Hydrology Report 1-18-08
BKBM
ENGINEERS -
._........~_.
5930 Brooklyn Boulevard
Minneapolis, MN 55429-2518
(763) 843-0420 Fax: (763) 843-0421
E-mail: bkbm@bkbm.com
HYDROLOGY FOR
JIMMY JOHN'S
CHANHASSEN, MN
JANUARY 18,2008
EXISTING SITE DESCRIPTION:
The existing site is located in Chanhassen, Minnesota at the Market Street Station development.
The site is specifically located in the northwest corner of the Market Street Station development,
near the north drive entrance, off of Market Boulevard.
EXISTING SITE DRAINAGE CHARACTERISTICS:
Table I briefly summarizes the ground cover characteristics and drainage routing of each
numbered drainage area. Currently the drainage on the site sheet flows to catch basins in the
parking area of the Market Street Station development.
Table 1: Existin Site Draina
Drainage
Area No.
Description
Drainage Routes to:
Sheet flows to catch basins in the
Market Street Station develo ment
Rough graded site to be
develo ed
EXISTING SITE DRAINAGE FLOW RATES:
HydroCAD using the NRCS Method of Abstractions was used for the existing site hydrologic
study, modeling with Type II, 24-hour rainfall events for Carver County, Minnesota. Table 2 lists
the derived curve runoff numbers for each cover type.
Table 2: NRCS Hydrologic Soil Group and Runoff Curve
Numbers
Ground Cover Type Hydrologic Soil Curve Number
Group (CN)
Grass Areas C 72
PavingJBldg Roofs C 98
Peak runoff computations were done for the 2-year, I a-year and I 00-year/24-hour return period
rainfall events (refer to Table 3). The weighted curve number for each drainage area is based on a
weighted average of each area of ground cover type as listed in Table 2. Time of concentration
was estimated to be 5 minutes. Peak HydroCAD runoff computations are summarized in Table 4
and are included as an appendix to this report. ::;!,'y' 0= Cr!Uj~f\S~-=~
PECf.:II/i=:1
BKBM ENGINEERS
An Equal Opportunity Employer
JAr,I; S 2008
CH,~~~rlASS~N Pl_A~J~J!~;G Di:P
Table 3: Carver County 24-
hour Duration Storm Events
for Each Return Period (inches)
2-year 10-year 100-year
2.75" 4.20" 5.95"
Table 4: Summary of Peak Runoff Rates:
Existin!! Draina!!e Areas
Drainage Carver County 24-hour Storm Events Peak
Area No. Runoff Rates
2-year lO-year lOO-year
(efs) (cfs) (cfs)
1 0.20 0.51 0.94
Total 0.20 0.51 0.94
PROPOSED DEVELOPMENT DESCRIPTION:
New construction on the site is to consist of an approximate 1,500 square-foot Jimmy John's
restaurant, sidewalks, and plaza area. The new construction would increase the impervious area on
site from 73 square-feet to 4,146 square-feet, an increase of54%.
PROPOSED SITE DRAINAGE ROUTING:
Table 5 gives a brief summary and routing of the proposed drainage patterns on site.
Table 5: Proposed Site Draina2e Descriptions
Drainage Description Drainage Routes to:
Area No.
Proposed building roof, sidewalks, Sheet flows to storm sewer system in
1 plaza the Market Street Station development
via yard drains and a roof drain lead
PROPOSED SITE STORM WATER TREATMENT AND RATE CONTROL:
It is the understanding of BKBM Engineers that the Market Street Station Master Plan has
accounted for this development in their storm water treatment and runoff rate control design. Due
to this, treatment and rate control are not part of the Jimmy John's project. Table 6 summarizes
proposed runoff rates for the site.
Table 6: Summary of Peak Runoff Rates:
Proposed Drainage Areas
Drainage Hennepin County 24-hour Storm Events Peak
Area No. Runoff Rates
2-year 10-year 100-year
( c fs) (cfs) (cfs)
I 0.46 0.85 1.32
Total 0.46 0.85 1.32
The proposed HydroCAD computations for runoff rates indicate an increase in storm water runoff
rates for the proposed site when compared to existing conditions. Table 7 summarizes the runoff
rates for existing and proposed conditions.
Table 7: Comparison of Peak Runoff
Rates: Existing vs. Proposed (cfs)
Condition 1- year! 10-year/ 100-year/
24-hr 24-hr 24-hr
Existing 0.20 0.51 0.94
Proposed 0.46 0.85 1.32
Existing
~Ubcay B ~ ~
Proposed
Drainage Diagram for 08170 . Jimmy John's (Existing & Propose
Prepared by BKBM Engineers, Printed 1/17/2008
HydroCAOO 8.50 sin 001655 @ 2007 HydroCAD Software Solutions LLC
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAD@ 8.50 sIn 001655 @ 2007 HydroCAD Software Solutions LLC
Type /I 24-hr 2-year Rainfal/=2.75"
Printed 1/17/2008
Paqe 2
Time span=0.01-28.00 hrs, dt=0.01 hrs, 2800 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+ Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Existing
Runoff Area=7,516 sf 0.97% Impervious Runoff Depth=0.66"
Tc=5.0 min CN=72 Runoff=0.20 cfs 0.010 af
Subcatchment2S: Proposed
Runoff Area=7,516 sf 55.16% Impervious Runoff Depth=1.45"
Tc=5.0 min CN=86 Runoff=0.46 cfs 0.021 af
Total Runoff Area = 0.345 ac Runoff Volume = 0.030 at Average Runoff Depth = 1.06"
71.93% Pervious = 0.248 ac 28.07% Impervious = 0.097 ac
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAD@ 8.50 sin 001655 @ 2007 HydroCAD Software Solutions LLC
Type /I 24-hr 2-year Rainfal/=2.75"
Printed 1/17/2008
Paqe 3
Runoff
Summary for Subcatchment 1S: Existing
=
0.20 cfs @ 11.97 hrs, Volume=
0.010 af, Depth= 0.66"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=2.75"
*
Area (sf)
7,443
73
7,516
7,443
73
*
Tc Length
(min) (feet)
5.0
0.22~
0.21-'
0.2~ .
0.19:
0.18': /
0.17~ :
0.16:
0.15~ :
0.14~ "
.. 0.13- .
~ 0.12~ .
~ 0.11-'
o _
u:: 0.1-:
0.09: /
0_08-' /
0.07~ :.
0.06-:
0.05~ /
0.04~
0.03~
0.02'
0.D1 ~ .
0'
CN Description
72
98
72 Weighted Average
Pervious Area
Impervious Area
Slope Velocity Capacity Description
(fUft) (fUsec) ( cfs)
Direct Entry,
Subcatchment 1S: Existing
Hydrograph
Type U24-hn2-year m
Ralnfali=2. "15"
t'{unoffArea=1~ 516 sf
RunoffVolurrie=O~01 Oaf
RurioffDepth=O.66"
m mTc=5.0miri
CN=72
> ,
2
i j;
12 14 16 18 20 22 24 26 28
Time (hours)
6 8
10
4
10 Runoffl
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAD@ 8.50 sIn 001655 @ 2007 HydroCAD Software Solutions LLC
Type /I 24-hr 2-year Rainfal/=2.75"
Printed 1/17/2008
Paqe 4
Runoff
5ummaryfor 5ubcatchment 25: Proposed
=
0.46 cfs @ 11.96 hrs, Volume=
0.021 af, Depth= 1.45"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 2-year Rainfall=2.75"
*
*
Area (sf)
3,370
4,146
7,516
3,370
4,146
CN Description
72
98
86 Weighted Average
Pervious Area
Impervious Area
Tc Length
(min) (feet)
5.0
Slope Velocity Capacity Description
(ftIft) (ftIsec) ( cfs)
, ,
0.5~ .
0.48~ ,
0.46, .
0.44: /
0.42:
0.4': .
0.38'
0.36, ,
0.34,: .
0.32~ ,
_ 0.3-:
-t 0.28c:
-; 0.26~
.2 0.24: ,
... 0.22~ .
0.2~ ,
0.18-:
0.16~ .'
O.14~
0.12-; .
0.1~ .
0.08~ ,
0.06"
0.045 /.
0.02;
0' ,
Direct Entry,
5ubcatchment 25: Proposed
Hydrograph
Typ.~'. JI24..hr.2..year
Rainfall==2.75" .
Runoff Area=7,516sf -
RunoffVolume=O~021af
...... ...... ............. no ... ...
Runoff Depth=1.45"
Tc=5.0 min
CN=86
, ,
26 28
,
2
,
6
10
, ,
12 14 16 18
Time (hours)
4
8
10 RunOff'
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAO@ 8.50 sIn 001655 @ 2007 HydroCAO Software Solutions LLC
Type 1/ 24-hr 10-year Rainfal/=4.20"
Printed 1 /17/2008
Paqe 5
Time span=0.01-28.00 hrs, dt=0.01 hrs, 2800 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+ Trans method - Pond routing by Stor-Ind method
Subcatchment1S: Existing
Runoff Area=7,516 sf 0.97% Impervious Runoff Oepth=1.60"
Tc=5.0 min CN=72 Runoff=0.51 cfs 0.023 af
Subcatchment2S: Proposed
Runoff Area=7 ,516 sf 55.16% Impervious Runoff Oepth=2.73"
Tc=5.0 min CN=86 Runoff=0.85 cfs 0.039 af
Total Runoff Area = 0.345 ac Runoff Volume = 0.062 af Average Runoff Depth = 2.17"
71.93% Pervious = 0.248 ac 28.07% Impervious = 0.097 ac
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAO@ 8.50 sIn 001655 @ 2007 HydroCAO Software Solutions LLC
Type /I 24-hr to-year Rainfal/=4.20"
Printed 1 /17/2008
Paqe 6
Runoff
Summary for Subcatchment 1S: Existing
=
0.51 cfs @ 11.97 hrs, Volume=
0.023 af, Depth= 1.60"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=4.20"
*
*
Area (sf)
7 ,443
73
7,516
7,443
73
CN Description
72
98
72 Weighted Average
Pervious Area
Impervious Area
T c Length
(min) (feet)
5.0
Slope Velocity Capacity Description
(ft/ft) (ft/sec) ( cfs)
lil
! 0.3~'
~ .
o .
u: 0.25'
Direct Entry,
Subcatchment 1 S: Existing
Hydrograph
0.5
,
24
26
0.55~ ~
0.45~
Type II 24~hr10~year
Rainfall=4.20"
Runoff Area=7,516 sf
Ru n offV6 I uri"e=O; 023m af "
Runoff Depth=1.60'"
Tc=5.0riiin
CN=72
Ok
0.35~ '
0.2~
0.15~
0.1":
0.05-
, '"
8 10
0-
, '
20
"" .
4
, .
18
,
2
22
6
12 14 16
Time (hours)
I 0 RunOff~
28
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAO@ 8.50 sin 001655 @ 2007 HydroCAO Software Solutions LLC
Type /I 24-hr 10-year Rainfal/=4.20"
Printed 1/17/2008
Paae 7
Runoff
=
Summary for Subcatchment 2S: Proposed
0.85 cfs @ 11.96 hrs, Volume=
0.039 af, Depth= 2.73"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 10-year Rainfall=4.20"
*
*
Area (sf)
3,370
4,146
7,516
3,370
4,146
Tc Length
(min) (feet)
5.0
: ,
o.g,'
: ,
0.85~
0.8~ '
0.75 -
0.7
0.65~
0.6': .
iii 0.55:
! 0.5:'
~ 0.45: '.
u: 0.4':
0.35:
0.3 :
0.25-
0.2:
0.15,
O.le
0.05-
O'
CN Description
72
98
86 Weighted Average
Pervious Area
Impervious Area
Slope Velocity Capacity Description
(ft/ft) (ft/sec) (cfs)
Direct Entry,
Subcatchment 2S: Proposed
Hydrograph
Type II 24-hr 10-year
. ... "'" ... ... n. m
Rainfall=4.20"
RUnoff Area=T516Sf
..mm 'mm m
RunoffVolume=O;039af
Runoff Depth:::2.73"
Tc=5.0min
CN=86
., .
2
. . 1<
8
, ,
26 28
, .
4
,
6
10
. ..
12 14 16 18
Time (hours)
I D Runoff~
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAO@ 8.50 sIn 001655 @ 2007 HydroCAO Software Solutions LLC
Type /I 24-hr 100-year Rainfal/=S.9S"
Printed 1/17/2008
Paqe 8
Time span=0.01-28.00 hrs, dt=0.01 hrs, 2800 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+ Trans method - Pond routing by Stor-Ind method
Subcatchment1S: Existing
Runoff Area=7,516 sf 0.97% Impervious Runoff Oepth=2.95"
Tc=5.0 min CN=72 Runoff=0.94 cfs 0.042 af
Subcatchment2S: Proposed
Runoff Area=7,516 sf 55.16% Impervious Runoff Oepth=4.36"
Tc=5.0 min CN=86 Runoff=1.32 cfs 0.063 af
Total Runoff Area = 0.345 ac Runoff Volume = 0.105 af Average Runoff Depth = 3.66"
71.93% Pervious = 0.248 ac 28.07% Impervious = 0.097 ac
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAD@ 8.50 sIn 001655 @ 2007 HydroCAD Software Solutions LLC
Type /I 24-hr 100-year Rainfal/=S.9S"
Printed 1/17/2008
Paqe 9
Runoff
=
Summary for Subcatchment 1S: Existing
0.94 cfs @ 11.96 hrs, Volume=
0.042 af, Depth= 2.95"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=5.95"
*
Area (sf)
7,443
73
7,516
7,443
73
*
Tc Length
(min) (feet)
5.0
1-
~
.!:!..
~
o
u:
0- .
CN Description
72
98
72 Weighted Average
Pervious Area
Impervious Area
Slope Velocity Capacity Description
(fUft) (fUse c) ( cfs)
Direct Entry,
Subcatchment 1 S: Existing
Hydrograph
2
,
4
,
6
Type II 24-hr 100-year
Rainfall=5.95"
Runoff Area=7,516sf
Runoff Volume=O.042 af
Runoff Depth=2.95"
Tc=5.0 min
CN=72
, I: .
12 14 16
Time (hours)
i >,
18 20
. ,
24
. " >, i:'
8 10
,
26
22
I 0 Runoff_
28
08170 - Jimmy John's (Existing & Proposed)
Prepared by BKBM Engineers
HydroCAO@ 8.50 sIn 001655 @ 2007 HydroCAO Software Solutions LLC
Type" 24-hr tOO-year Rainfal/=S.9S"
Printed 1/17/2008
Paqe 10
Runoff
=
Summary for Subcatchment 2S: Proposed
1.32 cfs @ 11.96 hrs, Volume=
0.063 af, Depth= 4.36"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.01-28.00 hrs, dt= 0.01 hrs
Type II 24-hr 100-year Rainfall=5.95"
*
Area (sf)
3,370
4,146
7,516
3,370
4,146
*
Tc Length
(min) (feet)
5.0
-;;
~
~
o
u:
o
CN Description
72
98
86 Weighted Average
Pervious Area
Impervious Area
Slope Velocity Capacity Description
(fUft) (fUsee) ( cfs)
Direct Entry,
Subcatchment 2S: Proposed
Hydrograph
Type 1I:24-hr 100-year
Rainfall=5.95"
Runoff Area=7,516 sf
Runoff Volume=O.063 af
Runoff Depth=4.36"
Tc=5.0 min
CN=86
2
, " i' >. . 1<
6 8
, ,
18
10
12 14 16
Time (hours)
4
20
, 'I
22
,
26
,
24
10 Runoffl
, ,
28
January 17,2008
MEEETING MINUTES
From:
Steve Doughty
Re:
Prior Lake YMCA at Shepherds' Path
PAl Project No. 85110.07206
Subject:
Date:
Project Meeting No.4
January II, 2008, at YMCA Metropolitan Minneapolis (Downtown Offices)
Present:
Phil Nyvall
Anita Lancello Bydlon
Rob Howard
Steve Doughty
Not Present:
Thomas LaSalle
Matt Jensen
Jon Donovan
Paul Kangas
Cory Casperson
Paul Holmes
Erica Larson
Dan Klecker
Ben Ptacek
Edward Ueda
Association Abbreviations:
YMCA YMCA
LSLL LaSalle Group, Ltd.
SHEP Shepherds Path, LLC
SUN Sunde Land Surveying
LCKS Loucks Associates
CPL City of Prior Lake
PAl Pope Associates Inc.
YMCA
YMCA
Pope Associates
Pope Associates
LaSalle Group
Dunham
Loucks Associates
Loucks Associates
Clark Engineering Corp.
Pope Associates
Pope Associates
Pope Associates
Pope Associates
Pope Associates
E.mail
pnyva tt@ymcampts.org;
alancelto@ymcampls.org
rhoward@popearch.com
sd 0 u ghtr@PJ?jJ~i!I:.f: h. ~.!!l
E-mail
tom tasa tte@lasattegrp.com
matt. jensen@dunhameng.com
idonova n@toucksassociates.com
pkangas@toucksassociates.com
ccasperson@clark.eng.com
pholmes@popearch.com
elarson@Popearch.com
d klecker@popearch.com
bptacek@popearch.com
eueda@p..QQearch.com
The following memorandum is submitted as representative of the items of Information exchanged, actions agreed upon and
discussions that took place. If no exceptions are received by Pope Associates Inc. within five (5) days of issuance of the
memorandum, then it shall be deemed all are in agreement with the contents of the memorandum.
Pope Associatt~S Inc.
1255 Energy Park Drive'l St. Paul, ~IN 55108.5118
M,lin ((,511 (,42"'200 I Fax (e.51) 642.1101
www.popeilrch.com
Prior Lake YMCA at Shepherds' Path
Project Meeting No.4
January II, 2008
Page 2 of 3
Review of Schedule
Info.
4.01
Info.
4.02
Site Related Issues
Info.
4.03
Info.
4.04
PAI/LCKS
4.05
PAI/LCKS
4.06
P AI/LCKS
4.07
Info.
4.08
Info.
4.09
Info.
4.10
A summary of the milestone project dates are as follows:
a.) PAl to provide current schematic, plants, and site plans to Phil Nyvall, no later than
Friday, January 18,2008, for inclusion into contractor RFP submittal.
b.) General Contractor RFP - will be issued by YMCA during the week of January 21,2008.
c.) City Submittal-Major Amendment to PUD - Feb. 11,2008 (City Submittal for
Administrative Subdivision to be submitted coincidentally).
d.) Commence Design Development - March 10,2008.
e.) City Submittal for Final PUD - April 12, 2008.
Next review meeting is scheduled for 2:30 pm, Friday, January 18, 2008, at the Minneapolis
YMCA (downtown) location. This will be the regularly scheduled meeting day/time until
further notice.
An updated draft of the YMCA land parcel was distributed on January 15, 2008 to all parties.
The updated existing conditions site survey has been received and was distributed to all
parties.
The YMCA site design will include a continuation of the existing fire lane_ This will require a
redefinition/relocation of the easement that is currently placed on the YMCA site locating
the future fire lane paving.
Heavy-duty pavement section will be required at this fire lane to accommodate fire
equipment. It was confirmed at the City that a portion of this fire lane will be located directly
on the loo-year high water line. The project will include a retaining wall to achieve this due to
the grade change. The retaining wall (heights dependent on finish grades) will be a maximum
of 2'-11" to avoid being defined as a building element. The fire lane will be approximately 12'-0"
wide and an additional retaining wall will be required at the northern edge of the fire lane to
accommodate larger play areas for the proposed YMCA.
The site design must address a school bus drop-off and will adequately address turning
radiuses at existing landscape islands.
It was confirmed that a traffic study will not be required for this project as per discussions
between Anita (YMCA) and City representatives.
Anita (YMCA) will obtain parking use studies from similar sized YMCAs, by February 4,2008.
The concept plans propose a shared use utility service area, currently located at the
northwest corner of the existing building. The size of this area and equipment requirements
are to be confirmed with mechanical and service functions for the building. It is estimated
that there will be weekly deliveries of miscellaneous building support materials for the
building occurring at this location. DUN has been asked to provide initial space requirement
for transformers or any other equipment that will be placed at this location.
Prior Lake YMCA at Shepherds' Path
Project Meeting NO.4
January 11,2008
Page 3 of 3
Info.
Info.
4.12
Building Design
Info.
4.13
Info.
4.14
4.11
Current plan square footage, as reflected on the concept plans:
. 27,000 sq. ft. ...................... 1st Floor
. 20,000 sq. ft. ..................... 2nd Floor
. 8,000 sq. ft. ......................... 1st Floor Future Expansion
. 5,000 sq. ft. ......................... 2nd Floor Future Expansion
· 60,000 sq. ft. ....................... Total sq. ft. (as requested within PUD Amendment)
Phil Nyvall (YMCA) is preparing a RFP for general contractor selection. This will be sent out
no later than the week of January 21, 2008. PAl will provide concept design documents for
that submittal. It is estimated, based on the schedule, by the first week of February, 2008,
that general contractor interviews will be held.
PAl will coordinate appropriately timed review meetings to ensure that the design
documents are accurately defining all material design detail approvals and shop drawings as
they relate to finish colors, locker types, toilet partitions, etc. This effort is to avoid any
discrepancies during the submittal review and construction process.
PAl will contact Fabcon regarding the possible incorporation of their structural panels to be
used on the project. It is unintended that the Fabcon panels will not be used as an
architectural finish panel; only to be used as a structural panel with an applied veneer finish
on the exterior. Special attention will be paid to electrical conduit, utility connections that
will be required within the panel as we proceed with the design process using this precast
panel system.
G:\8 SIIO\on06\Corr\Meeting Minutes\Project Meeting#o4_oH l-08.doc