Tharbad ruined by floods and deserted
Event Type: Environment/Disease
Age: 3rd Age - The Stewards
2912 Great floods devastate Enedwaith and Minhiriath. Tharbad is ruined and deserted.
The Return of the King, LoTR Appendix B, The Tale of Years: The Third Age
When the days of the Kings ended (1975-2050) and the waning of Gondor began […] the Royal Road was unkept in Enedwaith, and the Bridge of Tharbad becoming ruinous was replaced only by a dangerous ford.
Unfinished Tales, Part 3, Ch 5, The Battles of the Fords of Isen: Appendix
[The] great North-South Road, which was the chief route of communication between the [Arnor and Gondor] except by sea, ran through it from Tharbad to the Fords of Isen (Ethraid Engrin). Before the decay of the North Kingdom and the disasters that befell Gondor, indeed until the coming of the Great Plague in Third Age 1636, both kingdoms shared an interest in this region, and together built and maintained the Bridge of Tharbad and the long causeways that carried the road to it on either side of the Gwathló and Mitheithel across the fens in the plains of Minhiriath and Enedwaith. A considerable garrison of soldiers, mariners and engineers had been kept there until the seventeenth century of the Third Age. But from then onwards the region fell quickly into decay; and long before the time of The Lord of the Rings had gone back into wild fenlands.
Unfinished Tales, Part 2, Ch 4, Appendix D, The History of Galadriel and Celeborn: The Port of Lond Daer
[Note: the floods appear to be a consequence of the The Fell Winter of the previous year.]
added quotes/links: Tanaqui 13May05