HomeMy WebLinkAboutKING SOOPERS #146, MIDTOWN GARDENS MARKETPLACE - FDP210001 - DOCUMENT MARKUPS - ROUND 3 - DRAINAGE REPORT
PREPARED FOR:
Dillon Companies/King Soopers, Inc.
55 Tejon Street
Denver, Colorado 80223
Phone: (303) 778-3053
PREPARED BY:
Galloway & Company, Inc.
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
DATE:
February 3, 2021
REVISED:
March 24, 2021
MIDTOWN GARDENS MARKETPLACE
KING SOOPERS STORE #146
Fort Collins, Colorado
FINAL DRAINAGE REPORT
Fort Collins Water Utilities Comments
Matt Simpson
masimpson@fcgov.com
4/16/2021
Midtown Gardens Marketplace
3/24/2021
Galloway & Company, Inc. Page 12 of 19
Storm Water Detention
The proposed underground StormTech system, Pond A, will be designed as an LID basin for the site,
including Water Quality treatment and 100-year detention with a controlled 2-year historic release rate
of 0.50 cfs/acre. Detention storage has been designed for all of Basin A. The remainder of the site
will have only water quality provided in the underground system. Required volumes were determined
using the Modified FAA Method. Below is a summary of the total storage proposed. A tabulation of
the stage storage volume for Pond A can be found in Appendix C.
Table 2
Water Quality / LID Summary
New or Modified Impervious Area 10.06 AC
Impervious Area Captured 9.42 AC (94% of Total)1
WQCV Required 14,339 CF
WQCV Provided 23,251 CF
1. Per discussions with the City, remainder of impervious area is infeasible to be captured
Table 3
Detention Summary Table
Tributary Area (WQ / Detention) 10.46 AC / 6.98 AC
WSEL100 5016.97
Q100 Release Rate 3.49 CFS
V100 Required 58,096 CF
Total Volume Required (WQCV + V100) 72,435 CF
Total Volume PRovided (WQCV + V100) 72,653 CF
VII. Variance Requests
No variances are being requested with the proposed improvements described herein.
VIII. Erosion Control
A General Permit for Stormwater Discharge Associated with Construction Activities issued by the
Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division
(WQCD), will be acquired for the site. A Stormwater Management Plan (SWMP) should be prepared
to identity the Best Management Practices (BMPs) which, when implemented, will meet the
requirements of said General Permit. Below is a summary of SWMP requirements which may be
implemented on-site. A separate SWMP Report has been prepared for the site.
The following temporary BMPs may be installed and maintained to control on-site erosion and
prevent sediment from traveling off-site during construction:
· Silt Fence – a woven synthetic fabric that filters runoff. The silt fence is a temporary barrier that is
placed at the base of a disturbed area.
Add trib area for
detention
separated into 2 rows, 1
for WQ and 1 for deten-
tion
Project Number:King Soopers Store #146 Date:3/23/2021
Project Location:CO, Fort Collins
Calculations By:E. Mowinckel
Checked By:P. Dalrymple
Pond Description:Pond A Water Quality
User Input Cell:Blue Text
1/2 2-year 2163
0.89 0.05
3.48
0.81
minutes seconds in/hr cubic feet cubic feet cubic feet acre-feet
5 300 1.43 1321 241.8 1079 0.02
10 600 1.11 2048 483.6 1564 0.04
15 900 0.94 2599 725.4 1874 0.04
20 1200 0.81 2984 967.2 2017 0.05
25 1500 0.72 3313 1209 2104 0.05
30 1800 0.65 3614 1450.8 2163 0.05
35 2100 0.59 3795 1692.6 2102 0.05
40 2400 0.54 3966 1934.4 2032 0.05
45 2700 0.50 4128 2176.2 1952 0.04
50 3000 0.46 4263 2418 1845 0.04
55 3300 0.44 4434 2659.8 1774 0.04
60 3600 0.41 4559 2901.6 1658 0.04
65 3900 0.39 4698 3143.4 1555 0.04
70 4200 0.37 4735 3385.2 1350 0.03
75 4500 0.35 4865 3627 1238 0.03
80 4800 0.33 4893 3868.8 1024 0.02
85 5100 0.32 5041 4110.6 931 0.02
90 5400 0.31 5087 4352.4 735 0.02
95 5700 0.29 5106 4594.2 512 0.01
100 6000 0.28 5189 4836 353 0.01
105 6300 0.27 5254 5077.8 176 0.00
110 6600 0.26 5301 5319.6 -19 0.00
115 6900 0.26 5435 5561.4 -126 0.00
120 7200 0.25 5449 5803.2 -354 -0.01
Modified FAA Method - WQ Storage Volume Calculations
Inputs | Tributary Area Output | Detention Volume
Return Period for Detention Control: Required Storage, cubic feet:
Catchment 'C': Required Storage, ac-ft:
Average
Outflow
Storage
Volume
Storage
Volume
Catchment Drainage Area, ac:
Release Rate, cfs:
Storm
Duration Time Rainfall
Intensity Inflow Volume
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College Drake\3.04 Grading-Drainage Studies\3.04.2 Proposed Drainage Reports-
Info\Hydrology\KSS 146_Rational_Routing.xls Page 1 of 2 3/23/2021
Pond BC?
check
corrected as noted
0.89 per Composite C calculation
1 User Defined Stage-Area Booleans for Message
1 Equal Stage-Area Inputs Watershed L:W
1 CountA Watershed Lc:L
Watershed Slope
0 Calc_S_TC Booleans for CUHP
1 CUHP Inputs Complete
H_FLOOR 1 CUHP Results Calculated
L_FLOOR_OTHER
0.00 ISV 0.00 ISV
0.00 Floor 0.00 Floor
6.60 Zone 1 (User) 6.60 Zone 1 (User)
0.00 Zone 2 0.00 Zone 2
0.00 Zone 3 0.00 Zone 3
DETENTION BASIN STAGE-STORAGE TABLE BUILDER
MHFD-Detention, Version 4.03 (May 2020)
0.000
0.425
0.850
1.275
1.700
0.000
0.085
0.170
0.255
0.340
0.00 2.00 4.00 6.00 8.00 Volume (ac-ft)Area (acres)Stage (ft.)
Area (acres)Volume (ac-ft)
0
3700
7400
11100
14800
0
5
10
15
20
0.00 2.00 4.00 6.00 8.00 Area (sq.ft.)Length, Width (ft.)Stage (ft)
Length (ft)Width (ft)Area (sq.ft.)
MHFD-Detention_v4 03.xlsm, Basin 3/23/2021, 7:43 PM
Why is the area
curve/ data erratic
like this?
this is a result of the stage - area data ADS provides and the inverted nature of the cham-
bers (i.e. the most area/volume is at the bottom), and the stone void spaces.
We have updated the stage - area summary based on revised data from ADS to produce
a smoother curve
COCOEEVTECBGMEEEETLTLETLGMIRTLWMCOEKM
PJD
3/24/2021
PROPOSED DRAINAGE MAP
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SCALE: 1"=40'
0 20 40
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STAMP
H:\King Soopers - City Market\CO, Fort Collins - KSS000146 -#18 College & Drake\CADD\Exhibits\KSS146_Drainage_Proposed.dwg - Erland Mowinckel - 3/24/2021Init.#Issue / DescriptionDate
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NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED
WITHOUT THE WRITTEN CONSENT OF GALLOWAY.
COPYRIGHTS AND INFRINGEMENTS WILL BE
ENFORCED AND PROSECUTED.
COPYRIGHT
6162 S. Willow Drive, Suite 320
Greenwood Village, CO 80111
303.770.8884
Planning. Architecture. Engineering.
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C 2016. Galloway & Company, Inc. All Rights Reserved
PRELIMINARYNOT FOR BIDDINGNOT FOR CONSTRUCTIONDate:
Drawn By:
Project No:
Checked By:
KSS000146
OF 2PROPOSED DRAINAGE MAPMIDTOWN GARDENS MARKETPLACEKING SOOPERS MARKETPLACE #146S. COLLEGE AVE. & DRAKE RD.FORT COLLINS, COLORADOBASIN SUMMARY TABLE - PROPOSED
Tributary Area
C2 C100
tc | 2-Year tc | 100-Year Q2 Q100
Sub-basin (acres)(min)(min)(cfs)(cfs)
A-1 0.91 0.82 1.00 5.7 5.0 2.1 9.1
A-2 0.23 0.87 1.00 5.0 5.0 0.6 2.3
A-3 1.65 0.87 1.00 5.1 5.0 4.1 16.5
A-4 0.64 0.85 1.00 5.0 5.0 1.6 6.4
A-5 0.15 0.95 1.00 5.0 5.0 0.4 1.5
A-6 0.15 0.88 1.00 5.0 5.0 0.4 1.5
A-7 0.25 0.81 1.00 5.0 5.0 0.6 2.5
A-8 0.13 0.67 0.84 5.5 5.0 0.2 1.1
A-9 0.11 0.95 1.00 5.0 5.0 0.3 1.1
A-10 1.21 0.95 1.00 5.0 5.0 3.3 12.1
A-11 0.67 0.95 1.00 5.0 5.0 1.8 6.7
A-12 0.88 0.95 1.00 5.0 5.0 2.4 8.8
B-1 1.33 0.89 1.00 5.0 5.0 3.4 13.3
B-2 0.79 0.90 1.00 5.3 5.0 2.0 7.9
B-3 0.09 0.72 0.91 5.0 5.0 0.2 0.8
C-1 0.11 0.95 1.00 5.0 5.0 0.3 1.1
C-2 0.12 0.95 1.00 5.0 5.0 0.3 1.2
C-3 1.01 0.87 1.00 6.4 5.0 2.3 10.1
C-4 0.01 0.95 1.00 5.0 5.0 0.0 0.1
C-5 0.02 0.95 1.00 5.0 5.0 0.1 0.2
OS-1 0.51 0.54 0.68 13.6 13.6 0.5 2.4
OS-2 0.32 0.73 0.91 7.7 6.0 0.6 2.8
OS-3 0.10 0.91 1.00 5.0 5.0 0.3 1.0
OS-4 0.36 0.91 1.00 5.0 5.0 0.9 3.6
OS-5 0.71 0.87 1.00 5.0 5.0 1.8 7.1
OS-6 0.15 0.95 1.00 5.0 5.0 0.4 1.5
Please add a column
to this table indicating
"Detention & WQ" or
"WQ Only" for each
subbasin.
On the drainage map, I suggest turning off all
utilities except for storm.
Please make sure the roof drains are turned
on.
Check if the roof drain pipes from basin
A-12 connect to the detention portion of
the stormtech system.
(Note, an easy fix could be removing the
orifice plate between the BC pond and
the detention chambers. my $0.02 =)
Basins B-1, B-2, and C-3 each have a lot of area
(~1 acre each) draining to 1 storm inlet each inlet.
Will the nuisance flows be managed to your
satisfaction in this parking lot?
Basin C-3 has allot of area (1 acre) draining to 1
on-grade inlet. I know this is for WQ only,
however, will the nuisance flows be managed to
your satisfaction?
updated EX and PR maps to omit other utilities as
requested
Basin A-12 drains to the back side of the building
and the roof drains at this corner of the building cor-
respond to the C basins
corrected as noted
for Basins B-1 and B-2, the lip in the curb flow line
at the chase drains will be sufficient to capture the
nuisance flows.
For Basin C-3 & B-3, we have adjusted the curb
such that there is a small depression between the
curb return and the inlet to create a slight sump to
capture nuisance flows based on the nuisance flow
depth and allow higher flows to pass over and down
into the street as intended
see note above