Rivers Trust CaBA Workshop 22.6.2017

Managing Abstracon in the Rivers Wye and Usk Benefits of Evidence, Badgering and Collaboraon

John Lawson, FREng, FICE, FCIWEM Water Resources Adviser to WUF What I will cover • How a catchment partnership reconciled the needs of fish and water supplies

• How WUF campaigned prior to the partnership

• The importance of evidence

• The resulng improvements

The Wye/Usk Water Supply System Elan valley aqueduct

supplying 360Ml/d to

Birmingham

Releases from Elan valley to regulate flows in Wye R Wye Releases from Usk to support drought flows Hereford Usk Wye/Usk Crai transfer 125 Ml/d Upper Usk Talybont Monmouth supplying about 55 Ml/d Canal Llandegfedd to Swansea area Usk

Lower Usk Total all 175 Ml/d to Cardiff abstraction Cardiff and Newport c 900 Ml/d Supplying 3 million people Impacts on salmon WUF’s concerns: • Impact of the original dams • Major flow regime changes since 1970s • Much less spillage • Big fall in salmon numbers since 1970s • Salmon stuck in lower river • Uncontrolled canal abstraction Original 2007-10 proposals for Habitats Direcve Compliance • Focused on achieving HD “Ecological River Flows” • Used “benchmark flows”, ie dams are natural! • Didn’t reduce impacts of dams on spates • Didn’t achieve natural flow variaons • Had big impact on canal water supplies, probably requiring canal closure BUT, complied with “rules”, so deemed OK! WUF Whingeing & Badgering

• From 2007 to 2010, we wrote leers, had meengs, made FoI requests • And got nowhere!

NRW response to WUF Whingeing

• We’ve complied with “the rules” • Our modelling shows it’s OK • It’s been agreed by everyone • It’s too late to change

WUF Evidence Gathering

Our own investigation to break the impasse WUF tools for generang evidence • Whole river salmon catch analysis • Individual beat catch analysis • Modelling of water supplies, river flows, water temperature and salmon migraon Generang evidence-based counter-proposals

WUF Wye modelling tools Wye water resource model Water temperature • Daily flows 1973-2011 model • Elan reservoir storage • Daily flows • Transfers to B’ham & S. 1973-2011 • Daily temps • Farm supplies • Impact of reservoirs Wye Salmon Catch Analysis

For 4 beats: Analysis of daily catch v flow records for c.9000 salmon

For whole river: Analysis of 100 years of records by season and reach Sample evidence from beat catch analysis Summer Flow near – 600 Ml/d Combined catch and flow analysis Conclusions on the Wye abstracon impacts

• Migraon from the estuary curtailed in dry years

• Migraon within river delayed by spate clipping

• Situaon geng worse as abstracon increases WUF’s proposed soluon

• Make more use of the reservoirs to support river flows and ecology • Especially in non-drought years • Major improvement with no impact on water supplies More WUF Badgering

Using evidence to press for a better way Mid-2012: Formaon of Usk & Wye Abstracon Group (UWAG) Welsh Water, Severn Trent, NRW, EA, CRT and WUF

Working together to: • maximise ecological benefits • minimise impacts on water supplies • improve operaon rather than cut supplies • make beer use of reservoirs to help fish

Key players in UWAG

Gail Davies, Welsh Water Owain Sheppard, NRW

Supported by Cascade Consulting (now Ricardo) UWAG Evidence Gathering • Ecological walkover surveys • Fish and macrophyte surveys • Salmon tracking • Water quality monitoring • Temperature monitoring UWAG modelling tools Wye water resource model Water temperature • Daily flows 1973-2011 model • Elan reservoir storage • Daily flows • Transfers to B’ham & S. 1973-2011 Wales • Daily temps • Farm supplies • Impact of reservoirs

Usk water resource model Estuary salmon • Daily flows 1973-2011 migration models • 5 reservoirs storage • Daily flows 1973-2011 • Canal supplies • Daily salmon entry • Supplies to S.Wales • Impact of flow changes UWAG collaboraon • 4 working groups – strategic, technical, modelling, fisheries • 36 working group meengs in 2 years • Free sharing of data and dra papers • Sharing and harmonisaon of models • Numerous discussion papers, proposals and counter-proposals, leading to: UWAG Agreement of December 2014 The UWAG Agreement

Signed by affected parties, supported by NRW & EA Summary of Wye improvements New UWAG proposals Except in severe droughts, use Elan reservoirs to: • Release up to 700 Ml/d from Elan dams to boost exisng spates • Delay switch-off of regulaon for 7 days aer start of spates • Increase compensaon releases by up to 330 Ml/d to restore natural flows in Elan and Wye Redbrook flows With full use of existing licences 1994 4000 2400 3500 Spates clipped 2200 3000 2000 2500 1800 2000 1600 1500 1400 1000 1200 500 1000

River flow Ml/d 0 800 -500 Regulation switch-offs 600 -1000 400 -1500 200 -2000 0 Environmental releases Ml/d Natural flow reduced Natural flow increased Normal compensation HEP release Normal regulation Extra comp release Drought comp boost Spate boost Natural flow Scenario flow Redbrook flows With proposed licences 1994 4000 2400 3500 Higher spate peaks and 2200 3000 recession flows 2000 2500 1800 2000 1600 1500 1400 1000 1200 500 1000

River flow Ml/d 0 800 -500 600 -1000 More reservoir releases 400 -1500 200 -2000 0 Environmental releases Ml/d Natural flow reduced Natural flow increased Normal compensation HEP release Normal regulation Extra comp release Drought comp boost Spate boost Natural flow Scenario flow Improved migration from estuary Summer Flow near Erwood – 600 Ml/d Erwood 2004 With historic abstraction 4000 Spates much reduced 3000 by Elan dams

2000

1000 River flow Ml/d

0

Natural flow increased Natural flow reduced Reservoir outflow With historic abstraction Natural flow Erwood 2004 With proposed licences 4000

3000 Spates and natural recession Releases from restored by reservoir releases dams up to 2000 700 Ml/d

1000 River flow Ml/d

0

Natural flow increased Natural flow reduced Reservoir outflow With proposed licences Natural flow

Improved migration for adults and smolts Improvements achieved without impact on supplies

Summary of Usk improvements New UWAG proposals • Minimal Lower Usk pumping from April to October • Thereby also avoiding diurnal fluctuaons • Reservoir refill mainly in winter • Extra releases from upper reservoirs to boost spates • Releases from Usk reservoir to keep canal open while keeping Brecon flows within 5-10% of natural

With no addional effect on public water supplies Canal abstraction at Brecon weir

To Canal

• Canal & Rivers Trust have unlimited Licence of Right • Limited to 25 Ml/d under informal agreement in 1999 • Until 2007, no reliable means of regular measuring • Gaugings at 50 Ml/d + in 2007 Impact on low summer flow on Usk at Brecon

Flow above weir 80 Ml/d

Residual flow in river 40 Ml/d?

40 Ml/d diverted into canal? Historic flows at Brecon

Drought flows reduced by 50% UWAG improved flows at Brecon

Canal kept open by Usk reservoir releases and new canal feeders Low summer flow in the lower Usk

Stranded ranunculus from diurnal pumping variation Flow reduced by c.40%

Salmon migration to Salmon migration to end Sep % losses With With end September natural UWAG To end To end To end reduced by 1350 river flows proposals Diff June Sep Dec 5445 4093 1352 24.7% 24.8% 10.5% Much reduced pumping in migration season

1100 more salmon in Salmon migration to end Sep % losses

With With river by end Sep natural UWAG To end To end To end river flows proposals Diff June Sep Dec 5445 5175 270 4.1% 5.0% 2.4% Benefits of improvements • Reduced spate clipping in both rivers • Minimal summer abstracon from lower Usk • Daily pumping fluctuaons avoided • Much beer flows for spawning and juveniles • Much reduced migraon impacts • Canal operaon secured in droughts No addional impact on public water supplies

Recent progress • Draing and agreeing new licences and operang manuals (in progress) • New pumping staon, reservoir outlet valves and telemetry (designs ready for AMP6 installaon) • CRT and Welsh Water negoang terms for Usk reservoir support for canal supply • Connuing phased introducon (started 2016) Benefits already being seen

What we’ve learned • Whingeing without new evidence doesn’t work • Badgering with new evidence can change minds • Generaon of new evidence and proposals through collaboraon works best • Nothing gets achieved without mutual understanding of concerns and goals