HomeMy WebLinkAboutDrainage Reports - 08/31/2015 (2)Cit*lofFt..CoUi gprov Pfar
;Approved'BY 4-11
Date > ->
Prepared for:
Brad Florin
Fort Equity
1603 Oakridge Drive, Suite B
Fort Collins, CO 80527
Prepared by:
NORTHERN
ENGINEERING
200 South College Avenue, Suite 100
Fort Collins, Colorado 80524
Phone: 970.221.4158 Fax:
970.221.4159
n .northemengineenng.com
IA This Drainage Report Is consciously provided as a PDF.
Please consider the environment before printing this document in its entirety.
When a hard copy Is absolutely necessary, we recommend double -sided printing. Project Number: 963-001
' NorthernEngineering.com // 970.221.4158 _
I
1
1 W
1
1
1
1
1
i
1
1
11
1
NORTHERN
ENGINEERING
August 11, 2015
ADDRESS: PHONE:970.221.4158�
200 S. College Ave. Suite 10 WEBSI rthernengineering com
Port Collins, CO 80524 FAX: 970.221.4159
City of Fort Collins
Stormwater Utility
700 Wood Street
Fort Collins, Colorado 80521
RE: Final Drainage and Erosion Control Report for
Townhomes @ One Library Park
Dear Staff:
Northern Engineering is pleased to submit this Preliminary Drainage and Erosion Control Report for
your review. This report accompanies the 05.14.14 Basic Development Review submittal for the
proposed Townhomes @ One Library Park. Comments from the Basic Development Review Letter
dated October 22, 2013 have been addressed. Written responses thereto can be found in the
comprehensive response to comments letter on file with Current Planning.
This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM),
and serves to document the stormwater impacts associated with the proposed Townhomes @ One
Library Park project. We understand that review by the City is to assure general compliance with
standardized criteria contained in the FCSCM.
If you should have any questions as you review this report, please feel free to contact us.
Sincerely,
NORTHERN ENGINEERING SERVICES, INC.
Bud Curtiss, PE
1
Principle
Cb'd Snowdon
Project Engineer
NORTHERN
ENGINEERING
I
I
TABLE OF CONTENTS
I. GENERAL LOCATION AND DESCRIPTION..........:........................................................1
A. Location.......................................................................................................................................1
'
B.
C.
Description of Property................................................................................................................2
Floodplain....................................................................................................................................3
II.
DRAINAGE BASINS AND SUB-BASINS.......................................................................
5
'
A.
Major Basin Description...............................................................................................................5
B.
Sub -Basin Description..................................................................................................................5
'
III.
A.
DRAINAGE DESIGN CRITERIA......................................:............................................
Regulations..................................................................................................................................5
5
'
B.
C.
Four Step Process........................................................................................................................5
Development Criteria Reference and Constraints ......
:.................................................................. 6
D.
Hydrological Criteria.................................................................:..................................................6
'
E.
Hydraulic Criteria.........................................................................................................................7.
F.
G.
Floodplain Regulations Compliance..............................................................................................7
Modifications of Criteria..............................................................................................................7
IV.
DRAINAGE FACILITY DESIGN....................................................................................
7
A.
General Concept..........................................................................................................................7
B.
Specific Details.............................................................................................................................8
V.
A.
CONCLUSIONS........................................................................................................9
Compliance with Standards..........................................................................................................9
B. Drainage Concept........................................................................................................................9
References.......................................................................................................................10
rirruvun.w:
APPENDIX
A —
Hydrologic Computations
APPENDIX
B —
Hydraulic Computations
B.1 —
Storm Sewers Modeling
'
B.2 —
Inlets and Weir Computations
APPENDIX
C —
Water Quality Computations
APPENDIX
D —
Standard Operating Procedures (SOPs)
0
' Final Drainage Report
NORTHERN
ENGINEERING
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
LIST OF TABLES AND FIGURES:
Figure1 — Aerial Photograph................................................................................................ 2
Figure 2 — Proposed Site Plan...............................................................................................3
Figure 3 — Existing City Floodplains....................................................................................... 4
Final Drainage Report
NORTHERN
ENGINEERING
1. GENERAL LOCATION AND DESCRIPTION
A. Location
1. Vicinity Map
r
Fel
2. Townhomes @ One Library Park is located in the southwest quarter of Section 12,
Township 7 North, Range 68 West of the 6t" Principal Meridian, City of Fort Collins,
County of Larimer, State of Colorado.
3. The project site is located just northwest of the intersection of East Olive Street and
Mathews Street.
4. Currently the existing lot does not have any stormwater or water quality facilities. Due
to the proximity of the existing building to the property, all of the stormwater is
collected on top of the roof and discharged directly into the City Stormwater
Collections System via a roof drain leader. All of runoff, located within the public
Right -of -Way is discharged via overland flow into the street curb and gutter and
intercepted by an existing Type'R' Inlet into the aforementioned system.
5. The project is currently border to the south by East Olive Street, west by a public
alley, north by a multi -family complex and east by Mathews Street.
' Final Drainage Report 1
CI
1
[ I
11
L
C!
NORTHERN
ENGINEERING Townhomes @ One Library Park
B. Description of Property
1. Townhomes @ One Library Park property is approximately 0.289 net acres.
�4 r
Figure 1 — Aerial Photograph
2. Townhomes @ One Library Park project consists of one property that is entirely
consumed by an existing building. This building was owned and occupied previously
by the City of Fort Collins Utilities. On the southeast corner of the lot, there is an
existing Porte-cochere acting as an old drive-thru window. The existing building was
constructed with a flat roof collecting all stormwater through a central rooftop drain.
This drain was discharged directly into the City stormwater system through a
stormwater service pipe. Al stormwater surrounding the building was routed via
overland flow into the surrounding streets and public alleyway. No off -site stormwater
was routed on -site.
3. According to the United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) Soil Survey, 79 percent of the site consists of Fort
Collins loam, which falls into Hydrologic Soil Groups B, while the remaining site
consists of Satanta loam, which falls into Hydrologic Soil Groups B.
4. The proposed development will include the deconstruction of the old City building
along with all associated utility services. The proposed site will include two large
building, each being divided into five single family attached units, and a central
access drive composed of both permeable and inpermeable pavers. The site is
located in the Old Town master drainage basin, and therefore, on -site detention is not
required so long as the increase in impervious area is less than 5,000 square -feet.
The proposed development will be decreasing the amount of imperviousness by
approximately 2,746 square -feet (16,927-14,181). A detailed breakdown of the
existing and proposed impervious area is attached to this report. Although the project
site is located within the Uhdal Basin and water quality is not required, the center
section of drive constructed of permeable pavers will act as the projects water quality
facility.
Final Drainage Report
2
I
I
1
F
■� (NORTHERN
ENGINEERING Townhomes a One Library Park
r
Figure 2— Proposed Site Plan
t
,...,,..
�� 4
�•.
5. No irrigation facilities are known to be within the property limits.
6. The project site is within the Neighborhood Conservation Buffer (N-C-B) Zoning
District. The proposed project is not requesting a change in the land use.
C. Floodplain
1. The subject property is not located in a FEMA or City regulatory floodplain.
The FEMA Panel 08069C0979H, shown below, illustrates the proximity of the
project site to the nearest FEAM delineated regulatory floodplain. It is noted that the
vertical datum utilized for site survey work is the City of Fort Collins Benchmark #1-
13 (Elevation = 4976.58, Fort Collins NVGD 29 — Unadjusted)
Final Drainage Report 3
NORTHERN
ENGINEERING Townhomes @ One Library Park
�A9-
6
$Iik
9a >
YAP SCALE 1" = 500
SL 0 50C '00(
•
12
fF rT
MFTF
xLL0479
9
_ ...
YI11YtL W/YF
1
:_< FIRM
LL0490
:,... 1,.re
3 FLOOD R WAIANM RATE MAP
Y
LL 1029Y
I.It RI NIVR
lstft
r? C'OLOR.�00
AND Nt ORKMA1E1) AR1A5
LL
QM
T l
Q
PRIM m OF UN
Project
Site
My
QA.Y l s.l.....
7 .Mw
rat[
r
�
PM►tNEJI
Y4Mrtt�r�y. >t�N 1{r�.
�� nra. air w•v�•.���•w�.m �+
Figure 3 — Existing FEMA Floodplains
Y
nba - _w F
!th'a I ..rwc OIN
C4nYr toll tlYtla u
PM tM f
_.. 14
N ut ki ngfuwn •
I OW lfwn
Llb Ys
F 14
F
PROJECT.
coffins t.Mulnw Pc4Alro/9•
ry•St��r
St Aim 1
Figure 4 — Existing City Floodplains
N
E.Yu10Kry•C t�
I
Final Drainage Report 4
'
NORTHERN
ENGINEERING Townhomes @ One Library Par
II. DRAINAGE BASINS AND SUB -BASINS
A.
Major Basin Description
1. Townhomes @ One Library Park is located within the Old Town Basin, which is
'
located primarily in Old Town Fort Collins.
B.
Sub -Basin Description
1. The subject property primarily consists of a commercial building. This area routes
stormwater through a roof drain and directly into the City's Stormwater system. The
areas surrounding the building to the north, south and east route stormwater away
'
from the building and into the streets. Both streets discharge directly into the City's
Stormwater system via a curb inlet located at the southeast corner of the project site.
A more detailed description of the projects proposed drainage patterns follows in
'
Section IV.A.4., below.
2. No drainage is routed onto the property from the east, west, north or south.
'
III. DRAINAGE DESIGN CRITERIA
A.
Regulations
'
There are no optional provisions outside of the FCSCM proposed with Townhomes @ One
Library Park.
'
B.
Four Step Process
The overall stormwater management strategy employed with Townhomes @ One Library
'
Park utilizes the "Four Step Process" to minimize adverse impacts of urbanization on
receiving waters. The following is a description of how the proposed development has
incorporated each step.
Step 1 — Employ Runoff Reduction Practices
Several techniques have been utilized with the proposed development to facilitate the
reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the
current use by implementing multiple Low Impact Development (LID). strategies including:
Conserving existing amenities in the site including the existing vegetated trees along
Mathews Street and Olive Street.
Routing flows, to the extent feasible, through vegetated swales and grass buffers to
'
increase time of concentration, promote infiltration and provide initial water quality.
Providing permeable paver areas with underground detention area to increase time of
'
concentration promote infiltration and provide water quality.
Step 2 — Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with
Slow Release
Although this project site is located within the Udall Natural Area and Water Quality is not
required, approximately 70 percent of the building and the entire central drive aisle will
'
drain across or into the permeable paver section located within the drive. In addition, the
northern half of the northern building will drain into a grass lines swale achieving further
water quality.
' Final Drainage Report 5
.V NORTHERN
ENGINEERING Townhomes @ One Library ParF
Step 3 — Stabilize Drainageways
As stated in Section 1.B.5, above, there are no major drainageways in or near the subject
site. While this step may not seem applicable to Townhomes @ One Library Park, the
proposed project indirectly helps achieve stabilized drainageways nonetheless. Once again,
' site selection has a positive effect on stream stabilization. By repurposing an already
developed, under-utilized site with existing stormwater infrastructure, combined with LID,
the likelihood of bed and bank erosion is greatly reduced. Furthermore, this project will
pay one-time stormwater development fees, as well as ongoing monthly stormwater utility
fees, both of which help achieve Citywide drainageway stability.
' Step 4 — Implement Site Specific and Other Source Control BMPs.
This step typically applies to industrial and commercial developments and is not
applicable for this project.
C. Development Criteria Reference and Constraints
1.
There are no known drainage studies for the existing properties.
2.
There are no known drainage studies for any adjacent properties that will have any
'
effect on Townhomes @ One Library Park project.
3.
The subject property is essentially an "in -fill' development project as the property is
surrounded by currently developed properties. As such, several constraints have been
'
identified during the course of this analysis that will impact the proposed drainage
system including:
'
Existing elevations along the south, east and west property lines adjacent to Olive
Street, Mathews Street and the Public Alley will be maintained.
Existing trees along Mathews Street and Olive Street will be preserved.
As previously mentioned, overall drainage patterns of the existing site will be
'
maintained.
D. Hydrological Criteria
1.
The City of Fort Collins Rainfall Intensity -Duration -Frequency Curves, as depicted in
Figure RA-16 of the FCSCM, serve as the source for all hydrologic computations
associated with the Regency Lakeview development. Tabulated data contained in
Table RA-7 has been utilized for Rational Method runoff calculations.
2.
The Rational Method has been employed to compute stormwater runoff utilizing
'
coefficients contained in Tables RO-11 and RO-12 of the FCSCM.
3.
The Rational Formula -based Modified Federal Aviation Administration (FAA)
'
4.
procedure has been utilized for detention storage calculations.
Three separate design storms have been utilized to address distinct drainage
scenarios. A fourth design storm has also been computed for comparison purposes.
The first design storm considered is the 80" percentile rain event, which has been
'
employed to design the project's water quality features. The second event analyzed is
the "Minor," or "Initial" Storm, which has a 2-year recurrence interval. The third
'
event considered is the "Major Storm," which has a 100-year recurrence interval.
The fourth storm computed, for comparison purposes only, is the 10-year event.
5.
No other assumptions or calculation methods have been used with this development
'
that are not referenced by current City of Fort Collins criteria.
Final Drainage Report 6
1 NORTHERN
ENGINEERING
1
' IV
1
r�
1
1
E. Hydraulic Criteria
Townhomes @ One Library Park
1. As previously noted, the subject property historically drains directly into the City's
Stormwater system. The majority of the site drains stormwater via overland and pipe
flow.
2. All drainage facilities proposed with Townhomes @ One Library Park project are
designed in accordance with criteria outlined in the FCSCM and/or the Urban
Drainage and Flood Control District's (UDFCD) Urban Storm Drainage Criteria
Manual.
3. As stated in Section I.C.1, above, the subject property is not located within a FEMA
regulatory floodplain.
4. Townhomes @ One Library Park project does not propose to modify any natural
drainageways.
F. Floodplain Regulations Compliance
1. As previously mentioned, all structures are located outside of any FEMA 100-year
floodplain, and thus are not subject to any floodplain regulations.
G. Modifications of Criteria
1. The proposed Townhomes @ One Library Park development is not requesting any
modifications to criteria at this time.
DRAINAGE FACILITY DESIGN
A. General Concept
1. The main objectives of Townhomes @ One Library Park drainage design are to
maintain existing drainage patterns and ensure no adverse impacts to any adjacent
properties.
2. The existing site does not have off -site flows entering the site.
3. A list of tables and figures used within this report can be found in the Table of
Contents at the front of the document. The tables and figures are located within the
sections to which the content best applies.
4. Townhomes @ One Library Park project divided the site into four (4) major drainage
basins, designated as Basins A, B, C and OS. The project was not further subdivided.
The drainage patterns anticipated for each basin is further described below.
Basin A
Basin A consists of the northern half of the northern building and the landscapelwalk
north of the building. Runoff from this basin is routed through a combination of
overland and swale flow. The runoff from the roof is collected through a central drain
and discharged directly into the grass lined swale running along the north from west to
east. This runoff is discharged directly into the street section and finally intercepted
by the existing storm inlet located at the northwest corner of Mathews and Olive
Street.
' Basin B
Basin B consists of the 70 percent of both building and the entire central drive aisle.
Runoff from this basin is routed through a combination of overland and gutter flow.
Final Drainage Report
L�
7
' NORTHERN
ENGINEERING Townhomes @ One Library Park
The runoff from the roof is collected through a central drain and discharged directly
' into the paver section located in the center of the private drive. All runoff from the
private drive is routed across the pavers and intercepted by a combination inlet
located at the east end of the drive aisle. This private storm system is connected
' directly to the City's Stormwater system. In the case that the inlet is clogged, the
runoff will spill over the curb and gutter. The inlet/ will then act like a weir and is able
to handle 133 percent of the 100-year event.
' Basin C
Basin C consists of the southern half of the southern building and the landscape
between the building and the public walk. Runoff from this basin is routed through a
' combination of overland and pipe flow. The runoff from the roof is collected through a
central drain and discharged directly into the private storm sewer running along the
south from west to east. This runoff is discharged directly into the City's Stormwater
' system.
Basin OS
Basin OS consist entirely of the public sidewalk and landscape buffer. Runoff from
this basin is routed overland and discharged directly into the street section and finally
intercepted by the existing storm inlet located at the northwest corner of Mathews and
' Olive Street.
A Drainage Exhibit can be found at the end of this report.
' B. Specific Details
1. Although this located within the Udall Natural Area, water quality is always a
' concern. Additional treatment will include the proposed paver section within the
central drive aisle, which will treat 48 percent of the project site and a grass lined
swale located to the north of the property, which will treat and additional 17 percent
' of the site.
2. The project is located within the Old Town Master Drainage Basin, which does not
require detention as long as the addition imperviousness proposed is less than 500
square feet. Townhomes @ One Library Park will actually be reducing the overall
imperviousness of the site by 2,746 square -feet (14,181-16,927), therefore no
detention is required.
' 3. There are Nyloplast Drain Basins located along the southern and eastern sides of the
building. These area inlets are designed to intercept local flows, as well as the flow
generated by the proposed buildings. These basins will convey runoff through
' landscape areas before discharging into the drain system. The drain basin is
connected directly to City's Stormwater system.
4. The emergency spillway will be located at the low point on the eastern side of the
drive aisle. In the event that an emergency overflow occurs, the drainage will flow to
the east, into the existing street. Weir calculations are attached and only account for
the area directly above the inlet. More capacity is available along the entire section of
' the curb and gutter.
Final Drainage Report 8
NORTHERN
ENGINEERING
1
I
I
V. CONCLUSIONS
A. Compliance with Standards
1. The drainage design proposed with Townhomes @ One Library Park project complies
with the City of Fort Collins' Stormwater Criteria Manual.
2. The drainage design proposed with Townhomes @ One Library Park project complies
with the City of Fort Collins' Master Drainage Plan for Old Town.
3. There are no regulatory floodplains associated with Townhomes @ One Library Park
development.
4. The drainage plan and stormwater management measures proposed with Townhomes
@ One Library Park development are compliant with all applicable State and Federal
regulations governing stormwater discharge.
B. Drainage Concept
1. The drainage design proposed with this project will effectively limit any potential
damage or erosion associated with its stormwater runoff. Townhomes @ One Library
Park has decreased the amount of impervious area, therefore reducing the overall
amount of runoff generated from the site.
2. The proposed Townhomes @ One Library Park development will not have any impact
on the Master Drainage Plan recommendations for Old Town.
Final Drainage Report 9
W I NORTHERN
ENGINEERING
References
One Library Park
1. City of Fort Collins Landscape Design Guidelines for Stormwater and Detention Facilities,
November 5, 2009, BHA Design, Inc. with City of Fort Collins Utility Services.
2. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No.
174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code.
3. Larimer County Urban Area Street Standards. Adopted January 2, 2001, Repealed and
Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007.
4. Soils Resource Report for Larimer County Area, Colorado. Natural Resources Conservation
Service, United States Department of Agriculture.
5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control
District, Wright -McLaughlin Engineers, Denver, Colorado, Revised April 2008.
Final Drainage Report 1 10
1
1
AOO
J
A-
7
�i/
--_ ___m
' NorthernEngineering.com // 970.221.4158
I
0
P
I
I
I
I
I
I
I
I
I
I
�
.
�
« !
q{E}
■.ate!
_
{�]§§[
E0
,)A
q
\��
kk5k%m
9L
E W2=0
\ \\\0
w
o
®
)�66
I
�
_
k
\■(/2§�
�/k
(KK§5
!)\
qq
£}\
o0
$I_
_
\)�
j§\
)27
00
60
`
/
LU
5§
S
�!
u
:
_!-
■
D
-6
:!
§ 2�ol
ta
LL
§f�7al�24\«
-
$ %\A$!)§!of
|
.
3 _
j
&
(L
� \
w
I
_
£
{.
/2
}75
u.
f
$>A&■
$�«
§
�2
SOR00
:!]§
ee
/\\
PE
|
§
: »
�
!
Px$!,�
k
f.7§§
§
|!-
�I#ww
.&
f)$§§
�
k
-
� 3 (
�\\
�.@ :
■!
�� \//% !
k
�2
2
0
\
a
I
«
J
� j
k
0
0
P
I
I
I
I
I
I
I
I
I
Z■
m.lj
z/
�
�
I
�o-�-
2a£32
.
/0
/e}
3��
cy
£
%ca
IL
BƒkG§
3
$®k§(
.
\[
B
15 -
%
|
=
2
u
� j§ §4
Id
�.
k
e
mG
u
o0
kk§
)
LO
%
°
�
■;§| ;
e\
_
f&af
rtD
�
7iAf
r(D
/
(
k-
§j
)
fU
.
On
{
z
§
{
2
= u \
£
/ E
U
k \ m
a s
��
i«
22
2
2 ;
0
7
(L
m
a
.4
[1
11
s t
e g
o
u
a
u
o
u
0
c
0
c
C
E
OtOO
a
N
E
In�tovto
0
uo
Y It
Ip N Cl!
0
D_ N C
C
din
ISO VOA
a 3'" cT
�. �G u
r,O
n
t0
00
to
to
a)
a)OeO
H
�"
o
000
Z
cmm Ed
o
O U ¢ A
0
ll_
4y
W m A T
'O
w
Q
J
.r C�
G
N p U
OlO
l0
00
OI
l0
V
It)
N
I�
�i
0. o <n
�. S C
6EE�
00000
V
c
O
W
pNp
t0
00
t0
In
n
W
•N
N O S
0000
O
�
U
E
O c
S m'S
L
fn o
j
W
Inrnu��.
0 V
00000
p
33
LJL
N
Vi
O
p
e5
C^
OIn
OO
In
c
A d U
m
O
00000
N
O
O
N
s
` v
as
00000
Z
a
Q
a
o
0
0
0
0
o
N
y d
0
ti0
0
0
VO
0
N
N
0
0
`` q
0
00000
0
0
0
O
ZE
d _
d
a0
N
a
V
c
E
' u
In
0)0)In
In
O
In
01
0
-It
In
—N
In
a
ry
�/1
N
(N
N
0
00
C
N C
0.00.
C
O
O
O
O
O
O
O
C
O
O
O
O
O
W
3
0
U
d
a
`
t0
-+m
OD
N
OIn
In
N
m
c v
OoOo-.
�
a�g
00000
�
U
y
m
a
p
`o
m
„tom
00000
00000
C
d am
00000
O
o
Qay
60000
V
E
`o
N
N
W
L
0
0
0)
00
tom
o
c m
ONo
00000
-.v
Lair
W
v
a
W y
A
..a-.n00
K G
w
C ui
0
a
LO
0
001
0
00
0 y :
s
�"-
m0IN
V,.y
oN
U)
w
CO
J
U. C C
O
N
Q
W
d C 1` T
d N
pp
4 ac�.i
q
11
1
1
' =2E
Ww
w
C 0CD
ZW
T
F
c
•"
T C
o
�
u
�
C N
z a m
d
E
d fn m
c
O U ¢
m
c
c
~
¢ ¢
z z
¢ ¢
z z
a o
A
E
_ Uw
Ll
0
N
> s
Q Q
z z
Q Q
z z
d
>
y
.. ,
Q Q
z z
Q Q
z z
3
N
N
C J.�
0000
y
J
0000
min
000
�
ILL
>
0 0
o
Apyy
2
ao
6
G7 o.�inna
Oye
OOnLL
N N
O O
Q
y
e
i
J�
O O
n 0
2
n 0
C
d
ti ti�
ti
�
N O
O N
V
oO1
Jg•
LL
u
0
a n
W
4,,2mcn�nn
O
z
d ! .0 .0
HMn..
e
O
e
c
~
mrvf
inn
N E
M
y
00
O O
O O
W
y v
N N
i0 N
LL
t
NV.yN
�
V
O
G
U v
CT
0 9
O.'+O
0 tq
O
K
_
O
0
00 �
�
O N
N G
G
la
II
000o
W U
C tl
O1a
d
o A
C
• .a
U
l0 00
0000
t0 �
u
.N., II
d R (A 222
C
�T
V
ffi r.
d *' 0 m
C r `
\�N N
w
r 6
J N'
ZZZZ
I > >
Is M.
H n
_
.a 0 0
;
f O = ILL ILL
[� LL d d
C
¢mU0
LL °�°
M o
to
C
U d
d 11 I 0 0 FO
110
N
U O
0 C7 H F>> z
O 0.
O
Lo
a)
a
O 8-
tONj-
00
LL (gY
ONOO
w
Na!N
m
_o
p CY
OOO
O
LL
Y ti
� N
c
- v
O
In
in
c
p d u
LL
6
0
0
0
6
6
N N to
c
O U Q
u Co «
mrnrnrn
a e
8
d —
ai
of
of
of
m
c
u
ry
V
� ^
r\nr\oq
UaoUU
.cd.—
V
d'ct
,t
c
Z
cqcooqoq
W
N
N
N
N
O
o
C
ti
gg
o
�y yyy
o
to
000
O
00
00
lD
6yii
o
000n
� j
O
--
O
O
O M ry N 0
d
O��
f •
a
V
O
e
p
O
-It
sEp
�
00 W
to �u'f
�
O
0000
2
U
o
ci
Iq00Iq
Lq
W
x
o000
a
a e
O
p On Op
J
IYOI wNnN O. l�l
W
`
a ywsVO m
N C H .i LL
O F E
l[1
In
lL1
tL1
C
LL
U
T C
c F •E
u
Ln
u)
Ln
U
c
_m
0
W
e� ~ E
Ln
u'
Ln
Ln
o`
E
o`
N
Q w
c
=
N
00
ONO.
N
LO
.-i
8
a
o000
0
LL
O
(1
w
O �
V
LL
w Q
in
<
Co
0
Ly fi w
m
o s
m
p U � B
C
!
o d
U
_.
m E a `
n
LL Cc c
1
W
a
C
O
H
a N
0)
^
�
t0
w
1n
—
cM
r�
CJ v
ONOO
m—
N
0)
LnO
'
m
O
O
O
O
T C
O
O
O
O
O F '-
o E
Sri
Sri
Lri
Sri
o E
Lo
tri
0
tri
oo'
in
o
to
00
no00to
V
o-:o6
O
(00)
v
v
a
0o
to
Ln
0000
J Q N
Q
0)
00
t0
m
Q 0)
V
1-
ONO
.--�
It•--�
+
O Q
F ea
OOOO
z
�
a
m
C)
Q
O
00
z
2 z
W d
O
J
m
B.1 - Storm Sewers Modeling
B.2 - Inlets and Weir Computations
_.�w- • gilt
NorthernEngineering.com // 970.221.4158
1
F1
VJ/29 - Vobnty H.aa
NorthernEngineering.com // 970.221.4158
J
c
TM" O
N �
0
d
m
0
CM a
c
0
E
z
qcr
Lo
U)
a�
c
J
CDE
ci
LL
U
N
O
a
1N
Q
1O
J
O
L
O
a`
i
i
1
1
W
10
L
a
' L
1CO
E
L
i°
Cn
1
0
g
8
8
8 8 0
0
;no
is
f
r
CO N N
V
0•l
SOMME
;no
G :Wei
N
O
4
;no
IP
m U
f0
O
IY
;no
tt
o
O
a
u
:mo
ati•
L :u1
g
J
W
I�0
N
:u1
c7
2
0
L9"
0
8
a
8
o
W
8 8 8 8 8 8
CIOc Q 0
f f f f f f
8
A
:^Q
O
^a
6�
p :u�
r
Q � U
.u�
g
8
J
Lq
;no w
pZ•
:u1
NINEO J
O
S
�r
8 8 8 8 8 8
A A
W
All
1�
�I�IMIIII�
I'IN'NY�
I
�I
c
b
0
8 8 V 8 V 8
8
lit V
;nO
U
t :u1
w
umo
0
4;nQ
$
0 :ul
ul
"O m
a)
L :u't
S
8
J
VIC w
t
11 oil 1 111
O
u10 J
Lf
0
8 8 8 8 8 8
CD
_� Y
W
99 9Lef'13 •�ui
llef
L
• tfa•u«o as
w
0
,
9r9Lef •1� '�u1 �' _
Of'OLef '13 '�ul
OC'
Llef '13 'Pu�v
of :Ln
• Ofe'LL•o qo
1
eC'9Lef •� �u1
OC'9Lef 'i3 '�ui
eC
clef '13 'Pu�O
• ace oe•o As - -
fL'9Le4'13 .�ul
fL OLef 'i3 '�ul
N
1 t'
OLef '13 'PurO
- 900'Lf+O sae
ul e
O SL9q '13 Sul
00 9Lef '13 '�u1
eZ'
11Ef 13'PwO
:u�
- eep 91+0 'qv
o'9Lef '13 �u1
Llef la'Pu�o
11MM O • GO'00+0 IRS
1
I
1
I
[1
1
EJ
Y�I
1_ J
c
0
c O.
7 T
0
0
0
0
0
0
0
0
0
0
0
7 H
C
c
c
c
c
c
c
c
c
c
c
O
O
O
O
O
O
O
O
O
O
O
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z. -
O
N
W m
C
O
O
C C O
W
e-
N
Cl)
?
N
r
O
O
0
G J 2
m
N
O
R
N
a
O
V
c
a+
(' i
(O
W�
J O
e
(D
r
(D
r
(D
r
(D
r
P
r
I-
n
O
n
O
n
(D
r
co
r
t0
r
w
v
v
v
a
v
v
v
v
v
v
O W
C W
to
N
O
O
W
W
W
N
O
m
�
O
O
O
O
O
O
O
c
2
—a
O
O
O
O
O
CD
GOD
N
C')
O
O
7
N
N
a
a
O
J
(D
(O
0
r
n
O
W
(D
(D
(D
y
�7 n ^,
r
m
r
r
r
r
r
m
r
m
r
r
r
n
0)
a)
x:
v
v
v
v
v
v
v
c
w
•
w
w
O
•
N
ta)
�
N
?
V
7
O
c
m
CO
co
co
cD
n
(D
co
w
(o
(D
E
3
r
n
n
r
r
r
Ir
r
r
r
n
rn
a
G)
v
m
a
rn
v
rn
0)
v
m
v
W
v
rn
e
rn
v
m
a
Z
=oo
av
O
`°r
N
O
D)
C n
O
U)
OD
It
M
r
O)
O
O
O
O
)O
It
V'
)O
)O
)O
O
G
C
(V
N
N
O
G
(V
O
O
J fD
co
O
R
co
O)
(O
C
O
co
(O
(O
O
N
r
N
GD
('7
N
C7
Cl
V:
O
a
ui
(D
vi
(D
m
r
vi
vi
ID
IO
LO
x
r
r
r
r
r
r
r
n
r
r
r
W
>J
rn
a
rn
e
rn
v
rn
v
rn
v
m
a
rn
v
m
v
rn
o
rn
v
rn
v
eWx
o
GD
o
a
m
rn
m
v
o
GD
v)
O
O
N
fl�
N
O
O
N
(a)
M
R
t. c
L)
)0
(D
r
N
Ir
(D
r
coLO
r
r
ID
r
t0
r
�
r
N
r
n
E
W p
> J
r
rn
c
n
m
a
rn
v
0)
IT
CD
a
0)M
IT
Itv
m
m
c
CD
v
0)
v
c Lu
_
v
co
O
M
M
co
O
O)
n
O
(D
N
L
L
O
r
O
M
O
O
r
O
O
O)
0
0
O
O
O
M
7
O
O)
?
N
(D
O
c
C c
J 0
IT
N
N
co
N
CO
N
(a)
('M
CD
r
c
0
(D_
W W
Ft
J 0
-
3
C N C
>
J M G
O
J
=
co
CDN
It
N
to
O
co
N
M
N
•n--
coM
O
O
LL Lu`
N
O
0
O
O
O
O
N
N
G
CD
2)
W
u
E
G
(ryh
i(ryy0
N
N
Q
N
11
0
c
(y
(E
fVy
Q
Q
c
O
Q
Q
Q
Q
Q
.N-.
.N..
J
E
0
n
'a
0
n
0
a
'a
0
a
0
EL
'a
0
n
'a
0
n
'a
0
a
0
a
'a
0
n
0
n
'a
o
n
a
a
a
a
r
w
U
w
U)
U)
rn
rn
w
U)
U)
ui
�
Ww
O
0
o
D.
z
c d
1
N
(o
It
(D
to
r
GD
m
JZ
1
I
I
r
I
I
I
m
O
O
C0 m
N
O
O
m
O
m
O
p
O
O
O
C
O
C
O
O
O
0
0
O
O
O
O
O
O
J
0 Y
0
0
0
0
0
0
cow
V
V
w
O
O
G"
`O
OOpp
mm
O
O
O
O
NO
Wi O
O
O
C
C
cm7O
O
W �
Y
m
O
�
O
O
O
N
O
O
O
O
L
th
m
U
m
cD
V
N
V
O
O
M
M
M
O
O
p
Q y o
0
0
0
0
0
0
0
0
0
0
0
N
N
O
O
O
(DO
O
c
10
V
N
0
tD
O
O
M
00)
N
M
O
O
N
O
O
C
O
O
O
O
O
0
O
0
N
N
M
q
N
V
l0
V
V
0
0
co
co
r
c '
(0
(D
co
co
cc
O m—
r
n
r
n
r
r
r
Ir
Ir
v
n
v
r
v
w ro
v
o
v
v
v
a
o
o
A
N
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
N
LO
aO
V
W
CD
O
10�,
00
D
M
C
'
Y
N
N
N
N
N
N
O
O
_
O
m
o
O
O
r
IT
m
m
m
O
O
0
c0
N
N
7
O
O
r
r
r
N
N
a
a to
0
0
0
0
0
0
0
0
0
0
0
E
z
Z
t
C
Ib
r
O
U0
O
)0
w
i
O
O)
r
O)
O
O
O
)0
O
)0
G �
N N
O O O O G O O O — a 0
00D
N
M
O
N
N
V
V
V
ccoo
co
)0
m
V
n
m
co
co
co
(J9 m --
n
n
S m
v
Y
V
w
v
m
IT
M
v
v
v
V
V
<
O
O
V
tD
0)
0
V
O
OD
u)
0
O
N
r
N
O
M
N
M
M
V
)0
L'
0
0
0
co
co
r
10
U)
)0
)0
VI
m>
r
r
r
r
r
n
r
r
r
r
r
c m x
rn
v
V
v
0)rn
v
v
0)
v
m
v
0)
v
0)
v
0)v
v
v
vw
M
h
O
r
N
co0
O
A
O
w
0
M
V
O
O
co
V
CDm
0)
CD
CD
CD
N
N
N
N
J
M
M
M
M
7
0D
t0
O
O
Mp
f0
r
O
N
N
O
O
O
N
c00
O
V
O
0
C
a
O
M
O
M
O
P)
O
O
O
C
a
N
N
�
V
O
N
V
co
co
co
CD
(D
co(
co
J>
n
n
r
r
r
r
r
n
n
r
r
t, m �-
x
0)
v
0)
IT
m
It
0)
v
0)
v
m
V
m
v
rn
IT
0)
v
0)
v
0)
v
w m
x
0
a
'C
N
co
V
N
r
)0
O
O
II
cc
M
o
0
0
o
O
o
o
a
i L
0
O
O
O
0
0
0
O
O
O
0
o
O
0
a
�
m
O
fM0
N
<0
D.
cD
M
M
it
U
N
m
0)
O
O
O
r
V
CD
m
O
O
II
C
C
0
N
N
O
O
r
r
r
N
N
0
O
Q m
c
O
O
O
O
O
O
0.
E
G
r
)0
tD
)0
N
N
O
O
O
Y)
)0
m �^.
O
O
O
O
O
O
O
O
O
N
V
T
N
M
N
V
V
m
w
(D
CD
r
cD
r
(D
n
r
r
c0
n
c0
r
to
r
O
r
co
Ir
c
.Y
0)
W
W
0)
0)
(D
0)
0)
W
0)
0)
x m x
v
v
v
V
v
IT
v
v
It
v
v
o
U
O
0
O
V
0
0)
00
V
O
co
0
m
O
O
N
r
N
R
O
N
VM
M
V
E
c
C
Lo
c0
U)
U)
CD
CD
ui
ui
LO
LO
U)
m
m>
> m—
e m x
n
rn
v
r
0)
v
r
M
v
r
0
IT
n
m
IT
r
0)
It
r
0)
It
r
0)
It
r
M
IT
r
0)
IT
r
0)
v
Q
.^
=
c
o
m
(0D
R
M
N
O
N
m
N
co
O
O
E
(y
N
O
O
O
O
O
N
N
N
G
G
`0
vi
.0
U
(D
coW
0
co
co
CD
y
i
m
N
C
ll
H
N
—
(D
'p
J
F
11
I
I
North ernEngineering.com // 970.221.4158
LJ
h
u
I
I
DESIGN PEAK FLOW FOR ONE-HALF OF STREET BY THE RATIONAL METHOD
Project. Townhomes at One Library Park
Inlet ID: Design Point b
Design Flow = Gutter Flow + Carty -over Flow
SIDE
f OVERLAND
1 j STREET I `OV FLOW �y
f GUTTER LOV PLUS CARRY-OVER FLCVF ♦CUTTER FLOW Show Del
INLET INLET
112 0E STREET
r_
(b®l peak flow for 1/2 of street. plus flow bypassing upstream subcatchner/s):
1 vuu pi t emu a . jh,t, riem ... , ,: of the stwt and orocead to •her
Combination InletAs. Q-Peak
Slle Type
• SW is Umar
O Site R Nor Urban
.a
Subcatchment Area = Acres
Percent Imperviousness = /o
NRCS Soil Type = A, B. C, or D
Slope (fVft) Length (ft)
Overland Flow =
Gutter Flow =
Design Storm Return Period. T,
Return Period Ore -Hour PreuWtation, P,
C,
C2
C3
Uset-Defireo Storm Runoff Coefficient (leave this blank to accept a ralculatert value), C
User-Oefaeo Syr Runoff Coefhciert (leave this boric to accept a calculated value). C.,
Bypass (Carryover) Flow from upstream Subcatchments, ae
Total Design Peak Flow. O wl 0.5 1 2.2 1cfs
IN THIS SECTION
IN THE
TIONS BELOW
711712014, 9:25 AM
INLET IN A SUMP OR SAG LOCATION
Project 0 Townhomes at One Library Park
Inlet ID • Desipn Point b
Lo(G)
an Information (Inoutl
of Inie1
Inlet Type -
I Depression (additional to cor/Irwous gutter depression'a fmm'O-AlbW)
ate,.
Der of UM Inlets (Grate or Curb Opening)
No =
Depth outside of Loral Depression at Inlet
Flow Depth =
. Inkir lation
Ih of a Urn Grate
L. (G)
1 of a Unit Grate
W� :
Opening Ratio for a Grate (typical values 0. 15-0.90)
A,.,,'
ping Factor for a Single Grate (typical value 0.50 - 0.70)
Cr (G)
e Weir Coefficient (typical value 2 15 - 3 60)
C. (G)
t Orifice Coefficient (typical value 0 60 0.60)
Co (G) =
Opening Inlomration
In of a urn Curb Opening
L. (C) _
N of Vertical Curb Opening in Inches
R,.,r '
rr of Curb Orifice Throat in IrMres
Hn =
i of Throat (see USDCM Figure ST-5)
Tina =
Width for Depression Pen (typically the gutter width of 2 feet)
Wv a
ping Factor for a Single Curb Opening (typical value 0 10)
Cn (C) _
Opartp Weir Coe, icien (typical value 2 3.3 6)
C. (C) 2
Opening Orifice Coeffirent (typical value 0.60 - 0.70)
Cc (C) =
at Inlet Interception Capacity (assumes clogged condition)
0.2
Cape IS , i >0 PEAK
Orrex r€oura<o=
MINOR MAJOR
CDOT/Denier 13 Ccmbrretion
2.00
1
6.0
6.0
MINOR
inches
Inches
MAJOR
feet
feet
3.00
1.73
0.43
0.50
0.50
3.30
0.60
MINOR
MAJOR
3.00
6.50
5.25
0.00
2.00
0.10
0.10
370
0.66
MINOR MAJOR
feet
itches
inches
degrees
feet
Combination Inlet.tds. Inlet In Sump 7/1712014. 9:25 AM
1
1
1
i
1
1
1
1
1
m
L
U
m
0.
c.>
d
C
ate-.
'L^
V
Cm
G
O
N
m
C.
O
�.
Z
LJ
' HY-8 Culvert Analysis Report
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 0.1 cfs
Design Flow: 2.88 cfs
Maximum Flow: 20 cfs
I
I
I
I
ITable 1 - Summary of Culvert Flows at Crossing: Emergancy Overflow
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Headwater Elevation
(ft)
Total Discharge (cfs)
Outlet Pipe
Discharge (cfs)
Roadway Discharge
(cfs)
Iterations
4977.25
0.10
0.00
0.07
100
4977.44
2.09
0.00
2.07
11
4977.47
2.88
0.00
2.86
6
4977.57
6.07
0.00
6.03
5
4977.62
8.06
0.00
8.03
4
4977.66
10.05
0.00
9.99
3 _
4977.70
12.04
0.00
12.00
3
4977.73
14.03
0.00
14.01
3
4977.77
16.02
0.00
16.01
3
4977.80
18.01
1 0.00
17.96
2
4977.83
20.00
1 0.00
20.00
2
4977.22
0.00
1 0.00
0.00
Overtopping
C
' Rating Curve Plot for Crossing: Emergancy Overflow
' Total Rating Curve
Crossing Emergaacy Overflow
1 4977.8
'
4977.7
c
0
ZI-
4977.E
a)
w
24977.5
1
co
= 4977.4
'
4977.3
I
1
FI
L1
Total Discharge (ds)
11
' Table 2 - Culvert Summary Table: Outlet Pipe
1
1
1
[1
11
1
Total
Discharge
(cfs)
Culvert
Discharge
(cfs)
Headwater
Elevation (ft)
Inlet Control
Depth (ft)
Outlet
Control
Depth (ft)
Flow
Type
Normal
Depth (ft)
Critical
Depth (ft)
Outlet Depth
(ft)
Taltwater
Depth (ft)
Outlet
Velocity
(ft/s)
Tailwater
Velocity
(ft/s)
0.10
0.00
4977.25
-0.002
1.025
4-FFf
0.002
0.001
0.010
0.025
0.014
1.326
2.09
0.00
4977.44
-0.002
1.161
4-FFf
0.002
0.001
0.010
0.161
0.016
4.328
2.88
0.00
4977.47
-0.002
1.197
4-FFf
0.002
0.001
0.010
0.197
0.016
4.880
6.07
0.00
4977.57
-0.002
1.317
4-FFf
0.002
0.001
0.010
0.316
0.015
6.400
8.06
0.00
4977.62
-0.002
1.380
4-FFf
0.002
0.001
0.010
0.380
0.014
7.071
10.05
0.00
4977.66
-0.002
1.440
4-FFf
0.002
0.001
0.010
0.439
0.014
7.627
12.04
0.00
4977.70
-0.002
1.495
4-FFf
0.002
0.001
0.010
0.495
0.013
8.107
14.03
0.00
4977.73
-0.001
1.549
4-FFf
0.002
0.001
0.010
0.548
0.012
8.527
16.02
0.00
4977.77
-0.001
1.600
4-FFf
0.002
0.001
0.010
0.600
0.011
8.902
18.01
0.00
4977.80
-0.001
1.650
4-FFf
0.002
0.001
0.010
0.650
0.011
9.242
20.00
0.00
4977.83
-0.001
1.698
4-FFf
0.002
0.001
0.010
0.698
0.010
9.553
Straight Culvert
Inlet Elevation (invert): 4975.89 ft, Outlet Elevation (invert): 4975.84 ft
Culvert Length: 10.00 ft, Culvert Slope: 0.0050
I
1
1
1
I
1
1
Culvert Performance Curve Plot: Outlet Pipe
Perfonuance Curve
Cuh-ert: Outlet Pipe
49776
4977.4
it
49772
c
z
49770
w
4976.8
a'
4976.6
co
49764
a�
=
4976.2
49760
0
Inlet Control Elev Outlet Control Elev
Total Discharge (cfs)
�l
I
n
iI
Water Surface Profile Plot for Culvert: Outlet Pipe
Crossing - Emerganc`- Overflo« , Desian Discharge - 2.9 cfs
Cuh ert - Outlet Pipe: Cuh eft Discharge - U 0 cfs
4977.8
49776
49774
49772
4977
0
c
4976
8
w
4976.6
ERGY awl
49762
49760
49758
------------
----------- - x
:ate
-2 0 2 4 6 8 10 12
Station (ft)
Site Data - Outlet Pipe
Site Data Option: Culvert Invert Data
Inlet Station: 0.00 ft
Inlet Elevation: 4975.89 ft
Outlet Station: 10.00 ft
Outlet Elevation: 4975.84 ft
Number of Barrels: 1
Culvert Data Summary - Outlet Pipe
Barrel Shape: Circular
Barrel Diameter: 0.01 ft
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0120
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall
Inlet Depression: NONE
1
I
1 Table 3 - Downstream Channel Rating Curve (Crossing: Emergancy Overflow)
i
1
i
i
L
1
1
[1
1
1
1
Flow (cfs)
Water Surface
Elev (ft)
Depth (ft)
Velocity (ft/s)
Shear (psf)
Froude Number
0.10
4976.92
0.03
1.33
0.04
1.47
2.09
4977.05
0.16
4.33
0.25
1.90
2.88
4977.09
0.20
4.88
0.31
1.94
6.07
4977.21
0.32
6.40
0.49
2.01
8.06
4977.27
0.38
7.07
0.59
2.02
10.05
4977.33
0.44
7.63
0.69
2.03
12.04
4977.39
0.50
8.11
0.77
2.03
14.03
4977.44
0.55
8.53
0.86
2.03
16.02
4977.49
0.60
8.90
0.94
2.03
18.01
4977.54
0.65
9.24
1.01
2.02
20.00
4977.59
0.70
9.55
1.09
2.02
1
I
Tailwater Channel Data - Emergancy Overflow
Tailwater Channel Option: Rectangular Channel
Bottom Width: 3.00 ft
Channel Slope: 0.0250
'
Channel Manning's n: 0.0150
Channel Invert Elevation: 4976.89 ft
Roadway Data for Crossing: Emergancy Overflow
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
' Roadway Surface: Paved
Roadway Top Width: 9.00 ft
L
I
I
I
I
m
INorthernEngineering.com // 970.221.4158
Dcslgn Procedure Form: Permeable Pavement Systems (PPS)
Designer
Cody Snowdon
Company.
Northern Engineering
Date.
July 17, 2014
Project
One Library Park
Location.
Sheet 1 of
Choose One
t
Type of Permeable Pavement Section
No InFlRraUon
A) What type of section of permeable pavement is used?
0 Parbal frifil n Secbon
(Based on the land use and activities. proximity to adjacent
structures and soil characteristics 1
0 Full Inffttmtion Section
Choose One
8) What type of wearing course?
OO PICP
0 Concrete Gnd Pavement
0 Pervious Concrete
0 Porcus Gravel
2
Required Storage Volume
A) Effective Imperviousness of Area Tributary to Permeable Pavement, I,
I, = 100.0 %
B) Tributary Area's Imperviousness Ratio (I = I,/ 100)
i = 1.000
C) Tributary Watershed Area
Ara,. = 3,187 sq ft
(including area of permeable pavement system)
Of Area of Permeable Pavement System
Apes = 1,126 sq it
(Minimum recommended permeable pavement area = 1062 sq (1)
E) Impervious Tributary Ratio
R, = 1.8
(Contributing Imperviuos Area / Permeable Pavement Ratio)
F) Water Quality Capture Volume (WOCV) Based on 12-hour Drain Time
WQCV = 106 cu It
(WQCV=to.8 a(0.9111. 119'12+ 0 78 6 d/ 12)' Area)
Choose One
G) Is flood control volume being atlded?
O YES
OO NO
3
Depth of Reservoir
A) Minimum Depth of Reservoir
DM,,, - 12.0 inches
(Minimum recommended depth is 6 inches)
Choose One
B) Is the slope of :he reservoelsubgrade interface equal 10 0%?
0 YES- Flat or Stepped Instxllatxin
N0 Sloped Installation
C) Porosity (Pomus Gravel Pavement < 0 3 Others < 0 40)
P = 040
D) Slope of the Base Course/Subgrade Interface
S = 0.005 It I II
E) Length Between Lateral Flow Bamers (max = 94.35 I: )
L = 81 0 If
F) Volume Provided Based on Depth of Base Course
V = 322 cu It
Flat or Stepped. V = P' ((D,,,,,,.ty12) 0 Area
Sloped V - P - ((D.,,,,. (D,,,,,- 6'SL-1))1 121 Area
Volume assumes uniform slope d lateral flow barrier spacing
Calculate the vdume of each cell individually when this vanes
4
Lateral Flow Barriers
Choose Ohre
A) Type of Lateral Flow Barbers
Concrete Walk
0 PVC geornembrane Installed nomral to flow
0 N/A Flat installation
0 Other(Descnbe):
B) Number of Permeable Pavement Cells
Cells = 1
5
Perimeter Barnet
A) Is a perimeter Darner provided on all sides of the
+ts
pavement system?
(Recommeded for PICP. concrete gnd pavement. or for any
0 NO
no -infiltration section 1
LID-BMP_0.02.xis, PPS 7/17/2014, 9:04 AM
Design Procedure Form: Permeable Pavement Systems (PPS)
Designer: Cody Snowdon
Company: Northern Engln
Date: July 17. 2014
Project: One Library Pa
Location:
6 Filter Material and Underdraln System
A) Is the underdram placed below a 6-inch Tx:k layer of
COOT Class C filter matenaP
Clgose One
O yF5 COOT CLASS C FILTER MATERIAL RECOMMENDED
OO NO
O wA
B) Diameter of Slotted Pipe (slot dimensions per Table PPs-2)
Choose One
O 4IndI
6-Irxh
C) Distance from the Lowest Elevation of the Storage Volume
y = 03 r.
(i.e the bottom of the base course to the center of the onfx:e)
Impenneabie Ge imembrane Liner and Geotexhle Separator Fabric
At Is there a minimum 30 mil Tick impermeable PVC geomembrane
liner on the bottom and sides of the basin, extending up to the top
ChOOSe One
* YES
of the base courses
O NO
Choose One
B) CDOT Class B Separator Fabric
Q Placed above the Ilner
O Placed above and bebw the Ilnv
8 Outlet
(Assumes each cell has similar area. subgrade slope, and length
between lateral bamers (unless subgrade Is hat) Calculate cells
Individually where this vanes )
A) Depth of WOCV In the Reservoir
Dwocv = 5.26 Inches
(Elevation of the Flood Control Outlet)
B) Diameter of Orifice for 12-hour Orem Time
Du, = 0.36 Inches MINIMUM ORIFICE St2E IS 184NCHES
(Use a minimum onhre diameter of 3/8-inches)
Notes
JD-BMP v3.02.xis, PPS 7/17/2014, 9:04 AM
I
4
I
North ernEngineering.com // 970.221.4158
1
.V NORTHERN
ENGINEERING
C. Purpose
Townhomes at One Library Park
In order for physical stormwater Best Management Practices (BMPs) to be effective, proper
maintenance is essential. Maintenance includes both routinely scheduled activities, as well
as non -routine repairs that may be required after large storms, or as a result of other
unforeseen problems. Standard Operating Procedures (SOPS) should clearly identify BMP
maintenance responsibility. BMP maintenance is typically the responsibility of the entity
owning the BMP.
Identifying who is responsible for maintenance of BMPs and ensuring that an adequate
budget is allocated for maintenance is critical to the long-term success of BMPs.
Maintenance responsibility may be assigned either publicly or privately. For this project, the
privately owned BMPs shown in Section B below are to be maintained by the property
owner, homeowner's association (HOA), or property manager.
D. Site -Specific SOPs
The following stormwater facilities contained within Townhomes at One Library Park are
subject to SOP requirements:
- Directly Connected Downspouts
- Permeable Modular Block Pavers (MBPs)
- Storm Drains and Tree Roots
' The location of said facilities can be found on the Utility Plans and Landscape Plans for
Townhomes at One Library Park. Inspection and maintenance procedures and frequencies,
specific maintenance requirements and activities, as well as BMP-specific constraints and
' considerations shall follow the guidelines outlined in Volume 3 of the Urban Drainage and
Flood Control District (UDFCD) Urban Storm Drainage Criteria Manual.
1
1
SOP Maintenance Summary Table
Stormwater Facility /
Ownership /
UDFCD Maintenance Reference
BMP
Responsibility
Directly Connected
Follow guidelines for Roof Gutters and
Roof Gutters and
Private
Downspouts
Downspouts
Follow guidelines for Permeable Modular Block
Permeable Modular
Pavers (Chapter 6 — Section 11.0)
Block Pavers (MBPs)
Private
Refer to Section 5: Maintenance from
m
Permeable Interlocking Concrete Pavements, 4
Edition (PICP Manual
Follow applicable guidelines for Perforated
Perforated Subdrain
Private
Subdrain
Storm Drains and Private Follow guidelines for Storm Drains and Tree
Tree Roots Roots
The complete UDFCD BMP maintenance references listed above, except for the roof gutters
and downspouts, can be found in Chapter 6 of Volume 3. Applicable BMP maintenance
excerpts can be found at the end of this document.
Preliminary Erosion Control Report
' ■� NORTHERN
ENGINEERING
1
1
Townhomes at One Library Park
Directly Connected Downspouts
Many of the downspouts connect directly to the storm drain system. The following SOP generally
applies to all direct downspout connections, and more specifically to those which drain directly to
the reservoir areas beneath the Modular Block Pavers. At each of these connections, the downspout
discharges to a perforated drain basin. The drain basins discharge directly to the MBP reservoir. The
drain basins are designed to prevent debris and sediment from entering the MBP reservoir area.
Debris and sediment compromise the functionality and effectiveness of the system.
Routine Maintenance Table for Directly Connected Downspouts
Required Maintenance Objective Frequency of Action
Action
Inspect the downspout and basin
to ensure the system functions as
Inspections it was designed. Repair or Routine
replace damaged downspouts as
needed.
Sediment, Remove debris and litter from the Routine — just before annual storm seasons
Debris and basin. Remove sediment from the (i.e., April/May); at the end of storm
Litter removal sump. season after leaves have fallen; and
following significant rainfall events.
tPreliminary Erosion Control Report
' NORTHERN
ENGINEERING TownhomeS at One Library Park
Permeable Modular Block Pavers (MBPs)
' There is one large MBP sections associated with the project serving a critical role in the drainage
system. These systems provide storage and important water quality benefits.
' Proper maintenance is critical to ensure lasting performance and integrity of the system. The more
frequent and diligent the routine maintenance procedures are, the more likely it is to avoid and/or
' postpone significant repair and replacement actions. Such major remedies would include removal
of the surface pavers to access (and potentially replace) the underlying sub -base material and/or
underdrain pipes should either become clogged or otherwise fail to function properly.
' For additional information on the maintenance of the Modular Block Pavers, refer to Section 5:
Maintenance from Permeable Interlocking Concrete Pavements, 41' Edition (PICP Manual) by the
Interlocking Concrete Pavement Institute.
Routine Maintenance Table for Permeable Pavement Systems
' Required Maintenance Objective Frequency of Action
Action
' Inspect the pavement condition
and observe infiltration either
Inspection during a rain event or with a At least annually.
garden hose to ensure that water
infiltrates into the surface.
Debris Use a regenerative air or vacuum As necessary -the frequency depends on
Removal, sweeper to maintain infiltration use types foot traffic only versus
' Sweeping and rates. Replace infill aggregate as vehicle traffffic)ic) and patterns as well as
Vacuuming needed. specific site conditions such as tributary
basin characteristics.
' DO NOT apply sand to the MBP
Snow Removal surface. Mechanical snow and ice As necessary.
' removal should be used.
If the surface is completely clogged
and rendering minimal surface
Full and Partial infiltration rate, restoration of Routine — Annual inspection of hydraulic
Replacement surface infiltration can be achieved and structural facilities. Also check for
of the by removing the first'/z to 1 inch obvious problems during routine
Pavement or of soiled aggregate infill material maintenance visits, especially for plugging
Infill Material with a vacuum sweeper. Refill the of outlets.
openings with clean aggregate infill
materials.
Should stormwater leach out
Trash pollutants from the trash enclosure
Enclosure area, or should other similar As necessary, based on routine
' Leakage, or contaminants collect in the paver observation and inspection by the
other Surface joint filler aggregate, said material professional property management and
Contamination/ shall be removed and properly maintenance contractor.
Pollution disposed of, and replaced with new
infill aggregate.
' Preliminary Erosion Control Report
WINORTHERN
ENGINEERING
Townhomes at One Library Park
1
1
1
1
Perforated Subdrain Maintenance Plan
The perforated subdrain system storm drain outfall at the bottom of the Modular Block Paver (MBP)
system is critical to the overall function of the paver subbase. As such, special maintenance has
been identified to ensure these perforated drain systems perform as they were designed.
Routine Maintenance Table
`~"""' Maintenance Objective
Action
Frequency of Action
Use a video camera to inspect the
condition of the perforated drain
Inspection pipes. Cleanout pipes as needed. Every two to five years.
If the integrity of the pipe is
compromised, then repair the
damaged section(s).
Preliminary Erosion Control Report
NORTHERN
ENGINEERING
Townhomes at One Library Park
Storm Drain Lines Maintenance Plan
The storm drain lines are located in proximity to trees. The situation is unavoidable; therefore,
special maintenance has been identified to ensure these storm drain systems perform as they were
designed.
Routine Maintenance Table
Required Maintenance Objective Frequency of Action
Action
Use a video camera to inspect
the condition of the storm drain
Inspection pipes. Cleanout pipes as needed. Every two to five years.
If the integrity of the pipe is
compromised, then repair the
damaged section(s).
Preliminary Erosion Control Report
1 � ,
+s
\ J
1
lot
1
1
' North ernEngineering.com // 970.221.4158
Vft
CODf!�
I�
w
N
O
a
0
cr
a
>S
?
5�
b
sd
i
�66�s
m
�
m
E
C
W
�
C
°
3
`
o
S
�
P
^`
CL
C
M
�
N
U
v
p
N
V
0
W
U)
Ow
d
O
Q
a
�
06
O
cD
zOf
W
d
U
X�
W
;z
cr
We
SW
w
sE
�
z
E
Zw
I
[I
_ �I Y WAF
�r —\ -� ^ I .r- C E2
{�Y bA1NFn '
----.IOFAINR--1 , ll CHNCEIE ___-
r OIANBIdYI
l� 1
_________YCO��1
�
I
v
I~
_
YWPFB
V
L JJ ____
iWMRED�
I V
L______ -
coTVE¢
caw¢re
F
Y�XEpR�EB_
I
1
1
� 1FD1FD
rY.YP�CTI�WHO�tSN
'wivEDwxTE
I
�I%x1E�G HlTenw
FOswITE
°
-----
—�—
—�--I--
—V�-N=
immemot
1SOUMBAErx�
EwNEOlwx 4mav
wmm
l................o... C InmAIPP.I IL 1 �`
H
�� Fm Ewn4EOGemai®�1 ��� I I
�.- OLIVE STREETTHE
\
CROSS-SECTION A -A
f
81CIM CPMI
pEE&EFTgnit
r.t
W
rc
k N
ll
� ill
I 1
PRCfWEYEO }YVFATrlL�
BETO
I cuBzawnd 1
11
l / 1
1
mMt01V11 � 1 '1,
1�81ffrpN1 /
® NORTH
10 0 IB m So FMEt
N
I ANC - loft
LEGEND:
PROINEIY BOONDARTY
PROPOSED BASIN UNEC aal r
DIETING STORM SEVEN UNE
PROPOSED UNCERORAN �W^
PROPOSED STORY DRAWN
EXISTING NUT CRAZE ■
PEDPE' ED CONLWR
EXISTING CONTOUR - - - l01D - - -
REPOSF➢SYNEFROTO�...-...� —
am k GUTIFRO�
INOPOSEO RIBBON WIN
"PROPOSED OVER -AND ROW gISCION w�
ER
FROPOSEO PdWEA9F FAVORS
jaeo'¢(ea 9�p g] [{yd
Eat 18 - jp
BAOEUNEATw
EggBASIN
NsUOR RUNOFF ODEFACKIN
..... ACREAGE
CESGN PC1Ni
ZN A
LaJ c1f
NOTES:
1. THE SIM TPE AND LOCATION M AL MOM UNCERCR^JUNO UTUTES
=1
ARE A➢RppYAR 111 N ENOMN GN THESE ORARINGS YT WALL BE FINE
RESPONSIBILITY OF THE CONTRACTOR i0 KMFY THE EsEnENCE Cr ALL
Z
UNCERCAWND UTLTES IN THE AREA OF THE "K. BEFORE
Z W
CWRUICNC NEW CONSTRUCTOR, THE CONTRACTOR SHti1 BE
RE`POISIBHF FOR LOC TNG ALL UNDERCROUNO UTIRJI AND SHALL BE
HSIDCNSBIE FOR FOR ALL UNKNOWN UNDMO ND UIINTES
1. REFER 70 THE MT MR LET AREAS. TRACT Sns. E SGUENTi. LOT
II4(1HSW% UTILITY EASEMENTS. 01 EAEUAdfi. ANID OTHER S NfETINFORMATION
0. ALLFRBECT DATA IS Ox THE CITY a FORT COWxE IfRTCII DATHu;
EN (UXI➢52Da SEE COVERdCHR dF£i FOP BLARN
BRADL
1�1
IAF%XF£S.
e
fiS
IA
��
s$
EJ
SJ
a �
r m_
< T-
x
LLI
DN.d4 INTdD
1P `�
G0.O4DD
F IL
Q (D
u) Q
w z
MmAMaYet)BION.
Call DetOTe rouaq.
0 Q
WI.11.. IAMwn MMWWI
Z 0
City of Fort Collins. Colorado
UTILITY PLAN APPROVAL
0
APPROVED.
cur any...
a
CHECKED BY.
R.tn 4 Wub�sly Vtl4ty
Dnl+
dECKED BY:
ffismaawunity Oe
WEEKS) BY.
Sheet
aEalm BY.
/gy
C8.00
n.e Dm
CRECKED BY:
0.V