HomeMy WebLinkAboutGrading Plans - 12/04/2015FORBES ENGINEERING
Full Service Civil & Structural Engineering
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December 4, 2015 e(ihd 12/�/2o
Dan Morgen
City of Fort Collins
Stormwater Engineering
700 Wood Street
Fort Collins, CO 80521
RE: Grading & Drainage Memo for site improvements at
815 West Oak Street
Fort Collins, CO 80521
Mr. Morgen,
This letter and attached exhibit are to serve as a drainage certification for the
above referenced single family residential property. The property is located along
the south side of West Oak Street two doors east of South Washington Avenue.
The home was originally built in approximately 1900 and has one single family
residence and a detached garage/outbuilding on the property (see attached grading
plan). The surrounding neighborhood is all single family residential lots.
The proposed site improvements include constructing a new home with the same
building footprint & location as the original building (approximately 1152 sf) with
a basement addition at the location of the existing covered back porch. It is the
intent of the builder to maintain the current finish floor elevation. The existing
detached garage will remain as is. Site improvements will not include any
additional concrete for walks or drives.
The,existing spot elevations for the proposed grading & drainage plan are based
on survey data provided by Stewart & Associates Land Surveying, Inc. dated
November 25, 2015.
The full property lies within the City of Fort Collins moderate risk 100=year
Floodplain and the historic storm water runoff presently is directed. towards the .
street gutter system of West Oak (front yard) with a small, portion directed towards
the south and into the existing alley. The historic drainage pattern will be
maintained with a small change on the south portion. The south half of the
property has a very flat slope with a large portion of it draining to the north and
east, this towards an area that has a small depression between the property and the
lot to the east. To help alleviate the flat grade and to redirect most of the surface
flow, the proposed improvements will use roof gutters and downspouts to direct
the storm water runoff towards the north into the street gutter system and towards
the south into the alley (see attached proposed grading plan). The grade at the
face of the building will be elevated approximately 6 inches and the southern
portion will be regraded to slope (at 1% minimum) the drainage away from the
home towards the south and into the existing alley (again see attached proposed
grading plan). Any necessary erosion control measures will be provided at the
time of construction including, but not limited to, perimeter silt fencing and a
vehicle tracking control mat if necessary.
As previously stated, both the home and the detached garage are located fully
within the moderate risk flood fringe. The finish floor of the home is
approximately 4 feet above the detached sidewalk and the garage is approximately
6 inches above the alley, so the risk of flooding is very minimal.
It is my conclusion that with proper construction practice and observance to the set
finish floor elevation, no adverse affects to the site or to the surrounding
properties are anticipated from the proposed improvement of this site.
Sincerely, 1� GR€G'r
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35265
in Forbes, P.E. #35
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WEST OAK STREET
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PROPERTY INFORMATION
OWNER:
ADDRESS:
815 WEST OAK STREET
LEGAL DESCRIPTION:
LOT 19, BLOCK 289
LOOMIS ADDITION
PARCEL NUMBER:
97113-16-019
BENCH MARK
CITY OF FORT COLLINS
BENCH MARK #1-11
ELEVATION = 5005.44
LOCATED AT THE
SOUTHEAST CORNER OF
MULBERRY STREET AND
LOOMIS AVENUE, AT THE
NORTHEAST CORNER OF A
CONCRETE TRAFFIC SIGNAL
BASE.
THIS PROPERTY IS LOCATED
WITHIN THE CITY OF FORT
COLLINS MODERATE RISK
100 YEAR FLOOD PLAIN
PROPOSED GRADING
& DRAINAGE PLAN
SCALE 1" = 20'
N `o' ,•9 '�l
-265
PROPERTY. LINE
BUILDING WALL
• EXISTING FENCES—x—x—x—X—
U CONCRETE WALKS
�I EXISTING GROUND SHOT
• + PROPOSED FINISHED GRADE o\
20' ALLEY
FO R B ES ENGINEERING CLIENT' DICK JDW RIES PREPARED BY KEWN F01R810
2908 CHERLY STREET, PROJECT 815 MFST aw 57Rm, DRAWN. CA7F
Ft. Collins, Colorado 80524 Fr OMLA% CO KEF 12-4-15
Tele. (970) 295-4674 DESIM SHEET TITLE
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