Adjoining the back of the now-demolished residential and service building was a service area containing a huge brick-built well. The ruined remnants of water installations that originally served Sultan Qaitbey’s complex include an emplacement for a large waterwheel (saqiya) over the well, whose design is virtually identical with those used in Egypt in ancient Roman times. It certainly supplied water to the hawd drinking-trough for animals and most probably also to other parts of the complex including the mosque’s ablution area. Also preserved, although incomplete, are water conduits and a huge brick-built water tank that could hold 45,000 – 50,000 litres.
Water in wells was brackish in Cairo, so the installation supplied water for various household uses, but not for drinking. Potable Nile water distributed from the sabil charities had to be brought by pack animals.