In City of Tucson v. Whiteco Metrocom, Inc., 194 Ariz. 390, PP29-30, 983 P.2d 759, 767 (App. 1999) the Court applied that general principle where the trial court, instead of ordering removal of a billboard, had ordered removal of the second advertising face of the billboard, "thereby restoring the billboard to its nonconforming use configuration." 194 Ariz. 390, PP15, 18, 983 P.2d at 764. The Court noted that nothing in the relevant statute or the Tucson Code prohibited that action, and deferred "to the trial court's discretion in fashioning a remedy." Id. P19. In Whiteco Metrocom, we cited Valencia Energy Co. for the proposition that estoppel will apply against the government only if its conduct threatens to cause a serious injustice. Whiteco Metrocom, 194 Ariz. 390, P22, 983 P.2d at 765.