Western Land Equities, Inc. v. City of Logan, 617 P.2d 388 (Utah 1980), involved a developer who sought approval to build a single-family residential subdivision in an area zoned for such use; the municipality rejected the proposal and specifically amended its zoning ordinance to prohibit that particular subdivision. Id. at 389-90. The issue was whether the zoning amendment could be retroactively applied to prohibit the developer's project. Id. at 390. Citing the need to ensure that the developer's investment in the subdivision plan based on the original zoning would not be completely lost, the Court held that the developer was entitled to approval of the subdivision plan if it was in compliance with the zoning requirements in existence at the time of the application, before the municipality's zoning ordinance amendment. Id. at 396. The Court held "that an applicant is entitled to a building permit or subdivision approval if his proposed development meets the zoning requirements in existence at the time of his application and if he proceeds with reasonable diligence, absent a compelling, countervailing public interest." Id. at 396. The Court went on to provide, however, that an applicant is not entitled to rely on zoning ordinances in effect at the time of application if "proceedings to amend those zoning ordinances" are underway. Id. The latter limitation resonates nicely with estoppel principles, which provide the primary policy rationale underlying the development of the rule articulated in Western Land Equities. See id. at 391-93 (describing "zoning estoppel" and stating that it would be unfair to disallow development when an applicant has, reasonably and in good faith, detrimentally relied on government acts or omissions in pursuing what was perceived as a valid development project).