HomeMy WebLinkAboutBUCKING HORSE, THIRD FILING - FDP - FDP140015 - SUBMITTAL DOCUMENTS - ROUND 1 - EROSION CONTROL LETTER/REPORTJune 18, 2014
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Erosion Control Letter for
Bucking Horse Filing Three
Dear Staff:
Northern Engineering is pleased to submit this Erosion Control Letter for Bucking Horse-Filing Three.
This letter is an amendment to the previously approved Bucking Horse - Filing Two Erosion Control
Report dated December 14, 2012.
Project Description
Bucking Horse-Filing Three is a single family development located along the north side of Nancy Gray
Avenue and along the south side of Yearling Drive. There are 19 lots proposed with this project,
covering a total area of 3.18 acres.
General Requirements
All of the General Requirements described in the original report, including Objectives, SWMP
Availability, Definitions, and Additional Permitting still apply.
Narrative Site Description
All of the items described in the Narrative Site Description section of the original report remain
unchanged, with the exception of Section 2.5 (Site Disturbance). The originally approved project
anticipated disturbing 76.26 acres, while the new total disturbed area will be 77.13 acres. It should be
noted that the total disturbed area did not increase an equal amount to the size of Filing Three. This is
because most of the areas that make up Filing Three were already disturbed as a part of Filing Two.
Stormwater Management Controls
All of the items described in the Stormwater Management Controls still apply. In addition to the items
approved with Filing Two, Filing Three will also use Rock Socks where appropriate. As such, Section 3.3
(Structural Practices for Erosion and Sediment Control) is amended to include the following:
Rock Socks (Phases I - IV)
Rock socks are proposed along the north curbline of Nancy Gray Avenue to reduce the
velocity of water leaving the project site and introduce another opportunity for sediment
removal. Rock sock heights should allow for pools to develop upstream, creating minor
backwaters to both reduce velocities and to allow sediment deposition. The rock socks
should be spaced so that the top of each dam is equal in elevation to the toe of the next
upstream rock sock.
Rock socks should be inspected regularly for gaps or holes which would allow water to pass
through the structures untreated. The accumulated sediment should be removed and
typically prior to the sediment depth reaching half the height of the check dam.
In addition to the Rock Socks, Silt Fencing will be placed along the toe of any significant slopes, and inlet
protection shall be utilized for the existing inlets in Nancy Gray as well as for the proposed flared end
section. Riprap rundowns will be provided at the terminus of Miles House Avenue, and Straw Wattles
will be used in the temporary swale. Additional information about each of these Structural Practices,
including proper application and maintenance, can be found in Section 3.3 (Structural Practices for
Erosion and Sediment Control) of the approved report.
Final Stabilization
All of the items described in Final Stabilization of the original report will continue to apply. This includes
soil amendments, which shall be tilled into the soil to a minimum depth of 6”, and should comply with
the requirements found in City Code Section 12-132 (refer also to Land Use Code 3.8.21), as well as final
vegetation requirements.
Inspection, Maintenance and Record Keeping
Regular inspection of BMP’s as well as accurate documentation shall continue as outlined in the original
Erosion Control Report.
If you should have any questions or comments as you review this report, please feel free to contact me
at your convenience.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Andy Reese
Project Engineer