Commissioners question using retention basins as 100% open space credit

Commissioners spent several minutes discussing whether retention basins should count as full open space when developers use them to meet park or open‑space requirements.

One commissioner said, “I still really just struggle with using retention basins as open space at least a 100% value because I feel like we shortchange the residents when we allow developments to use retention basins as open space,” and suggested the city could give partial credit (for example, 50%) or require minimum dimensions so small basins cannot be treated as full open space. The comment framed basins as often unsuitable for recreational amenities such as courts or playgrounds.

Staff responded that a code rewrite is underway and that the suggested language could be discussed with the city attorney drafting the code. Staff also noted technical constraints and existing standards: basins generally must meet a 5:1 slope threshold to qualify and design choices (for example, buried systems) change usability and cost. Commissioners and staff discussed incentives that could reward larger or better‑designed basins that provide usable open space instead of small, fenced basins that collect debris.

The conversation did not produce a formal motion; staff said they would raise the topic with the attorney working on the code rewrite.