Premise: Thorley Wash or Thorley Flood Pound is a 17.3 hectare biological Site of Special Scientific Interest in Thorley, south of Bishop's Stortford in Hertfordshire. It was formerly a flood pound for the Stort Navigation, which was decommissioned in 2004 and converted to a more natural state. It was purchased by the Herts and Middlesex Wildlife Trust from the Environment Agency in 2011.
Hypothesis: Thorley Wash is more than 17 hectares in area.