The work relates to the draft inventory of OMH published in 2013 and not updated since. The scale of the change in the extent of OMH since 2013 was unknown so in 2024 a contract was let to compare the polygons within the draft inventory against the latest available aerial imagery. This confirmed that 25% of the polygons no longer contained OMH and should be removed from the inventory and in another 30% of the polygons OMH was still present but the boundary of the polygon required amendment to account for partial loss from development or vegetation succession.
The work is to use the data from the 2024 contract and remove and amend the polygons from the draft inventory where OMH has been lost to create a more accurate GIS layer.