanks (SH), EA

Alison Williams (AW), EA

Claire Walker (CW), EA

HephNeate (HN), EA

Oliver Nyland (ON), EA

Sarah Wardell (SW), EA

Jackie Spencer (JS), EA

Kevin Voyce (KV), EA

Ros Challis (RC), EA

Helen Tidridge (HT), NRW

David Lee (DL), NRW

Jonathan Gilpin (JG), NRW

Jason Jones (JJ), NRW

Objectives of meeting:

  • To discuss the Lake Vyrnwy supported Severn Thames transfer option
  • To review the environmental and hydrological impact of the option
  • To discuss the River Severn regulatory requirements for the option
  • To discuss promotion of the Lake Vyrnwy option

Notes:

  1. BHSdescribed the current assumed operation of the scheme. JJ queried where the Aber Conduit goes – BHS stated that it is an alternative conduit linking into the aqueduct to Oswestry.
  2. PS stated the Clywedog option is not being offered to Thames Water Utilities Ltd (TWUL) currently but may be a viable option in the long term. AW queried why - PSstated that sufficient work not yet completed for this stage of the WRMP and the option is currently more expensive than Vyrnwy. However it remains on the unconstrained list for STW’s WRMP19.
  3. PS provided update on Severn Trent Water’s (STW) purchase of Dee Valley Water Company. STW purchased Dee Valley Water last autumn, and due to the mixture of English and Welsh licences, the current proposal is to have a STW England and a STW Wales region, with some areas currently under Dee Valley Water moving to STW England (eg Chester) and some areas currently under current STW moving to STW Wales (this will include Vyrnwy and Clywedog). The change is intended to be in place for PR19 but as the negotiations and assessments are very complex this is not certain. LF concurred that this would be a very complex and difficult change. PSstated that any changes in regulation will be feed through to a change in the scheme.AW stated that there will need to be Section 20 changes.
  4. MF began presenting the attached slides on the environmental impact consultation with NRW and the EA.MF thanked NRW for data provided to date and stated that available WFD data had been used where data from NRW is still outstanding. DL queried what data is still outstanding. MF stated that species level data for macrophytes and data on sensitive species. ACTION:JJ agreed to chase this up.
  5. MF queried what baselines and scenarios NRW and the EA would require to be modelled. AW queried whether UU modelling took account of regulation requirements of Vyrnwy. MS stated that yes, this was accounted for as far as possible, however some regulation requirements further down the Severn catchment may not have been explicitly modelled. ACTION: MS to circulate UU modelling assumptions
  6. SC queried how the water released is allocated in the model - MS stated that modelling assumes that the water released is split between UU and TWUL, with the ratio governed by TWUL requirements. PS stated that this would involve combining 2 different regulation systems. CL stated that the Thames system is driven by long term droughts and the operating requirement for all new strategic schemes is likely to be the same as the operating strategy in place for existing schemes such as the Gateway desalination plant.
  7. JJ queried whether the current requirements of strategic schemes take into account climate change and stochastic droughts as this may increase the frequency of future releases. CL stated that they currently don’t, as historic droughts only cover up to a 1 in 125 year drought, but that this work is ongoing through Atkins. CL stated that this information would be shared with regulators. ACTION: CL to share stochastic data with attendees when available.
  8. AW queried whether the option is considered to be resilient,CL stated that the option is considered resilient due to winter recharge. ST queried the option capacity, MS stated that this is currently stated as 180 Ml/d but further work has shown that a small amount (< 5 Ml/d) more is available and this figure would be shared with stakeholders. ACTION: MS to clarify the precise capacity of the Vyrnwy option.
  9. CL stated that total amount that could be abstracted by Thames at Deerhurstwould be based upon a ‘put and take’ relationship as discussed at a national level meeting with the EA. A loss of 10% of the transfer is currently assumed between the release from Vyrnwy and abstraction at Deerhurst. AW queried where the 10% figure was derived from. CL stated figure came from the EA. CW stated that this figure would likely only cover losses up to the confluence with the River Severn and that the losses would ultimately depend upon the frequency and intermittency of the scheme. KV stated that currently, a loss of 32% is assumed at Bewdley for the Shropshire Groundwater Scheme regulation flows. AW queried how to take this work forward and CW stated that the EA would free up resources to determine an acceptable figure and confirmed that this work would also look at losses from the Minworth and Draycote options. It was agreed that CL would send a formal request. ACTION: CL to send a formal request to CW regarding the level of losses to assume for the Vyrnwy transfer.
  10. AW queried whether 1975/76 drought and 1984 drought had been considered - MF stated that all years within the time period had been considered.
  11. CL queried how the drought permit for Vyrnwy operates – MS stated that there is no specific trigger in place for the drought permit and that there is a reduction in the compensation flow from 45 Ml/d to 25 Ml/d. JJ stated that NRW is reviewing the environmental impact of this drought permit.
  12. JJ queried what level of natural flow the releases from Vyrnwy correspond to i.e. Q50, Q20 etc as a Q20 flow would be a high flow to be regularly going through in August. ON stated that gauges are in place to measure high flow, not low flow. JJ suggested installing a gauge at an intermediate location before the first current gauge. CW stated that the flows presented didn’t include the Vyrnwy Water Bank regulation releases to Bewdleyand the 180 Ml/d would be additional to this. MF stated that Ricardo need the regulation scenarios. ACTION: MF to formally request data from CW and Rob Stroud.
  13. MF clarified that flood drawdowns would take precedence over TWUL water supply in order to maintain flood protection.
  14. JJ stated that more detail around hydromorphology is required to ascertain the depth of releases. ACTION: MF to follow up with JJ.
  15. MF presented temperature analysis and next steps regarding monitoring, JJ stated that some river temperature data was not accurate. CL queried whether it is likely to have a significant impact – JJ stated that there is the potential for this depending upon the timing. ACTION: MF to follow up with JJ.
  16. MF presented species data. RC stated that there may be Sea Lamprey below the waterfall but this is not in the data as there is no monitoring for Sea Lamprey. MF stated that there was no NERC data to assess. JG stated that there is interest in CoedCopierCraig due to interest in the flood plain. ACTION: MF to follow up with JG/RC.
  17. JJ stated that the scheme could have an effect on WFD status of the reach immediately below Lake Vyrnwy as the status could change from ‘High’ to ‘Good’. This would contravene the no deterioration legislation for fish and macro-invertebrates. ACTION: MF/Ricardo to assess and propose mitigation on behalf of TWUL.
  18. JJ stated that the Welsh government recently published ‘Managing Resources for Future Generations’ and that this scheme should need to meet the objectives of this document. ACTION: MF/Ricardo to obtain copy of this document and assess compliance.
  19. CW queried whether future growth in TWUL area would need a more frequent release. CL stated that TWUL would likely take the maximum that could be offered through the scheme and the objective should be to determine what is the maximum volume and frequency of release that is acceptable to all stakeholders. CW stated that any analysis should ensure that licences are being utilised to their maximum along the route, as historical data may not show the true potential impacts of licences due to underuse. JJ stated that impacts are more likely if the frequency of releases increases and it is hard to ascertain what the acceptable limit is. Ricardo to analyse environmental impacts of this and share with stakeholders to determine acceptability.
  20. ON suggested more flow gauges could be installed along the route to improve accuracy of flow impact analysis. ACTION: MF to liaise with ON regarding viability and cost of this.
  21. PS outlined a joint proposal from UU/STW to transfer 30 Ml/d directly from Oswestry to Shrewsbury via pipeline which would mean that the STW Shelton abstraction could be reduced by 30 Ml/d and the release from Lake Vyrnwy could then be reduced to 150 Ml/d whilst still providing 180 Ml/d of support to TWUL.HT/AW queried why pipelines couldn’t be used for more of the transfer to reduce the environmental impact on sensitive upper reaches of River Vyrnwy and River Severn. BHS surmised this may be due to cost considerations as it could add a significant level of cost to the project which would make it uncompetitive with other TWUL WRMP19 options. However if release from the dam proves unacceptable then a pipeline from Oswestry to the River Vyrnwy/Severn is one possible mitigation.
  22. JSgave a brief run through of River Severn regulation. CW stated that more detail is available publically.
  23. KV queried how to proceed with the combination of different regulatory regimes for Vyrnwy scheme and wider River Severn regulations – MF stated John Sanders (Ricardo) has considered this and will provide a briefing note for attendees. BHS summarised that the proposal was to change the operating rules so that the flow at Bewdley is calculated, adjusting the measured flow to take account of the “put and take” agreement (less losses) – this could allow the 850 Ml/d minimum residual flow specified in legislation to remain unchanged, although some minor changes to abstraction licences may be neededACTION: MF to circulate John Sanders’ notes to attendees when available.
  24. It was suggested that legal advice regarding regulatory changes should be sought and advice discussed at a subsequent meeting. ACTION: SH to engage EA legal helpdesk and PS to engage STW legal team.
  25. MS provided update on Vyrnwy from UU, including engagement with UU stakeholders. HT queried whether local Welsh residents and the Welsh people had been consulted – MS replied that this hadn’t been specifically done yet. It was agreed by all that more local and targeted engagement should take place once regulator’s concerns had been addressed. ACTION: HT to provide list of local stakeholders to attendees once sufficient level of investigation has been completed.
  26. EA stated that concerns regarding invasive non-native species should be addressed to Martin Fenn.

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