City of Denton engineering staff on Wednesday described a package of technical updates to the city’s Design Criteria Manual that would change standards for stormwater, drainage, pipes and other public‑infrastructure elements and create a new chapter on environmentally sensitive areas.

The presentation, given at a Planning & Zoning Commission work session by Brett Bush, the city engineer, said staff will post the draft document for public comment Friday and plans a sequence of briefings and hearings through November and December with formal adoption now targeted for a Jan. 1 effective date.

The draft covers multiple manuals used by the city for design and construction, Bush said. “These are very technical documents that are used to design all the different infrastructure for the city,” he told the commission, and staff intends broad outreach to the development community and professional organizations before final action.

Staff highlighted several substantive changes. The stormwater chapter would separate flood‑control (detention) requirements from water‑quality treatment for developments of one acre or larger to align with regional iSWM guidance and anticipated EPA direction. That change is intended to let developers use smaller detention basins while treating runoff through other on‑site measures such as bioswales, rain gardens or filter strips.

The water/wastewater chapter would require geotechnical reports and cathodic‑protection design where soil corrosivity threatens metallic pipe longevity; the city also is seeking cathodic protection for ductile iron pipe in corrosive soils. The list of acceptable pipe products would expand beyond reinforced concrete to allow polypropylene pipe as an alternate, which staff said should reduce costs through increased competition.

A new section on environmentally sensitive areas (ESA) documents how to identify and treat ESAs and includes an appendix vegetation list and native seeding mixes, city staff said. The ESAs guidance specifies temporary protective fencing and a minimum four‑foot maintenance buffer near protected features; Jennifer Avesi of Environmental Services explained the 4‑foot minimum was chosen to allow maintenance access and space for silt‑fence trenching.

Transportation and street‑design revisions include new cross‑sections, updated on‑street parking guidance and a change in the traffic‑impact threshold used for scoping studies. Raki Bulalom, a transportation planner, said the formal threshold in the checklist was lowered from 100 to 50 trips to match currently used practice. The draft also removes an experimental “bike‑ped traffic impact analysis” added in a prior revision on the grounds that it was not yet industry standard and users found it difficult to apply; staff said bicycle and pedestrian connectivity will instead be addressed through scoping meetings and existing mobility‑plan checklists.

On solid‑waste standards, staff restored flexibility for side‑load dumpster enclosures where front loading is not feasible. The manual also adds guidance on lift station design and a new streetlight pole requested by developers.

Floodplain administrator Mike Linder said the changes to water‑quality treatment could reduce the clogging problems that occur with extended‑detention basins by allowing developers to choose from many treatment options in the iSWM manual that emphasize infiltration and vegetation.

Commissioners asked about the new ESA language, the 4‑foot buffer and how parks and detention maintenance will be enforced going forward. Staff noted that recent criteria changes already require privately owned detention facilities to have maintenance agreements and operation manuals; those provisions, staff said, are intended to ensure the city can require corrective work and recover costs when private facilities are neglected.

The commission did not take a vote Wednesday. Staff said it will present the draft to the Texas Society of Professional Engineers and other city boards before sending it to City Council, and will accept public comments online after Friday’s posting.

What’s next: staff will post the full draft for public comment on Friday, present the draft to professional and advisory bodies in November, and ask City Council to consider adoption in December with an effective date of Jan. 1, 2026.