Thornton council adopts new development code, stormwater permitting and related fee changes; approves Parterre zoning amendment

Thornton City Council unanimously approved a set of land-use and public-works measures Tuesday night that included a complete reenactment of Chapter 18 (a new development code), a new stormwater quality permitting program, updates to several fee and rate ordinances, and a zoning amendment for the Parterre subdivision.

The package centers on the citywide development code overhaul. Karen Wodomski, long-range planning manager, told council the new Chapter 18 replaces the existing development code, updates district names on the official zoning map and repeals an older 1996 ordinance that conflicted with the new code. The new code is scheduled to take effect Sept. 1, 2025; Wodomski said the ordinance includes two clerical corrections made after first reading to clarify application-processing dates and how existing conceptual site plans will be handled under the new code.

Why it matters: the code rewrite consolidates many planning rules, renames some land-use terms and changes several procedural items that affect how future development applications will be filed and reviewed. City staff and the council said the updates are intended to align terminology across city ordinances and move technical standards to the appropriate chapters of the municipal code.

Stormwater permitting and fees: Keith Bisbee, the city's stormwater coordinator, presented an ordinance adopting stormwater and floodplain revisions and adopting by reference the Mile High Flood District urban storm drainage criteria manual. The revisions create a stormwater quality permit for construction sites that disturb 1 acre or more — or any site under an acre that is part of a larger common plan of development — and extract stormwater review costs from general development fees into a stormwater enterprise fund.

Bisbee described a bracketed permitting fee structure tied to site acreage and an administrative renewal fee of $150 for annual permit renewals or significant permit amendments. The draft also adds enforcement measures: limiting active disturbance on a site to 40 acres at a time (with variances possible), authority to charge reinspection fees for repeat violations and escalation to a stop-work order for noncompliance. Bisbee reported stakeholder outreach to the Home Builders Association and to council on July 22 and recommended approval. Council voted to adopt the ordinance on second reading unanimously.

Parterre zoning amendment: Council approved on first reading a zoning amendment to the Parterre planned development to relocate one of two private recreation centers from Planning Area 1A to a planning area south of E‑470, add eight single-family detached lots on a former 3.5-acre clubhouse site, and convert 2.5 acres into a publicly accessible park. Colin Weihap, principal planner, and Brad Hague, the applicant’s representative, said the change reflects a shift in product type (an active-adult product is no longer proposed on the north parcel) and will keep the overall planned-unit maximum below the previously approved cap (the total units would rise from 391 to 399, still under a 420-unit cap). Several residents asked about notification and who will pay and maintain the park; staff said park construction is part of the development and maintenance is expected to be handled by the project's HOA and Metro district. Council carried the first-reading ordinance unanimously.

Fee and code cleanups: Council also approved several companion measures intended to align other city ordinances with the new Chapter 18 and the stormwater changes. Those included: - A resolution updating city fees (moving some stormwater-related reinspection fees and restructuring permit fees) effective Sept. 1, 2025. - Amendments to three rate-and-fee ordinances (water, sewer/trash and stormwater) to harmonize terminology (e.g., single-family/multifamily definitions) with the reenacted code. - An ordinance that updates cross-references and moves blighted-property rehabilitation language from the development code into Chapter 38 (property maintenance), a relocation staff said is organizational only and not a policy change.

Council action and next steps: All measures were adopted by unanimous vote in the meeting's roll calls. The new development code is scheduled to take effect Sept. 1, 2025; stormwater permitting and the revised fee schedule take effect the same date per the adopted resolution. The Parterre amendment will return for a required second reading before final adoption. City staff said they will continue public outreach on how existing applications will transition under the new code.

Council and staff members who presented or moved the proposals emphasized that these were technical and organizational changes intended to improve clarity, enforcement and the city’s ability to recover review costs for stormwater work. Several members of the public used the meeting’s public-comment period to raise separate concerns about communications, neighborhood nuisance issues and code enforcement in mobile-home communities; councilors acknowledged those comments and referred residents to staff follow-up and future study sessions.