Beginning in spring 2018, police began more actively enforcing the noise ordinance and City staff began monitoring noise levels at various locations downtown. We determined the City’s previous noise ordinance, which measured sound 200 feet from the property line of the source of noise, had not been effective in addressing the problem.

The amendment added a new section to the noise ordinance previously in place. The amendment imposes stricter standards to the Mixed Use 1 (MU-1) zoning district in downtown. By requiring noise measurement at the property line, the ordinance is now easier for Police to enforce, and it reduces the levels of sound reaching residences as well as limit the times when outdoor music can be played.

The amendment, which applies only to the MU-1 district, requires outdoor music venues to apply for a permit. Businesses are required to obtain a permit annually from the City to operate as an outdoor music venue, which is essentially any business amplifying sound not fully enclosed by walls and a roof, or sound that is regularly projected out a doorway.

Permit holders are required to follow the time of day restrictions below:

• They shall not operate sound equipment in excess of 80 decibels as measured at the property line of the business from 10 a.m. to 10 p.m. Sunday through Thursday; and from 10 a.m. to midnight on Friday and Saturday.
• At all other times, permit holders shall not operate sound equipment in excess of 60 decibels as measured at the property line of the business. Note: The originally proposed amendment was 50 dB, but after taking some measurements we determined the ambient noise level — often referred to as background noise — is roughly 55 dB in Downtown at night. A 50 dB limit did not meet the intended outcome for the ordinance amendment.

A permit holder who has been found guilty of violating any provisions of this section three times in a 12-month period will have their permit revoked by the Police Chief. The period of revocation will be one year from the date of revocation.

Previous to the amendment, noise could not exceed 75 decibels from 9 p.m. to 7 a.m., measured from 200 feet from the property line, in the MU-1 district.

To give an example of the practical difference in the previous ordinance and adopted amendment:

• Noise that measures 75 dB 200 feet from a property line (previous ordinance) would measure 89 dB at the property line, assuming the source of the noise (amplified speakers) is 25 feet inside the property line.
• Noise that measures 80 dB at the property line (current ordinance) would measure 61 dB at 200 feet away, assuming the the source of the noise (amplified speakers) is 25 feet inside the property line.

To put those noise levels in perspective, 90db is equivalent to a lawn mower; 80dB is equivalent to an alarm clock or garbage disposal; 75 dB is equivalent to a vacuum cleaner; 60 dB is equivalent to conversational speech or an air conditioner. You can find noise level charts that provide additional examples of various decibel levels here, here and here.

The maps below provide an example scenario depicting a noise source originating 25 feet from a property line measuring 80 decibel levels at the property line vs. a noise source originating from the same location that measures 75 decibels 200 feet from the property line. As you can see, the previous ordinance restriction yields higher decibel levels over a much greater area than the new ordinance that’s currently in place.

During the public input process, we also provided an interactive graph to illustrate the difference in decibel levels over distance between the old ordinance and amended ordinance standards. With both versions of the ordinance, the distance from the property line that a noise originates from is an important variable in determining decibel levels over distance beyond the property line. The interactive graph provides an interactive slider that allows adjustment of the noise source from the property line to illustrate this effect and compare the old ordinance vs. the amended ordinance.