storm drainage report - marin county

24
MARIN GENERAL HOSPITAL WEST WING ADDITION GREENBRAE, CALIFORNIA STORM DRAINAGE REPORT PREPARED BY: KPFF CONSULTING ENGINEERS 45 FREMONT STREET, 28 TH FLOOR SAN FRANCISCO, CA 94105 FOR: MARIN HEALTHCARE DISTRICT C/O VERTRAN ASSOCIATES, LLC 242 BUTTERFIELD ROAD SAN ANSELMO, CA 94960 DATE: MARCH 29, 2019

Upload: others

Post on 25-Feb-2022

4 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: STORM DRAINAGE REPORT - Marin County

MARIN GENERAL HOSPITAL

WEST WING ADDITION

GREENBRAE, CALIFORNIA

STORM DRAINAGE REPORT

PREPARED BY:

KPFF CONSULTING ENGINEERS

45 FREMONT STREET, 28TH FLOOR

SAN FRANCISCO, CA 94105

FOR:

MARIN HEALTHCARE DISTRICT

C/O VERTRAN ASSOCIATES, LLC

242 BUTTERFIELD ROAD

SAN ANSELMO, CA 94960

DATE: MARCH 29, 2019

Page 2: STORM DRAINAGE REPORT - Marin County

KPFF Consulting Engineers Marin General Hospital

March 29, 2019 Storm Drainage Report

Page 1 of 3

45 Fremont St, 28th Floor San Francisco, CA 94105 415.989.1004 kpff.com

INTRODUCTION

KPFF Consulting Engineers has compiled this report to evaluate the proposed stormwater

design for the planned Marin General Hospital West Wing Addition project. The scope of this

report is the compilation of the analysis examining drainage patterns, stormwater runoff,

and the storm drain system for the purpose of meeting the requirements of the authorities

having jurisdiction for permitting of the project.

The Marin General Hospital West Wing Addition project consists of several improvements to

the existing campus located at 250 Bon Air Road in Greenbrae, California. The proposed

redevelopment consists of the remodel of the West Wing building (ground and partial first

floor) on the Marin General Hospital campus along with a building addition at the north side,

site improvements of approximately 80,000 square feet and a new median curb cut and left

turn lane on Bon Air Road.

EXISTING CONDITIONS

The existing project site consists of the existing west hospital wing, surface parking lots, and

undeveloped landscape areas throughout the site. The Marin General Hospital site is located

northwest of highway US101, bound by the Larkspur City limits on the south, Bon Air Road

and Creekside Park on the north and west, and Marin County Property on the east.

The project site generally slopes from east to the west with elevations ranging from

approximately 10-15’ above mean sea level. The catch basins drain directly into the Marin

General Hospital storm drain system. The existing surface lot drains to the existing on-site

storm drainage system and conveys the stormwater runoff through the site into the Marin

County public drainage system in Bon Air Road which eventually drains directly to Corte

Madera Creek through a 72-inch diameter outfall located just southwest of the West Wing

main Hospital entrance.

PROPOSED IMPROVEMENTS

The proposed Marin General Hospital West Wing Addition project consists of a number of

improvements, including the following:

• Addition to existing West Wing building totaling approximately 3,900 square feet.

• Addition of site improvements of approximately 80,000 square feet including new

round-about and drop off area.

• Addition of new median curb cut and ADA path across Bon Air road along with left

turn lane on Bon Air Road.

Runoff from the proposed West Wing addition will be mostly captured by the pervious

asphalt pavement and bioretention. One bioretention area will capture runoff from the new

West Wing addition structure and treat low volume storms before releasing into the Marin

Page 3: STORM DRAINAGE REPORT - Marin County

KPFF Consulting Engineers Marin General Hospital

March 29, 2019 Storm Drainage Report

Page 2 of 3

General Hospital drainage system via perforated pipe underdrains. Runoff volumes that

exceed the scope of treatment requirements will enter overflow drains.

In order to comply with Table 1-1 of the BASMAA Post-Construction Manual which requires

the area of impervious surfaces created or replaced is less than 50% the original pre-2015

condition, pervious pavement will be utilized in the vehicular travelways as shown in the

exhibits provided in Appendix B.

Impervious area exhibits for each phase is shown on sheets C14.1-C14.2. Plan sheet C14.1

shows that the pre-developed existing impervious area of 389,613 sq. ft., of which 50% is

194,807 sq. ft. Plan sheet C14.2 shows that after the final phase of the Marin General

Hospital project, the total impervious area added/replaced in the entire site is 188,267 sq. ft.

The total impervious added/replaced is roughly 6,000 sq. ft. less than 50% of the original

pre-2015 condition.

STORMWATER ANALYSIS SUMMARY

Stormwater analysis for the Marin General Hospital West Wing Addition was performed in

two phases. First, in order to meet Marin County Municipal Code Section 24.04.520,

impervious and pervious areas were calculated for each phase of the project to determine

the hydrological effect on the site. This analysis is intended to confirm that the post-

developed site has less impervious area than the pre-developed condition and therefore will

have no additional impacts to the Marin County public drainage system. Second, a hydraulic

design is prepared for the proposed Marin General Hospital drainage system upgrades. This

design is intended to confirm that proposed pipes are sized adequately to convey the design

storm. In both cases, the 100-year design storm is used.

For the West Wing Addition project site, the pre-developed existing has a total impervious

area of 32,756 sq. ft. The total impervious area post construction of the site is 12,117 sq. ft.

Therefore post-development impervious area is less than the pre-developed existing

impervious. Using the rational method, the decrease in total impervious area will lower the

overall curve number of the site and therefore decrease the peak runoff volume of the site

during a storm event.

HYDRAULIC ANALYSIS SUMMARY

Rational methodology was employed for the hydraulic modelling. The proposed drainage

pipe network was designed using AutoCAD Civil 3D 2018 to conform to the proposed site

plan. Inlet structures, manholes, and conveyance pipes were all modelled into a single 3D

model of the project. Once this information was correctly placed, the network was exported

to Hydraflow Storm Sewers, an extension of AutoCAD Civil 3D. With catchment area

characteristics applied to each inlet and an applied 100-year storm event intensity, the pipe

network was analyzed to confirm the pipes are capable of conveying the peak flow. A

Page 4: STORM DRAINAGE REPORT - Marin County

KPFF Consulting Engineers Marin General Hospital

March 29, 2019 Storm Drainage Report

Page 3 of 3

hydraulic grade line (HGL) at the Bon Air Road point of connection was set at 7.0’ amsl,

approximately equal to the 100-year flood water surface elevation (WSEL).

Hydraulic Model

Rainfall intensity logged in the NOAA Rainfall Atlas was used to create a 10-year and 100-

year IDF curve for the project site. This IDF curve was applied to the catchments and overall

model for the West Wing Addition project. Ideally, all storm water would be conveyed in the

pipes and no surcharge would be applied at the inlet structures and manholes. Several

structures did have a hydraulic grade line above the crown of the inlet and outlet pipes. In

each of these structures, however, the HGL did not encroach to within 2.0-feet of the grate

elevation during the 100 year storm. The surcharged inlets and associated elevations are

listed in the table below:

Structure Name HGL Elevation (ft) Rim Elevation (ft) Freeboard (ft)

SDMH #1 7.06 11.76 4.70

SDCB #3 7.09 12.71 5.62

JB #2 7.54 13.17 5.63

SDCB #2 8.03 11.27 3.24

SDCB #1 8.14 11.38 3.24

DI #1 7.65 14.33 6.68

The 10-year design storm was also analyzed to confirm that no surcharge occurred in any

storm drain structure.

See Appendix B for more information.

CONCLUSION

The proposed improvements associated with the Marin General West Wing Addition project

will not have an increased impact on the Bon Air Road public storm drain system, and the

private storm drainage system associated with the Hospital Replacement Building is

designed to meet the requirements of Marin County Municipal Code Section 24.04.520.

Page 5: STORM DRAINAGE REPORT - Marin County

APPENDIX A

VICINITY MAP & PLAN SET

Page 6: STORM DRAINAGE REPORT - Marin County
Page 7: STORM DRAINAGE REPORT - Marin County
Page 8: STORM DRAINAGE REPORT - Marin County
Page 9: STORM DRAINAGE REPORT - Marin County

V

A

N

V

A

N

N

O

P

A

R

K

I

N

G

HOSPITAL

REPLACEMENT BUILDING

DMA #1

DMA #3

DMA #7

DMA #8

DMA #6

(E) CENTRAL

WING

(E) WEST WING

DMA #4

BON AIR ROAD

DMA #5

DMA #2

1"=20'

STORMWATER CONTROL PLAN

WEST WING ADDITION

C7.1

N

O

T

F

O

R

C

O

N

S

T

R

U

C

T

I

O

N

Revisions:

Key Plan/

North Arrow

Issue

Date:

Scale:

Sheet

Title:

Sheet

Number:

5510 Lincoln Blvd. Suite 250

Los Angeles, California 90094

Phone (310) 829-2249

Fax (310) 829-1736

Revision # Revision Description Revision Date

Perkins Eastman

Client

Project

PE

Job Number:

OSHPD

Number:

35587.00

MGH: WW REMODEL/ADDITION

STRUCTURAL ENGINEER

MECHANICAL / PLUMBING / ELECTRICAL ENGINEER

CIVIL ENGINEER

LANDSCAPE ARCHITECT

INTERIOR DESIGNER

KPFF Consulting Engineers

45 Fremont Street, 28th Floor

San Francisco, CA 94105

Mazzetti

220 Montgomery Street, Suite 650

San Francisco, CA 94104

KPFF Consulting Engineers

45 Fremont Street, 28th Floor

San Francisco, CA 94105

SWA

2200 Bridgeway Boulevard

Sausalito, CA 94966

Forrest Perkins

100 Montgomery Street, Suite 2300

San Francisco, CA 94104

Consultants:

Marin Healthcare District

AIM

J. H

JAS

ON

MAY 31, 2019REN. DATE

NO. C-27994

AINROFILACFOET

ATS

T

D ARCHI TEC

ESNECIL

250 Bon Air Road

Greenbrae, CA 94904

McCarthy Building Companies

1265 Battery Street, 3rd Floor

San Francisco, CA 94111

General

Contractor:

Construction

Manager:Vertran Associates

250 Bon Air Road

Greenbrae, CA 94904

OSHPD

Approval:

TIME STAMP:

01/31/2019 - Design Review

Application Backcheck

C

MYRO

N

STATE OF CALIFORNIA

REENI

GNELANOISSEFORPDERETSIGER

L

NABEI

No. 84348

LIVIC

N

CHA

O

Exp. 09/30/2019

1COUNTY BACKCHECK 01/31/2019

1

1

2COUNTY BACKCHECK 2 03/29/2019

2

2

AutoCAD SHX Text
WV
AutoCAD SHX Text
3"pipe
AutoCAD SHX Text
co
AutoCAD SHX Text
co
AutoCAD SHX Text
co
AutoCAD SHX Text
EX 66"SD
AutoCAD SHX Text
EX 18"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
EX 10"SD
AutoCAD SHX Text
EX 66"SD
AutoCAD SHX Text
EX 18"SD
AutoCAD SHX Text
EX 18"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
EX 10"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
12"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
EX 24"SD
AutoCAD SHX Text
EX 10"SD
AutoCAD SHX Text
4"SD
AutoCAD SHX Text
4"SD
AutoCAD SHX Text
4"SD
AutoCAD SHX Text
EX 15"SD
AutoCAD SHX Text
EX 10"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
EX 12"SD
AutoCAD SHX Text
6"PERF SD
AutoCAD SHX Text
6"PERF SD
AutoCAD SHX Text
6"PERF SD
AutoCAD SHX Text
4"SD
AutoCAD SHX Text
LEGEND:
AutoCAD SHX Text
DRAINAGE AREA BOUNDARY
AutoCAD SHX Text
BIORETENTION AREA
AutoCAD SHX Text
STORMWATER CONTROL NOTES:
AutoCAD SHX Text
1. THE CALCULATIONS ON THIS SHEET ARE BASED ON THE THE CALCULATIONS ON THIS SHEET ARE BASED ON THE STORMWATER QUALITY MANUAL FOR DEVELOPMENT PROJECTS IN MARIN COUNTY HANDBOOK. 2. A TREATMENT MEDIUM SIZING FACTOR OF 0.04 WAS A TREATMENT MEDIUM SIZING FACTOR OF 0.04 WAS ASSUMED WHEN DETERMINING THE TREATMENT CONTROL METHOD AREA REQUIRED.
AutoCAD SHX Text
TREATMENT CONTROL METHOD (TCM) SUMMARY TABLE
AutoCAD SHX Text
AREA
AutoCAD SHX Text
IMPERVIOUS AREA (SF)
AutoCAD SHX Text
PERVIOUS AREA (SF)
AutoCAD SHX Text
TCM TYPE
AutoCAD SHX Text
TCM AREA REQUIRED (SF)
AutoCAD SHX Text
TCM AREA PROVIDED (SF)
AutoCAD SHX Text
ROOF
AutoCAD SHX Text
HARDSCAPE
AutoCAD SHX Text
LANDSCAPE
AutoCAD SHX Text
PERVIOUS PAVEMENT
AutoCAD SHX Text
DMA #1
AutoCAD SHX Text
0
AutoCAD SHX Text
1,686
AutoCAD SHX Text
5,903
AutoCAD SHX Text
7,726
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #2
AutoCAD SHX Text
0
AutoCAD SHX Text
0
AutoCAD SHX Text
3,821
AutoCAD SHX Text
0
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #3
AutoCAD SHX Text
0
AutoCAD SHX Text
329
AutoCAD SHX Text
0
AutoCAD SHX Text
1,724
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #4
AutoCAD SHX Text
0
AutoCAD SHX Text
665
AutoCAD SHX Text
0
AutoCAD SHX Text
3,640
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #5
AutoCAD SHX Text
3,370
AutoCAD SHX Text
0
AutoCAD SHX Text
378
AutoCAD SHX Text
0
AutoCAD SHX Text
BIORETENTION
AutoCAD SHX Text
152
AutoCAD SHX Text
234
AutoCAD SHX Text
DMA #6
AutoCAD SHX Text
0
AutoCAD SHX Text
2,044
AutoCAD SHX Text
4,053
AutoCAD SHX Text
6,330
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #7
AutoCAD SHX Text
0
AutoCAD SHX Text
0
AutoCAD SHX Text
8,658
AutoCAD SHX Text
0
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
DMA #8
AutoCAD SHX Text
0
AutoCAD SHX Text
509
AutoCAD SHX Text
1,815
AutoCAD SHX Text
3,923
AutoCAD SHX Text
SELF-TREATING
AutoCAD SHX Text
N/A
AutoCAD SHX Text
N/A
AutoCAD SHX Text
40'
AutoCAD SHX Text
20'
AutoCAD SHX Text
10'
AutoCAD SHX Text
20'
AutoCAD SHX Text
SCALE: 1" = 20'
Page 10: STORM DRAINAGE REPORT - Marin County
Page 11: STORM DRAINAGE REPORT - Marin County
Page 12: STORM DRAINAGE REPORT - Marin County

APPENDIX B

HYDROLOGIC MODELLING DATA & RESULTS

Page 13: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
10-YEAR STORM
Page 14: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
10-YEAR STORM
Page 15: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
10-YEAR STORM
Page 16: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
10-YEAR STORM
Page 17: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
100-YEAR STORM
Page 18: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
100-YEAR STORM
Page 19: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
100-YEAR STORM
Page 20: STORM DRAINAGE REPORT - Marin County
dluo
Text Box
100-YEAR STORM
Page 21: STORM DRAINAGE REPORT - Marin County

��������� ����� �������������� � �������

������������������ ������������������ ����� �����!"#" �$�%��&%'("��$)����'�'&(� � $�������(����$���"��(�����$��� ��&

*+,,-,./01-234-56/789-:4-59;1<6=->-?6@0.<6=-=089A-B;99=C;094-D0/<E6;=<04-FG,H-?0.<.7I9A-JKLM3KNO4-?6=P<.7I9A-Q2>>LNJN3O-

R/9S0.<6=A-JNLTU-E.HHV��������W�XY�Z ���VV��������[�\�

]+*_-] RD]_,_+*-a RbFR*Dc-RG_d,_RG

� �e ���� f�� � �����gf�� � ��h�!f�i"" ��h���f�j g�����Z � � f���k�� ��Z ���f�� ��� � �"��f�Y�� ��X��f�l �"�m��� "�nf�� "��[����f�����"��o �f�Z� �"�o�n� f�m ��p� �f�\�������

q����f�� ��"�q�����f�i)l�� ��l���f�m���� �g�k�nf�r����o ��� �

stuuf�s ��� "�v� ����������f��"���������f�Z ��" ��

�� � k�" ��w��� �� �� "�w�Z �� ( �� "�

]a-.0C7/0;

]xGQC019I-y6<=.-y;9@<y<.0.<6=-E;9z79=@{-91.<80.91-|<.}-MT~-@6=E<I9=@9-<=.9;S0/1-�<=-<=@}91�}67;�2

x7;0.<6=,S9;0P9-;9@7;;9=@9-<=.9;S0/-�{90;1�

2 > N 2T >N NT 2TT >TT NTT 2TTT

NQ8<= >LTU����'����'�

>LNM���������&�

JLJT��������%��

JLMT���&��&�&��

3LKU�&����'�%��

NL3U�&�'����%��

:L>J�&��%�%����

KLT3�'�&&������

UL>T�����������

ML23���&�������

2TQ8<= 2L3M�����������

2LUN����'������

>LJ:�����������

>LUT���&�������

JL3>������&����

JLMJ������&����

3L3:���'��'��'�

NLTN�����������

NLUK�&�������%�

:LNN�&���������

2NQ8<= 2L>T����%������

2LNT��������%��

2LMT���������%�

>L>:�����������

>LK:�����������

JL2K�����������

JL:T����%�&�'��

3LTK����&�'����

3LK3���&����'��

NL>U���%��%�'��

JTQ8<= TLUM:���%��������

2L2>�����&����%�

2L3>�����������

2L:M���&�����&�

>LT:���%&���&%�

>LJK����&������

>L:M����'���&��

JLT3����'����%�

JLN3������&����

JLMN���%��'��'�

:TQ8<= TL:3J���'%����%���

TLUTJ���%�&�������

2LT>�����%����%�

2L>2�����������

2L3U����'���%%�

2LKT���&�������

2LMJ���'&���&&�

>L2U�����������

>LN3����%���&��

>LU3������&����

>Q}; TL3UT���&�%���'&&�

TLNM:���'������%%�

TLKNM����%������&�

TLUMM���%��������

2L2T������������

2L>K����&���'��

2L33����'������

2L:3���������&�

2LM2���&�������

>L23���'�����%�

JQ}; TL3TU���������&���

TLNT:���&'����'%'�

TL:3J���'%����%���

TLK:>����������%��

TLMJJ���%�%������

2LTK������������

2L>>����%%���''�

2LJM����%������

2L:>�����������

2LU>�����������

:Q}; TLJTJ����%�����&��

TLJK:�����'���&�%�

TL3KU���&�&���'&&�

TLN:N���&������'��

TL:MT���'���������

TLKM2����'�����%��

TLUMM���%������&�

2LT>���%�&������

2L2U������������

2LJ>������������

2>Q}; TL>22�������������

TL>::�����%�������

TLJ32�������������

TL3T3����'&���&�&�

TL3M2���&�&���'���

TLN:2���&���������

TL:J3���'���������

TLK22���'&��������

TLU2M������������

TLMT:������������

>3Q}; TL23:�������������

TL2UK�������������

TL>3>�����%����%'�

TL>UK����'��������

TLJ3M���������&���

TLJMU�����%���&%��

TL33K����%����''��

TL3MM���&�&�������

TLNK2���&&&���%&��

TL:>K���&%�����&��

>QI0{ TLTM:�������������

TL2>J����������&��

TL2:T����&��������

TL2UM�����������%�

TL>JT����������%��

TL>:2�����������&�

TL>MJ����&��������

TLJ>K�����&���&���

TLJK>���������&���

TL3TU���������''��

JQI0{ TLTKJ�������������

TLTM3�����&�����%�

TL2>2�������������

TL233�����������'�

TL2KN����'��������

TL2MU�������������

TL>>J�����'����%&�

TL>3U�������������

TL>U>�������������

TLJTU���������&�%�

3QI0{ TLT:T����'&�������

TLTKU����%��������

TL2T2�����������&�

TL22M�����������%�

TL23N�����'����%��

TL2:3�����������%�

TL2U3����'��������

TL>T3�����'����'��

TL>J>�����������&�

TL>N3����������&��

KQI0{ TLT3>����������&��

TLTN3����&��������

TLTKT�������������

TLTUJ����%&�����'�

TL2TT�����%�������

TL223�����������%�

TL2>K����������'%�

TL232�����&����%��

TL2:T�����'�������

TL2KN�����������%�

2TQI0{ TLTJ3�������������

TLT33����&�����'��

TLTNK����'������'�

TLT:K����������%%�

TLTU2����%������'�

TLTM2����%��������

TL2T>�����'�������

TL22J����������&��

TL2>U�����������%�

TL2JM�����'�������

>TQI0{ TLT>>�����������'�

TLT>M�������������

TLTJK����������&��

TLT33����������'��

TLTN>����&'�������

TLTNM����'�����%��

TLT:N����'&�������

TLTK>����'��������

TLTUT�����������'�

TLTU:�����'�����%�

JTQI0{ TLT2U�������������

TLT>J�����������%�

TLTJT�����%�����&�

TLTJN����������&��

TLT3>����������&��

TLT3K����&�����'��

TLTN2����&��������

TLTN:����&'����%��

TLT:>����&��������

TLT:K����'��������

3NQI0{ TLT2N�����&�����%�

TLT2M�����%�������

TLT>3�������������

TLT>U�����'�������

TLTJ3����������&��

TLTJK����������&'�

TLT32�����&����'��

TLT33����������''�

TLT3U�������������

TLTN2����������%��

:TQI0{ TLT2J�����������'�

TLT2K�����'�������

TLT>>�����������'�

TLT>N�������������

TLT>M�����'�����&�

TLTJ>�����%�������

TLTJN����������&��

TLTJU����������&��

TLT32����������'&�

TLT33����������'��

������� ���������������������! ����������� k"�� ���k ���������������� � "�������� �� "���� ����������������

s�!k������� ��������� ���������! ���� ��"����� ���������k������������������������������ "��m������k k"����� ������� ����������������! ��������� �������� ���� ��� ��� ����������������� "���""�k����� ������ ������������k���������"������ ������"�����k��������'���W��! ���� ��������k������ ��������n��� � �������k k"��! �!�!������ ������Z������! ���� ���! ��k���������� ��������"��� "���Z��� "����

�"� ������������stuu�u�" ���&����!��������!��������! ����

q n����m��

]a-P;0y}<@0/

Page 22: STORM DRAINAGE REPORT - Marin County

��������� ����� �������������� � �������

������������������ ������������������ ����� �����!"#" �$�%��&%'("��$)����'�'&(� � $�������(����$���"��(�����$��� ��&

* +����,��

-./0121.345.60

78.66109.631:344.5;

Page 23: STORM DRAINAGE REPORT - Marin County

��������� ����� �������������� � �������

������������������ ������������������ ����� �����!"#" �$�%��&%'("��$)����'�'&(� � $�������(����$���"��(�����$��� ��&

*+,-./01+2./3.,,+45

*+,-./01+2./6+7

*+,-./01+2./+.,4+2

8

9:;6

<64

8

9=>>;6

?>64

8

9=>>;6

?>64

Page 24: STORM DRAINAGE REPORT - Marin County

��������� ����� �������������� � �������

������������������ ������������������ ����� �����!"#" �$�%��&%'("��$)����'�'&(� � $�������(����$���"��(�����$��� &�&

�* +����,��

���

-����� ��!�������.�!!����/ ��� "�0� �� ���1�!�������1�!���� ����

/ ��� "�2� �����������/ ��� "�2 ����.���������'�3 ���2����4��� ���"���������5�6��������

7�������#��4��.�7�������8�� ������

��" !���

9

:;<<=>

?<>@