A pollution incident upstream could affect 16 public water supply intakes in the Thames basin. How long will it take?
Time for WHS
WHS needed to develop an operational tool to map the travel time of a pollution incident at any upstream location to the intakes.
We tackled the task in three phases between autumn 2013 and spring 2015:
Phase 1 We conducted an initial pilot study to map the travel time of a pollution incident from source to the public water supply intake at Farmoor.
Phase 2 We developed our velocity model further and applied our time-of-travel methodology to the nine intakes in non-navigable reaches of the Thames basin.
Phase 3 We extended the travel-time maps to all sixteen intakes, with bespoke local calibration of the velocity model in the Thames basin’s navigable reaches.
Result: A map the client can use to determine the travel time of solute or in-suspension pollutants from an incident point in the catchment to the surface water intake for a given flow condition.
‘Thank you for all the work producing these maps. They will be a great help to us.’
Water Quality Scientist (Catchment Control), Thames Water