HomeMy WebLinkAboutDrainage Reports - 10/14/2016AI- EX Engineering
908 Laporte Avenue ■ Fort Collins, Colorado 80521 970,219.2834 ■ bob@apex-engineer.com
October 11, 2016
Mr. Dan Mogen, El, CFM
Development Review Engineer
City of Fort Collins
Via: hand delivery
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RE: Drainage Memo for 427 Wood Street, Fort Collins, Colorado
Dear Mr. Mogen,
The purpose of this letter is to document the proposed drainage impacts of the home
construction proposed at 427 Wood Street, Fort Collins, Colorado. The existing lot is
8500 square feet in size, and is bordered by Wood Street to the east and a public alley to
the west. This lot is located within the Old Town basin. There are existing single-family
homes to the north and south. There is an existing single-family home on the property,
with an attached garage, two accessory buildings and associated concrete hardscape
and sidewalks. The balance of the site consists of landscaping. The existing lot generally
drains easterly from the back to the front, with a small amount of drainage exiting to the
existing alley behind the lot. Currently, the lot functions as a modified type "A" lot, with
most runoff exiting the site towards the existing curb and gutter along the west side
Wood Street. The total existing impervious cover is approximately 1820 square feet.
The proposed project includes the demolition and removal of the existing single-family
home, garage, driveway, sidewalks and accessory structures. Once the site has been
cleared, a new single-family home with a detached garage and sidewalks will .be
constructed on the existing lot. The proposed project also includes a driveway off the
alley in back of the lot. The proposed Grading Plan for the project, prepared by Apex
Engineering, calls for the existing drainage patterns to be maintained. Most of the lot
will continue to drain towards the east through side lot swales proposed for both sides
of the house. A small area of the back yard will drain towards the existing alley to the
west. The total proposed impervious cover is 4060 square feet, which equates to an
impervious percentage of 48%. Detention is not required since the additional
impervious area is 2240 square feet.
Water quality treatment will be accomplished by releasing runoff from the roof and
hardscape areas directly to turf and landscaped areas surrounding the proposed
improvements. Runoff will be allowed to infiltrate into vegetated areas and/or filtered as
it travels slowly through the landscaped areas.
Negative impacts to surrounding properties resulting from this project are not expected.
Please contact me at (970) 219-2834 if you have any questions.
Best Regards,
Bob Gowing, P.E.
APEX Engineering
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NOTES:
1. NO UNDERGROUND EXPLORATION OR POTHOUNG HAS BEEN
PREFORMED FOR THIS PROJECT. THEREFORE. ALL
INFORMATION SHOWN REGARDING UNDERGROUND UTILITIES OR
FEATURES IS APPROXIMATE. APEX DOES NOT GUARANTY
THAT THE INFORMATION SHOWN HEREIN IS COMPLETE OR
ACCURATE.
2. THE OWNER AND/OR CONTRACTOR SHALL COORDINATE THE
MARKING OF UNDERGROUND UTILITIES PRIOR TO
COMMENCEMENT OF CONSTRUCTOR. SHOULD UTILITIES BE
IDENTIFIED THAT MAY CONFLICT WITH THE GRADING
IMPROVEMENTS SHOWN, THE CONTRACTOR SHALL CONTACT
THE ENGINEER IMMEDIATELY.
3. OWNER AND/OR CONTRACTOR SHALL BE RESPONSIBLE FOR
COORDINATING ALL PERMITS.
4. OWNER AND/OR CONTRACTOR SHALL BE RESPONSIBLE FOR
COORDINATING WITH ADJACENT PROPERTY OWNERS
REGARDING ANY IMPACTS TO OFF —SITE PROPERTIES.
5. SPOT ELEVATION SHOWN ARE FLOWJNE OR TOP OF
SURFACE, UNLESS OTHERWISE INDICATED.
B. SURVEY INFORMATION PROMDED BY PERKINS LAND
SURVEYING AND THE PROPERTY OWNER.
]. ALL DISTURBED AREA SHALL BE REVEGETATED AS PER THE
UNDSCAPE PUN.
B. ALL RECOMMENDATIONS OF THE GEOTECHNICAL AND/OR
STRUCTURAL ENGINEER REGARDING FOUNDATONS AND
GRADING SHALL BE FOLLOWED.
9. VERTCAL BENCHMARKS, AS PROMDED BY PERKINS LAND
SURVEYNG. ME AS FOLLOWS:
FORT COLLINS CITY BENCHMARK W-97
LOCATED ON THE WEST END OF THE SOUTH HEADWALL
OF THE BRIDGE OVER THE NEW MERCER CANAL
AT ONE DR. JUST EAST OF MERCER DR.
NAVDBB�5064.31
FORT COLLINS CITY BENCHMARK 1-00
LOCATED ON A CATCH BASIN AT THE SOUTHEAST CORNER
OF MINE DR. AND COLLEGE AA.
NAVDBBm4989.74
15
Know what's below.
Call before you dig.
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