HomeMy WebLinkAboutGrading Plans - 06/06/2022�CTL I THOMPSON
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June 4, 2022
Old Town Designs, Inc.
210 E. Oak Street
Suite C
Fort Collins, Colorado 80524
Grading/Stormwater Plan Accepted
(Building Permit Released)
Accepted by: Dan Mogen
Date: 06/06/2022
Attn: Ms. Keira Harkin
Subject: Drainage Memo
409 South Grant Avenue
Fort Collins, Colorado
Project No. iNY02052.000-500
Dear Ms. Harkin,
The above referenced lot has historically drained from the west to the east. The drainage flows from
the high side at the west alley to the east to Grant Avenue. This lot has slopes that ranged from
0.4% to 2.5%.
The current impervious area consists of the house/garage with an approximate square footage of
1,425 sf and 1,451 square feet of sidewalk and driveway for a total existing area of approximately
2,876 sf. The total lot area is approximately 9,500 square feet. The proposed impervious area will
include the original house at 1,425 square feet plus the proposed 790 square foot addition and the
existing sidewalk and driveway of 1,451 for a total of 3,665 square feet. This increases the
impervious surface area by 790 sf or 27%.
Attached is a drainage plan that includes drainage around the existing and proposed addition. This
drainage plan will conduct water away from the proposed and existing structures and direct the
drainage water around the existing house in the same direction as it has historically flowed. Swales
will be cut in between the addition and the property lines on the north and south sides of the
addition to direct the drainage to the east towards Grant Avenue. This drainage will drain across the
turF, gravel drive and landscaping towards the east property line and then to Grant Avenue. We
recommend that the new downspouts on the addition be installed to discharge drainage waterto the
east to not direct roof drainage water at the adjacent properties. The drainage recommendation for
this lot will not have any adverse impacts on the adjacent lots.
Thank you for selecting CTL�THOMPSON for your engineering needs. When we can be of
additional service, please contact the undersigned.
Very truly yours,
CTL�THOMPSON, INC. ,��;��;=e��'��.
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Wy tt M. Knut on, P.E: no''z/,�':
Vice President � Regional Manager -,,:���.,;
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Attachment: Drainage Plan �
1103 Old Town Lane � Suite 201 B � Cheyenne, Wyoming 82009 � Telephone: 970-206-9455 � www.ctlt.coin
. GRANT AVENUE
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SITE PLAN FOR
LOT 5, BLOCK 287, LOOMIS
409 SOUTH GRANT AVENUE
FORT COLLINS, COLORADO
OLD TOWN DESIGNS
MARCH, 2022
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I LOT 5 �
I 9500 sq. ft. I
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S90°00'W 50.00'
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SCALF: I'=20'