The image shows a large crack appearing above the left arch, just to the right of the key stone and the blocks are out of alignment by several centimetres. This may be due to subsidence. It may be that this will need to be scaffolded until permanent repairs can be carried out to prevent risk of a partial collapse of this wall. Click on the image to zoom in.
It appears that the site has been allowed to deteriorate, in a manner that clearly violates the regulations on maintenance of Grade-A listed sites, for which owners have statutory duty of care. This is what is stated on the Historic Scotland website:
What will happen if I don’t repair my listed building?
If you fail to keep a listed building in a reasonable state of repair, the planning authority may serve a Repairs Notice. If you fail to comply with this notice the planning authority, with the consent of the Scottish Ministers, may be entitled to acquire it through compulsory purchase.
If you deliberately neglect the building to justify its demolition and redevelopment of the site, the planning authority can buy the building at a price which excludes the value of the land for redevelopment.
Planning authorities are able to undertake urgent works to preserve an unoccupied listed building (or unoccupied parts of an occupied listed building), provided that the owner is given seven days notice of the intention. The cost of these urgent works can be reclaimed from the owner.
The images below show the state of the bank along the riverside behind the pump house where there has been erosion and partial collapse of the wall.
There is also evidence of subsidence on other areas of the site and cracks showing in the quay wall opposite Pacific Quay.