Council introduces updated floodplain and stormwater ordinance to modernize drainage rules

The Cathedral City Council voted unanimously on May 13 to introduce an ordinance updating municipal code chapter 8.24 to modernize floodplain management and stormwater storage requirements.

Public works director John Corella (presenting) said the ordinance updates dated standards, clarifies drainage law, modernizes design criteria for retention basins (freeboard, drawdown times and bicycle-compliant inlet grates), and extends code coverage to large regional stormwater facilities anticipated in the city's North growth area. He cited lessons from the February 2019 flood and Tropical Storm Hillary (2023) as impetus for the update.

Corella explained that the code would reaffirm upstream and downstream maintenance obligations, require basin depth markers and safer slopes, and set drawdown requirements (36 hours for smaller basins; 48 hours for larger regional facilities) and breakout routing standards for events greater than design storms. He said the changes are not retroactive for past construction but will apply to new development and to projects that alter existing facilities.

Council briefly questioned whether standards apply retroactively; Corella said they would not be applied retroactively to as-built projects except when a new application or discretionary permit requires compliance. Council then introduced the ordinance by title and set a second reading and adoption timeline consistent with state notice requirements.