HomeMy WebLinkAboutNCR PARKING LOT EXPANSION IP SITE PLAN REVIEW - 35 93 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTNCR Parking Lot hApansion
Final Drainage Report
Page 3
IV. EROSION CONTROL
Due to its small size, it is anticipated that the project
will be completely built within a months time, beginning
approximately in the first part of June.
After the lot is graded and the storm sewer constructed, a
gravel filter will be placed around the area inlet for temporary
erosion control. The condition and effectiveness of the gravel
filter is to be monitored by the contractor during construction
and maintained as required. The disturbed areas around the
parking lot will have grass seed or sod placed according to the
landscape plan. The berm will be landscaped as well.
f
NCR Parking Lot Expansion
Final Drainage Report
Page 2
I
II. SITE DESCRIPTION
The project site is just west of the NCR building located at
2001 Danfield Court, Fort Collins,. Colorado. The project will
tie into NCR's previous parking lot expansion done in 1988/1989.
The site is bounded on the east by Timberline Road, to the
south by Platte River Power Authority, to the west by a railroad
easement and to the north by Danfield Court. The land slopes
gently downward from west to east/southeast and is covered with
lawn grass.
. Most of the runoff from the site is collected by a storm
sewer on the east side of the entrance drive. Runoff is
concentrated at an existing inlet just west of the northwest
corner of the building. The area that contributes to this runoff
is designated Sub -Basin H1 on the plans. A small portion of the
site drains southeast onto the adjacent land. This area has been
identified as Sub -Basin H2 in this study (see Drainage and
Grading Plan).
III. PROPOSED IMPROVEMENTS
The plan is to construct a new parking lot as an extension
to the existing lot. The drainage pattern for the existing lot
I will remain mostly unchanged. The existing curb and gutter along
the north edge of the new lot will be cut to allow for three
access ways to be built. The grade along this existing curb will
be held as the drainage basin boundary between the existing north
and proposed south parking lots. Rain falling into the south lot
will runoff towards an inlet proposed for storm sewer line 'A'.
The runoff will be detained in the parking lot and released at
the two year historic rate (Q1=0.44 cfs) using an orifice plate
at the pipe exiting the inlet..
A landscape berm is proposed along the west side of the new
I parking lot. A sump area will result and requires a small
drainage pipe from the west side of the berm into the parking
lot. The drain will be built integral to the curb as shown on
plan sheet 4 of 6. The remaining runoff will be less than
historic and will continue toward the south and east from the
Final Drainage Report
for
NCR PARKING LOT EXPANSION
Fort Collins; Colorado
May, 1993
I. GENERAL
This report summarizes the results of a stormwater drainage
and erosion control study conducted for the proposed parking lot
at NCR located in Section 30, Township 7 North,.Range 68 West of
the 6th Principal Meridian, in Fort Collins, Colorado.
Methods outlined in the City of Fort Collins' Storm Drainage
Design Criteria and Construction Standards were used in the
calculations for the stormwater runoff portion of this study,
while the City's Erosion Control Criteria was used as a guide in
preparing the erosion control plan. Summary calculations and
other supporting material are contained in an appendix to this
report.
The Rational Method was used to calculate stormwater runoff
from the site, while calculations based on the Modified Universal
Soil Loss Equation (MUSLE) were used in the erosion study.
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VICINITY MAP
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Northern Engineering Services, Inc.
May 6, 1993
Mr. Glen Schleuter
Stormwater Utility
City of Fort Collins
235 Mathews
P.O. Box 580
Fort Collins, Colorado 80522-0580
re: NCR Parking Lot Expansion
Fort Collins, Colorado
Project No. 9308.00
Dear Glen:
Northern Engineering is pleased to submit this Drainage Study
for your review. It represents a study of the existing and
proposed runoff characteristics of an IL/IP Site. Soil erosion has
also been included as an item of study in this report.
Your input during the initial design of this project have been
greatly appreciated. If you should have any questions or comments
as you review this report, please feel free to contact me at your
earliest convenience.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Terry P. McEnany
Michael F. Jones, P.E.
1 420 S. Howes • Suite 106 • Fort Collins. Colorado 80521 • (303) 221-4158 • Fax (303) 221-4159
FINAL DRAINAGE REPORT
for
N C R
P A R K I N G L O T E X P A N S T O N
Fort Collins, Colorado
APRIL, 1993
prepared by
NORTH ERN ENG T NE ER T NG S ERV T C E S , T NC .
420 South Howes, Suite 106
Fort Collins, Colorado 80521
(303) 221-4158.
Project No. 9.308.00