Iowa City moves to adopt statewide SUDAS design manual, adds new stormwater and pavement standards

City Engineer Jason Havel presented a proposal to adopt the Statewide Urban Design and Specifications (SUDAS) design manual as Iowa City’s supplemental design manual, saying the change would modernize the city’s 1996 design standards and improve consistency with nearby municipalities.

Havel said the update includes two principal changes likely to affect local projects: a requirement for a drainable subbase and subdrain under pavements to extend pavement life, and revised stormwater-management formulas that add a water-quality component and provide additional options such as rain gardens, bioswales and pervious pavements. He said the new approach would create standardized drainage reports so consultant submittals are easier to compare.

Councilors asked whether the stormwater changes would improve outcomes in large rain events; Havel replied the updates are an “advancement” in handling stormwater though not flood-proof. He also said smaller or constrained sites may qualify for exemptions or scaled approaches where strict compliance is impractical, but applicants would need to show a good-faith effort to address site conditions.

The item was opened for public hearing; no members of the public spoke on the record. Council voted 7–0 to give first consideration to the ordinance and to advance the adoption process; staff said the ordinance would return for additional readings and final adoption in November, followed by annual updates as needed.

The council packet and staff presentation cite improved long-term lifecycle costs from better drainage and pavement design and note the city will continue outreach to developers and engineers to ease the transition.

Next steps: the council will consider final readings and adoption in November; staff expects to continue annual updates to stay aligned with SUDAS revisions.