Water Catchment Management and No-Till

Water companies are increasingly working with farmers to improve water quality at source. No-till farming, cover crops, and improved soil health are key tools. Based on articles from Affinity Water (Shaun Dowman) and Thames Water in Direct Driller Issue 4.

Affinity Water

Affinity Water supplies drinking water in an area classed as “serious water-stress” in south-east England. Every drop is sourced from the natural environment — what happens on farm directly affects water quality.

Cover Crops for Nitrate Capture

  • Three-year trial testing different cover crop mixes in drinking water catchments
  • Results confirm cover crops are effective at capturing nitrate
  • Planning to incentivise farmers to grow cover crops in nitrate leaching problem areas

No-Till and Water Recharge

  • “It is generally acknowledged that no-till soils have better water infiltration than a tilled soil”
  • Hypothesis: greater no-till area → greater water recharge into aquifers
  • Research planned to test this at catchment scale

[Source: dd-issue-04, 2026-04-11]

Thames Water — Evenlode No-Till Trial

  • River Evenlode catchment (west of Oxford, partly within Cotswolds AONB)
  • 5-year trial started September 2018 with research support from Innovative Farmers
  • Testing whether no-till reduces loss of soil and phosphorus to watercourses
  • Also testing whether no-till increases farm profitability and efficiency
  • Farmer-led: participants can test additional topics (soil health, nutrition, cost vs yield)
  • Thames Water funds machinery costs and cover crop seed to remove risk from participants
  • Field-scale soil and water quality monitoring throughout

[Source: dd-issue-04, 2026-04-11]

Policy Implications

  • Post-Brexit agricultural policy increasingly focused on “public goods” including water quality
  • California’s Healthy Soils Program (referenced in Farmerama podcast, Issue 4): paying farmers $50,000 to sequester 345.6 tonnes of GHGs/year via min-till, cover crops, and compost
  • Finnish government pays €30–40/ha for no-till to prevent phosphate run-off during snowmelt (see No-Till Economics — Benchmarking and Cost of Production)
  • UK water companies may become significant funders of no-till transition

[Source: dd-issue-04, 2026-04-11]

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