Planning commission approves amending tower setback rule to allow engineer-certified fall zones

The Florence City Planning Commission voted to approve a text amendment to Section 1-2.806(a)(6) of the Unified Development Ordinance to allow tower and antenna setbacks to be measured by a tower’s certified fall zone rather than by a one-to-one height-to-setback ratio.

The change, requested by Duke Energy, replaces the current code language that requires a tower’s setback from a residential property line equal to the tower’s height (for example, 300 feet for a 300-foot tower) with a requirement that the setback equal or exceed the tower’s fall zone as certified by a professional engineer.

Planning staff said the amendment is prompted by modern tower design and an upcoming tower replacement on North Douglas Street. Staff described the existing tower as end-of-life and said replacement would trigger current standards because the existing tower would be removed. Staff noted other jurisdictions have adopted fall-zone language and that the proposed change would still require any specific tower to seek a special exception from the Board of Zoning Appeals.

Duke Energy representatives said the replacement tower would be self-supporting and designed so that if it failed the structure would fold inward rather than tip over. Sarah Spruill of the law firm representing Duke Energy told the commission the company sought the text amendment because zoning special-exception relief is not permitted under the code for the condition at issue. Patrick Verrier, Duke Energy senior project manager, and Caleb Jurgensen, a licensed engineer with Burns & McDonnell, explained technical aspects of inward-folding designs and how engineers size members to create a controlled failure point in upper sections of a tower rather than at the base.

Commissioners asked about examples of the design failing and about the local setback distances. Caleb Jurgensen said he did not have field examples in the room to show but described the engineering rationale: member sizing to produce an inward fold under extreme conditions. Duke counsel said indemnity and special-exception application requirements provide protections and that final approval of any tower at a specific site would still go to the Board of Zoning Appeals.

After public testimony from Duke Energy’s team, the commission closed the public hearing, moved to approve the text amendment, and approved it by voice vote. The commission chair noted the discussion had been technical and thanked presenters.

The amendment changes how future tower replacements and installations will be evaluated in Florence City and leaves site-specific review and public hearings for subsequent special-exception or permitting steps.