HomeMy WebLinkAboutPETERSON PLACE - Filed GC-GENERAL CORRESPONDENCE - 2003-11-04ANdERSON CONSUITINq ENGINEERS, INC.
Civil Water Resources • Environmental
September 26, 2002
Ms. Marsha Hilmes-Robinson
Floodplain Administrator
City of Fort Collins Utilities
700 Wood Street
Fort Collins, CO 80521
RE: Floodplain Evaluation for the Peterson Townhomes
(ACE Project No. COBKMCO1)
Dear Marsha:
On behalf of Mr. Bruce Froseth of B.K. Maxwell Co., Inc, Anderson Consulting Engineers, Inc.
(ACE) has completed its evaluation of floodplain issues associated with the proposed Peterson
Townhomes, to be located west of the existing house at 611 Peterson Street in Fort Collins,
Colorado.
This evaluation was based on the most recent floodplain mapping available for this area, namely that
which is documented in the Old Town Basin Master Drainage Plan, Baseline Hydraulics, Volume
III [ACE, May 13, 2002]. Based on the floodplain mapping documented in that report, the subject
property is located in an approximate flood zone of no greater than one foot.
As part of this evaluation, we have reviewed the "Utility Plans for the Peterson Townhomes"
prepared by Loonan & Associates [dated October 8, 2001 ] and conducted a site visit to assess local
conditions. (A copy of the final grading on which this evaluation was based is attached.) Based on
our review of the referenced information, it is our opinion that the proposed site improvements will
not create a rise in the 100-year water level. This opinion is based primarily on existing conditions
associated with properties adjacent to the site. Existing obstructions including structures, fencing
and landscaping would limit the effective flow path in this area primarily to the alley corridor.
Considering: (a) the 56-foot setback of the proposed building from the edge of the alley, (b) the
removal of two existing structures in the vicinity of the proposed building, and (c) the minimal
changes in the local topography proposed for the area between the alley and the building, it appears
that any impacts to 100-year water surface elevations would be negligible.
In addition to potential floodplain impacts, we have also arrived at a recommended minimum
finished floor elevation for the proposed building. The proposed finished floor elevation for the
building, as shown on the "utility plans" is 4986.70 ft, NGVD. A careful review of the existing
topography shown on the plans indicates that the highest existing ground elevation within the
footprint of the proposed building is 4984.5 ft, NGVD. Using the approximate 100-year flood depth
P: ICOBKMCOIICOBKMC01-LTR. WPD September 26, 1002
772 Whalers Wav, Suite 200• Fort Collins, CO. 80525
Phone: (970) 226-0126 • Fax: (970) 226-0121 - www.acewater.com
Ms. Marsha Hilmes-Robinson
September 26, 2002
Page Two
of 1 foot and adding 18 inches of freeboard above this level, per City criteria, the recommended
finished floor elevation for the proposed building is 4987.0 ft, NGVD.
If you have any questions or comments concerning the information provided in this letter, or any
other floodplain issue associated with this project, please do not hesitate to contact me.
Sincerely,
ENGINEERS, INC.
Attachment
cc: Mr. Bruce Froseth
P. ICOBKMCOI ICOBKMCOI-LTR. WPD September 26. 2002