HomeMy WebLinkAboutGARDENS ON SPRING CREEK - MAJOR AMENDMENT - MJA150006 - SUBMITTAL DOCUMENTS - ROUND 4 - SUPPORTING DOCUMENTATIONMarch 11, 2016
Mr. Craig Russell, Principal
Russell + Mills Studios
141 S College Street, Suite 104
Fort Collins, Colorado 80524
RE: Gardens on Spring Creek – Updated Sound Mitigation Narrative (DLAA #9678C)
Dear Craig,
Per your request we have updated our noise model based on meeting noise code requirements at
the adjacent HOA property line rather than the property lines of the individual residences. Since
the HOA property line is closer, the mitigation requirements will need to be expanded to meet
the criteria.
Too meet these requirements we recommend adding an additional sound barrier along the
western Gardens property line. This location has been coordinated with you and the rest of the
design team, and, by our understanding, does not interfere with flood plain requirements.
With this additional barrier, the calculated noise level along the HOA property line is within
code without requiring alterations to the three original barriers near the audience area or lowering
the maximum noise level at the predicted mixing console location. The minimum height of the
additional barrier is 14’ above the ground. The barrier should be located at the southeast corner
of the adjacent HOA property line and extend directly north at least 220’. Calculated results are
shown in the attached Figure 1.
Similarly to the near barriers, the additional western barriers should have a minimum surface
density of 10 pounds per square foot in order to effectively block low frequency sound. The
barrier should be solid with no leaks or cracks directly through it. If gabion walls are used,
careful design consideration must be done to ensure there are no gaps in the filling and the
minimum surface density is maintained.
Please let us know if you have any questions.
Sincerely,
Ian Patrick
Staff Consultant
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> -99.0 dB
> 35.0 dB
> 40.0 dB
> 45.0 dB
> 50.0 dB
> 55.0 dB
> 60.0 dB
> 65.0 dB
> 70.0 dB
> 75.0 dB
> 80.0 dB
> 85.0 dB
Stage walls
Zoning
boundary
Property Line
Employment Zoning
(70 dBA)
Residential Zoning
(55 dBA)
West wall 12'
above stage
minimum
Predicted Sound Level Map Figure 1
March 11, 2016 not to scale
Centre Ave.
Min19.5' above
stage level.
Min 17' above
stage level.
Min 19' above stage level
61.8
62.3
67.0
63.1
59.2
50.0
47.1
53.8
48.6
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48.1
90
67.9
47.7
50.6
50.6
54.0
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53.2
Min. 14' Tall
barrier
< 35.0 dB