Kirkwood council approves ordinance amending outdoor lighting rules after debate over color temperature

Kirkwood City Council passed an ordinance amending the municipal code’s outdoor lighting provisions (Bill 11066a) after a lengthy public discussion about color temperature and visibility.

The ordinance, described at the meeting as an update to Chapter 25, Section 25-52 for outdoor lighting requirements, drew testimony from residents demonstrating how Kelvin (color temperature) and lumens (brightness) affect perception. Council members voted 4-2 to adopt the bill.

The debate focused on whether to restrict the color temperature (measured in degrees Kelvin) of new outdoor lighting for non‑single‑family development. City staff recounted the Planning & Zoning Commission’s recent review: the commission considered limits at 2,700 K and 3,000 K, and ultimately recommended limitations closer to 4,000 K for new nonresidential lighting while allowing existing fixtures to be grandfathered. Several council members and members of the public discussed tradeoffs between lower Kelvin ratings (which tend to appear warmer and reduce blue light) and higher Kelvin ratings (which can increase visibility and contrast).

Resident Don Ficken showed a demonstration bulb and explained how the same fixture can produce different perceived brightness at the same Kelvin setting, saying the display illustrated “there’s a misunderstanding between Kelvin and what’s called CCT.” He told the council that color temperature can be altered without changing lumen output and warned that higher‑Kelvin, bluer light “is not good for your health, it’s not good for nature.”

Resident Barrett Williams said online claims that the city was “considering dimming the requirements for local street lighting to below 3,000 Kelvin” were misleading. Williams urged critics to attend lighting seminars and distinguished between lumen output (brightness) and Kelvin (color), saying “the intensity, the brightness is measured in lumens, and the color of the light is measured in Kelvin.”

Council members spoke about federal guidance and local practice. One council member recalled federal highway guidance that had recommended 3,000 K in earlier research but noted that available fixtures and technology have changed. Another said many local businesses already use fixtures rated at or near 4,000 K and argued that site‑specific factors should guide final designs.

Mayor Gibbons and four council members voted in favor of Bill 11066a; two council members voted no. The ordinance amends the city’s outdoor lighting code and applies to new outdoor lighting installations; existing fixtures are grandfathered, the staff presentation said. The council did not take additional immediate amendments on the floor.

Councilmembers and speakers emphasized that glare control, fixture height, shielding and lumen levels affect pedestrian and driver visibility as much as Kelvin ratings, and that lumen depreciation over time can reduce illumination if fixtures are not maintained. No new enforcement timeline or implementation date for the ordinance was specified at the meeting.

The council’s vote concluded the item; no further motions were recorded on this bill during the session.