in which estoppel is invoked.”); Dillard v. Austin Indep. Sch. Dist., 806 S.W.2d 589, 594 (Tex.App.-Austin 1991, writ denied) (calling bar against invoking estoppel on city acting in its governmental capacity a corollary to sovereign immunity); see also Black & Daniel, supra, at 243 (stating because sovereign immunity tends to insulate city from negligent acts associated with zoning, Texas courts are reluctant to uphold estoppel against city’s enforcement of zoning ordinances). The caselaw suggests that in order to apply estoppel the trial court must determine the following: (1) whether the landowner is relying on an authorized act of a city official or employee, see Stapf, 101 S.W.2d at 232; Deutsch, 91 S.W.2d at 310; Krause v. City of El Paso, 101 Tex. 211, 106 S.W. 121, 123 (1907) (<HOLDING>); Rosenthal II, 239 S.W.2d at 643 (holding
holding that because a city inspector was not entitled to official immunity the city was not entitled to vicarious official immunity holding that a city may not act arbitrarily in adopting a moratorium ordinance in order to prevent a party from obtaining a building permit to delay or prevent a single project the city must exercise the authority for the purpose of protecting the planning process holding city could not enforce through administrative adjudication a city ordinance limiting vehicle weight holding landowner entitled to rely on permit from mayor and survey of city engineer both of which city ordinance required her to obtain before building holding that city attorneys promise in an oral settlement agreement for city to annex and rezone land was within the legal authority of the city of joliet to accomplish and were not absolutely void acts per se therefore city could be estopped from avoiding enforcement of contract