HomeMy WebLinkAboutCAMBRIDGE LOFTS APARTMENTS - PDP - 6-03C - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTChannel to Shields
Worksheet for Rectangular Channel
Project Description
Worksheet
Channel to Shiel
Flow Element
Rectangular Cha
Method
Manning's Forme
Solve For
Bottom Width
Input Data
Mannings Coeffic ).013
Slope
1.00 %
Depth
0.50 ft
Discharge
15.70 cfs
Results
Bottom Width
4.93 ft
Flow Area
2.5 ft'
Wetted Perimi
5.93 ft
Top Width
4.93 ft
Critical Depth
0.68 ft
Critical Slope
0.39 %
Velocity
6.37 ft
Velocity Head
0.63 It
Specific Enerc
1.13 It
Froude Numb,
1.59
Flow Type
supercritical
Project Engineer: Patricia Kroetch
d:\haestadVmw\cambridge.fm2 North Star Design, Inc. FlowMaster v6.1 [614n]
12/09/03 05:34:24 PM O Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
LOCATION: Cambridge Lofts December 9, 2003
DESIGN STORM: 100-YEAR DEVELOPED
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
O = CC, iA
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.25
tc
(min)
i
(in/hr)
Q
(cfs)
1
1
0.58
0.78
1.00
5.2
9.37
5.5
2
2
1.26
0.86
1.00
5.0
9.95
12.5
3
3
0.15
0.75
1.00
5.0
9.95
1.5
1
1.2
1.84
0.83
1.00
7.2
8.62
15.8
Total to Concrete Channel
6of6
IM =1 M M = r = 1=1 = = 1=1 = =1 M = M M =1 =1
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION:
DESIGN STORM:
COMPUTATIONS BY:
SUBMITTED BY:
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Cambridge Lofts
10-YEAR DEVELOPED
PPk
NORTH STAR DESIGN
n = rr. in
December 9, 2003
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.00
tc
(min)
i
(in/hr)
O
(cfs)
1
1
0.58
0.78
0.78
8.5
4.02
1.82
2
2
1.26
0.86
0.86
5.5
4.59
4.97
3
3
0.15
0.75
0.75
5.0
4.87
0.55
1
1,2
1.84
0.84
0.84
9.6
3.82
5.87
Total to Concrete Channel
5of6
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION:
DESIGN STORM:
COMPUTATIONS BY:
SUBMITTED BY:
STORM DRAINAGE SYSTEM DESIGN
(RATIONAL METHOD PROCEDURE)
Cambridge Lofts
2-YEAR DEVELOPED
ppk
NORTH STAR DESIGN
Q = CC, iA
December 9, 2003
DIRECT RUNOFF
REMARKS
Des.
Point
Area
Design.
A
(ac)
C
CCf
Cf =
1.00
tc
(min)
i
(in/hr)
Q
(cfs)
1
1
0.58
0.78
0.78
8.5
2.35
1.07
2
1 2
1.26
0.86
0.86
5.5
2.69
2.92
3
3
0.15
0.75
0.75
5.0
2.85
0.32
1
1,2
1.84
0.84
0.84
9.6
2.22
3.41
Total to Concrete Channel
4of6
M M M M r M M M M= M M M M M M M M M
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION:
Cambridge Lofts
DESIGN STORM:
100 YEAR, Cf = 1.25
COMPUTATIONS BY:
ppk
SUBMITTED BY:
NORTH STAR DESIGN
STANDARD FORM SF-8
TIME OF CONCENTRATION
VP1 from Mnnnn„r� Pn rR=n 1
DATE: December 9, 2003
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME III)
TRAVEL TIME I GUTTER OR CHANNEL FLOW
(tt)
tc CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
BASIN
DESIGN
POINT
Area
(ac)
C
C'Cf
Length
(ft)
Slope
(%)
If
(min)
Length
(ft)
Slope
(%)
n
Manning
Val.
(fps)
it
(min)
lc =
ti+Il
Total L
(ft)
tc=(1/180)+10
(min)
(min)
1
1
0.58
0.87
1.00
40
0.50
1.5
350
0.6
0.016
1.56
3.7
5.2
390
12.2
5.2
MINIMUM tc = 5
2
2
1.26
0.81
1.00
65
1.00
1.5
260
1.2
0.016
2.20
2.0
3.5
325
11.8
5.0
3
3
0.15
0.83
1.00
55
1.00
1.4
0
1.2
0.016
2.20
0.0
1.4
55
10.3
5.0
1,2
1
1.84
0.83
1.00
40
0.50
1.5
350
0.6
0.016
1.56
3.7
260
1.2
0.016
2.20
2.0
7.2
650
13.6
7.2
3 of
s r r M= r= M M M M M ■r M M M M M M
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
LOCATION: Cambridge Lofts
DESIGN STORM: 2 YEAR, Cf= 1
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
STANDARD FORM SF-8
TIME OF CONCENTRATION
vei F..- RA-i-'. c,, ID-n n
DATE: December 9, 2003
SUB -BASIN
DATA
INITIAL /OVERLAND
TIME (0)
TRAVEL TIME I GUTTER OR CHANNEL FLOW
40
tc CHECK
(URBANIZED BASIN)
FINAL
tc
REMARKS
BASIN
DESIGN
POINT
Area
(ac)
C
C'Cf
Length
(it)
Slope
(%)
ti
(min)
Length
(ft)
Slope
(%)
n
Manning
Vel.
(fps)
tt
(min)
tc=
ti+tt
Total
(ft)
tc=(1/180)+10
(min)
(min)
1
1
0.58
0.78
0.78
40
0.5
4.8
350
0.6
0.016
1.56
3.7
8.5
390
12.2
8.5
MINMUM tc = 5
2
2
1.26
0.86
0.86
65
1.0
3.6
260
1.2
0.016
2.20
2.0
5.5
325
11.8
5.5
3
3
0.15
0.75
0.75
55
1.0
4.9
0
1.2
0.016
2.20
0.0
4.9
55
10.3
5.0
'
1,2
1
1.84
0.84
0.84
40
0.5
3.9
350
0.6
0.016
1.56
3.7
260
1.2
0.016
2.20
2.0
9.6
650
1 13.6
9.6
2 of
M M M M = = r M M M M M a MIM
North Star Design, Inc.
700 Automation Drive, Unit I
Windsor Co, 80550
12/9/03
LOCATION: Cambridge Lofts
ITEM: COMPOSITE "C" CALCULATIONS
COMPUTATIONS BY: ppk
SUBMITTED BY: NORTH STAR DESIGN
HISTORIC C VALUES
AREA
DESIGNATION
TOTAL
AREA
AREA OF
IMPERVIOUS
RUNOFF
COEFF.
AREA OF
LANDSCAPE
RUNOFF
COEFF.
COMPOSITE C
VALUE
1
0.58
0.52
0.95
0.06
0.20
0.87
2
1.26
1.02
0.95
0.24
0.20
0.81
3
0.15
0.13
0.95
0.03
0.20
0.83
PROPOSED C VALUES
AREA
DESIGNATION
TOTAL
AREA
AREA OF
IMPERVIOUS
RUNOFF
COEFF.
AREA OF
LANDSCAPE
RUNOFF
COEFF.
COMPOSITE C
VALUE
1
0.58
0.45
0.95
0.13
0.20
0.78
2
1.26
1.11
0.95
0.15
0.20
0.86
3
0.15
0.11
0.95
0.04
0.20
0.75
1 of 6
PROJ
LOCA'
w
W
ULSER
YST
N
W PLUM
ELIZABETH STR ET
I
O
W
HORSETOOTH ROAD
O
DATE: 12/3/03
SCALE: 1" = 2000'
DESIGNED BY: TUN
JOB NO.: 136-02
CAMBRIDGE LOFTS
MINOR SUBDIVISION
VICINITY MAP
SHEET 1 OF 1 1
,,North Star
design, inc.
700 Automation Drive, Unit I
Windsor, Colorado 80550
Phone: 970-686-6939
Fax: 970-686-1188
I
I
APPENDIX
VICINITY MAP, HYDRAULIC & HYDROLOGIC CALCULATION
I
I
I
I
I
I
I
I
I
I
rl
I
I
I
I
maintain the existing drainage patterns and the existing imperviousness for this site.
I Conveyance elements have been.designed to pass required storm flows and to minimize
future maintenance.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit will be required.
1
i
1
1
I
[J
1
1
[1
1
1
1
i
r
4.3 Drainage Summary
The existing and proposed drainage facilities located outside the right of way will be
' maintained by the site owner or the Home Owner's Association.
1 5. EROSION CONTROL
5.1 General Concept
This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort
' Collins Zone Maps. The potential exists for silt movement from the site and into Spring
Creek. Potential also exists for tracking of mud onto existing streets which could then
' wash into existing storm systems.
The erosion control escrow amount will be calculated with the final design of this site.
5.2 Specific Details
To limit the amount of silt leaving the site several erosion control measures shall be
implemented during construction. All boundaries shall have silt fence installed and a
vehicle tracking pad shall be installed at the drive to control the mud being tracked onto
the street. During demolition, disturbed areas are to be kept in a roughened condition and
watered to reduce wind erosion.
6. CONCLUSIONS
'
6.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
City Fort Collins Erosion Control Reference Manual for Construction Sites
of and the
Storm Drainage Design Criteria Manual.
6.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
I
.I
3.4 Hydraulic Criteria
' All preliminary hydraulic calculations within this report have been prepared in
accordance with the City of Fort Collins Drainage Criteria and are included in the
Appendix of this report. The sidewalk culverts and the concrete channel at the southeast
corner of the site were sized to carry the 100 year storm event.
4. DRAINAGE FACILITY DESIGN
4.1 General Concept
All of the runoff from this site currently drains to the adjacent streets and is either
collected in the storm system on Plum Street or Shields Street. Both storm systems
convey the runoff to Spring Creek. There is currently no detention or water quality
provided on site. It is proposed that a similar runoff pattern be maintained with the
redevelopment of the east portion of this site.
4.2 Specific Flow Routing
A summary of the drainage patterns within each basin is provided in the following
paragraphs.
Basin 1 contains the existing east parking lot and the proposed building. The runoff from
this basin currently flows to Shields Street via the drive entrances. These drive entrances
will be removed with the proposed redevelopment and the water will be directed to the
southeast corner of the parking lot, into a concrete channel and into Shields Street.
Basin 2 contains a portion of the existing buildings and parking lot on the east and south
sides of these existing buildings. It is proposed to add twelve parking stalls in this area
and reinstall a fire lane. Runoff from this basin flows east into Basin 1.
Basin 3 contains the eastern half of the building and the existing and proposed walks and
' landscape between. the building and Shields Street. Runoff from this basin will enter
Shields Street directly via overland flow or minor sidewalk culverts.
I
2.2 Sub -basin Description
This site drains to Shields Street or Plum Street and is conveyed in the streets to the storm
system. This storm system carries the water east and south under Shields Street to Spring
Creek.
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations
1 This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage
Design Criteria Manual' specifications. Where applicable, the criteria established in the
"Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver
Regional Council of Governments, has been used.
3.2 Development Criteria Reference and Constraints
The runoff from this site has been routed to conform to the requirements of the City
Stormwater Department. Because there is no increase in impervious area on this site,
detention and water quality are not proposed for this site.
The majority of the site will be routed to the southeast corner of the site and will be
conveyed via a concrete channel and sidewalk culverts to Shields Street. The building,
sidewalk area and the landscaped area on the east side of the site adjacent to Shields will
discharge directly to the adjacent streets.
3.3 Hydrologic Criteria
Runoff computations were prepared for the 2-year minor and 100-year major storm
frequency utilizing the rational method.
All preliminary hydrologic calculations associated with the basins are included in the
Appendix of this report. Standard Form 8 (SF-8) provides time of concentration
calculations for all sub -basins. Standard Form 9 (SF-9) provides a summary of the design
flows for all Sub -basins and Design Points associated with this site.
I
L GENERAL LOCATION AND DESCRIPTION
1.1 Location
The Cambridge Lofts is located in Old Town Fort Collins. This project is located in the
Northeast Quarter of Section 15, Township 7 North, Range 69 West of the Sixth Principal
Meridian, in the City of Fort Collins, Larimer County, Colorado. See the location map in
the Appendix.
The project is located in the southwest corner of the intersection of Plum Street and
Shields Street. The project is bounded on the north by a church and Plum Street, on the
' east by the Shields Street and on the south and west by existing development.
1.2 Description of Property
The entire project consists of approximately 3.4 acres of land. This property currently has
' 6 existing residential buildings and parking lot. The land currently slopes to the north and
southeast at a range of approximately 0.5% to 1%. The existing buildings will remain
without modification.
The proposed redevelopment consists of removal of existing parking, construction of a
single building on the east end of the site, replacement of a portion of the parking and
addition of parking at the south end of the existing buildings.
The site currently drains into Plum Street and into Shields Street. It is not proposed to
modify the area that drains to Plum Street, therefore this area was not reanalyzed. The
area that drains to Shields is being modified and is therefore being reanalyzed with this
report.
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description
The proposed development lies within the Spring Creek Master Drainage Basin. This site
is not located in a 100-year floodplain or in a `Flooded Area' designated in Figure 4 of
the above reference report.
11
TABLE OF CONTENTS
TABLEOF CONTENTS...............................................................................................................
iii
1.
GENERAL LOCATION AND DESCRIPTION
1.1 Location...................................................................................................................I
1.2 Description of Property............................................................................................I
2.
DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description..........................................................................................1
1
2.2 Sub -Basin Description.............................................................................................2
3.
DRAINAGE DESIGN CRITERIA
3.1 Regulations..............................................................................................................2
3.2 Development Criteria Reference and Constraints....................................................2
3.3 Hydrologic Criteria..................................................................................................3
3.4 Hydraulic Criteria....................................................................................................3
4.
DRAINAGE FACILITY DESIGN
1
4.1 General Concept.......................................................................................................4
4.2 Specific Flow Routing.............................................................................................4
4.3 Drainage Summary ...................................................................................................5
5.
EROSION CONTROL
5.1 General Concept......................................................................................................5
5.2 Specific Details
........................................................................................................5
6.
CONCLUSIONS
6.1 Compliance with Standards....................................................................................6
6.2 Drainage Concept.....................................................................................................6
I
I
ri
I
December 13, 2003
Basil Hamdan
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
RE: Preliminary Drainage and Erosion Control Study for the Cambridge Lofts Minor
Subdivision
Dear Basil,
I am pleased to submit for your review and approval, this revised Preliminary Drainage and
Erosion Control Study for the Cambridge Lofts Minor Subdivision. I certify that this report for
the drainage design was prepared in accordance with the criteria in the City of Fort Collins Storm
Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Sincerely
7DIJ
Patricia Kroetch, P.E.
ii
;.
/
{ t I t1 t
v e a, v t, t
4 ,(.• • 1
•
t. i S -S
,1
•J
'
..t
r t I.
:• o
ly
t \. i
'4 1"` f
., ( J S 1
y
t` ti ,1 , r , S l
.1,
t 51 ,
}
..,t
y , y^. F , i? LI
1 t - ,
. t
. t , ` }
1 i' 1 .
,
r• ! ' y
+oy
? F
.l F_! 1 1
1
♦1
j r
t. ` i
J ; Yl .,
.
S
, - .Jr- - , R r. t .
\
" r ..
PRELIMINARIiDRAINAGE AND EROSION , 1.
' \ ,
1 ;
1£ {t s
CONTROL STUDY, -
\ �; 1 ' 6 r b'� - a!
n
For V ;
1 °.:
C.AMBRIDGE
LOFTS MINOR SUBDIVISIONti , _
r
j It
- t , ,,
,' i-
1
S w \
A t a
, .1
, ,
i
" . ..
v
5 - , ,�
. 1 I 1
{ yt t 't .
:. ,
1 1 t' S
.. 1
1
1 ,
l
r
,
` 1 3 y5
' I
Y 4`'f
Gi t
1,1
-I \ 1 4 4
1
,
1. 1
` `
'' 4 , f4 , '' , { ! 2
1
1
, (1
, ' ' Prepared for � '1
..
A , .
.•y ,!, t , ..! M ti t
t `
�.
1
_.�
VI antagerPropert�es r
T 1 ' <"'1
t
West P1uin Street
,<
fbrit`Collhi CO'80521
, - ,
.,
1
'
- ' r Prepared by
, , - t -,
f
f...
_ ' t _ , , , t
,
1 ; 1
•, ;I,
North Star Design `r
*
:700 Automation Dnve;,Umt I
1
I .T t-.
Windsor, Colorado 80550
>. r -4... .. 3 ,.1 t '..
K
I
14 J
� � L' I
- { a,. �
• r - 'k t f c
! ' t"
1�
l .;
5 t t - % ',-.', f d j' .' ,
.r
r ,
•_ D.ecembei,-13;:2'003
,.
s Job Number 136-02
t t t
-a
1 C " t to P. '1. :.' r. :+.:
.
1
y 7
M h 1 1E r 4„
, ! `
I
( 1 4 S y y 'L , `I
F
�J
F .1 .,
1
t1. . , , 1. ,
a.t _
/' 1 2 r.V 3 4-
.., -i ,i" 4 -.. . ,..,. ,. .. it - , "I 1 _.. .. _ . ..... "l is �. 5 11