Water for the palace came from the Jadro River near Salona. Along the road from Split to Salona impressive remains of the original Roman aqueduct can still be seen. They were extensively restored in the 19th century.The British neo-classical architect Robert Adam surveyed the ruins of the palace and published Ruins of the Palace of the Emperor Diocletian at Spalatro in Dalmatia in 1764.

In November 2006 the City Council of Split has decided to approve construction of over 20 new buildings within the palace (including a shopping garage complex), despite the fact that the palace has been declared UNESCO World Heritage Monument. According to many sources, the decision appears to be primarily politically motivated and largely due to lobbying efforts of local real-estate developers.