Stormwater Management Criteria Update

The City of Manhattan amended the Stormwater Design Criteria to adopt the new Stormwater Management Criteria, 2023 (PDF) edition.

The new criteria took effect on November 1, 2023. This document replaced the previous technical design standards contained in the Stormwater Management Master Plan (SWMMP), which had been in place since 1994.

An amendment to the City’s Post-Construction Best Management Practices Manual has also been issued with the same effective dates.

Submittals based on these designs must use the new Design Submittals Workbooks.

These documents have been formally adopted and are available from the Standard Specifications page.

In addition, the City is proposing to adopt updated Standard Drawings and Construction Specifications, which would supersede those currently in effect when finalized. Work is continuing on these documents, and they will be issued at a later date.

A public comment period, including two public meetings on October 18, 2022, was held in the fall of 2022.

A second public comment period, which ran from August 12, 2023, through September 7, 2023, is now closed.  The City Commission received a presentation on the new standards at its work session on August 22, 2023.

Comments or questions regarding these standards should be sent to Bill Heatherman, Stormwater Compliance Engineer, by contact form, or phone at 785-587-4578.

Proposed Criteria & Standards, Still Under Development

Supporting Materials