The destruction of Pacheco’s Walnut Creek shipping channel occurred gradually over many years and for many reasons. Man-made ecologic damage eventually combined with a series of fires and floods, as well as an earthquake, destroyed the town and filled the Slough with silt during the 1860s, to ruin Pacheco's growing prosperity just as similar ones had done to the great classic ports of Ephesus and Troy. Pacheco was subsequently depopulated by the attraction of the nearby town of Todos Santos, later to be known as Concord.