The Colorado Supreme Court ruled on Monday that rezonings of planned-unit developments cannot occur through a vote at the ballot box, reversing an appellate decision that found such changes were fair game for a popular vote.

In contrast to traditional, or “Euclidean,” zoning, which separates land uses by type, planned-unit developments are based on negotiated agreements specifying the types of land uses within a defined area. The Supreme Court held in 1981 that traditional zoning and rezoning decisions are legislative in nature and therefore subject to ballot initiatives.

But what about changes to PUDs after the plan is approved?

“To be sure, a PUD is a form of zoning,” wrote Justice Maria E. Berkenkotter in the June 15 opinion. But in the face of a proposal to change a parcel of open space to housing, “the initiative process is not equipped to address the complex assessments required by the Town’s enabling ordinance, such as how to best mitigate geologic hazard areas and high groundwater tables or how to maintain transportation linkage for adjacent properties.”

The case from Telluride centers on an area in the Butcher Creek PUD known as “Lot A,” an open space that owner Brighton Properties seeks to rezone to permit affordable housing. The town rejected a proposed ballot initiative to that effect, claiming that an amendment to the 30-year-old PUD agreement needed the homeowners’ approval.

Brighton Properties sued the town clerk, seeking a declaration that it is legally permitted to pursue rezoning through a ballot initiative.

Acknowledging court precedent that labeled zoning a legislative act normally subject to the initiative process, then-District Court Judge Mary E. Deganhart believed Brighton Properties’ case was “more complex than the simple rezoning of a single parcel.” After a trial, she sided against Brighton Properties, concluding the land-use designation for Lot A could not be changed without the consent of the lot owners.

Brighton Properties appealed, arguing that if original zoning decisions are legislative, so are rezoning decisions. Deganhart’s interpretation of the law meant all PUDs would become “a refuge” from citizen-initiated rezoning measures, the developer noted.

A three-judge Court of Appeals panel sided with the developer, holding that both zoning and rezoning decisions are legislative actions within the initiative process. However, the panel declined to answer whether the legal rights of the other lot owners were implicated, deeming it an issue to be addressed if the initiative ultimately passed.

“If the ordinance is adopted, the other lot owners may assert whatever rights they believe they possess to challenge the validity of the ordinance on its merits,” wrote then-Judge Anthony J. Navarro.

Telluride, in appealing to the Supreme Court, received support from the Colorado Municipal League, which argued “substantial public resources are wasted” in conducting a rezoning vote, only for neighboring property owners to later invalidate the results by asserting their own rights. The league also noted zoning decisions made by localities are quasi-judicial and apply facts to legal criteria — which does not happen in a popular election.

“What’s to stop the electorate from undoing the entire PUD?” wondered Chief Justice Monica M. Márquez during oral arguments.

“This feels like somewhat of a ‘hostile zoning’,” added Justice Richard L. Gabriel.

Brighton Properties’ attorney, Patricia A. Mellen, said it is possible to educate voters about the technical aspects of a rezoning, and there was no reason to limit their rights when a rezoning initiative happens to focus on a PUD.

“It is simply a different means to an end. It’s a valid option for a party to seek a ballot initiative in the same way it is to seek approval through the town itself,” she said.

But the justices saw a distinction between a local government’s adoption of “broad public policy” through an original PUD ordinance and the “administrative power” it exercises to carry out those goals in a development.

“The Town reviewed the application based on case-specific considerations that require specialized knowledge,” wrote Berkenkotter. “By attempting to override the proper procedure to amend the PUD Agreement, Brighton invaded the Town’s administrative authority.”

The case is Kavanaugh v. Telluride Locals Coalition Petitioners’ Committee et al.