HomeMy WebLinkAboutFile Documents.1310 Red Butte Dr.0114.2018 (18).ARBK
592 Highway 133 • Carbondale, CO 81623 • 970.948.7474 • www.rfeng.biz
April 24, 2017
Hailey Gugielmo
City of Aspen Engineering Department
201 N. Mill Street, Suite 101
Aspen, CO 81611
RE: Red Butte No Rise Certification Letter
Hailey,
1310 Red Butte Drive is located along the Roaring Fork River approximately 300 feet upstream of the
Cemetery Lane Bridge. As part of the upgrades to the property, an existing wood foot bridge on
concrete abutments is being upgraded to provide structural stability and needed safety improvements.
The foot bridge spans a seasonal flowing channel and allows the residence access to an island formed by
the channel and Roaring Fork River. This structure is within the 100 year floodplain of the Roaring Fork
River and below the 100 year water surface elevation of 7713 (NVGD 29). The residence and all other
improvements to the site are outside and above the stream margin and 100 year water surface
elevation.
Roaring Fork Engineering has reviewed the plans, provided by Resource Engineering Group, to stabilize
and improve safety of the existing bridge and compared these improvements to the existing structure
regarding total cross‐sectional area and elevation differences. The structural improvements to the
bridge will in no way change the cross‐sectional area of the existing bridge due to the improvements
only fortifying existing components and replacing the bridge decking with materials similar in size and
shape.
Given the cross‐sectional area of the bridge is remaining the same, RFE has concluded the
improvements will not change the 100 year water surface elevation in any way compared to existing
conditions and there would be no adverse effect or damage on upstream or downstream structures do
to these bridge improvements. This analysis would negate the need for a FEMA no rise certification and
the corresponding studies and analysis that go along with that certification. This conclusion can be
fortified with RFE’s understanding of the programing used to develop the base FIS model (HEC 1) for this
area and the flood modeling programing that would be used in the no rise certification procedure (HEC‐
RAS).
If you have any questions regarding the above information or need additional clarification to support
our conclusion please feel free to contact me.
Sincerely,
Daniel Stewart, PE
Roaring Fork Engineering
07/13/2018
Reviewed by Engineering
07/27/2018 4:50:48 PM
"It should be known that this review shall not
relieve the applicant of their responsibility to
comply with the requirements of the City of
Aspen. The review and approval by the City is
offered only to assist the applicant's
understanding of the applicable Engineering
requirements." The issuance of a permit based
on construction documents and other data shall
not prevent the City of Aspen from requiring the
correction of errors in the construction
documents and other data.