HomeMy WebLinkAboutFF Subdivision - Storm Water Design Report 4-30-19 DESIGN REPORT
for
STORM WATER MANAGEMENT
LOT 4, SPRING CREEK VILLAGE RESORT SUBDIVISION
(MINOR SUBDIVISION NO. 295A)
Prepared for:
Delaney & Company, Inc.
101 East Main Street, Bozeman, MT 59715
Prepared by:
C & H Engineering and Surveying, Inc.
1091 Stoneridge Drive
Bozeman, MT 59718
(406) 587-1115
Project No.: 11019
June 2013
Introduction
Lot 4, Spring Creek Village Resort Subdivision is located north of Huffine Lane (U.S. Highway
191), south of Fallon Street, west of Resort Drive and east of Cottonwood Road in Bozeman,
Montana. Lot 4, Spring Creek Village Resort Subdivision consists of 21 commercial lots. This
project will include construction of all streets within the subdivision and shall tie into the City of
Bozeman water and sewer utilities.All streets will be constructed with curb and gutter to a width of
35 feet from back of curb to back of curb.
Storm Water Management
Storm water run-off from the site will be directed by curb and gutter to retention ponds. These
retention areas will filter sediment and oils from the storm run-off. The retention ponds were sized
for the 10-year/2-hour storm event.
Storm Water Retention for Streets
In accordance with City of Bozeman policy, the storm water retention ponds must be sized for a
storm intensity having a 10-year frequency and a 2-hour duration. The equation used to model the
intensity of the 10-year frequency storm is given by the City of Bozeman Design Standards and
Specifications Policy. The design intensity for this report was calculated as follows:
i = 0.64(t-0.61) i=rainfall intensity(in/hr)
t=2 hrs t= storm duration (hours)
i = 0.64(2-o.6s) = 0.408 in/hr= 0.034 ft/hr d=2 hr water depth=0.068 ft
Storm Water Runoff(Post Development)
The storm water run-off for all drainage areas on the attached drainage exhibit were calculated as
follows:
The storm water run-off rate was calculated with the rational formula as shown. A run-off
coefficient (C) of 0.85 was applied to roof areas. A run-off coefficient (C) of 0.90 was applied to
hardscaping. A run-off coefficient(C)of 0.30 was applied to landscaping. The storm water run-off
rate for each respective drainage area was calculated as follows:
Q = CiA Q = storm water run-off rate (cfs)
i= (0.408 in/hr)x(1 ft/12 in)x(2hr) C =weighted run-off coefficient
d= 0.068 ft i= storm water intensity (in/hr)
A= surface area of drainage area(ft )
V=CdA
2
Drainage Area 1:
Roof Area = 0 ft2
Hardscape Area = 88,985 ft2
Landscape Area = 31,991 ft2
TOTAL = 120,976 ft2
Weighted Runoff Coefficient:
C = (0 ft2 x 0.85)+(88,985 ft2*0.90)+(31,991 ft2x0.30)
120,976 ft2
C = 0.74
Runoff Volume
V = 0.068x0.74xl20,976 ft2= 6,088 ft3
Drainage Area 2:
Roof Area = 5,913 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 5,913 ft2
Weighted Runoff Coefficient:
C = (5,913 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
5,913 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x5,913 ft2 = 342 ft3
3
Drainage Area 3:
Roof Area = 3,320 ft2
Hardscape Area = 0 ft'-
Landscape Area = 0 ft2
TOTAL = 3,320 ft2
Weighted Runoff Coefficient:
C =(3,320 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
3,320 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x3,320 ft2 = 192 ft3
Drainage Area 4:
Roof Area = 8,812 ft'-
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,812 ft2
Weighted Runoff Coefficient:
C = (8,812 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
8,812 ft2
C = 0.85
Runoff Volume
V= 0.068x0.85x8,812 ft2 = 509 ft3
4
Drainage Area 5:
Roof Area = 8,824 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,824 ft2
Weighted Runoff Coefficient:
C = (8,824 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
8,824 ft2
C = 0.85
Runoff Volume
V= 0.068x0.85x8,824 ft2= 510 ft3
Drainage Area 6:
Roof Area = 0 ft2
Hardscape Area = 41,373 ft2
Landscape Area = 14,307 ft2
TOTAL = 55,680 ft2
Weighted Runoff Coefficient:
C =(0 ft2 x 0.85)+(41,373 ft2*0.90)+(14,307 ft2x0.30)
55,680 ft2
C = 0.75
Runoff Volume
V = 0.068x0.75x55,680 ft2=2,840 ft3
5
Drainage Area 7:
Roof Area = 8,792 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,792 ft2
Weighted Runoff Coefficient:
C=(8,792 ft2 x 0.85)+(0 ft2*0.90)++(0 ft2x0.30)
8,792 ft2
C = 0.85
Runoff Volume
V= 0.068x0.85x8,792 ft2 = 508 ft3
Drainage Area 8:
Roof Area = 9,219 ft2
Hardscape Area = 18,964 ft2
Landscape Area = 17,999 ft2
TOTAL = 46,182 ft2
Weighted Runoff Coefficient:
C =(9,219 ft2 x 0.85)+(18,964 ft2*0.90)+(17,999 ft2x0.30)
46,182 ft2
C = 0.66
Runoff Volume
V = 0.068x0.66x46,182 ft2 =2,073 ft3
6
Drainage Area 9:
Roof Area = 8,170 ft2
Hardscape Area = 20,711 ft2
Landscape Area = 6,295 ft2
TOTAL = 35,176 ft2
Weighted Runoff Coefficient:
C = (8,170 ft2 x 0.85)+(20,711 ft2*0.90)+(6,295 ft2x0.30)
35,176 ft2
C = 0.78
Runoff Volume
V = 0.0680.7805,176 ft2= 1,866 ft3
Drainage Area 10:
Roof Area = 8,812 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,812 ft2
Weighted Runoff Coefficient:
C =(8,812 ft2 x 0.85)++(0 ft2*0.90)+(0 ft2x0.30)
8,812 ft2
C = 0.85
Runoff Volume
V= 0.068x0.85x8,812 ft2= 509 ft3
7
Drainage Area 11:
Roof Area = 8,170 ft2
Hardscape Area = 31,465 ft2
Landscape Area = 10,122 ftZ
TOTAL = 49,757 ft2
Weighted Runoff Coefficient:
C = (8,170 ft2 x 0.85)+31,465 ft2*0.90)+(10,122 ft2x0.30)
49,757 ft2
C = 0.77
Runoff Volume
V = 0.068x0.77x49,757 ft2=2,605 ft3
Drainage Area 12:
Roof Area = 0 ft2
Hardscape Area = 22,938 ft2
Landscape Area = 1,774 ft2
TOTAL = 24,712 ft2
Weighted Runoff Coefficient:
C = (0 ft2 x 0.85)+(22,938 ft2*0.90)+(1,774 ft2x0.30)
24,712 ft2
C = 0.86
Runoff Volume
V = 0.068x0.86x24,712 ft2= 1,445 W
8
Drainage Area 13:
Roof Area = 6,548 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 6,548 ft2
Weighted Runoff Coefficient:
C =(6,548 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
6,548 ftz
C = 0.85
Runoff Volume
V = 0.068x0.85x6,548 ft2 = 378 ft3
Drainage Area 14:
Roof Area = 6,560 W
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 6,560 ft2
Weighted Runoff Coefficient:
C =(6,560 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
6,560 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x6,560 ft2 = 379 ft3
9
Drainage Area 15:
Roof Area = 8,812 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,812 ft2
Weighted Runoff Coefficient:
C = (8,812 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
8,812 ft2
C =0.85
Runoff Volume
V = 0.068x0.85x8,812 ft2 = 509 ft3
Drainage Area 16:
Roof Area = 0 ft2
Hardscape Area = 22,938 ft2
Landscape Area = 1,774 ft2
TOTAL = 24,712 ft2
Weighted Runoff Coefficient:
C = (0 ft2 x 0.85)+(22,938 ft2*0.90)+(1,774 ft2x0.30)
24,712 ft2
C = 0.86
Runoff Volume
V= 0.068x0.86x24,712 ft2 = 1,445 ft3
10
Drainage Area 17:
Roof Area = 8,824 ft2
Hardscape Area = 28,531 ft2
Landscape Area = 11,191 ft2
TOTAL = 48,546 ft2
Weighted Runoff Coefficient:
C= (8,824 ft2 x 0.85)+(28,531 ft2*0.901+(11,191 ft2x0.30)
48,546 ft2
C = 0.75
Runoff Volume
V = 0.068x0.75x48,546 ft2=2,476 ft3
Drainage Area 18:
Roof Area = 8,812 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 8,812 ft2
Weighted Runoff Coefficient:
C= (8,812 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
8,812 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x8,812 ft2 = 509 ft3
11
Drainage Area 19:
Roof Area = 6,560 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 6,560 ft2
Weighted Runoff Coefficient:
C = (6,560 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
6,560 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x6,560 ft2= 379 ft3
Drainage Area 20:
Roof Area = 6,548 W
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 6,548 ft2
Weighted Runoff Coefficient:
C =(6,548 ft2 x 0.85)+(0 ft2*0.90)(0 ft2x0.30)
6,548 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x6,548 ft2 = 378 ft3
12
Drainage Area 21:
Roof Area = 0 ft2
Hardscape Area = 195,582 ft2
Landscape Area = 101,089 ft2
TOTAL = 296,671 ft2
Weighted Runoff Coefficient:
C =(0 ft2 x 0.85)+(195,582 ft2*0.90)+(101,089 Wx0.30)
296,671 ft2
C = 0.70
Runoff Volume
V= 0.068x0.70x296,671 ft2 = 14,122 ft3
Drainage Area 22:
Roof Area = 15,186 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 15,186 ft2
Weighted Runoff Coefficient:
C =(15,186 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
15,186 ft2
C =0.85
Runoff Volume
V = 0.068x0.85x15,186 ft2= 878 ft3
13
Drainage Area 23:
Roof Area = 4,300 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 4,300 ft2
Weighted Runoff Coefficient:
C =(4,300 W x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
4,300 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x4,300 ft2 =249 ft3
Drainage Area 24:
Roof Area = 1,400 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 1,400 ft2
Weighted Runoff Coefficient:
C = (1,400 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
1,400 ft2
C = 0.85
Runoff Volume
V = 0.068x0.85x1,400 ft2= 81 W
14
Drainage Area 25:
Roof Area = 4,300 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 4,300 ft2
Weighted Runoff Coefficient:
C = (4,300 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
4,300 ft2
C =0.85
Runoff Volume
V = 0.068x0.85x4,300 ft2=249 ft3
Drainage Area 26:
Roof Area = 15,186 ft2
Hardscape Area = 0 ft2
Landscape Area = 0 ft2
TOTAL = 15,186 ft2
Weighted Runoff Coefficient:
C = (15,186 ft2 x 0.85)+(0 ft2*0.90)+(0 ft2x0.30)
15,186 ft2
C = 0.85
Runoff Volume
V= 0.068x0.85xl5,186 W = 878 ft3
15
Drainage Area 27:
Roof Area = 0 ft2
Hardscape Area = 81,372 ft2
Landscape Area = 46,756 ft2
TOTAL = 128,128 ft2
Weighted Runoff Coefficient:
C = (0 ft2 x 0.85)+(81,372 ft2*0.90)+(46,756 ft2x0.30)
128,128 ft2
C = 0.68
Runoff Volume
V = 0.068x0.68x128,128 ft2 = 5,925 ft3
Distribution of Drainage Areas to Retention Ponds:
Retention Pond 1: Drainage Areas 6 (except 803 ft3), 12, and 21.
Volume Required: 17,604 ft3
Volume Supplied: 17,700 ft3
Retention Pond 2: Drainage Areas 1, 16, 17, and 27.
Volume Required: 15,934 ft3
Volume Supplied: 17,700 ft3
Retention Pond 3: 803 ft3 of Drainage Area 6.
Volume Required: 803 ft3
Volume Supplied: 803 ft3
Retention Pond 4: Drainage Area 8.
Volume Required: 2,073 ft3
Volume Supplied: 2,720 ft3
16
Retention Pond 5: Drainage Area 9.
Volume Required: 1,866 ft3
Volume Supplied: 2,457 ft3
Retention Pond 6: Drainage Area 11.
Volume Required: 2,605 ft3
Volume Supplied: 2,720 ft3
Percolation Basins: Drainage Areas 2, 3,4, 5, 7, 10, 13, 14, 15, 18, 19, 20, 22,23,24,25,
and 26. All drainage areas flowing to percolation basins are purely
roof drainage areas. See Attachment 1 for an example percolation
basin calculation.
g:\C&MI 1\110190rainage Calculations\strmwtr.wpd
17
O
I W w Z o w w
I U
a >
C7a� Za F� y za €� z a.
, e9
oN4Y OJT a oNLLY� O e
Z Wi
c oaw8" _ oaw8� oa. I O O
� G d UO�c� N OHM UO�d�
O 0
art iitosau I °'
-- N o
='.XJ
- - - -- -
r
�'°Q=a ga ,; SE W l --— - I r 1 jc m j! z ` vl
Iri M Z 1��b 'l�. m� .IJ_l� J—L1_f^ _ 11 W I~ Y
�� Li
' Oho ?� i_tn^1y I_joL O
�4 O •L Q O _ a `i I I I� .-'� o :� I - O r J
U
� Z' I - I 1
Lo
o�h p
b
I I
So z Mrs NAY I
za I
I I I r / �d
i j iT I - I s Z €
ao Z� I o Ya 1
W o o, < i I .? I I , I
�N�' `+�� Z� Q� ) wY: I .�."1 I r�Sfy '1.; �� I �oaQgW
I d Z �j aWs r i:. ��m H r� p COxo�
I C7� z R .��� JC4' ggiw3 1
a n , _.
W 111 � b
J f
jI F Y h anuaaV �LXodr.
0
LO
N IN I N g Y
� M �J a°� I C
n
p N Jan l-)(
� �Cg Q I II 4`I II 1I.II` C9•� ! II I (
e.IaS
SL e 111
I N
;�� I % ����� a ( 0�d Ii II I a a
I,
w I p m S a W
F ' _
I I Leo :�•C �0 1 I I i�- .�) � I I
Y
I J
-A A i
h I
� s 1 I;.. l�4€
i� ►-�� I. LZ
Zi5Oj
a n a
c< I r. ��I I I 1 °1
r - p p 1 C CO
,. RollidI---------------
CD
- -
----------------
I � p�3� I I o O.Pee8 m �npeq Is~pee$ I m ; s
8 ONf1021VN2lfll OV3H213WWVH ,O6 ' � -az I C > E
ONnONVNHn-L Od3H83WWVH .06 I c0i
I I N I� N
__j S 1 J� I J� I 9 m N �
- c
i c
Project Number �. ..
ENGINEERING AND U
M
SURVEYING, INS': Project Name:�Sf�p�W ���4r-J
o Civil Engineering -;+Structural Engineering •Lend Siwmying. Date: 3 A 8 /OO� Fig By M�
— ,
` 2415 W.Main Street,Suite 1 (406)5877MS i j
Bozeman:Montana 59718 Faxa(40 .587-9768 , Subject: ROOF LA A BN�1�e % &�cJ tC Paget
A I
_u G�A sort to C C ra r C C li Ltd
— - ------;— 4--
s
;
s
f / —!
s i
3 S
t!M > C
,
_
. .0 - 3.
_. _
. i
i
,
F
_ i
Vd�UNI� �rsit rA,q -
' /t E
161
i
Jr. . otaME Ojr A�J
•
f
Al id—t1 G� _ Jr"
•
_� on
, �r j
h
,
d1 Sy�#L A r i J ,�-
,
i
. E
- ► �R = 4
,
:
�s
7
v
_...........� ; s
• ♦ iF
•
..i.r
t �
t
_ W�F
_..__.F GLJ r I —
:
•
L ADtY�s
s t
i—
_
,
I
{ s
--i
.—'t
i
f t - 1
:
, � f
.z......_.�W.,.._..........._.., i U. _
- ( i
s L cr sI'7'.; I Slvnrc r GRs lti c t