EAS were tasked with consulting the Environment Agency (EA) on their requirements, and then constructing a hydraulic model to help design the new channel. The EA required a ‘high flows’ and a ‘low flows’ channel, so the design was such that both events could be contained without posing a flood risk to others. A 1D HECRAS hydraulic model was constructed to assess the various options and identify any areas where the cross section of the channel needed to be adjusted to contain the water.
Blockage scenarios were also modelled to determine the impact on the flow events.
EAS also made the Environmental Permit application on behalf of East Herts, which the EA required to carry out the works and to ensure the impact to the watercourse were limited.