Noise and light from on-campus stadium expected to impact campus

Developers of Colorado State University’s on-campus stadium say the light and noise emitted from the stadium will be directed north – towards residence halls and other academic buildings on campus – to help shield nearby neighborhoods.

Members of the stadium advisory comittee listen to presentations July 7 2014. (Photo Credit: Skyler Leonard)
Members of the stadium advisory comittee listen to presentations July 7, 2014. (Photo Credit: Skyler Leonard)

The drafts of noise and light impact studies were presented to the Community Design Development Authority Committee Monday night by experts in each field.

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The committee, comprised of community members ranging from the Mayor of Fort Collins to neighborhood representatives and ASCSU President Sam Guinn, is tasked with providing community input and advice for CSU going forward with the proposed stadium design.

The Sound

Monday night’s meeting started with the presentation for noise impacts. Greg Hughes, a representative from WJHW, a consulting firm specializing in acoustics, created a digital 3-D model of the stadium to predict how the sound would travel in and out of the structure.

According to Hughes, the highest sound level anticipated at the stadium in spectator seats is 95 dBA (weighted sound pressure level) which is about the same volume as a lawn mower.

Traveling outside of the stadium, this sound would lessen to 80-85 dBA on the north side of campus. In other surrounding neighborhoods, the level would drop to 65 dBA, comparable to what a normal conversation with a person three feet away sounds like.

This volume would lessen by an estimated 22 dBA if in a building.

A draft impact of noise that will emit from CSU's on-campus stadium. Sounds are expected to be louder moving towards campus,
A draft impact of noise that will emit from CSU’s on-campus stadium. Sounds are expected to be louder moving toward campus. (Taken from the draft impact study)

According to Hughes, the stadium utilizes tall grandstands that act as “shadow zones,” that block nearby neighborhoods from some of the noise.

However, because of the way the sound will be directed in the horseshoe-shaped structure, buildings and residence halls on the north end of campus would still hear noise from the stadium at levels of 70 dBA.

According to Hughes, the model only used the expected volume from the stadium’s sound system, so the test did not take into account the sound of the crowd, marching band or the CSU cannon.

The Light

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Much like sound, the light from the stadium is expected to leak out north towards campus.  Although, light is anticipated to be less noticeable.

A draft analysis of the light which will emit from the on-campus stadium.
A draft analysis of the light which will emit from the on-campus stadium. (Taken from the draft impact study)

According to Scott Gerrard, a representative from ME Engineers, a normal collegiate stadium emits 125-200 foot candles (a measurement of illumination). In comparison, a classroom emits 40-70 FC and a sunny day is measured as 3,000-5,000 FC.

Gerrard conducted a computer analysis using 23 points in areas around the proposed stadium to study the potential for light to leak out.

North of the stadium, light currently would leak out at 0.1 FC near the tip of the intramural fields. That number would increase to 5 FC farther south towards the stadium.

“Levels in excess of 5 FC generally interfere with light-sensitive activities such as sleep, which rely on dark conditions,” states the draft light analysis.

The next committee meeting in August will review a transportation and parking study.

Collegian Senior Reporter Skyler Leonard can be reached at news@collegian.com