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C O N S U L T I N O ,
RESPONSES TO COMMENTS
APPENDICES
VOLUME VI
NEWPORT BANNING RANCH PROJECT
CITY OF NEWPORT BEACH
STATE CLEARINGHOUSE No. 2009031061
Prepared for City of Newport Beach
3300 Newport Boulevard
Newport Beach, California 92663
Prepared by BonTerra Consulting
2 Executive Circle, Suite 175
Irvine, California 92614
T: (714) 444 -9199 F: (714) 444 -9599
March 16. 2012
APPENDIX A
PRELIMINARY WATER QUALITY MANAGEMENT PLAN
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PRELIMINARY WATER QUALITY MANAGEMENT PLAN
(P -WQMP)
Newport Beach, California
Prepared For
NEWPORT BANNING RANCH, LLC
1300 Quail Street, Suite 100
Newport Beach, CA 92660
Prepared By
Fuscoe Engineering, Inc.
16795 Von Korman, Suite 100
Irvine, California 92606
949.474.1960
www.fuscoe.com
Project Manager:
John Olivier, PE
Date Prepared: February 3, 2012
Job Number: 821.01.06
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PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
NEWPORT BEACH, CA
February 3, 2072
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NEWPORT BANNING RANCH °
FUSCOE o
NEWPORT BEACH, CA N
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February 3, 2012
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP) o
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FUSCOE NEWPORT BEACH, CA
I i 1 M I E N I II f 00
February 3, 2072
PRELIMINARY
WATER QUALITY MANAGEMENT PLAN
(P -WQMP)
NEWPORT BANNING RANCH
City of Newport Beach, County of Orange
TENTATIVE TRACT MAP NO. 17308
APN NOS. 114-170-24, 43, 49, 50, 52, 72, 75, 77, 79, 83 & 424 -041 -04
Prepared for:
NEWPORT BANNING RANCH, LLC
1300 Quail Street, Suite 100
Newport Beach, CA 92660
Prepared by:
FUSCOE ENGINEERING, INC.
1 6795 Von Karman, Suite 100
Irvine, CA 92618
949.474.1960
Date Prepared: February 3, 2012
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
PROJECT OWNER'S CERTIFICATION
Permit /Application No.: I PA2008 -114 I Grading Permit No.: I Pending
Tract /Parcel Map and TTM 17308 Building Permit No.: Pending
Lot(s)No.:
Address of Project Site and APN: 114-170-24, 43, 49, 50, 52, 72, 75, 77, 79, 83 &
424 - 041 -04
This Water Quality Management Plan (WQMP) has been prepared for NEWPORT BANNING
RANCH, LLC by FUSCOE ENGINEERING, INC. The WQMP is intended to comply with the
requirements of the County of Orange NPDES Stormwater Program requiring the preparation of the
plan.
The undersigned, while it owns the subject property, is responsible for the implementation of the
provisions of this plan , including the ongoing operation and maintenance of all best management
practices (BMPs), and will ensure that this plan is amended as appropriate to reflect up -to -date
conditions on the site consistent with the current Orange County Drainage Area Management Plan
(DAMP) and the intent of the non -point source NPDES Permit for Waste Discharge Requirements for
the County of Orange, Orange County Flood Control District and the incorporated Cities of Orange
County within the Santa Ana Region. Once the undersigned transfers its interest in the property, its
successors -in- interest shall bear the aforementioned responsibility to implement and amend the
WQMP. An appropriate number of approved and signed copies of this document shall be available
on the subject site in perpetuity.
OWNER:
Name:
Title:
Company:
Address:
Email:
Telephone:
Signature:
Date:
NEWPORT BANNING RANCH, LLC I OWNER'S CERTIFICATION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
TABLE OF CONTENTS
SECTION I DISCRETIONARY PERMITS AND WATER QUALITY CONDITIONS ............................1
SECTION II PROJECT DESCRIPTION ........................................................ ..............................2
11.1 Project Description ........................................................................ ...............................
2
11.2 Potential Storm Water Pollutants ..................................................... ...............................
5
11.3 Hydrologic Conditions of Concern .................................................. ...............................
6
11.4 Post Development Characteristics ................................................... ...............................
8
11.5 Property Ownership/ Management .................................................. ...............................
9
SECTION III SITE DESCRIPTION ......................................................... ...............................
11
111.1 Physical Setting ........................................................................... ...............................
11
111.2 Site Characteristics ...................................................................... ...............................
11
111.3 Watershed Description ................................................................. ...............................
13
SECTION IV BEST MANAGEMENT PRACTICES ( BMPs) .......................... ...............................
14
IV.1 Project Performance Criteria ......................................................... ...............................
14
IV.2 Site Design and Drainage Plan ..................................................... ...............................
14
IV.2.1 Site Design BMPs ................................................................. ...............................
14
IV.2.2 Drainage Management Areas ............................................... ...............................
15
IV.3 LID BMP Selection and Project Conformance Analysis .................... ...............................
16
IV.3.1 Hydrologic Source Controls ( HSCs) ........................................ ...............................
17
IV.3.2 Infiltration BMPs ................................................................... ...............................
17
IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs ...................... ...............................
18
IV.3.4 Biotreatment BMPs ................................................................. .............................24
IV.3.5 Hydromodification Control BMPs ............................................. .............................29
IV.3.6 Regional /Sub - Regional LID BMPs .......................................... ...............................
29
IV.3.7 Treatment Control BMPs ....................................................... ...............................
29
IV.3.8 Non - Structural Source Control BMPs ...................................... ...............................
30
IV.3.9 Structural Source Control BMPs ............................................. ...............................
32
IV.4 Alternative Compliance Plan ........................................................ ...............................
34
IV.4.1 Water Quality Credits ........................................................... ...............................
34
IV.4.2 Alternative Compliance Plan Inf ormation ................................ ...............................
35
SECTION V INSPECTION /MAINTENANCE RESPONSIBILITY FOR BMPs ............... ....................
36
SECTION VI SITE PLAN AND DRAINAGE PLAN .................................... ...............................
44
Exhibits..............................................................................._................. ...............................
44
BMPDetails ............................................................................................ .............................44
NEWPORT BANNING RANCH, LLC 11 TABLE OF CONTENT$
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION VII EDUCATIONAL MATERIALS ............................................. ............................... 45
APPENDICES.......................................................................................... ............................... 46
Appendix .......................................... ............................... ......................Supporting Calculations
Appendix B ......................... ............................... .........................Notice of Transfer of Responsibility
Appendix C ................................................................... ............................... Educational Materials
Appendix D ................................... ............................... BMP Maintenance Supplement / O &M Plan
Appendix E ............................ .....................Conditions of Approval (Placeholder — Pending Issuance)
Appendix F ................. ............................... .....................Memorandum on Limitations for Infiltration
Appendix G ......................... ............................... .................Planning -Level Water Quality Modeling
NEWPORT BANNING RANCH, LLC III TABLE OF CONTENT$
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION I DISCRETIONARY PERMITS AND WATER QUALITY
CONDITIONS
NEWPORT BANNING RANCH, LLC 1 DISCRETIONARY PERMITS & WATER QUALITY CONDITIONS
PROJECT INFORMATION
Permit /Application No.:
PA2008 -114
Tract /Parcel Map No.:
TTM 17308
Address of Project Site
114- 170 -24, 43, 49, 50, 52, 72, 75, 77, 79, 83 &
and APN:
424- 041 -04
- WATER QUALITY CONDITION
Water Quality
Pending. To be provided in the Final WQMP.
Conditions:
WATERSHED -BASED PLAN CONDITIONS
Applicable conditions
from watershed - based
Not Applicable.
plans including WIHMPs
and TMDLS:
NEWPORT BANNING RANCH, LLC 1 DISCRETIONARY PERMITS & WATER QUALITY CONDITIONS
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION II PROJECT DESCRIPTION
11.1 PROJECT DESCRIPTION
The purpose of this P -WQMP is to fulfill the requirements of the 2011 Model WQMP which requires
preparation of a P -WQMP at the CEQA level of entitlement. The majority of the information provided
has been previously summarized and reported in Section 4.4 Hydrology and Water Quality and
Appendix C of the draft environmental impact report (DEIR) (Hydrology and Water Quality Appendix).
In some instances, additional assessments and calculations consistent with the 2011 Model WQMP
and Project Description have been provided that supports the original feasibility assessments and
conclusions provided in Section 4.4 and Appendix C of the DEIR. In other instances, additional
details are provided to further clarify water quality measures previously discussed within the Project
Description, Section 4.4 and Appendix C.
The Newport Banning Ranch property encompasses approximately 401 .1 acres within unincorporated
County of Orange (City of Newport Beach sphere of influence) and portions of the City of Newport
Beach, California. The property is bounded on the south by the West Coast Highway (WCH), to the
west by the Santa Ana River channel, and by existing residential and commercial developments to the
north and east (see Vicinity Map in Section VI). The entire property is situated within the Coastal Zone
Jurisdictional Boundary as established by the California Coastal Act, and is therefore also subject to
the planning and regulatory jurisdiction of the California Coastal Commission. The southwestern
border of the property is less than one half mile from the Pacific Ocean and adjoining beaches. The
City of Costa Mesa, including Talbert Regional Park, is adjacent to the northern and a portion of the
eastern project boundaries. Wetland areas restored by the US Army Corp of Engineers (USACOE)
extend up the Site's western boundary and separate the site from the Santa Ana River channel. The
City of Huntington Beach is located west of the Santa Ana River, adjacent to the Site's western
boundary.
For more than 50 years, the site has been used as an operating oil field and today, remnants of old
wells and pipelines coexist with currently operating pump and processing facilities. Most of the active
oil facilities are located in the central portion of the Upland Mesa and adjoining Lowland Area of the
property. Currently, there are over 460 producing, potentially producing, and abandoned wells along
with related roads, pipelines, and associated facilities located throughout the Newport Banning Ranch
property.
The proposed Newport Banning Ranch Project includes the development of roughly 149 acres of the
larger 401 -acre project site for residential, commercial, and recreational land uses. Over fifty percent
of the property will be retained as open space, with restored wetland and habitat areas located
throughout the Lowland and Upland Mesa areas. Below is a summary of the proposed development:
Residential Areas: Approximately 76 acres (or 16 %) of the project site will be devoted to
Residential Land Use. This type of land use is divided into the following districts:
o Low Density Residential (LDR) District: Approximately 13 acres of LDR use development is
planned that may include custom homes or larger individual lots.
NEWPORT BANNING RANCH, LLC 2 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
• Low - Medium Density Residential (LMDR) District: Approximately 21 acres of LMDR land
use is planned that may include single - family detached homes, single - family attached
homes as well as multi - family housing.
• Medium Density Residential (MDR) District: Approximately 42 acres of MDR land use is
planned that may include single - family detached homes, single - family attached homes
and multi - family residential projects. This land use will also include smaller convenience
commercial sales sites and service sites to encourage pedestrian and bicycle use.
• Mixed Use /Residential (MU /R) District: Approximately 21 acres of MU /R land use is
planned along the eastern side of North Bluff Road. It adjoins Costa Mesa's "Mesa West
Bluffs Urban Plan Area" (proposed mixed -use redevelopment) to the east, which currently
is made up of light industrial developments and mobile home parks. Consistent with
Costa Mesa's MesaWest Bluffs Urban Plan, this will be the most -urban environment within
the Newport Banning Ranch site. The MU /R District will allow 3 -, 4 -, and 5 -story attached
residential neighborhoods with innovative architecture, creative parking solutions, and on-
site recreation centers with the potential for lofts, live -work units, and /or commercial
development as part of a vertically and /or horizontally integrated mixed use development.
It is anticipated that this higher density residential area could also accommodate
affordable housing units as defined by the City of Newport Beach and described in an
Affordable Housing Implementation Plan (AHIP) prepared for the Project, and potentially
in the future Pre - Annexation Development Agreement (PADA) between the
Landowner /Master Developer and the City.
• Visitor - Serving Resort: The Visitor - Serving Resort Overlay District will provide a maximum of 75
overnight accommodations in an "inn" type setting integrated within the base Residential District.
The design will include an iconic architectural element for the community and permit a spa and
wellness center, restourant(s), and limited visitor - serving commercial facilities as part of the resort.
The residential units permitted in the base district will be conventionally owned but have
opportunities to use the spa and wellness center, restaurants, and /or other facilities and amenities
provided by the resort.
• Parks and Recreational Areas: Both active and passive public parks will be located throughout the
project site. Multiple trails will be located throughout the site and adjacent areas to connect to the
regional recreational facilities. In addition, smaller greenways and neighborhood focal points will
be placed within the residential areas.
Open Space Areas: various open space uses are proposed throughout the Lowland, Upland,
Bluff, and Arroyo areas, including trails, habitat, wetlands, and arroyos.
Green Streets: Many of the larger streets and arterials throughout the project site will be designed
with "green street" and other low impact development (LID) features. Green streets are carefully
designed roadways that incorporate sustainable design elements that may include narrower
pavement widths, canopy street trees, traffic calming features, and alternative street lighting
systems. In addition, landscaping along the street edges and within setback areas provide
additional opportunities for treatment of storm water runoff from the streets and adjacent
development areas.
Oil Consolidation Sites: Since on -site oil operations are expected to continue, the Project will
include a phased abandonment and consolidation of facilities to specific areas of the site to
continue operations after development. Well abandonment and remediation processes will be
conducted in accordance with all relevant Federal, State, and local laws and regulations.
NEWPORT BANNING RANCH, LLC 3 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
DESCRIPTION OF PROPOSED PROJECT
I . New development projects that create 10,000 square feet or more of
WQMP
impervious surface. This category includes commercial, industrial,
Development
residential housing subdivisions, mixed -use, and public projects on private
Category:
or public property that falls under the planning and building authority or the
Permittees.
401 .1 gross acres
Project Area:
235.8 acres open space / 165.3 acres of development including 51.4 acres of
public parks /recreation
# of Dwelling
1,375
Units:
SIC Code:
Pending —to be provided in Final WQMP.
Narrative Project
See above.
Description:
An appropriate number of trash enclosures will be located within the higher -
density development areas of the project site (e.g., apartments). Specific
number and locations of the trash enclosures will be documented in the Final
WQMP. Trash enclosures will be covered and walled on 3 sides to preclude
rainfall and runoff (gate comprising the fourth side). Any restaurants /food
preparation areas included as part of the Visitor Serving Resort land uses will be
handled indoors, and the eating area tables will be covered with a canopy and
Project Features
designed to preclude precipitation and runoff. Grease interceptors will be
located in the sanitary sewer systems where applicable.
No loading docks, outdoor material storage areas, wash areas or fueling areas
are proposed as part of the project. In the event site features are added to the
proposed Project that are not identified in this WQMP, these features will be
designed in accordance with the Orange County Drainage Area Management
Plan (OC DAMP) Model WQMP requirements and City LIP and verified during
the precise grade plan check review process.
Project Area:
Pervious Area
Pervious Area
Impervious Area
Impervious Area
(ac or ft)
Percentage
(ac or ft)
Percentage
Pre - Project
Conditions':
355 ac
77%
46 ac
1 1 %
Post- Project
301 ac
75%
100 ac
/o
25%
' Approximately 185 acres of the 401 acre site are currently used for oil field operations including oil wells, infrastructure,
trailers, compacted dirt roads, storage facilities and paved parking areas. A conservative 25% impervious amount has been
assumed.
NEWPORT BANNING RANCH, LLC 4 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
DESCRIPTION OF PROPOSED PROJECT
In general, the Project's natural drainage flows from the higher elevations in the
east toward lower elevations to the west. Off -site drainage from the existing
Pollutant
urban areas of the cities of Costa Mesa and Newport Beach enter the project
site through storm drain culverts at the upstream ends of the Arroyos. Within
the project boundary, the Northern and Southern Arroyos and Semeniuk Slough
convey runoff towards the Salt Marsh Basin and Lowland Area. There are no
c
major existing storm drain facilities within the project boundary. In the
Drainage
southern -most portion of the site, an existing Caltrans -owned underground
Patterns/
reinforced concrete box (RCB) storm drain along West Coast Highway (WCH)
Connections:
also collects runoff from the site, discharging to the Semeniuk Slough channel.
0
There are several tidal gates and control pipes that regulate tidal flows between
0 a
C N
O
the Santa Ana River and the Semeniuk Slough and Lowland Area of the project
m
Olt �A
a
site. The default position of the gates is open to allow tidal flows to circulate
s C
through the Marsh basin. The water surface elevation of the Santa Ana River
a- O E
controls the gates and determines whether local storm water runoff can be
N O
discharged into the river. Refer to Section 11.4 for a description of the proposed
a
.N
drainage facilities.
11.2 POTENTIAL STORM WATER POLLUTANTS
The table below, derived from Table 2 of the Countywide Model WQMP Technical Guidance
Document (May 2011), summarizes the categories of land use or project features of concern and the
general pollutant categories associated with them.
ANTICIPATED & POTENTIAL POLLUTANTS GENERATED BY LAND USE TYPE Ir
General
Pollutant
Categories
0 4
c
a
Priority Project Categories
and /or Project Features
C v Q)
0
o o
0 a
C N
O
-a
m
Olt �A
a
V C r
x o
s C
a- O E
i
N O
O
0 `u
a
.N
O d
o
F m Q.
-0
Oi 0
N
U
Detached Residential
E
E
N
E
E
E
N
E
Development
Attached Residential
Development
E
E
N
E
E
E(2)
N
E
Commercial /Industrial
Er)
Ei'i
Ei5i
Ei'i
E(')
E
E
E
Development
Restaurants
E0 )(2
Ei'i
E(2)
E
E(')
E
N
E
Parking Lots
E
E(1)
E
E(")
E (1)
E
E
E
Streets, Highways, &
E
E °)
E
E(")
E0)
E
E
E
Freewa s
NEWPORT BANNING RANCH, LLC 5 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
ANTICIPATED &POTENTIAL POLLUTANTS GENERATED BY LAND USE TYPE
General Pollutant Categories
Priority Project Categories t c y
and /or Project Features c a a) c G'r v df N E 0
rn m a ;? a L O o o
t
L o 01 a
at
V1 ) o> O o Z Ma
U
Notes:
E = expected to be of concern N = not expected to be of concern
(1) Expected pollutant if landscaping exists on -site, otherwise not expected.
(2) Expected pollutant if the project includes uncovered parking areas, otherwise not expected.
(3) Expected pollutant if land use involves food or animal waste products, otherwise not expected.
(4) Bacterial indicators are routinely detected in pavement runoff.
(5) Expected if outdoor storage or metal roofs, otherwise not expected.
Source: County of Orange. (2011, May 19). Technical Guidance Document for the Preparation of Conceptual/ Preliminary and /or
Project Water Quality Management Plans (WQMPs). Table 2.1.
POLLUTANTS OF CONCERN
E = Expected to be of
Pollutant
concern
N =Not Expected to
Additional Information and Comments
be of concern
Suspended Solid/
E
Sediment
Nutrients
E
Heavy Metals
E
Pathogens
E
303(d) Impairment (Newport Slough)
Bacteria/Virus
Pesticides
E
Oil & Grease
E
Toxic Organic
E
Compounds
Trash & Debris
E
11.3 HYDROLOGIC CONDITIONS OF CONCERN
The purpose of this section is to identify any hydrologic conditions of concern (HCOC) with respect to
downstream flooding, erosion potential of natural channels downstream, impacts of increased flows
on natural habitat, etc. As specified in Section 2.3.3 of the 2011 Model WQMP, projects must
identify and mitigate any HCOCs. A HCOC is a combination of upland hydrologic conditions and
stream biological and physical conditions that presents a condition of concern for physical and /or
biological degradation of streams or natural drainage channels.
NEWPORT BANNING RANCH, LLC 6 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
In the North Orange County permit area, HCOCs are considered to exist if any streams located
downstream from the project are determined to be potentially susceptible to hydromodification
impacts and either of the following conditions exists:
• Post - development runoff volume for the 2 -yr, 24 -hr storm exceeds the pre - development runoff
volume for the 2 -yr, 24 -hr storm by more than 5 percent
or
• Time of concentration (Tc) of post - development runoff for the 2 -yr, 24 -hr storm event exceeds
the time of concentration of the pre - development condition for the 2 -yr, 24 -hr storm event by
more than 5 percent.
If these conditions do not exist or streams are not potentially susceptible to hydromodification impacts,
an HCOC does not exist and hydromodification does not need to be considered further. In the North
Orange County permit area, downstream channels are considered not susceptible to
hydromodification, and therefore do not have the potential for a HCOC, if all downstream
conveyance channels that will receive runoff from the project are engineered, hardened, and regularly
maintained to ensure design flow capacity, or drain into ❑ tidally influenced water body and no
sensitive habitat areas will be affected.
Is the proposed project potentially susceptible to hydromodification impacts?
❑ Yes ® No (show map)
As part of the 2011 Model WQMP, channels susceptible to hydromodification were analyzed for each
watershed. Figure XVI -3c of the Technical Guidance Document (May 2011) demonstrates that the
project location does not fall within an area susceptible to hydromodification. This is primarily due to
the fact the project drains into tidally influenced receiving water bodies which are less susceptible to
hydromodification impacts. In addition, a majority of the project site drains into the lowlands area of
the site which is a flat low -lying area that allows storm flows to disperse into a series of sump
conditions which is less susceptible to channel scour and erosion.
For the portion of the project site that drains into a more defined natural channel (Southern Arroyo
and Semeniuk Slough), additional calculations were performed. In order to demonstrate the changes
in runoff as a result of the proposed project, a variety of analyses were calculated including net
volume, peak flow and Time of Concentration (Tc) for the 2 -year, 24 -hour storm event for existing
and proposed conditions for areas tributary to the Semeniuk Slough (including contributions from the
Caltrans box culvert drainage area). The following table originates from the Newport Banning Ranch
Watershed Assessment Report dated June 30, 2011 (Table 4.3, DEIR Appendix C).
NEWPORT BANNING RANCH, LLC 7 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SEMENIUK SLOUGH
PROPOSED CONDITION RUNOFF VOLUME EV EVENTS
Sub - Watershed
Drainage Area
2 -Year Volume
100 -Year Volume
(acres)
(ac -ft)
(ac -ft)
"A"
322.0
18.3
81.2
"F"
5.8
0.5
1.6
'G'
1.8
0.2
0.5
'H'
7
0.6
1.9
11"
1.1
0.1
0.3
"J"
11
0.9
3.0
'K'
6.3
0.5
1.7
Salt Marsh Basin
54
6.5
20.2
Total
409.0 ( -27.6)
27.6(+1.0)
110.4 ( -4.0)
PROPOSED
CONDITION
PEAK FLOW RATE (EV EVENTS)
Drainage Area
2 -Year Peak Flow
100 -Year Peak Flow
Location
acres
cfs / Tc b
cfs
Node 19
145.8 ( -9.3)
72.7 ( -8.1) / 19.54
302.2 ( -21.2)
u stream
+0.03
Node 23
322.0 ( -27.6)
128.1 ( +6.8) / 37.51
513.9 ( +12.7)
downstream
+0.06
Note: Numbers in parentheses represent change as compared to existing condition,
cfs cubic feet per second
a For the Salt Marsh area, the runoff volume is estimated by the following: Precipitation (in) x Area (ac) / 12
b Tc = Time of Concentration noted for 2-year event per Section XII.D of fourth -term MS4 Storm Water Permit
Based on the analysis, the results demonstrate the 2 -year will increase 1.0 cf between existing and
proposed which is less than 5% change from the existing condition (3.7%). In addition, Time of
Concentrations (Tc) will also remain within 5% of existing conditions. Therefore, the Project does not
have a hydrologic condition of concern for flows directed to the Semeniuk Slough.
Lastly, to further protect existing drainage channels, both the Southern Arroyo and Northern Arroyo
drainage courses were analyzed to determine existing flow rates, channel hydraulics and tributary
drainage areas. Through grading and storm drain design objectives, these existing conditions were
maintained under the proposed condition to reduce the potential for long -term channel degradation
within the Southern and Northern Arroyo. See Newport Banning Ranch Watershed Assessment Report
dated June 30, 2011 (Section 3.3, DEIR Appendix C).
11.4 POST DEVELOPMENT CHARACTERISTICS
The proposed condition contains six primary on -site storm drain systems that will drain Project flows to
downstream receiving water bodies. They are described below as follows:
NEWPORT BANNING RANCH, LLC B PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
• Storm Drain A (Drainage Area "A"): Discharges to the existing Caltrans box culvert under the
West Coast Highway (WCH). Storm Drain A (SD -A)is designed to reduce the tributary drainage
area of this storm drain system as compared to the existing condition to account for the increase
in Project runoff in the proposed condition.
• Storm Drains B and C (Drainage Area "A "): Collect flows from the development areas adjacent
to the Southern Arroyo and delivers these flows to a diffuser basin located downstream of the
Arroyo adjacent to the Semeniuk Slough. The design of Storm Drains B and C (SD -B, SD -C)
serves three primary functions: 1) to minimize the discharge of storm water flows directly to the
Arroyo channel to protect the long -term channel stability, 2) dissipate erosive energy before flows
enter the Semeniuk Slough, and 3) control sediment contributions to the Semeniuk Slough.
• Storm Drains D and E (Drainage Area "C "): Collect flows from the larger development areas of
the Project and delivers storm flows to the Lowland Area. Under the existing conditions, a portion
of drainage from Storm Drain D (SD -D) is tributary to the Southern Arroyo and Semeniuk Slough.
The proposed drainage re- direction is specifically designed to maximize the amount of flow to be
directed towards the Lowland Area in order to reduce the flood loading of the Semeniuk Slough.
A second diffuser basin will be installed downstream of Storm Drains D and Storm Drain E (SD -E)
to reduce the momentum of the flows from the pipes and to spread the distribution of runoff to the
Lowland in a manner that will enable future habitat restoration efforts.
• Storm Drain F (Drainage Area "B "): Collects flows from the northernmost development area. The
tributary drainage area has been designed to match existing runoff conditions to the Northern
Arroyo. An energy dissipater will be installed at the outlet to Storm Drain F (SD -F) to transition
flows from erosive velocities to mild velocities, and to deliver non - erosive flows to the natural
channel.
• Storm Drain G (Drainage Area "D "): Collects flows from the northerly most portion of the
northern development area. Flow in Storm Drain G (SD -G) is delivered to the Lowland Area via a
culvert and a storm drain located in the new Bluff Road roadway extension to 19" Street.
11.5 PROPERTY OWNERSHIP /MANAGEMENT
PROPERTY OWNERSHIP /MANAGEMENT
Public Streets:
City of Newport Beach
Private Streets:
HOA
Landscaped Areas:
Public Areas: City of Newport Beach
Private Areas: HOA / Individual Homeowner / Resort Operator
Open Space:
Conservation Entity / HOA
Easements:
Orange County Sanitation District , Standard Oil & Gas Co. Oil Easements,
City of Newport Beach, State of California (per TTM 1 7308)
Parks:
Public Parks: City of Newport Beach
Private Parks: HOA
Buildings:
HOA / Individual Homeowners/ Resort Operator
Oil Consolidation
Elo�
Sites
NEWPORT BANNING RANCH, LLC 9 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
PROPERTY OWNERSHIP /MANAGEMENT
Structural BMPs:
Public Areas: City of Newport Beach
Private Areas: HOA
A Home Owners Association (HOA) will be formed upon project completion. The HOA will be
responsible for inspecting and maintaining all BMPs prescribed for Newport Banning Ranch. Until a
HOA is formally established, Newport Banning Ranch, LLC shall assume all BMP maintenance and
inspection responsibilities for the proposed project. Inspection and maintenance responsibilities are
outlined in Section V of this report.
The City of Newport Beach shall assume all BMP maintenance and inspection responsibilities for the
public streets and public park areas of the proposed project.
Inspection and maintenance responsibilities for structural BMPs are outlined in Section V of this report.
NEWPORT BANNING RANCH, LLC 10 PROJECT DE5CRIPTION
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
SECTION III SITE DESCRIPTION
111.1 PHYSICAL SETTING
FEBRUARY 3, 2012
Planning Area/
Newport Banning Ranch
Community Name
Within the project boundary, there are several primary landforms of
North of West Coast Highway (WCH), south of 19t1' Street, east of the
Santa Ana River channel, and west of the cities of Newport Beach and
Location /Address:
Costa Mesa.
5200 West Coast Highway, Newport Beach CA 92663
The Newport Banning Ranch Project site encompasses approximately
Topography:
401 .1 acres. Approximately 40 acres of the Project site are located
within the incorporated boundary of the City of Newport Beach; the
Project Area Description
remainder of the Project site is located within unincorporated Orange
County, in the City's adopted Sphere of Influence. The entire Project
site is within the boundary of the Coastal Zone, as established by the
California Coastal Act.
Current: Oil Extraction
Land Use:
Proposed: Residential, Park, Oil Extraction /Open Space, Commercial,
Coastal Inn
Zoning:
Per the Newport Banning Ranch Planned Community
Acreage:
401 .1 gross ac
C (northern portions primarily within Lowlands)
Predominant Soil Type:
D (entire mesa area)
A southern portion)
111.2 SITE CHARACTERISTICS
Precipitation Zone:
0.7 inch Design Capture Storm
Within the project boundary, there are several primary landforms of
concern that are referenced throughout this report:
• Lowland Area: Located in the northeasterly portion of the
property, and currently consists of degraded wetland and ruderal
vegetation, as well as roads, pipelines, and other facilities
associated with oil operations. The Lowland Area also consists of
Topography:
several narrow channels and shallow depressions.
Upland Mesa: Located in the eastern portion of the properly, and
currently consists of existing pipelines, roads, buildings, and other
equipment related to oil extraction activities.
• Bluffs: Located adjacent to the Lowland Area and include west
and southwest facing slopes of varying steepness.
NEWPORT BANNING RANCH, LLC 11 SITE DE5CRIPTION
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
2 GMU Geotechnical, Inc. Report of Geotechnical Studies. Proposed Newport Banning Ranch Development, City of
Newport Beach /County of Orange. Draft March 2008.
NEWPORT BANNING RANCH, LLC 12 SITE DE5CRIPTION
• Arroyos: There are several existing drainage courses (generally
referred to as "Arroyos') that fall gradually from the eastern project
boundary across the Mesa and Bluffs towards the Semeniuk
Slough in the western portion of the site. The two largest Arroyos,
designated as the Northern and Southern Arroyos, are considered
significant drainage features and convey runoff from upstream
areas (primarily off -site contributions) through the project site.
Semeniuk Slough (Oxbow Loop): Consists of a meandering
drainage course that flanks the southern portion of the site. The
Semeniuk Slough, also known as Oxbow Loop or Newport Slough,
receives runoff from both on -site and off -site areas, and drains
generally west and north towards the Lowland Area. However, a
small dike separates the Lowland Area from the Semeniuk Slough
channel, and there are several culverts that allow for tidal
exchange between the areas.
Drainage
Proposed drainage conditions are discussed in Section 11.4 of this
Patterns /Connections:
report.
Within the vicinity of the project site, three general soil units are
present: San Pedro Formation bedrock, marine terrace deposits, and
river alluvium. The San Pedro Formation bedrock generally consists of
gray and dark gray to reddish yellow- stained siltstone and clayey
siltstone, with sandstone interbeds. The marine terrace deposits
Soil Type, Geology, and
generally consist of rounded cobbles, shells, and angular rocks similar
Infiltration Properties:
to materials found in tidal zones. Both the bedrock and marine terrace
deposits occur beneath the Mesa and elevated portions of the project
site. Soils within the Lowland Area of the site are primarily alluvium,
which consist of relatively young sediments of grovel, sand, and clay
deposits. In addition, artificial fill is located throughout the site, mainly
associated with the construction of the on -site oil facilities .2
Within the vicinity of the project site, groundwater elevation is
generally at mean sea level within the Lowland and Upland areas, and
Hydrogeologic
perched groundwater above mean sea level may existing sporadically
(Groundwater)
within the Upland. Within the Lowlands, groundwater is roughly 5 -10
Conditions:
feet below existing grade. Throughout portions of the site,
groundwater may become perched due to presence of clay layers
and /or bedrock.
Infiltration on the project site may be limited or infeasible in certain
regions due to geotechnical concerns and presence of shallow
groundwater. Within the upper Mesa, soils generally consist of sandy
Geotechnical Conditions
marine deposits under lain by bedrock (San Pedro formation) and
(relevant to infiltration):
overlain by silty to sandy clays. Given the above soil stratigraphy,
shallow infiltration would be precluded due to low infiltration of the
upper soil zone and future engineered fills. Deep infiltration into the
bedrock is likewise also not feasible. Infiltration below the upper fine
2 GMU Geotechnical, Inc. Report of Geotechnical Studies. Proposed Newport Banning Ranch Development, City of
Newport Beach /County of Orange. Draft March 2008.
NEWPORT BANNING RANCH, LLC 12 SITE DE5CRIPTION
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
111.3 WATERSHED DESCRIPTION
Receiving Waters:
grained zone into the Marine Terrace deposits is feasible from an
303(d) Listed
infiltration perspective. However, seepage into this zone would
Impairments:
"perch" on top of the bedrock and flow towards the bluff face (see
Applicable TMDLs:
Exhibit A in Appendix F of this P -WQMP) causing local slope
instability. The local bluff stability would also lead to increased rates
Pollutants of Concern for
of erosion potentially damaging proposed improvements.
the Project:
Within the Lowlands, soils generally consist of alluvial deposits (Group
A soils) with areas containing lenses of finer grained sandy silts to silty
clay (Group B to D soils). However, the groundwater table is largely
within a few feet of the existing topographic grade. In these locations,
infiltration of runoff in these soils may be limited.
Off -site drainage from the existing urban areas of the cities of Costa
Off -Site Drainage:
Mesa and Newport Beach enter the project site through storm drain
and Special Biological
Significant Areas:
culverts at the upstream ends of the Arroyos.
There are existing utility easements along portions of the project site
for the City of Newport Beach and Orange County Sanitation District.
Existing easements are outlined on TTM 17308, a copy of which is
included in Section VI.
Utility and Infrastructure
Information:
The Project proposes approximately 16.5 gross acres of the open
space area as Interim Oil Facilities. As a part of the proposed Project,
the Applicant would abandon and remediate the existing surface oil
operations within the Project site to consolidate the oil facilities into
approximately 16.5 gross acres.
111.3 WATERSHED DESCRIPTION
Receiving Waters:
Semeniuk Slough (also known as Oxbow Loop or Newport Slough)
303(d) Listed
Newport Slough: Enterococcus, Fecal Coliform, Total Coliform (2010)
Impairments:
Applicable TMDLs:
None
Suspended Solid/ Sediment Pesticides
Pollutants of Concern for
Nutrients Oil & Grease
the Project:
Heavy Metals Toxic Organic Compounds
Pathogens Bacteria/Virus Trash & Debris
Portions of the project site drain to Semeniuk Slough (aka. Newport
Slough), which is listed as impaired for bacteria indicators on the
CWA Section 303(d) list, and therefore is considered and ESA.
The entire project site is within the Coastal Zone as defined by the
Environmentally Sensitive
Coastal Act.
and Special Biological
Significant Areas:
Approximately 53.76 acres of USACE jurisdictional areas occur on
site, of which 53.15 acres consist of jurisdictional wetlands. The
Project's Master Development Plan designates a minimum of 220
gross acres of the Project site as wetland restoration /water quality
areas, habitat restoration areas, and habitat preservation areas.
NEWPORT BANNING RANCH, LLC 13 SITE DE5CRIPTION
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION IV BEST MANAGEMENT PRACTICES (BMPs)
IV.1 PROJECT PERFORMANCE CRITERIA
Is there an approved WIHMP or equivalent for the project area that includes more stringent LID
feasibility criteria or if there are opportunities identified for implementing LID on regional or sub -
regional basis?
❑ Yes ❑ No
PROJECT PERFORMANCE CRITERIA
Hydromodification
Control Performance
The volumes and time of concentration of storm water runoff for the
Criteria
post - development condition do not significantly exceed those of the
predevelopment condition for a two -year frequency storm event (a
(Model WQMP Section
difference of five percent or less is considered insignificant).
7.11- 2.4.2.2)
LID Performance
Infiltrate, harvest and use, evapotranspire, or biotreat /biofilter, the 85"
Criteria
percentile, 24 -hour storm event (Design Capture Volume).
LID BMPs must be designed to retain, on -site, (infiltrate, harvest and
(Model WQMP Section
use, or evapotranspire) storm water runoff up to 80 percent average
7.11- 2.4.3)
annual capture efficiency
Treatment Control
If it is not feasible to meet LID performance criteria through retention
BMP Performance
and /or biotreatment provided on -site or at a sub - regional /regional
Criteria
scale, then treatment control BMPs shall be provided on -site or offsite
prior to discharge to waters of the US. Sizing of treatment control BMP(s)
(Model WQMP Section
shall be based on either the unmet volume after claiming applicable
7.11- 3.2.2)
water quality credits, if appropriate.
Total development area 149.42 ac (excludes off -site tributary, oil
LID Design Storm
consolidation site & open space areas)
Capture Volume
---64% impervious
DCV = 240,992 ft3 (5.53 ac -ft)
IV.2 SITE DESIGN AND DRAINAGE PLAN
The following section describes the site design BMPs used in this project and the methods used to
incorporate them. Careful consideration of site design is a critical first step in storm water pollution
prevention from new developments and redevelopments.
IV.2.1 Site Design BMPs
Minimize Impervious Area
Dry weather flows and low flows from the project development areas will be routed through low
impact development (LID) BMPs with vegetation and /or infiltration characteristics in accordance with
the Model WQMP criteria.
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
Maximize Natural Infiltration Capacity
Although infiltration will be limited in the Upland Mesa development areas, there are opportunities for
dispersion and infiltration of storm water runoff in the Lowlands portion of the project site. Consistent
with existing drainage patterns, the majority of the project drainage will be directed towards the
Lowlands which has the highest infiltration potential within the project boundary.
Preserve Existing Drainage Patterns and Time of Concentration
Under the existing conditions, storm flows drain to either the Semeniuk Slough or the Lowlands before
ultimately discharging into the Santa Ana River. Under the proposed conditions, storm water runoff
will continue to drain into the Slough and Lowlands. Existing drainage patterns will be maintained
and Time of Concentrations will be preserved to the existing drainage channels and receiving waters.
In order to maintain existing runoff volumes to the Slough and maintain existing flood protection, a
portion of drainage will be diverted to the Lowlands which has capacity to accept the additional
drainage.
Disconnect Impervious Areas
Impervious surfaces have been minimized by incorporating landscaped areas over substantial portions
of the site including common areas, parkways, medians, in addition to larger parks and open space
areas. The streets and sidewalks will be designed with minimum width requirements to minimize
impervious surfaces where feasible.
Protect Existing Vegetation and Sensitive Areas, and Revegetate Disturbed Areas
Approximately 235.8 acres will be retained as open space. Native trees and shrubs will be preserved
in natural open space areas and native or drought tolerant plants will be used in development plant
palettes.
IV.2.2 Drainage Management Areas
In accordance with the MS4 permit and the new Model WQMP, the Design Capture Volumes (DCVs)
presented in the following table represent the minimum volume of storm water runoff required to be
treated by LID and /or treatment control BMPs for the proposed project. The total DCV noted in the
table represents the treatment requirement for all of the development areas. Preliminary footprints
and depths required by each BMP are summarized in the following sections. Detailed calculations are
provided in Appendix A. Final design and calculations will be identified and documented during
project Final WQMP development.
DEVELOPMENT DRAINAGE MANAGEMENT AREAS
Drainage
o
ro
Runoff
Design
Drainage
DCV
Area ID
Land Use Type
impervious
Coefficient
Storm
Area
BMP Type
(ft)
Depth in
ac
WCH Tributary - Storm Drain A
A19.4
Community Pork
15%
0.26
0.7
3.90
2,616
Bioretention
A19.2
Community Park
15%
0.26
0.7
6.81
4,568
Bioretention
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
DEVELOPMENT DRAINAGE MANAGEMENT AREAS
Drainage
Area ID
Land Use Type
°
/°
impervious
Runoff
Coefficient
Design
Storm
Depth in
Drainage
Area
(ac)
DCV
(fT )
BMP Type
A7.3
Community Park
15%
0.26
0.7
4.18
2,804
Bioretention
South Arroyo Tributary - Southerly Drainage
Areas (Storm Drain B)' c
TOTAL
68.24%
0.66
1 0.7
33.47
56,412
Bioretention
South Arroyo Tributary - Northerly Drainage
Areas (Storm Drain C)
TOTAL
65.39%
0.64
0.7
22.94
37,417
Bioretention
Lowlands Tributary - West of "B" Street (Storm
Drain D)
TOTAL'
66.28%
0.65
0.7
55.43
91,356
Bioretention
Lowlands Tributary - East of "B" Street (Storm
Drain E)
C12.2
Mixed Use/
Residential
80%
0.75
0.7
5.11
9,758
Bioretention
Lowlands Tributary - Storm Drain F
B11.1
Mixed Use/
Residential
80%
0.75
0.7
4.57
8,727
Bioretention
Arterial Streets w/ Landscaped Biocells (stand
alone - not included in drainage areas above)
Al 9.1
Arterial Road
90%
0.83
0.7
1.09
2,289
LS Biocell
A19.3
Arterial Road
90%
0.83
0.7
1.58
3,318
LS Biocell
Al 9.5
Arterial Road
90%
0.83
0.7
2.93
6,153
LS Biocell
Al 9.7
Arterial Road
90%
0.83
0.7
2.52
5,292
LS Biocell
A7.5
Arterial Road
90%
0.83
0.7
1.9
3,990
LS Biocell
B11.3
Arterial Road
1 90%
1 0.83
1 0.7
2.21
4,641
LS Biocell
D3.2
Arterial Road
90%
0.83
0.7
2.72
5,712
LS Biocell
Water Quality Detention Basin for Off -Site Runoff
TOTAL
86.67%
0.80
0.7
47.81
97,370
Detention
Basin
Total
Development
Area ai
64.43%
0.63
0.7
149.4
240,992
Notes:
1. Includes 1.94 acres of upstream, off -site tributary area.
2. Excludes tributary from off-site drainage areas in Storm Drain D, open space areas, and oil consolidation sites.
IV.3 LID BMP SELECTION AND PROJECT CONFORMANCE ANALYSIS
Low Impact Development (LID) BMPs are required in addition to site design measures and source
controls to reduce pollutants in storm water discharges. LID BMPs are engineered facilities that are
designed to retain or biotreat runoff on the project site. The 4' Term MS4 Storm Water Permit (Order
R9- 2009 -0009) requires the evaluation and use of LID features using the following hierarchy of
NEWPORT BANNING RANCH, LLC 16 BEST MANAGEMENT PRACTICES
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
treatment: infiltration, evapotranspiration, harvest /reuse, and biotreatment. The following sections
summarize the LID BMPs proposed for the project in accordance with the permit hierarchy and
performance criteria outlined in Section IV.I .
IV.3.1 Hydrologic Source Controls (HSCs)
Hydrologic source controls (HSCs) can be considered to be a hybrid between site design practices and
LID BMPs. HSCs are distinguished from site design BMPs in that they do not reduce the tributary area
or reduce the imperviousness of a drainage area; rather they reduce the runoff volume that would
result from a drainage area with a given imperviousness compared to what would result if HSCs were
not used.
HSC's will be accounted for during final design and the cumulative volume of the HSC's will be
subtracted from the required treatment volume in the Final WQMP.
IV.3.2 Infiltration BMPs
Infiltration BMPs are LID BMPs that capture, store and infiltrate storm water runoff. These BMPs are
engineered to store a specified volume of water and have no design surface discharge (underdrain or
outlet structure) until this volume is exceeded. Examples of infiltration BMPs include infiltration
trenches, bioretention without underdroins, drywells, permeable pavement, and underground
infiltration galleries.
INFILTRATION
ID Name Included?
INF -3 Bioretention Without Underdrains ❑
INF -4 Rain Gardens ❑
NEWPORT BANNING RANCH, LLC 17 BEST MANAGEMENT PRACTICES
HYDROLOGIC SOURCE CONTROLS Fm
ID
Name
Included?
HSC -1
Localized on -lot infiltration
❑
HSC -2
Impervious area dispersion (e.g. roof top disconnection)
❑
HSC -3
Street trees (canopy interception)
❑
HSC -4
Residential rain barrels (not actively managed)
❑
HSC -5
Green roofs /Brown roofs
❑
HSC -6
Blue roofs
❑
HSC -7
Impervious area reduction (e.g. permeable pavers, site design)
❑
HSC's will be accounted for during final design and the cumulative volume of the HSC's will be
subtracted from the required treatment volume in the Final WQMP.
IV.3.2 Infiltration BMPs
Infiltration BMPs are LID BMPs that capture, store and infiltrate storm water runoff. These BMPs are
engineered to store a specified volume of water and have no design surface discharge (underdrain or
outlet structure) until this volume is exceeded. Examples of infiltration BMPs include infiltration
trenches, bioretention without underdroins, drywells, permeable pavement, and underground
infiltration galleries.
INFILTRATION
ID Name Included?
INF -3 Bioretention Without Underdrains ❑
INF -4 Rain Gardens ❑
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As discussed under Section 111.2, infiltration within the Mesa development areas will be limited due to
the presence of bedrock may cause perched groundwater to flow towards the bluff face and cause
local slope instability. Although infiltration in portions of the Lowlands may be feasible, the areas may
be limited due to presence of high groundwater and localized areas with clay soils. As a result,
infiltration of the entire project design capture volume is considered infeasible.
Although the general or broad use of infiltration has been determined infeasible as an LID approach
for the Newport Banning Ranch project at the CEQA level, there may prove to be limited opportunities
to implement infiltration on a more local or micro scale as a hydrologic source control. The use of
infiltration in this regard will be determined during later stages in the project's design, and subsequent
infiltration studies will be provided in Appendix F of the Final WQMP.
IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs
Evapotranspiration BMPs are a class of retention BMPs that discharges stored volume predominately
to ET, though some infiltration may occur. ET includes both evaporation and transpiration, and ET
BMPs may incorporate one or more of these processes. BMPs must be designed to achieve the
maximum feasible ET, where required to demonstrate that the maximum amount of water has been
retained on -site. Since ET is not the sole process in these BMPs, specific design and sizing criteria
have not been developed for ET -based BMPs.
NEWPORT BANNING RANCH, LLC 18 BEST MANAGEMENT PRACTICES
INFILTRATION
ID
Name
Included?
Porous Landscaping
❑
Infiltration Planters
❑
Retention Swales
❑
INF -2
Infiltration Trenches
❑
INF -1
Infiltration Basins
❑
INF -5
Drywells
❑
INF -7
Subsurface Infiltration Galleries
❑
French Drains
❑
Permeable Asphalt
❑
INF -6
Permeable Concrete
❑
Permeable Concrete Pavers
❑
Other:
❑
As discussed under Section 111.2, infiltration within the Mesa development areas will be limited due to
the presence of bedrock may cause perched groundwater to flow towards the bluff face and cause
local slope instability. Although infiltration in portions of the Lowlands may be feasible, the areas may
be limited due to presence of high groundwater and localized areas with clay soils. As a result,
infiltration of the entire project design capture volume is considered infeasible.
Although the general or broad use of infiltration has been determined infeasible as an LID approach
for the Newport Banning Ranch project at the CEQA level, there may prove to be limited opportunities
to implement infiltration on a more local or micro scale as a hydrologic source control. The use of
infiltration in this regard will be determined during later stages in the project's design, and subsequent
infiltration studies will be provided in Appendix F of the Final WQMP.
IV.3.3 Evapotranspiration, Rainwater Harvesting BMPs
Evapotranspiration BMPs are a class of retention BMPs that discharges stored volume predominately
to ET, though some infiltration may occur. ET includes both evaporation and transpiration, and ET
BMPs may incorporate one or more of these processes. BMPs must be designed to achieve the
maximum feasible ET, where required to demonstrate that the maximum amount of water has been
retained on -site. Since ET is not the sole process in these BMPs, specific design and sizing criteria
have not been developed for ET -based BMPs.
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Bioretention BMPs are proposed which utilize evapotranspiration as physical process for runoff volume
reduction. Bioretention BMPs are described further in Section IV.3.4.
Harvest and use (aka. Rainwater Harvesting) BMPs are LID BMPs that capture and store storm water
runoff for later use. These BMPs are engineered to store a specified volume of water and have no
design surface discharge until this volume is exceeded. Harvest and use BMPs include both above-
ground and below - ground cisterns. Examples of uses for harvested water include irrigation, toilet and
urinal flushing, vehicle washing, evaporative cooling, industrial processes and other non - potable uses.
EVAPOTRANSPIRATION
ID
Name
Included?
HU -1
HSCs, see Section IV.3.1
❑
HU -2
Surface -based infiltration BMPs
❑
--
Biotreatment BMPs, see Section V1.3.4
❑
Other:
❑
Bioretention BMPs are proposed which utilize evapotranspiration as physical process for runoff volume
reduction. Bioretention BMPs are described further in Section IV.3.4.
Harvest and use (aka. Rainwater Harvesting) BMPs are LID BMPs that capture and store storm water
runoff for later use. These BMPs are engineered to store a specified volume of water and have no
design surface discharge until this volume is exceeded. Harvest and use BMPs include both above-
ground and below - ground cisterns. Examples of uses for harvested water include irrigation, toilet and
urinal flushing, vehicle washing, evaporative cooling, industrial processes and other non - potable uses.
In order to evaluate the feasibility of harvest and use, the Technical Guidance Document (TGD),
dated May 19, 2011 provides a two -step process to determine feasibility and applicability to the
proposed project. Step 1 is the initial screening and is found within Appendix X of the TGD, and Steps
2 and 3 are more detailed assessments, either of which may be used and are found within the BMP
Fact Sheets (XIVA Harvest and Use — HU).
Step 1: Determine if the Project Meets the Minimum Harvested Water Demand Threshold
In order to quantify harvested water demand, the Modified Estimated Applied Water Use (EAWU)
method was used, consistent with Appendix X of the Model WQMP's Technical Guidance Document
(TGD), dated May 19, 2011. The Modified EAWU method is modified from the OC Irrigation Code
(County Ordinance No. 09 -010) to account for the wet season demand and storm events (assuming
that no irrigation would be applied for approximately 30% of the days in the wet season).
The equation used to calculate the Modified EAWU is:
NEWPORT BANNING RANCH, LLC 19 BEST MANAGEMENT PRACTICES
HARVEST & REUSE / RAINWATER HARVESTING
ID
Name
Included?
HU -1
Above - ground cisterns and basins
❑
HU -2
Underground detention
❑
--
Other:
❑
In order to evaluate the feasibility of harvest and use, the Technical Guidance Document (TGD),
dated May 19, 2011 provides a two -step process to determine feasibility and applicability to the
proposed project. Step 1 is the initial screening and is found within Appendix X of the TGD, and Steps
2 and 3 are more detailed assessments, either of which may be used and are found within the BMP
Fact Sheets (XIVA Harvest and Use — HU).
Step 1: Determine if the Project Meets the Minimum Harvested Water Demand Threshold
In order to quantify harvested water demand, the Modified Estimated Applied Water Use (EAWU)
method was used, consistent with Appendix X of the Model WQMP's Technical Guidance Document
(TGD), dated May 19, 2011. The Modified EAWU method is modified from the OC Irrigation Code
(County Ordinance No. 09 -010) to account for the wet season demand and storm events (assuming
that no irrigation would be applied for approximately 30% of the days in the wet season).
The equation used to calculate the Modified EAWU is:
NEWPORT BANNING RANCH, LLC 19 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
Modified EAWU =
(ET o .t x KL x LA x 0.015)
/E
FEBRUARY 3, 2012
Where:
MOdlsedEAWU= estimated daily average water use during wet season
ETo,et= average reference ET from November through April (inches per month) per Table X.2 of
the TGD
KL = landscape coefficient (Table X.4 of the TGD)
LA = landscape area irrigated with harvested water (square feet)
!E= irrigation efficiency (assumed at 90 %)
Note: In the equation, the coefficient (0.015) accounts for unit conversions and shutdown of irrigation
during and for three days following a significant precipitation event.
For a system to be considered "feasible ", the system must be designed with a storage volume equal to
the DCV from the tributary area and achieve more than 40% capture. The system must also be able
to drawdown in 30 days to meet the 40% capture value. In addition, Table X.6 of the Technical
Guidance Document sets forth the demand thresholds for minimum partial capture.
TABLE X.6: HARVESTED WATER DEMAND THRESHOLDS FOR
MINIMUM PARTIAL CAPTURE
Design Capture Storm
Depth, inches
Wet Season Demand Required for
Minimum Partial Capture, gpd per
impervious acre
0.60
490
0.65
530
0.70
570
0.75
610
0.80
650
0.85
690
0.90
730
0.95
770
1.00
810
Several of the land use and /or product types proposed for the Newport Banning Ranch project were
evaluated using typical impervious /pervious land area ratios and planting types to estimate the
feasibility for harvest and reuse systems on -site. Although specific irrigated areas and landscaping
types are not available at this time, assumptions can be made based on similar product types and
associated landscaping irrigation demands.
The following table summarizes the estimated applied water use for these areas of the project.
NEWPORT BANNING RANCH, LLC 20 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
STEP 1: ESTIMATED APPLIED WATER USE (EAWU) FOR COMMON AREA LANDSCAPING
Modified
Minimum
Meet
Land Use
Total
a
/°
Impervious
Irrigated
DCV
Ein
Modified
EAWU per
Capture
Dr(days)
Minimum
Landscape Type
y
Area
Impervious
Tributary
LS Area
(gal)
(in /mo)
/m
KL I21
EAWU
impervious
Threshold s)
(days)
Feasibility
(ac)
(ac)
(sfl
(gpd)
acre
acre
Threshold?
1 Single Family
4,000ftzlot
0.092
60%
0.055
1,600
1,047.2
2.75
0.7
51.3
931.7
610
20.4
Yes
40% Active Turf
Attached Condos
15%
Conservation
2.0
85%
1.70
13,068
29,935.5
2.75
0.35
209.6
123.3
610
142.8
No
Design Landscape
Community Park
4.1
20%
0.82
142,876
23 378.2
2.75
0.7
4,583.9
5,590.2
610
5,1
Yes
80% Active Turf
Notes:
1 Per Table X.2 for Laguna Beach Region (similar climate type), Model WQMP Technical Guidance Document, dated May 19, 2011.
2 Per Table X.4 of the Model WQMP Technical Guidance Document, dated May 19, 2011.
3 Per Table X.6 of Model WQMP Technical Guidance Document, dated May 19, 2011.
NEWPORT BANNING RANCH, LLC 21 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
Based on the results of the Step 1 minimum threshold analysis, harvest and use is considered feasible
for the following product types: traditional single - family lot detached and recreational park uses.
Harvest and use is not considered feasible for condominium uses as the irrigation demand is
insufficient to meet the minimum harvest demand threshold. With attached condominiums, a typical
lot is approximately 85% impervious, with 15% landscaping primarily consisting of "conservation
design ", which is defined as "non- active turf" in the TGD. Under this scenario, the conservation
landscaping utilizes less water for irrigation, and thus has a lower demand and the system would not
be able to draw down within the 30 days required for feasibility. Similarly, the resultant irrigated area
to tributary impervious area is below the minimum threshold for capture feasibility. As a result, harvest
and reuse is not recommended for attached condominiums and land uses with similar landscape
design and imperviousness, such as mixed use, commercial and retail developments.
In accordance with the TGD, if the project meets or exceeds the minimum harvested water demand
thresholds, continue to Step 2 or Step 3 (both are considered equally - allowable pathways) using the
BMP Fact Sheets (XIV.4. Harvest and Use BMP Fact Sheets HU). The Step 2 "pathway" requires the
cistern volume be sized to result in an 80% capture of average annual runoff volume. This particular
sizing requirement is not feasible for either land use (single family home / park) because the 80%
capture efficiency method would result in significantly larger sizing volumes than the DCV based on
the fact the drawn downs are significantly greater than 48 hours. Reliance on a cistern only for 80%
capture of average annual runoff volume is considered infeasible. Therefore, the Step 3 "pathway"
was analyzed for determining cistern volume and drawdown to achieve maximum practicable capture
efficiency.
Step 3: Determine Cistern Volume and Drawdown to Achieve Maximum Practicable Capture Efficiency
In accordance with the TGD, Step 3 computes the maximum feasible fraction of storm water that can
be retained with harvest and use BMPs. The following steps and decision criteria are provided:
• Compute the drawdown time of the cistern as follows:
Volume (f t3) x 7.48 fi3 x 24 hr
Drawdown Time (hr) = gal day
Demand (da )
Y
• Based on the DCV and the drawdown time, calculate the long term average capture efficiency
using the Capture Efficiency Method for Volume- based, constant drawdown BMPs (TGD
Appendix 111.3.2).
• If capture efficiency is less than 40 %, harvest and use is not required to be considered for use
on the project.
• If capture efficiency is greater than 40 %, provide a cistern sized for the DCV and provide
volume or flow rate to treat the remaining volume up to 80 percent total average annual
capture using biotreatment BMP.
Capture efficiency was evaluated for the single family residential lots and community parks. Results
are summarized below:
NEWPORT BANNING RANCH, LLC 22 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
STEP 3: PRACTICAL CAPTURE EFFICIENCY FOR COMMON AREA LANDSCAPING
Land Use &
Total Area
DCV (U
Demand ('I
Drawdown
%, Capture
Meet Minimum
Landscape Type
(ac)
(ff3)
(EAWU,in
(hr)
Efficiency (2)
Capture
d
Efficiency?
1 Single Family
4,000 ft2 lot
0.092
140.0
51.3
489
47%
Yes
40% Active Turf
Community Park
4.1
3,125.4
5,590.2
100
68%
Yes
80% Active Turf
Notes:
1. Per Step 1.
2. Per Appendix 111.3.2 and Figure 111.2 of the Model WQMP Technical Guidance Document, dated May 19, 2011.
Based on this Partial Capture Efficiency Evaluation, the single family detached residential lots meets
the minimum 40% capture efficiency requirements (47 %) and harvest and use is required to be
considered for this land use with the development. However significant obstacles to implementation
and maintenance occur with this specific land use. For example, the DCV for a single family lot is
approximately 150 cubic feet of runoff, or 1,122 gallons, which for exceeds the capacity of the 55-
gallon rain barrels commonly utilized for single - family residences. In this situation, 20 rain barrels
would be needed at 55 gallons each in order to capture the DCV for one 4,000 square foot lot,
which is not practical for one single family residence of that size. In addition, placing a cistern
underground would create excess infrastructure including pump systems, larger filtration systems and
back -up irrigation systems for each lot. Further, implementing harvest and reuse at the single - family
lot scale would place the reuse of the storm water and maintenance of the system burden on the
homeowner, which may be difficult to enforce over time. Although harvest and reuse of the entire
design capture volume for each residence is not practical, this does not preclude the developer from
offering the 55- gallon rain barrels as a sustainable option for those homeowners interested in
reducing runoff, reusing storm water and decreasing potable water consumption.
For the recreational park uses, the estimated capture efficiency of 68% exceeds the 40% threshold and
harvest and use must be considered feasible for these land uses. It's important to note this evaluation
assumes the parks are designed with primarily turf grass requiring higher water demands and does not
account for any off -site tributary development areas surrounding the parks. Implementation of less
turf grass and more water conserving landscaping will lower the estimated capture efficiency. If
harvest and use was evaluated to factor in runoff from the surrounding neighborhood developments,
the design capture volume would greatly exceed the landscaping demand and the capture efficiency
would drop below the 40 % threshold. Therefore, harvest and use systems should only be considered
feasible within the park drainage areas only with sufficient turf grass.
Based on the results of this analysis, the following findings can be concluded:
• Single family lots exhibit sufficient irrigation demand using the initial feasibility screening
assessment (Step 1) and meet the minimum capture efficiency evaluation (47 %) in accordance
with the TGD (Step 3). Therefore, harvest and use systems should be considered feasible for
further consideration based on irrigation demand only. However, this land use presents
significant obstacles to harvest and reuse implementation including spatial constraints of
single family detached homes which limits a consolidated or centralized subterranean storage
system and requires individual storage units per home. In addition, if rain barrels are used the
NEWPORT BANNING RANCH, LLC 23 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
FEBRUARY 3, 2012
quantity required for the DCV come prohibitive ( >20 55- gallon barrels /home) and requires
additional plumbing infrastructure and reliance on individual homeowners to maintain these
systems. Rain barrels should be available as an option for homeowners to support water
harvesting objectives on a smaller scale
• Higher density product types such as condos or alley- loaded attached units do not exhibit
sufficient irrigation demand using the initial feasibility screening (Step 1) and harvest and reuse
is considered infeasible.
• Park areas within the proposed development exhibit sufficient irrigation demand and can be
designed with the proper storage infrastructure (likely subterranean) to accommodate harvest
and reuse systems. Harvest and reuse systems are considered feasible for such land uses and
should be sized to the Design Capture Volume. Biotreatment should be utilized to treat the
remainder of the 80% capture efficiency volume.
IV.3.4 Biotreatment BMPs
Biotreatment BMPs are a broad class of LID BMPs that reduce storm water volume to the maximum
extent practicable, treat storm water using a suite of treatment mechanisms characteristic of
biologically active systems, and discharge water to the downstream storm drain system or directly to
receiving waters. Treatment mechanisms include media filtration (though biologically- active media),
vegetative filtration (straining, sedimentation, interception, and stabilization of particles resulting from
shallow flow through vegetation), general sorption processes (i.e., absorption, adsorption, ion -
exchange, precipitation, surface complexation), biologically- mediated transformations, and other
processes to address both suspended and dissolved constituents. Examples of biotreatment BMPs
include bioretention with underdrains, vegetated swales, constructed wetlands, and proprietary
biotreatment systems.
NEWPORT BANNING RANCH, LLC 24 BEST MANAGEMENT PRACTICES
BIOTREATMENT
ID
Name
Included?
Bioretention with underdrains
BIO -1
Storm Water planter boxes with underdrains
❑
Rain gardens with underdrains
3I0-5
Constructed wetlands
❑
BIO -2
Vegetated swales
BIO -3
Vegetated filter strips
❑
3I0-7
Proprietary vegetated biotreatment systems
❑
BIO -4
Wet extended detention basin
❑
BIO -6
Dry extended detention basins
❑
Other:
❑
NEWPORT BANNING RANCH, LLC 24 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
In accordance with the 2011 Model WQMP, a properly designed biotreatment system may only be
considered if infiltration, harvest and reuse, and evapotranspiration (ET) cannot be feasibly
implemented for the full design capture volume. In this case, infiltration, harvest and reuse, and ET
practices must be implemented to the greatest extent feasible and biotreatment may be provided for
the remaining design capture volume.
For the purposes of the CEQA impact assessment provided in the project DEIR, biotreatment BMPs in
the form of landscaping biocells and larger bioretention cells were assumed to serve as a primary
mechanism to demonstrate the Project's ability to treat the required design capture volume per the
fourth -term MS4 Permit.
Parkway Landscaping Biocells
The primary features proposed for the larger, arterial streets are referred to as landscaping biocells,
which will be incorporated into select portions of the parkway bioswales identified in the arterial and
collector street cross sections on the Tentative Tract Map No. 17308. These features function as a
soil and plant -based filtration device that removes pollutants through a variety of physical, biological,
and chemical treatment processes. The major treatment of runoff occurs through the percolation of
runoff through several layers of the biocell within the parkway bioswole prior to either infiltrating into
the ground (if feasible) or collected by sub - drains and returned back to the storm drain system.
Landscaping biocells are typically sized based on the water stored within the cell and the amount of
water filtering through the biocell during storm events.
Biocells function similarly in nature to bioretention cells and rain gardens but tend to have shallower
depths based on a higher reliance on sand -based soil amendments. Biocells remove storm water
pollutants through processes such as adsorption, filtration, plant uptake, microbial activity,
decomposition, sedimentation and volatilization.' Adsorption is the process whereby particulate
pollutants attach to soil (e.g., clay) or vegetation surfaces. Filtration occurs as runoff passes through
the biocell media, such as the plant cover and planting soil which aids in dropping out particulates,
sediment and pollutants adsorbed onto sediment (including, for example certain pesticides and
pathogens). Pollutants removed by adsorption include metals, phosphorus, and hydrocarbons.
The following properties of landscaping Biocells within the streets were used to calculate the water
quality treatment potential for these features:
• 8 -inch gravel base above the sub -grade with perforated drainage pipes
• 24 inch of amended soil with filter fabric to separate from the gravel base
• 2 -4 inch of mulch
6 inch pending depth where the bottom occurs at the top of the mulch and the top occurs at
the spillover elevation where water will bypass the biocell and drain towards the nearest catch
basin inlet when at full capacity.
Drainage from the roadways and adjacent lot drainage may be directed to the parkway bioswales with
the landscaping biocell features via sheet flow, curb cuts and shallow first -flush collection pipes for
3 US Environmental Protection Agency (US EPA). Storm Water Phase II Proposed Rule Fact Sheet Series, Fact Sheet 3.0.
April 1999.
NEWPORT BANNING RANCH, LLC 25 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
water quality treatment. In some instances, a surface slope (longitudinally) may be required within the
biocell. In these instances, the slope and ponding depth will be accounted for in the treatment
volume calculation.
The profile and depths of the biocell will vary in the final design, and all changes will be accounted for
in the treatment volume calculations. In most instances, it will not be necessary to construct the
biocell sub- surface design feature into all portions of the parkway bioswale locations. Based on the
upstream tributary areas and the treatment capacity of the biocells, only a portion of the parkway
bioswale will need to include the biocell sub - surface design feature to meet the volume treatment
requirements of the upstream road runoff. In the event it is feasible to direct surface runoff from the
lots in addition to the road runoff into the parkway bioswales, the size of biocell component will be
increased accordingly.
Bioretention Cells with Underdrains
The proposed project will incorporate water quality bioretention cells to provide the backbone
treatment system for the majority of the project site.
Bioretention cells (also known as rain gardens or biocells) are vegetated basins that promote filtration
of storm water runoff. They combine shrubs, grasses, and flowering perennials in depressions
(approximately 6 to 8 inches deep) that allow water to pool, infiltrate, evaporate and /or slowly drain
out within 48 to 72 hours. Similar to the landscaped biocells, bioretention cells function as a soil and
plant -based filtration devices that removes pollutants through a variety of physical, biological, and
chemical treatment processes. The major treatment of runoff occurs through the percolation of runoff
through several layers prior to either infiltrating into the ground (if feasible) or collected by sub - drains
and returned back to the storm drain system. Pollutants are removed through processes such as
adsorption, filtration, plant uptake, microbial activity, decomposition, sedimentation and volatilization.
Consistent with the Model WQMP TGD, the following properties of the bioretention cells were used to
calculate the water quality treatment potential:
• 8 -inch gravel base above the sub -grade with perforated drainage pipes
• 24 inch of amended soil with filter fabric to separate from the gravel base
• 2 -4 inch of mulch
• 18 inch maximum ponding depth, where the bottom occurs at the top of the mulch and the
top occurs at the spillover elevation where water will bypass into the storm drain system.
For those located along the fringes of the development adjacent to the coastal bluff -tops and where
infiltration is infeasible, the entire system must be lined with sub - drains to reduce infiltration into the
soils and provide long -term integrity of the soils.
Drainage from the adjacent development areas may be directed to the bioretention cells via curb cuts,
low -flow diversions from the storm drain system or use of shallow first -flush collection pipes for water
quality treatment. Detailed drainage calculations, grading, and confirmation of sizing will occur
during the detailed design phase and subsequent Final WQMP documentation.
NEWPORT BANNING RANCH, LLC 26 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
Preliminary Design Calculations
In accordance with the MS4 permit and the new Model WQMP, the proposed LID BMPs were
evaluated to determine the appropriate footprints and depths required to treat the required Design
Capture Volumes (DCVs) for each of the on -site drainage areas identified in Section IV.2.2. Where
both landscaped biocells and bioretention cells are proposed within the some larger drainage area,
the bioretention cell was assumed to serve as primary treatment and does not exclude the biocell's
tributary drainage area. Footprints for the bioretention cells and landscaped biocells were determined
in accordance with BMP Fact Sheet 13I0-1 included in Appendix XIV of the TGD. Final design and
calculations will be identified and documented during project Final WQMP development. General
locations and the footprints of the evaluated BMPs are illustrated in the Preliminary Water Quality
Management Plan Exhibit, included in Section VI. Detailed calculations are provided in Appendix A.
NEWPORT BANNING RANCH, LLC 27 BEST MANAGEMENT PRACTICES
PRELIMINARY DESIGN CALCULATIONS SUMMARY FOR LID BMPs
Drainage
Area ID
Land Use Type
Drainage
Area (ac)
DCV
(ft')
Bioretention With
Underdrains
Biotreatment
Landscaped Biocells
(Bioretention w/
Underdrains
Ponding
Depth
ft
Depth
Filtered
ft
Footprint
Needed
ft z
Ponding
Depth
ft
Depth
Filtered
ft
Footprint
Needed
ft2
WCH Tributary - Storm Drain A
A19.4
Community Park
3.90
2,616
1.5
0.625
1,231.2
A19.2
Community Park
6.81
4,568
1.5
0.625
2,149.8
A7.3
Community Park
4.18
2,804
1.5
0.625
1,319.6
South Arroyo Tributary - Southerly Drainage Areas (Storm Drain B)
TOTAL
I -
33.47
56,412
1.5
0.625
26,546.8
South Arroyo Tributary - Northerly Drainage Areas (Storm Drain C)
TOTAL
I --
1 22.94
37,417
1.5
0.625
17,608.1
Lowlands Tributary - West of "B" Street (Storm Drain D)
TOTAL"
55.43
91,356
1.5
0.625
42,990.9
Lowlands Tributary - East of "B" Street (Storm Drain E)
C12.2
Mixed
Use /Residential
5.11
9,758
1.5
0.625
4,591.9
Lowlands Tributary - Storm Drain F
311.1
Mixed
Use /Residential
4.57
8,727
1.5
0.625
1 4,106.7
Arterial Streets w/ Landscaped Biocells (stand alone - not included in drainage areas above)
Al 9.1
Arterial Road
1.09
2,289
0.50
0.50
2,289.1
A19.3
Arterial Road
1.58
3,318
0.50
0.50
3,318.2
A19.5
Arterial Road
2.93
6,153
0.50
0.50
6,153.4
A7 9.7
Arterial Road
2.52
5,292
0.50
0.50
5,292.3
NEWPORT BANNING RANCH, LLC 27 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
PRELIMINARY DESIGN CALCULATIONS SUMMARY FOR LID BMPs
Parameter
Units
Existing
Conditions
Developed
Conditions
w/o PDFs
Bioretention With
Landscaped Biocells
7'T,
mg /L
171
117
Underdrains
(Bioretention w/
Total Phosphorous
Use Type
Drainage
DCV
Biotreatment
Underdrains
Ponding
Depth
Footprint
Ponding
Depth
Footprint
Nitrate -N
mg /L
Area (ac)
(ft3)
0.6
-0.4
Ammonia -N
mg /L
Depth
Filtered
Needed
Depth
Filtered
Needed
2.0
2.3
1.6
-0.4
(ft)
(ft)
( )
(ft)
(ft)
(ftZ)
A7.5
Arterial Road
1.9
3,990
12
-8
Total Lead
0.50
0.50
3,990.3
311.3
Arterial Road
2.21
4,641
0.50
0.50
4,641.3
D3.2
Arterial Road
2.72
5,712
0.50
0.50
51712.4
Notes:
1. Includes 1.94 acres of upstream, off -site tributary area.
Planning -Level Water Quality Modeling
To analyze the effectiveness of the proposed bioretention features and the extended detention basin
for off -site runoff (discussed further in Section IV.3.7), water quality modeling was conducted to predict
anticipated changes in storm water runoff quality and quantity for proposed versus existing conditions
(see Appendix G). The model does not take into account hydrologic source controls, storm drain
routing, Time of Concentration, pipe storage or other drainage design features that would reduce the
predicted storm water volumes.
The results of the planning -level water quality modeling demonstrate the following: (i) a calculated
increase in storm water runoff volume, (ii) limited calculated overall changes in pollutant loads
(existing versus post - development condition), and (iii) improved calculated water quality (i.e., reduced
concentrations) in the post - development condition given the change in land uses and implementation
and maintenance of project design features (PDF). A summary of the predicted calculated average
annual pollutant concentrations are provided below. See additional details in Appendix G.
PREDICTED CALCULATED AVERAGE ANNUAL POLLUTANT CONCENTRATIONS,
ON -SITE PLUS OFF -SITE
Parameter
Units
Existing
Conditions
Developed
Conditions
w/o PDFs
Developed
Conditions
w/ PDFs
Change
TSS
mg /L
171
117
72
-99
Total Phosphorous
mg /L
0.3
0.3
0.2
-0.1
Dissolved Phosphorus
mg /L
0.18
0.26
0.15
-0.03
Nitrate -N
mg /L
1.0
0.9
0.6
-0.4
Ammonia -N
mg /L
0.5
0.6
0.3
-0.2
Total Kleldahl Nitrogen
mg /L
2.0
2.3
1.6
-0.4
Dissolved Copper
pg /L
6.1
10.1
5.9
-0.2
Total Copper
pg /L
20
23
12
-8
Total Lead
pg /L
8
8
5
-3
NEWPORT BANNING RANCH, LLC 28 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
FEBRUARY 3, 2012
PREDICTED CALCULATED AVERAGE ANNUAL POLLUTANT CONCENTRATIONS,
ON -SITE PLUS OFF -SITE
ID
Name
Existing
Developed
Developed
❑
Parameter
Units
Conditions
Conditions
Conditions
Change
PRE -2
Catch Basin Insert
❑
w/o PDFs
w/ PDFs
Dissolved Zinc
µg /L
111
100
60
51
Total Zinc
µg /L
150
149
69
-81
Note: Model results are rounded per the following convention: results are rounded to a uniform level of precision for each parameter
such that at least one significant figure is reported for each value, or such that numbers are rounded to the nearest integer, whichever
results in greater precision. The number of reported significant figures is intended to prevent introduction of rounding errors; it is not
intended to imply model prediction certainty,
IV.3.5 Hydromodification Control BMPs
Not applicable. LID BMPs utilizing biofiltration will be utilized for water quality treatment on -site in
accordance with the MS4 Permit hierarchy identified at the beginning of this Section.
IV.3.6 Regional /Sub - Regional LID BMPs
Not applicable. LID BMPs utilizing biofiltration will be utilized for water quality treatment on -site in
accordance with the MS4 Permit hierarchy identified at the beginning of this Section.
IV.3.7 Treatment Control BMPs
Treatment control BMPs can only be considered if the project conformance analysis indicates that it is
not feasible to retain the full design capture volume with LID BMPs.
I'IM
TREATMENT CONTROL BMPs
ID
Name
Included?
TRT -1
Sand Filters
❑
TRT -2
Cartridge Media Filter
❑
PRE -1
Hydrodynamic Separation Device
❑
PRE -2
Catch Basin Insert
❑
TC -22
Other: Extended Detention Basin
For on -site development areas, LID BMPs will be utilized in lieu of treatment control BMPs for water
quality treatment on -site in accordance with the MS4 Permit hierarchy identified at the beginning of
this Section.
Although not a requirement of the Project, the Project proposes a water quality basin located near 16"
Street to treat 48 acres of off -site Costa Mesa runoff that flows onto the project site that does not co-
NEWPORT BANNING RANCH, LLC 29 BEST MANAGEMENT PRACTICES
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
mingle with project flows. The regional facility will be designed to accommodate approximately 2.3-
acre -feet of water quality treatment, which will accommodate all urban runoff (dry weather) and the
majority of the 85" percentile storm event. Due to sizing limitations and other physical constraints, it
is not feasible to design this basin to treat the entire 85'h percentile 24 -hour storm event nor is it a
requirement of the Project. The basin would be designed to treat as much as can be physically
accommodated at this location and provide a reduction in peak flows to reduce scour potential within
the Southern Arroyo.
Extended detention basins are basins whose outlets have been designed to detain storm water runoff
for some minimum time (e.g., 48 -72 hours) to allow particles and associated pollutants to settle.
They do not have a permanent pool and are designed to drain completely between storm events. The
slopes and bottom of the basins are typically vegetated, and can also be used to provide additional
flood control benefits by modifying the outlet structure and providing additional storage.
The proposed extended detention basin for off -site flows has a bottom footprint of approximately
21,164 ft2 and a max ponding depth of 5 ft, for an approximate capacity of 2.3 acre -feet.
IV.3.8 Non - Structural Source Control BMPs
The table below indicates all BMPs to be incorporated in the project. For those designated as not
applicable (N /A), a brief explanation why is provided.
NEWPORT BANNING RANCH, LLC 30 BEST MANAGEMENT PRACTICES
■
NON - STRUCTURAL SOURCE CONTROL BMPs
ID
Name
Included?
Not
If Not Applicable, Provide
Applicable?
Brief Reason
N1
Education for Property Owners,
®
❑
Tenants and Occupants
N2
Activity Restrictions
®
❑
N3
Common Area Landscape
®
❑
Management
N4
BMP Maintenance
®
❑
N5
Title 22 CCR Compliance
❑
®
Not applicable. No industrial
How development will comply)
land uses proposed.
Local Industrial Permit
The City of Newport Beach
N6
El
does not issue water quality
Compliance
permits.
N7
Spill Contingency Plan
El
Not applicable. No industrial
land uses proposed.
N8
Underground Storage Tank
❑
®
Not applicable. No industrial
Compliance
land uses proposed.
N9
Hazardous Materials
❑
®
Not applicable. No industrial
Disclosure Compliance
land uses proposed.
N10
Uniform Fire Code
❑
®
Not applicable. No industrial
Implementation
land uses proposed.
NEWPORT BANNING RANCH, LLC 30 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
NON - STRUCTURAL SOURCE CONTROL BMPs
ID
Name
Included?
Not
If Not Applicable, Provide
Applicable?
Brief Reason
N 1 1
Common Area Litter Control
®
❑
N12
Employee Training
®
❑
N13
Housekeeping of Loading
®
❑
Docks
N14
Common Area Catch Basin
®
❑
Inspection
N15
Street Sweeping Private Streets
®
❑
and Parking Lots
No retail gasoline outlets are
N16
Retail Gasoline Outlets
❑
®
proposed as part of the
project.
N1, Education for Property Owners, Tenants and Occupants
Educational materials will be provided to residents /tenants, including education materials and
restrictions to reduce pollutants from reaching the storm drain system. Examples include tips for pet
care, proper waste oil disposal, and other household tips. Tenants will be provided storm water
pollution prevention materials by the Property Management prior to occupancy. Materials will be
provided periodically thereafter. Refer to Section VII for a list of educational materials to be provided.
NZ Activity Restrictions
The HOA shall restrict activities that have the potential to create adverse impacts on water quality.
Activities include but are not limited to: prohibiting vehicle maintenance activities within parking areas
and stalls, prohibiting long -term parking without prior authorization, and prohibiting outdoor vehicle
washing. Restriction shall begin upon occupancy.
N3, Common Area Landscape Management
Common area landscape management that includes minimizing fertilizer and pesticide application,
use of slow - release fertilizers, maintenance activities, providing education to homeowners and tenants
(via project owner and /or HOA), and providing education and training for employees on
management of landscape materials and storm water management. Maintenance shall be conducted
on a monthly basis at a minimum, and management measures shall be implemented upon
completion of landscaping for the project.
N4 BMP Maintenance
The HOA will be responsible for the implementation and maintenance of each applicable non-
structural BMP, as well as scheduling inspections and maintenance of all applicable structural BMP
facilities through its staff, landscape contractor, and /or any other necessary maintenance contractors.
Details on BMP Maintenance ore provided in Section V of this P -WQMP.
NEWPORT BANNING RANCH, LLC 31 BEST MANAGEMENT PRACTICES
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
N11 Common Area Litter Control
The HOA will be responsible for performing trash pickup and sweeping of littered common areas as
needed and weekly at a minimum. Any trash /debris waste collected shall be properly disposed of in
accordance with local regulations. Responsibilities will also include noting improper disposal of
materials by the public and reporting such violations for further investigation.
N12 Employee Training
All employees of the HOA and any contractors will require training to ensure that employees are
aware of maintenance activities that may result in pollutants reaching the storm drain. Training will
include, but not be limited to, spill cleanup procedures, proper waste disposal, housekeeping
practices, etc.
N13, Housekeeping of Loading Docks
No below -grade loading docks are proposed. Housekeeping measures will be implemented to keep
any delivery areas clean and orderly condition. These measures include but are not limited to
sweeping, removal of trash & debris on a weekly basis, and use of dry methods for cleanup.
N14, Common Area Catch Basin Inspection
All on -site storm drain inlets, curb and gutters and ribbon gutter systems shall be inspected and
cleaned out by the HOA at least once a year, prior to the rainy season, no later than October 1 ' of
each year. All public drainage facilities will be maintained by the City of Newport Beach.
N15, Street Sweeping Private Streets and Parking Lots
The HOA shall be responsible for the street sweeping of all private street, drive aisles and parking
areas within the project quarterly, and prior to the rainy season, no later than October 1" each year.
The City of Newport Beach shall be responsible for sweeping of public streets.
IV.3.9 Structural Source Control BMPs
The table below indicates all BMPs to be incorporated in the project. For those designated as not
applicable (N /A), a brief explanation why is provided.
STRUCTURAL SOURCE CONTROL BMPs
ID
Name
Included?
Not
If Not Applicable, Provide
Applicable?
Brief Reason
Sl
Provide storm drain system
®
El
stenciling and si na e
S2
S2
Design and construct outdoor
No outdoor material storage
SD -34
material storage areas to
❑
®
areas are proposed as part
reduce pollution introduction
of the project.
53
Design and construct trash and
SD -32
waste storage areas to reduce
®
❑
pollution introduction
NEWPORT BANNING RANCH, LLC 32 BEST MANAGEMENT PRACTICES
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
STRUCTURAL SOURCE CONTROL BMPs
ID
Name
Included?
Not
If Not Applicable, Provide
Applicable?
Brief Reason
Use efficient irrigation systems
S4
& landscape design, water
®
❑
SD -12
conservation, smart controllers,
and source control
S5
Protect slopes and channels
®
❑
and provide energy dissipation
S6
Properly Design: Dock areas
❑
®
No below -grade loading
SD -31
docks are proposed.
S7
Properly Design: Maintenance
El
®
No maintenance bays are
SD -31
bas
proposed.
S8
Properly Design: Vehicle wash
❑
®
No vehicle wash areas are
SD -33
areas
proposed.
S9
Properly Design: Outdoor
❑
®
No outdoor processing areas
SD -36
processing areas
are proposed.
S10
Properly Design: Equipment
❑
®
No equipment wash areas
wash areas
are proposed.
S11
Properly Design: Fueling areas
❑
❑
No fueling areas are
SD -30
proposed.
Project is not located in a
S12
Properly Design: Hillside
El
®
hillside area. Slopes will be
SD -10
landscaping
protected in accordance with
BMP S5.
Properly Design: Wash water
S13
control for food preparation
®
❑
areas
S14
Properly Design: Community
❑
Z
No community car wash
car wash racks
racks are proposed as part
of the project.
S1 /SD -13, Provide storm drain system stenciling and signaae
The phrase "NO DUMPING! DRAINS TO OCEAN" or an equally effective phrase approved by the
City, will be stenciled on all major storm drain inlets within the project site to alert the public to the
destination of pollutants discharged into storm water. Stencils shall be in place by completion of
construction.
S3 /SD -32, Design and construct trash and waste storage areas to reduce pollution introduction
All trash and waste shall be stored in containers that have lids or tarps to minimize direct precipitation
into the containers. Any trash storage areas will be paved, covered, and either be sloped to
landscaping areas or include a barrier to keep drainage out of the storm drain. The HOA shall
ensure trash is stored properly and does not come into contact with storm water runoff.
NEWPORT BANNING RANCH, LLC 33 BEST MANAGEMENT PRACTICES
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
S4 /SD -12 Use efficient irrigation systems & landscape design, water conservation, smart controllers,
and source control
Irrigation systems would be designed to meet City standards for water efficient landscaping, as
applicable in accordance with Newport Beach Municipal Code Chapter 14.17 and Chapter 5 (Master
Landscape Plan) of the Master Development Plan. Where feasible, includes incorporation of native
tolerant species for landscaping, protection of slopes and efficient irrigation. May be used in
conjunction with educational materials to homeowners /tenants as well as activity restrictions.
Maintenance of the irrigation systems shall be conducted monthly at a minimum, and shall be
implemented upon completion of landscaping for the project.
S5, Protect slopes and channels and provide energy dissipation
All disturbed slopes will be re- vegetated and stabilized to prevent erosion. A diffuser basin will be
located downstream of the Southern Arroyo and Storm Drains B and C to provide channel stability,
dissipate erosive energy before flows enter the Semeniuk Slough, and control sediment contributions
to the Semeniuk Slough. A diffuser basin will also be installed downstream of Storm Drains D and
Storm Drain E to reduce the momentum of the flows from the pipes and to spread the distribution of
runoff to the Lowland in a manner that will enable future habitat restoration efforts.
S 13, Properly Design: Wash water control for food preparation areas
All wash water from food preparation areas will be conveyed to the site's sewer system. Food
preparation facilities shall meet all health and safety, building and safety and any other applicable
regulations, codes requirements. Grease interceptors will be located in the sewer lines were
applicable.
IV.4 ALTERNATIVE COMPLIANCE PLAN
IV.4.1 Water Quality Credits
Local jurisdictions may develop a water quality credit program that applies to certain types of
development projects after they first evaluate the feasibility of meeting LID requirements on -site. If it is
not feasible to meet the requirements for on -site LID, project proponents for specific project types can
apply credits that would reduce project obligations for selecting and sizing other treatment BMPs or
participating in other alternative programs.
WATER QUALITY CREDITS
Credit
Applicable?
Redevelopment projects that reduce the overall impervious footprint of the project site.
❑
Brownfield redevelopment, meaning redevelopment, expansion, or reuse of real
property which may be complicated by the presence or potential presence of hazardous
❑
substances, pollutants or contaminants, and which have the potential to contribute to
adverse ground or surface water quality if not redeveloped.
NEWPORT BANNING RANCH, LLC 34 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
FEBRUARY 3, 2012
WATER QUALITY CREDITS
Credit
Applicable?
Higher density development projects which include two distinct categories (credits can
only be taken for one category): those with more than seven units per acre of
development (lower credit allowance); vertical density developments, for example,
❑
those with a Floor to Area Ratio (FAR) of 2 or those having more than 18 units per acre
(greater credit allowance)
Mixed use development, such as a combination of residential, commercial, industrial,
office, institutional, or other land uses which incorporate design principles that can
demonstrate environmental benefits that would not be realized through single use
❑
projects (e.g. reduced vehicle trip traffic with the potential to reduce sources of water or
air pollution).
Transit - oriented developments, such as a mixed use residential or commercial area
designed to maximize access to public transportation; similar to above criterion, but
where the development center is within one half mile of a mass transit center (e.g. bus,
❑
rail, light rail or commuter train station). Such projects would not be able to take credit
for both categories, but may have greater credit assigned
Redevelopment projects in an established historic district, historic preservation area, or
similar significant city area including core City Center areas (to be defined through
❑
mapping).
Developments with dedication of undeveloped portions to parks, preservation areas
El
and other pervious uses.
Developments in a city center area.
❑
Developments in historic districts or historic preservation areas.
❑
Live -work developments, a variety of developments designed to support residential and
vocational needs together — similar to criteria to mixed use development; would not be
❑
able to take credit for both categories.
In -fill projects, the conversion of empty lots and other underused spaces into more
E]
beneficially used spaces, such as residential or commercial areas.
At this time, however, no water quality credits have been applied to the project's DCV. Should any
applicable credits be applied in the future, they shall be documented in the Final WQMP.
IV.4.2 Alternative Compliance Plan Information
Not applicable. LID BMPs will be utilized for water quality treatment on -site in accordance with the
MS4 Permit hierarchy identified at the beginning of this Section.
NEWPORT BANNING RANCH, LLC 35 BEST MANAGEMENT PRACTICES
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION V INSPECTION /MAINTENANCE RESPONSIBILITY
FOR BMPs
It has been determined that the Owner, via HOA shall assume all BMP inspection and maintenance
responsibilities for the Newport Banning Ranch project.
Contact Name:
Pending —to be provided in the Final WQMP
Title:
Company:
Address:
Phone:
Fax:
Email:
Should the maintenance responsibility be transferred at any time during the operational life of
Newport Banning Ranch, such as when an HOA or POA is formed for a project, a formal notice of
transfer shall be submitted to the City of Newport Beach at the time responsibility of the property
subject to this WQMP is transferred. The transfer of responsibility shall be incorporated into this
WQMP as an amendment.
The HOA shall verify BMP implementation and ongoing maintenance through inspection, self -
certification, survey, or other equally effective measure. The certification shall verify that, at a
minimum, the inspection and maintenance of all structural BMPs including inspection and
performance of any required maintenance in the late summer / early fall, prior to the start of the rainy
season. A form that may be used to record implementation, maintenance, and inspection of BMPs is
included in Appendix D.
The City of Newport Beach may conduct verifications to assure that implementation and appropriate
maintenance of structural and non - structural BMPs prescribed within this WQMP is taking place at the
project site. The HOA shall retain operations, inspections and maintenance records of these BMPs
and they will be made available to the City or County upon request. All records must be maintained
for at least five (5) years after the recorded inspection date for the lifetime of the project.
Long -term funding for BMP maintenance shall be funded through fees paid into the HOA. Newport
Banning Ranch, LLC, which will set up the HOA shall oversee that adequate funding for BMP
maintenance is included within the HOA fee structure including annual maintenance fees and long-
term maintenance reserve funds.
NEWPORT BANNING RANCH, LLC 36 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
BMP
Inspection /Maintenance Activities
Minimum
Responsible
Frequency
Parf
BIOTREATMENT BMPs
Inspections should occur semi - annually or
after major storm events to check for the
following and remove accordingly:
standing water, sediment, and trash &
Private Areas:
debris. Inspections should also look for
HOA
potential clogging and clean planters or, if
BIO -1
Landscaped Biocells
necessary, replace the entire filter bed.
2x per year
Public Areas:
Inspect for weeds, and prune and /or
City of Newport
replace plants in accordance with routine
Beach
landscape maintenance activities. Replace
mulch as necessary. Conduct routine
mowing of grass in swale to maintain
appropriate rass height.
Inspections should occur semi - annually or
after major storm events to check for the
following and remove accordingly:
Private Areas:
standing water, sediment, and trash &
HOA
debris. Inspections should also look for
BI0-1
Bioretention Cells
potential clogging and clean planters or, if
2x per year
Public Areas:
necessary, replace the entire filter bed.
City of Newport
Inspect for weeds, and prune and /or
Beach
replace plants in accordance with routine
landscape maintenance activities. Replace
mulch and prune shrubs as necessa .
TREATMENT CONTROL BMPs
NEWPORT BANNING RANCH, LLC 37 BMP INSPECTION & MAINTENANCE
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
NEWPORT BANNING RANCH, LLC 38 BMP INSPECTION & MAINTENANCE
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
BMP
Inspection /Maintenance Activities
Minimum
Responsible
Frequency
Party
Inspections should occur for standing
water, slope stability, sediment
accumulation, trash & debris, and
presence of burrows at the beginning and
end of wet season at a minimum. Routine
maintenance includes trash and debris
Extended Detention Basin (for off -site flows)
removal in the basin and around the riser
2x per year
HOA
pipe. Inspect for weeds, and prune and /or
replace plants in accordance with routine
landscape maintenance activities. Remove
accumulated sediment when volume
exceeds 10% of the basin volume, typically
every 10 years.
NON - STRUCTURAL SOURCE CONTROL BMPs
Educational materials will be provided to
tenants annually. Materials to be
N
Education for Property Owners, Tenants
distributed are found in Appendix C of this
Annually
HOA
and Occupants
WQMP. Tenants will be provided these
materials by the Property Management
prior to occupancy and annually thereafter.
The Owner will prescribe activity
restrictions to protect surface water quality,
through lease terms or other equally
N2
Activity Restrictions
effective measure, for the property.
Ongoing
HOA
Restrictions include, but are not limited to,
prohibiting vehicle maintenance or vehicle
washing.
NEWPORT BANNING RANCH, LLC 38 BMP INSPECTION & MAINTENANCE
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NEWPORT BANNING RANCH FEBRUARY 3, 2012
NEWPORT BANNING RANCH, LLC 39 BMP INSPECTION & MAINTENANCE
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
BMP
Inspection /Maintenance Activities
Minimum
Responsible
Frequency
Party
Maintenance shall be consistent with City
requirements. Fertilizer and /or pesticide
usage shall be consistent with County
Management Guidelines for Use of
Fertilizers (OC DAMP Section 5.5) as well
as City requirements. Maintenance
includes mowing, weeding, and debris
Private Areas:
removal on a weekly basis. Trimming,
HOA
N3
Common Area Landscape Management
replanting, and replacement of mulch shall
Monthly
be performed on an as- needed basis to
Public Areas:
prevent exposure of erodible surfaces.
City of Newport
Trimmings, clippings, and other landscape
Beach
wastes shall be properly disposed of in
accordance with local regulations.
Materials temporarily stockpiled during
maintenance activities shall be placed
away from water courses and storm drains
inlets.
Maintenance of structural BMPs
Private Areas:
implemented at the project site shall be
HOA
performed at the frequency prescribed in
N4
BMP Maintenance
this WQMP. Records of inspections and
Ongoing
Public Areas:
BMP maintenance shall be kept by the
City of Newport
Owner and shall be available for review
Beach
upon request.
N5
Title 22 CCR Compliance (How
Not applicable.
development will comply)
N6
Local Industrial Permit Compliance
Not applicable.
N7
Spill Contingency Plan
Not applicable.
NEWPORT BANNING RANCH, LLC 39 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
NEWPORT BANNING RANCH, LLC 40 BMP INSPECTION & MAINTENANCE
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
BMP
Inspection /Maintenance Activities
Minimum
Responsible
Frequency
Party
N8
Underground Storage Tank Compliance
Not applicable.
No
Hazardous Materials Disclosure
Not applicable.
Compliance
N10
Uniform Fire Code Implementation
Not applicable.
Litter patrol, violations investigations,
Private Areas:
reporting and other litter control activities
HOA
N11
Common Area Litter Control
shall be performed on a weekly basis and
Weekly
Public Areas:
in conjunction with routine maintenance
City of Newport
activities.
Beach
Educate all new employees/ managers on
storm water pollution prevention,
N12
Employee Training
particularly good housekeeping practices,
Annually
HOA
prior to the start of the rainy season
(October 1). Refresher courses shall be
conducted on an as needed basis.
Sweep delivery areas weekly and remove
any trash /debris. Keep area clean of trash
N13
Housekeeping of Loading Docks
and debris at all times. Spills shall be
Weekly
HOA
cleaned up immediately using dry
methods.
Catch basin inlets and other drainage
Private Areas:
facilities shall be inspected after each
HOA
N14
Common Area Catch Basin Inspection
storm event and once per year. Inlets and
Annually
Public Areas:
other facilities shall be cleaned prior to the
City of Newport
rainy season, by October 1 each year.
Beach
NEWPORT BANNING RANCH, LLC 40 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
N15
Der
FEBRUARY 3, 2012
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
Street Sweeping Private Streets and Parking
Lots
Inspection /Maintenance Activities
Streets & parking lots must be swept at
least quarterly (every 3 months), including
prior to the start of the rainy season
(October 1'J.
N16 I Retail Gasoline Outlets I Not applicable.
I STRUCTURAL SOURCE CONTROL BMPs i
Storm drain stencils shall be inspected f
legibility, at minimum, once prior to the
S1 Provide storm drain system stenciling and storm season, no later than October 1s'
SD -13 signage each year. Those determined to be
illegible will be re- stenciled as soon as
S2 Design and construct outdoor material
SD -34 storage areas to reduce pollution Not applicable.
introduction
Minimum l Responsible
HOA
Quarterly Public Areas:
City of Newport
Beach
Private Areas:
HOA
Annually Public Areas:
City of Newport
S3
SD -32
Design and construct trash and waste
storage areas to reduce pollution
introduction
Sweep trash area at least once per week
and before October 1 "each year.
Maintain area clean of trash and debris at
all times.
Weekly
HOA
In conjunction with routine maintenance
activities, verify that landscape design
Private Areas:
continues to function properly by adjusting
HOA
S4
Use efficient irrigation systems & landscape
properly to eliminate oversproy to
SD -12
design, water conservation, smart
hardscape areas, and to verify that
Monthly
Public Areas:
controllers, and source control
irrigation timing and cycle lengths are
City of Newport
adjusted in accordance with water
Beach
demands, given time of year, weather, and
day or night time temperatures.
NEWPORT BANNING RANCH, LLC 41 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
NEWPORT BANNING RANCH, LLC 42 BMP INSPECTION & MAINTENANCE
BMP INSPECTION & MAINTENANCE RESPONSIBILITY MATRIX
BMP
Inspection /Maintenance Activities
Minimum
Responsible
Frequency
Party
To be performed in conjunction with
maintenance activities. Maintain vegetative
cover and /or mulch to eliminate exposed
S5
Protect slopes and channels and provide
soils. Any eroded surfaces to be repaired
Monthly
HOA
energy dissipation
immediately. Inspections to be performed
twice each year (spring and fall) and after
major storm events to check for signs of
erosion, gullies, and sloughing.
S6
SD -31
Properly Design: Dock areas
Not applicable.
S7
SD -31
Properly Design: Maintenance bays
Not applicable.
S8
SD -33
Properly Design: Vehicle wash areas
Not applicable.
S9
Properly Design: Outdoor processing
Not applicable.
SD -36
areas
S10
Properly Design: Equipment wash areas
Not applicable.
S11
SD -30
Properly Design: Fueling areas
Not applicable.
S12
SD -10
Properly Design: Hillside landscaping
Not applicable.
Food preparation areas will be inspected
on a regular basis to ensure proper waste
Properly Design: Wash water control for
disposal and water usage procedures. Any
HOA / Resort
S13
food preparation areas
grease interceptors shall be inspected and
Quarterly
Operator
maintained in accordance with
manufacturer's recommendations (typically
quarterly).
S14
Properly Design: Community car wash
Not applicable.
racks
NEWPORT BANNING RANCH, LLC 42 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
Any waste generated from maintenance activities will be disposed of properly. W
not to be discharged or disposed of into the storm drain system. Clippings from
and disposed of properly off -site, and will not be washed into the streets, local are
a
FEBRUARY 3, 2012
ash water and other waste from maintenance activities is
landscape maintenance (i.e. prunings) will be collected
drains /conveyances, or catch basin inlets.
NEWPORT BANNING RANCH, LLC 43 BMP INSPECTION & MAINTENANCE
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
SECTION VI SITE PLAN AND DRAINAGE PLAN
The exhibits provided in this section are to illustrate the post construction BMPs prescribed within this
WQMP. Drainage flow information of the proposed project, such as general surface flow lines,
concrete or other surface drainage conveyances, and storm drain facilities are also depicted. All
structural source control and treatment control BMPs are shown as well.
EXHIBITS
• Vicinity Map
• Site Plan
• Preliminary WQMP Exhibit
• Typical Cross Sections
BMP DETAILS
• BI0-1 Bioretention With Underdrains
• TC -22 Extended Detention Basin
NEWPORT BANNING RANCH LLC 44 SITE PLAN & DRAINAGE PLAN
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NEWPORT BANNING RANCH Master Development Plan
MASTER DEVELOPMENT PLAN
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Project Site Boundary
OPEN SPACE PRESERVE
Upland Open Space Habitat Conservation,
Restoration, and Mitigation Areas
Lowland Open Space Habitat Conservation,
Restoration, and Mitigation Areas
®
Public Interpretive Trails
_
Drainage Management Areas
Consolidated Oil Sites (Interim Use)
_
Oil Site Buffers
PARKLANDS
_
Public Community Park
_
Public Bluff Park
_
Public Interpretive Parks
VILLAGES AND COLONIES
North and South Family Villages
Urban Colony
Resort Colony
'`1 Pedestrian Passe
ROADWAYS
® Public Roads
Private. Roads /Alleys
Tap of Edge of Bluff
60 Foot Setback from Top of Edge of Bluff
for Habitable Structures
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NEWPORT BANNING RANCH Master Development Plan
MASTER DEVELOPMENT PLAN
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PROFILE
TECHNICAL GUIDANCE DOCUMENT APPENDICES
XIV.5. Biotreatment BMP Fact Sheets (BIO)
Conceptual criteria for biotreatment BMP selection, design, and maintenance are contained in
Appendix X1I. These criteria are generally applicable to the design of biotreatment BMPs in
Orange County and BMP - specific guidance is provided in the following fact sheets.
Note: Biotreatment BMPs shall be designed to provide the maximum feasible infiltration and ET based on
criteria contained in Appendix X1.2.
BI0-1: Bioretention with Underdrains
Bioretention stormwater treatment facilities are landscaped
shallow depressions that capture and filter stormwater
runoff. These facilities function as a soil and plant -based
filtration device that removes pollutants through a variety of
physical, biological, and chemical treatment processes. The
facilities normally consist of a ponding area, mulch layer,
planting soils, and plants. As stormwater passes down
through the planting soil, pollutants are filtered, adsorbed,
biodegraded, and sequestered by the soil and plants.
Bioretention with an underdrain are utilized for areas with
low permeability native soils or steep slopes where the
underdrain system that routes the treated runoff to the storm
drain system rather than depending entirely on infiltration.
Bioretention must be designed without an underdrain in areas of
high soil permeability.
Screening Considerations
➢ Rain gardens with
underdrains
➢ Vegetated media filter
➢ Downspout planter boxes
Bioretention
Source: Geosyntec Consultants
• If there are no hazards associated with infiltration (such as groundwater concerns, contaminant
plumes or geotechnical concerns), bioinfiltration facilities, which achieve partial infiltration,
should be used to maximize infiltration.
• Bioretention with underdrain facilities should be lined if contaminant plumes or geotechnical
concerns exist. If high groundwater is the reason for infiltration infeasibility, bioretention facilities
with underdrains do not need to be lined.
Opportunity Criteria
• Land use may include commercial, residential, mixed use, institutional, and subdivisions.
Bioretention may also be applied in parking lot islands, cul -de -sacs, traffic circles, road shoulders,
road medians, and next to buildings in planter boxes.
Drainage area is <_ 5 acres.
• Area is available for infiltration.
XIV -51 May 19, 2011
TECHNICAL GUIDANCE DOCUMENT APPENDICES
• Site must have adequate relief between land surface and the stormwater conveyance system to
permit vertical percolation through the soil media and collection and conveyance in underdrain to
stormwater conveyance system.
OC- Specific Design Criteria and Considerations
El greater depth should not exceed 18 inches; fencing may be required if ponding depth is
greater than 6 inches to mitigate drowning.
❑ The minimum soil depth is 2 feet (3 feet is preferred).
Eldrawdown maximum drawdown time of the bioretention ponding area is 48 hours. The maximum
drawdown time of the planting media and gravel drainage layer is 96 hours, if applicable.
Infiltration pathways may need to be restricted due to the close proximity of roads, foundations,
❑or other infrastructure. A geomembrane liner, or other equivalent water proofing, may be placed
along the vertical walls to reduce lateral flows. This liner should have a minimum thickness of
30 mils.
If infiltration in bioretention location is hazardous due to groundwater or geotechnical concerns,
❑ a geomembrane liner must be installed at the base of the bioretention facility. This liner should
have a minimum thickness of 30 mils.
ElThe planting media placed in the cell shall be designed per the recommendations contained in
MISC -1: Planting /Storage Media
Plant materials should be tolerant of summer drought, ponding fluctuations, and saturated soil
❑ conditions for 48 hours; native place species and /or hardy cultivars that are not invasive and do
not require chemical inputs should be used to the maximum extent feasible
The bioretention area should be covered with 24 inches (average 3 inches) or mulch at the
El start and an additional placement of 1 -2 inches of mulch should be added annually.
Underdrain should be sized with a 6 inch minimum diameter and have a 0.5% minimum slope.
❑ Underdrain should be slotted polyvinyl chloride (PVC) pipe; underdrain pipe should be more
than 5 feet from tree locations (if space allows).
A gravel blanket or bedding is required for the underdrain pipe(s). At least 0.5 feet of washed
El aggregate must be placed below, to the top, and to the sides of the underdrain pipe(s).
❑ An overflow device is required at the top of the bioretention area ponding depth.
Elbasin flow or energy dissipation (i.e. splash rocks) for piped inlets should be provided at
basin inlet to prevent erosion.
Ponding area side slopes shall be no steeper than 3:1 (H:V) unless designed as a planter box
El BMP with appropriate consideration for trip and fall hazards.
Method for Bioretention with Underdrain
If the Simple Design Capture Volume Sizing Method described in Appendix III.3.1 is used to size a
bioretention with underdrain facility, the user selects the basin depth and then determines the appropriate
surface area to capture the DCV. The sizing steps are as follows:
Step 1: Determine DCV
Calculate the DCV using the Simple Design Capture Volume Sizing Method described in Appendix
III.3.1.
XIV -52 May 19, 2011
TECHNICAL GUIDANCE DOCUMENT APPENDICES
Step 2: Verify that the Ponding Depth will Draw Down within 48 Hours
The ponding area drawdown time can be calculated using the following equation:
DDP = (dp / KMEDIA) x 12 in /ft
Where:
DDP = time to drain ponded water, hours
dp = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
KMEDIA = media design infiltration rate, in /hr (equivalent to the media hydraulic conductivity with a
factor of safety of 2; KMEDIA of 2.5 in /hr should be used unless other information is available)
If the drawdown time exceeds 48 hours, adjust ponding depth and /or media infiltration rate until 48
hour drawdown time is achieved.
Step 3: Determine the Depth of Water Filtered During Design Capture Storm
The depth of water filtered during the design capture storm can be estimated as the amount routed
through the media during the storm, or the ponding depth, whichever is smaller.
dFILTERED - Minimum ( ((KMEDIA x TROUTING) /12), dp)
Where:
dFILTERED = depth of water that may be considered to be filtered during the design storm event, ft
KMEDIA = media design infiltration rate, in /hr (equivalent to the media hydraulic conductivity with a
factor of safety of 2; KMEDIA of 2.5 in /hr should be used unless other information is available)
TROUTING = storm duration that may be assumed for routing calculations; this should be assumed to be
no greater than 3 hours. If the designer desires to account for further routing effects, the Capture
Efficiency Method for Volume- Based, Constant Drawdown BMPs (See Appendix III.3.2) should be
used.
dp = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
Step 4: Determine the Facility Surface Area
A = DCV/ (dp + dFILTERED)
Where:
A = required area of bioretention facility, sq -ft
DCV = design capture volume, cu -ft
dFILTERED = depth of water that may be considered to be filtered during the design storm event, ft
dp = depth of ponding above bioretention area, ft (not to exceed 1.5 ft)
Method for Bioretention with Underdrains
If the bioretention geometry has already been defined and the user wishes to account more explicitly for
routing, the user can determine the required footprint area using the Capture Efficiency Method for
Volume- Based, Constant Drawdown BMPs (See Appendix III.3.2) to determine the fraction of the DCV
that must be provided to manage 80 percent of average annual runoff volume. This method accounts for
drawdown time different than 48 hours.
Step 1: Determine the drawdown time associated with the selected basin geometry
DD = (dp / KDESIGN) x 12 in /ft
Where:
DD = time to completely drain infiltration basin ponding depth, hours
XIV -53 May 19, 2011
TECHNICAL GUIDANCE DOCUMENT APPENDICES
dE = bioretention ponding depth, ft (should be less than or equal to 1.5 ft)
KDESicN = design media infiltration rate, in /hr (assume 2.5 inches per hour unless otherwise proposed)
If drawdown is less than 3 hours, the drawdown time should be rounded to 3 hours or the Capture
Efficiency Method for Flow -based BMPs (See Appendix III.3.3) shall be used.
Step 2: Determine the Required Adjusted DCV for this Drawdown Time
Use the Capture Efficiency Method for Volume- Based, Constant Drawdown BMPs (See Appendix 1II.3.2)
to calculate the fraction of the DCV the basin must hold to achieve 80 percent capture of average annual
stormwater runoff volume based on the basin drawdown time calculated above.
Step 3: Determine the Basin Infiltrating Area Needed
The required infiltrating area (i.e. the surface area of the top of the media layer) can be calculated using
the following equation:
A = Design Volume / dP
Where:
A = required infiltrating area, sq -ft (measured at the media surface)
Design Volume = fraction of DCV, adjusted for drawdown, cu -ft (see Step 2)
dP = ponding depth of water stored in bioretention area, ft (from Step 1)
This does not include the side slopes, access roads, etc. which would increase bioretention footprint. If
the area required is greater than the selected basin area, adjust surface area or adjust ponding depth and
recalculate required area until the required area is achieved.
Configuration for Use in a Treatment Train
• Bioretention areas may be preceeded in a treatment train by HSCs in the drainage area, which
would reduce the required design volume of the bioretention cell. For example, bioretention could
be used to manage overflow from a cistern.
• Bioretention areas can be used to provide pretreatment for underground infiltration systems.
Additional References for Design Guidance
• CASQA BMP Handbook for New and Redevelopment:
httpV/www.cabmphandbooks.conVDocuments/DevelopmentIrC-32.pdf
• SMC LID Manual (pp 68):
htt ;tl www. lowimpactdevelopment .org /guest75/pub /All Projects/SoCal LID Manual/SoCa1L
ID Manual FINAL 040910.pdf
• Los Angeles County Stormwater BMP Design and Maintenance Manual, Chapter 5:
httv;/ /dyw.lacounty.8ov/DES /design manuals/ StormwaterBMPDesignandMaintenance .ydf
• San Diego County LID Handbook Appendix 4 (Factsheet 7):
httt)V/www.sdcoun!y.ca.gov/dylu/docs/LID-Appendices.p df
Los Angeles Unified School District (LAUSD) Stormwater Technical Manual, Chapter 4:
http;// www. laschools .orglemployee /design/fs- studies -and-
re p orts/download/white_paper _ re port_material/Storm_W ater_Technical_Manual_2009-opt-
re d.pdf ?versio n_id= 76975850
• County of Los Angeles Low Impact Development Standards Manual, Chapter 5:
http;/ /dpw.lacounty_. goy /wmd/LA_ County, _ LID _Manual.pdf
XIV -54 May 19, 2011
Extended Detention Basin
Description
Dry extended detention ponds (a.k.a. dry ponds, extended
detention basins, detention ponds, extended detention ponds)
are basins whose outlets have been designed to detain the
stormwater runoff from a water quality design storm for some
minimum time (e.g., 48 hours) to allow particles and associated
pollutants to settle. Unlike wet ponds, these facilities do not have
a large permanent pool. They can also be used to provide flood
control by including additional flood detention storage.
California Experience
Caltrans constructed and monitored 5 extended detention basins
in southern California with design drain times of 72 hours. Four
of the basins were earthen, less costly and had substantially
better load reduction because of infiltration that occurred, than
the concrete basin. The Caltrans study reaffirmed the flexibility
and performance of this conventional technology. The small
headless and few siting constraints suggest that these devices are
one of the most applicable technologies for stormwater
treatment.
Advantages
■ Due to the simplicity of design, extended detention basins are
relatively easy and inexpensive to construct and operate.
■ Extended detention basins can provide substantial capture of
sediment and the toxics fraction associated with particulates.
■ Widespread application with sufficient capture volume can
provide significant control of channel erosion and
enlargement caused by changes to flow frequency
TC -22
Design Considerations
in Tributary Area
• Area Required
• Hydraulic Head
Targeted Constituents
Q
Sediment
Q
Nutrients
•
Q
Trash
■
Q
Metals
Q
Bacteria
Q
Oil and Grease
Q
Organics
Legend (Removal Effectiveness)
• Low ■ High
Medium
January 2003 California Stormwater BMP Handbook 1 of 10
Errata 5 -06 New Development and Redevelopment
www.cabmphandbook.com
TC -22 Extended Detention Basin
relationships resulting from the increase of impervious cover in a watershed.
Limitations
■ Limitation of the diameter of the orifice may not allow use of extended detention in
watersheds of less than 5 acres (would require an orifice with a diameter of less than 0.5
inches that would be prone to clogging).
■ Dry extended detention ponds have only moderate pollutant removal when compared to
some other structural stormwater practices, and they are relatively ineffective at removing
soluble pollutants.
■ Although wet ponds can increase property values, dry ponds can actually detract from the
value of a home due to the adverse aesthetics of dry, bare areas and inlet and outlet
structures.
Design and Sizing Guidelines
■ Capture volume determined by local requirements or sized to treat 85% of the annual runoff
volume.
■ Outlet designed to discharge the capture volume over a period of hours.
■ Length to width ratio of at least 1.5:1 where feasible.
■ Basin depths optimally range from 2 to 5 feet.
■ Include energy dissipation in the inlet design to reduce resuspension of accumulated
sediment.
■ A maintenance ramp and perimeter access should be included in the design to facilitate
access to the basin for maintenance activities and for vector surveillance and control.
■ Use a draw down time of 48 hours in most areas of California. Draw down times in excess of
48 hours may result in vector breeding, and should be used only after coordination with
local vector control authorities. Draw down times of less than 48 hours should be limited to
BMP drainage areas with coarse soils that readily settle and to watersheds where warming
may be determined to downstream fisheries.
Construction/ Inspection Considerations
■ Inspect facility after first large to storm to determine whether the desired residence time has
been achieved.
■ When constructed with small tributary area, orifice sizing is critical and inspection should
verify that flow through additional openings such as bolt holes does not occur.
Performance
One objective of stormwater management practices can be to reduce the flood hazard associated
with large storm events by reducing the peak flow associated with these storms. Dry extended
detention basins can easily be designed for flood control, and this is actually the primary
purpose of most detention ponds.
2 of 10 California Stormwater BMP Handbook January 2003
New Development and Redevelopment Errata 5 -06
www.cabmphandbooks.com
Extended Detention Basin TC -22
Dry extended detention basins provide moderate pollutant removal, provided that the
recommended design features are incorporated. Although they can be effective at removing
some pollutants through settling, they are less effective at removing soluble pollutants because
of the absence of a permanent pool. Several studies are available on the effectiveness of dry
extended detention ponds including one recently concluded by Caltrans (2002).
The load reduction is greater than the concentration reduction because of the substantial
infiltration that occurs. Although the infiltration of stormwater is clearly beneficial to surface
receiving waters, there is the potential for groundwater contamination. Previous research on the
effects of incidental infiltration on groundwater quality indicated that the risk of contamination
is minimal.
There were substantial differences in the amount of infiltration that were observed in the
earthen basins during the Caltrans study. On average, approximately 40 percent of the runoff
entering the unlined basins infiltrated and was not discharged. The percentage ranged from a
high of about 6o percent to a low of only about 8 percent for the different facilities. Climatic
conditions and local water table elevation are likely the principal causes of this difference. The
least infiltration occurred at a site located on the coast where humidity is higher and the basin
invert is within a few meters of sea level. Conversely, the most infiltration occurred at a facility
located well inland in Los Angeles County where the climate is much warmer and the humidity
is less, resulting in lower soil moisture content in the basin floor at the beginning of storms.
Vegetated detention basins appear to have greater pollutant removal than concrete basins. In
the Caltrans study, the concrete basin exported sediment and associated pollutants during a
number of storms. Export was not as common in the earthen basins, where the vegetation
appeared to help stabilize the retained sediment.
Siting Criteria
Dry extended detention ponds are among the most widely applicable stormwater management
practices and are especially useful in retrofit situations where their low hydraulic head
requirements allow them to be sited within the constraints of the existing storm drain system. In
addition, many communities have detention basins designed for flood control. It is possible to
modify these facilities to incorporate features that provide water quality treatment and /or
channel protection. Although dry extended detention ponds can be applied rather broadly,
designers need to ensure that they are feasible at the site in question. This section provides
basic guidelines for siting dry extended detention ponds.
In general, dry extended detention ponds should be used on sites with a minimum area of 5
acres. With this size catchment area, the orifice size can be on the order of 0.5 inches. On
smaller sites, it can be challenging to provide channel or water quality control because the
orifice diameter at the outlet needed to control relatively small storms becomes very small and
thus prone to clogging. In addition, it is generally more cost - effective to control larger drainage
areas due to the economies of scale.
Extended detention basins can be used with almost all soils and geology, with minor design
adjustments for regions of rapidly percolating soils such as sand. In these areas, extended
detention ponds may need an impermeable liner to prevent ground water contamination.
January 2003 California Stormwater BMP Handbook 3 of 10
Errata 5 -06 New Development and Redevelopment
www.cabmphandbook.com
TC -22 Extended Detention Basin
The base of the extended detention facility should not intersect the water table. A permanently
wet bottom may become a mosquito breeding ground. Research in Southwest Florida (Santana
et al., 1994) demonstrated that intermittently flooded systems, such as dry extended detention
ponds, produce more mosquitoes than other pond systems, particularly when the facilities
remained wet for more than 3 days following heavy rainfall.
A study in Prince George's County, Maryland, found that stormwater management practices can
increase stream temperatures (Galli,19go). Overall, dry extended detention ponds increased
temperature by about 5 °F. In cold water streams, dry ponds should be designed to detain
stormwater for a relatively short time (i.e., 24 hours) to minimize the amount of warming that
occurs in the basin.
Additional Design Guidelines
In order to enhance the effectiveness of extended detention basins, the dimensions of the basin
must be sized appropriately. Merely providing the required storage volume will not ensure
maximum constituent removal. By effectively configuring the basin, the designer will create a
long flow path, promote the establishment of low velocities, and avoid having stagnant areas of
the basin. To promote settling and to attain an appealing environment, the design of the basin
should consider the length to width ratio, cross - sectional areas, basin slopes and pond
configuration, and aesthetics (Young et al., 1996).
Energy dissipation structures should be included for the basin inlet to prevent resuspension of
accumulated sediment. The use of stilling basins for this purpose should be avoided because the
standing water provides a breeding area for mosquitoes.
Extended detention facilities should be sized to completely capture the water quality volume. A
micropool is often recommended for inclusion in the design and one is shown in the schematic
diagram. These small permanent pools greatly increase the potential for mosquito breeding and
complicate maintenance activities; consequently, they are not recommended for use in
California.
A large aspect ratio may improve the performance of detention basins; consequently, the outlets
should be placed to maximize the flowpath through the facility. The ratio of flowpath length to
width from the inlet to the outlet
should be at least 1.5:1(L:W)
where feasible. Basin depths
optimally range from 2 to 5 feet.„ _
The facility's drawdown time
should be regulated by an orifice
or weir. In general, the outflow
structure should have a trash
rack or other acceptable means
of preventing clogging at the
entrance to the outflow pipes.
The outlet design implemented
by Caltrans in the facilities
constructed in San Diego County
used an outlet riser with orifices
i
Figure 1
Example of Extended Detention Outlet Structure
4 of 10 California Stormwater BMP Handbook January 2003
New Development and Redevelopment Errata 5 -06
www.cabmphandbooks.com
Extended Detention Basin
TC -22
sized to discharge the water quality volume, and the riser overflow height was set to the design
storm elevation. A stainless steel screen was placed around the outlet riser to ensure that the
orifices would not become clogged with debris. Sites either used a separate riser or broad crested
weir for overflow of runoff for the 25 and greater year storms. A picture of a typical outlet is
presented in Figure 1.
The outflow structure should be sized to allow for complete drawdown of the water quality
volume in 72 hours. No more than 50% of the water quality volume should drain from the
facility within the first 24 hours. The outflow structure can be fitted with a valve so that
discharge from the basin can be halted in case of an accidental spill in the watershed.
Summary of Design Recommendations
(1) Facility Sizing - The required water quality volume is determined by local regulations
or the basin should be sized to capture and treat 85% of the annual runoff volume.
See Section 5.5.1 of the handbook for a discussion of volume -based design.
Basin Configuration — A high aspect ratio may improve the performance of detention
basins; consequently, the outlets should be placed to maximize the flowpath through
the facility. The ratio of flowpath length to width from the inlet to the outlet should
be at least 1.5:1 (L:V). The flowpath length is defined as the distance from the inlet
to the outlet as measured at the surface. The width is defined as the mean width of
the basin. Basin depths optimally range from 2 to 5 feet. The basin may include a
sediment forebay to provide the opportunity for larger particles to settle out.
A micropool should not be incorporated in the design because of vector concerns. For
online facilities, the principal and emergency spillways must be sized to provide l.o
foot of freeboard during the 25 -year event and to safely pass the flow from loo -year
storm.
(2) Pond Side Slopes - Side slopes of the pond should be 3:1(H:V) or flatter for grass
stabilized slopes. Slopes steeper than 3:1(H:V) must be stabilized with an
appropriate slope stabilization practice.
(3) Basin Lining — Basins must be constructed to prevent possible contamination of
groundwater below the facility.
(4) Basin Inlet — Energy dissipation is required at the basin inlet to reduce resuspension
of accumulated sediment and to reduce the tendency for short- circuiting.
(5) Outflow Structure - The facility's drawdown time should be regulated by a gate valve
or orifice plate. In general, the outflow structure should have a trash rack or other
acceptable means of preventing clogging at the entrance to the outflow pipes.
The outflow structure should be sized to allow for complete drawdown of the water
quality volume in 72 hours. No more than 50% of the water quality volume should
drain from the facility within the first 24 hours. The outflow structure should be
fitted with a valve so that discharge from the basin can be halted in case of an
accidental spill in the watershed. This same valve also can be used to regulate the
rate of discharge from the basin.
January 2003 California Stormwater BMP Handbook 5 of 10
Errata 5 -06 New Development and Redevelopment
www.cabmphandbook.com
TC -22 Extended Detention Basin
The discharge through a control orifice is calculated from:
Q = CA(2g(H -Ha))° 5
where: Q = discharge (ft3 /s)
C = orifice coefficient
A = area of the orifice (ft2)
g = gravitational constant (32.2)
H = water surface elevation (ft)
Ho= orifice elevation (ft)
Recommended values for C are o.66 for thin materials and o.8o when the material is
thicker than the orifice diameter. This equation can be implemented in spreadsheet
form with the pond stage /volume relationship to calculate drain time. To do this, use
the initial height of the water above the orifice for the water quality volume. Calculate
the discharge and assume that it remains constant for approximately 10 minutes.
Based on that discharge, estimate the total discharge during that interval and the
new elevation based on the stage volume relationship. Continue to iterate until H is
approximately equal to Ho. When using multiple orifices the discharge from each is
summed.
(6) Splitter Box - When the pond is designed as an offline facility, a splitter structure is
used to isolate the water quality volume. The splitter box, or other flow diverting
approach, should be designed to convey the 25 -year storm event while providing at
least l.o foot of freeboard along pond side slopes.
(7) Erosion Protection at the Outfall - For online facilities, special consideration should
be given to the facility's outfall location. Flared pipe end sections that discharge at or
near the stream invert are preferred. The channel immediately below the pond
outfall should be modified to conform to natural dimensions, and lined with large
stone riprap placed over filter cloth. Energy dissipation may be required to reduce
flow velocities from the primary spillway to non - erosive velocities.
(8) Safety Considerations - Safety is provided either by fencing of the facility or by
managing the contours of the pond to eliminate dropoffs and other hazards. Earthen
side slopes should not exceed 3:1 (H:V) and should terminate on a flat safety bench
area. Landscaping can be used to impede access to the facility. The primary spillway
opening must not permit access by small children. Outfall pipes above 48 inches in
diameter should be fenced.
Maintenance
Routine maintenance activity is often thought to consist mostly of sediment and trash and
debris removal; however, these activities often constitute only a small fraction of the
maintenance hours. During a recent study by Caltrans, 72 hours of maintenance was performed
annually, but only a little over '7 hours was spent on sediment and trash removal. The largest
recurring activity was vegetation management, routine mowing. The largest absolute number of
hours was associated with vector control because of mosquito breeding that occurred in the
stilling basins (example of standing water to be avoided) installed as energy dissipaters. In most
cases, basic housekeeping practices such as removal of debris accumulations and vegetation
6 of 10 California Stormwater BMP Handbook January 2003
New Development and Redevelopment Errata 5 -06
www.cabmphandbooks.com
Extended Detention Basin TC -22
management to ensure that the basin dewaters completely in 48 -72 hours is sufficient to prevent
creating mosquito and other vector habitats.
Consequently, maintenance costs should be estimated based primarily on the mowing frequency
and the time required. Mowing should be done at least annually to avoid establishment of
woody vegetation, but may need to be performed much more frequently if aesthetics are an
important consideration.
Typical activities and frequencies include:
• Schedule semiannual inspection for the beginning and end of the wet season for standing
water, slope stability, sediment accumulation, trash and debris, and presence of burrows.
• Remove accumulated trash and debris in the basin and around the riser pipe during the
semiannual inspections. The frequency of this activity may be altered to meet specific site
conditions.
• Trim vegetation at the beginning and end of the wet season and inspect monthly to prevent
establishment of woody vegetation and for aesthetic and vector reasons.
• Remove accumulated sediment and re -grade about every 10 years or when the accumulated
sediment volume exceeds 10 percent of the basin volume. Inspect the basin each year for
accumulated sediment volume.
Cost
Construction Cost
The construction costs associated with extended detention basins vary considerably. One recent
study evaluated the cost of all pond systems (Brown and Schueler,1997). Adjusting for
inflation, the cost of dry extended detention ponds can be estimated with the equation:
C = 12.4V° 760
where: C = Construction, design, and permitting cost, and
V = Volume (ft3).
Using this equation, typical construction costs are:
$ 41,60o for a 1 acre -foot pond
$ 239,000 for a 10 acre -foot pond
$1,380,00o for a loo acre -foot pond
Interestingly, these costs are generally slightly higher than the predicted cost of wet ponds
(according to Brown and Schueler, 1997) on a cost per total volume basis, which highlights the
difficulty of developing reasonably accurate construction estimates. In addition, a typical facility
constructed by Caltrans cost about $16o,000 with a capture volume of only 0.3 ac -ft.
An economic concern associated with dry ponds is that they might detract slightly from the
value of adjacent properties. One study found that dry ponds can actually detract from the
January 2003 California Stormwater BMP Handbook 7 of 10
Errata 5 -06 New Development and Redevelopment
www.cabmphandbook.com
TC -22 Extended Detention Basin
perceived value of homes adjacent to a dry pond by between 3 and 10 percent (Emmerling-
Dinovo, 1995)•
Maintenance Cost
For ponds, the annual cost of routine maintenance is typically estimated at about 3 to 5 percent
of the construction cost (EPA website). Alternatively, a community can estimate the cost of the
maintenance activities outlined in the maintenance section. Table 1 presents the maintenance
costs estimated by Caltrans based on their experience with five basins located in southern
California. Again, it should be emphasized that the vast majority of hours are related to
vegetation management (mowing).
Table 1
Estimated Average
Annual Maintenance Effort
Activitv
Labor Hours
Equipment &
Cost
-
Material ($)
Inspections
4
7
183
Maintenance
49
126
2282
Vector Control
0
0
0
Administration
3
0
132
Materials
-
535
535
Total
56
$668
$3,132
References and Sources of Additional Information
Brown, W., and T. Schueler. 1997. The Economics of Stormwater BMPs in the Mid - Atlantic
Region. Prepared for Chesapeake Research Consortium. Edgewater, MD. Center for Watershed
Protection. Ellicott City, MD.
Denver Urban Drainage and Flood Control District. 1992. Urban Storm Drainage Criteria
Manual — Volume 3: Best Management Practices. Denver, CO.
Emmerling - Dinovo, C. 1995• Stormwater Detention Basins and Residential Locational
Decisions. Water Resources Bulletin 31(3): 515 -521
Galli, J. 199o. Thermal Impacts Associated with Urbanization and Stormwater Management
Best Management Practices. Metropolitan Washington Council of Governments. Prepared for
Maryland Department of the Environment, Baltimore, MD.
GKY,1989, Outlet Hydraulics of Extended Detention Facilities for the Northern Virginia
Planning District Commission.
MacRae, C. 1996. Experience from Morphological Research on Canadian Streams: Is Control of
the Two -Year Frequency Runoff Event the Best Basis for Stream Channel Protection? In Effects
of Watershed Development and Management on Aquatic Ecosystems. American Society of
Civil Engineers. Edited by L. Roesner. Snowbird, UT. pp. 144 -162.
8 of 10 California Stormwater BMP Handbook January 2003
New Development and Redevelopment Errata 5 -06
www.cabmphandbooks.com
Extended Detention Basin TC -22
Maryland Dept of the Environment, 2000, Maryland Stormwater Design Manual: Volumes 1 &
2, prepared by MDE and Center for Watershed Protection.
http: / /www.mde. state. md. us / environment/ wma /stormwatermanual /index.html
Metzger, M. E., D. F. Messer, C. L. Beitia, C. M. Myers, and V. L. Kramer. 2002. The Dark Side
Of Stormwater Runoff Management: Disease Vectors Associated With Structural BMPs.
Stormwater 3(2): 24-39•
Santana, F., J. Wood, R. Parsons, and S. Chamberlain. 1994• Control of Mosquito Breeding in
Permitted Stormwater Systems. Prepared for Southwest Florida Water Management District,
Brooksville, FL.
Schueler, T. 1997. Influence of Ground Water on Performance of Stormwater Ponds in Florida.
Watershed Protection Techniques 2(4) :525 -528•
Watershed Management Institute (WMI). 1997. Operation, Maintenance, and Management of
Stormwater Management Systems. Prepared for U.S. Environmental Protection Agency, Office
of Water. Washington, DC.
Young, G.K., et al., 1996, Evaluation and Management of Highway Runoff Water Quality,
Publication No. FHWA -PD -96 -032, U.S. Department of Transportation, Federal Highway
Administration, Office of Environment and Planning.
Information Resources
Center for Watershed Protection (CWP), Environmental Quality Resources, and Loiederman
Associates. 1997. Maryland Stormwater Design Manual. Draft. Prepared for Maryland
Department of the Environment, Baltimore, MD.
Center for Watershed Protection (CWP). 1997. Stormwater BMP Design Supplementfor Cold
Climates. Prepared for U.S. Environmental Protection Agency, Office of Wetlands, Oceans and
Watersheds. Washington, DC.
U.S. Environmental Protection Agency (USEPA).1993• Guidance Specifying Management
Measures for Sources ofNonpoint Pollution in Coastal Waters. EPA- 84o -B -92 -002. U.S.
Environmental Protection Agency, Office of Water, Washington, DC.
January 2003 California Stormwater BMP Handbook 9 of 10
Errata 5 -06 New Development and Redevelopment
www.cabmphandbook.com
TC -22 Extended Detention Basin
MAXIMUM ELEVATI(
OF SAFETY STORM
OF ED POOL + C3„
SPILLWAY
•
ye:x ,_ \ ++ n'I ACS,, �y
1
4,
j .•, "� a \'i..
INFLOW
�.�yy
arm
IS
PLAN VIEW
FILTER DIAPHRAGM
PROFILE
Schematic of an Extended Detention Basin (MDE, 2000)
10 of 10 California Stormwater BMP Handbook January 2003
New Development and Redevelopment Errata 5 -06
www.cabmphandbooks.com
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH
SECTION VII EDUCATIONAL MATERIALS
FEBRUARY 3, 2012
The educational materials included in this WQMP are provided to inform people involved in future
uses, activities, or ownership of the site about the potential pitfalls associated with careless storm water
management. "The Ocean Begins at Your Front Door" provides users with information about storm
water that is /will be generated on site, what happens when water enters a storm drain, and its ultimate
fate, discharging into the ocean. Also included are activities guidelines to educate anyone who is or
will be associated with activities that have a potential to impact storm water runoff quality, and provide
a menu of BMPs to effectively reduce the generation of storm water runoff pollutants from a variety of
activities. The educational materials that may be used for the proposed project are included in
Appendix C of this WQMP and are listed below.
EDUCATION MATERIALS
Residential Materials
(http: / /www.ocwatersheds.com)
Check If
Applicable
Business Materials
(http://www.ocwatersheds.com)
Check If
Applicable
The Ocean Begins at Your Front Door
®
Tips for the Automotive Industry
❑
Tips for Car Wash Fund - raisers
❑
Tips for Using Concrete and Mortar
❑
Tips for the Home Mechanic
❑
Tips for the Food Service Industry
Homeowners Guide for Sustainable
Water Use
®
Proper Maintenance Practices for Your
Business
Household Tips
❑
Other Materials
(http: / /www.ocwatersheds.com)
(hftp: / /www.cabmphandbooks.com)
Check If
Attached
Proper Disposal of Household
Hazardous Waste
®
Recycle at Your Local Used Oil
Collection Center North County)
El
DF -1 Drainage System Operation &
Maintenance
Recycle at Your Local Used Oil
Collection Center Central Count
®
R -1 Automobile Repair &Maintenance
Recycle at Your Local Used Oil
Collection Center South County)
❑
R -2 Automobile Washing
Tips for Maintaining Septic Tank Systems
❑
R -3 Automobile Parking
Responsible Pest Control
Z
R -4 Home & Garden Care Activities
Sewer Spill
❑
R -5 Disposal of Pet Waste
Tips for the Home Improvement Projects
®
R -b Disposal of Green Waste
Tips for Horse Care
❑
R -7 Household Hazardous Waste
Tips for Landscaping and Gardening
®
R -8 Water Conservation
Tips for Pet Care
®
SD -10 Site Design & Landscape Planning
Tips for Pool Maintenance
®
SD -11 Roof Runoff Controls
Tips for Residential Pool, Landscape and
Hardsca e Drains
®
$D -12 Efficient Irrigation
❑
Tips for Projects Using Paint
SD -13 Storm Drain Signage
Other:
❑
SD -31 Maintenance Bays & Docs
❑
Other:
❑
SD -32 Trash Storage Areas
NEWPORT BANNING RANCH, LLC 45 EDUCATIONAL MATERIALS
PRELIMINARY WATER QUALITY MANAGEMENT PLAN (P -WQMP)
NEWPORT BANNING RANCH FEBRUARY 3, 2012
APPENDICES
Appendix ..................... ............................. ............................................. Supporting Calculations
Appendix B ......................... ............................... .........................Notice of Transfer of Responsibility
Appendix C ................................................................... ............................... Educational Materials
Appendix D ................................... ............................... BMP Maintenance Supplement / O &M Plan
Appendix E ............................ .....................Conditions of Approval (Placeholder — Pending Issuance)
Appendix F ................. ............................... .....................Memorandum on Limitations for Infiltration
Appendix G ................_.......... _.............................. ...............Planning -Level Water Quality Modeling
NEWPORT BANNING RANCH, LLC 46 APPENDICES
APPENDIX A
SUPPORTING CALCULATIONS
Water Quality LID Calculations - Newport Banning Ranch
Land Use Plan December 2009
For modeling purposes 12/22/2011
mon wnn unaerarams careen aireeis
(Biotreatment) I (Bioretention w/ Underdrains)
Drainage
Area ID
Land Use Type
%
impervious
Runoff
Coefficient
Design
Storm
Depth
Drainage
Area (ac)
Impervious
Area (ac)
Unit
Conversion
Treatment
Required
( s)
DCV ft
Ponding
Depth (ft)
Depth
Filtered
(ft )
Footprint 2
Needed (ft)
Ponding
Depth (ft)
Depth
Filtered
ft
( )
Footprint
Needed
(ftz)
Length
Required
6' Wide
(total. ftl
Length
Required
(each
side. ft)
Approx.
Length
Avail. ft
( )
WCH Tributa
- Storm Drain A
A19.4
Community Park
15%
0.26
0.7
3.90
0.59
3630
2,616
1.5
0.625
1,231.2
A19.2
Community Park
15%
0.26
0.7
6.81
1.02
3630
4,568
1.5
0.625
2,149.8
A7.3
Community Park
15%
0.26
0.7
4.18
0.63
3630
2,804
1.5
0.625
1,319.6
South Arroyo Tributa - Southerly Draina a Areas Storm Drain B
Al2.1
Low Density Resid.
80%
0.75
0.7
2.97
2.38
3630
5,671
1.5
0.625
2,668.9
Al2.10
Visitor Resort/Resid.
80%
0.75
0.7
4.62
3.70
3630
8,822
1.5
0.625
4,151.6
Al2.11
Bluff Park
5%
0.19
0.7
0.41
0.02
3630
197
1.5
0.625
92.7
Al2.12
Visitor Resort/Resid.
80%
0.75
0.7
5.47
4.38
3630
10,445
1.5
0.625
4,915.4
Al2.13
Bluff Park
5%
0.19
0.7
1.80
0.09
3630
864
1.5
0.625
406.8
Al2.14
Bluff Park
5%
0.19
0.7
1.26
0.06
3630
605
1.5
0.625
284.8
Al2.15
Bluff Park
5%
0.19
0.7
1.03
0.05
3630
495
1.5
0.625
232.8
Al2.2
Collector Road
90%
0.83
0.7
0.83
0.75
3630
1,743
1.5
0.625
820.3
Al2.3
Medium Density Resid.
80%
0.75
0.7
2.67
2.14
3630
5,099
1.5
0.625
2,399.3
Al2.4
Collector Road
90%
0.83
0.7
0.82
0.74
3630
1,722
1.5
0.625
810.4
Al2.5
Low Density Resid.
80%
0.75
0.7
2.11
1.69
3630
4 029
1.5
0.625
1,896.1
Al2.6
Collector Road
90%
0.83
0.7
0.90
0.81
3630
1,890
1.5
0.625
889.5
Al2.7
Low Density Resid.
80%
0.75
0.7
2.19
1.75
3630
4,182
1.5
0.625
1,968.0
Al2.8
Medium Density Resid.
80%
0.75
0.7
3.98
3.18
3630
7,600
1.5
0.625
3,576.5
Al2.9
Collector Road
90%
0.83
0.7
1.17
1.05
3630
2,457
0.50
0.50
2,457.2
A20.4
Bluff Park
50
0.19
0.7
1.24
0.06
3630
596
1.5
0.625
280.2
TOTAL
68.25%
0.66
0.7
33.47
22.84
3630
56,418
1.5
0.625
26,549.5
South Arroyo Tributary - Northerly Drainage Areas (Storm Drain C)
A11.4
Medium Density Resid.
80%
0.75
0.7
3.27
2.62
3630
6,244
1.5
0.625
2,938.5
A11.1
Arterial Road
90%
0.83
0.7
0.57
0.51
3630
1,197
0.50
0.50
1,197.1
A11.10
Low - Medium Resid.
80%
0.75
0.7
0.93
0.74
3630
1,776
1.5
0.625
835.7
-
A11.11
Bluff Park
15%
0.26
0.7
0.85
0.13
3630
570
1.5
0.625
268.3
A11.12
Collector Road
90%
0.83
0.7
0.50
0.45
3630
1,050
1.5
0.625
494.1
A11.13
Bluff Park
15%
0.26
0.7
0.85
0.13
3630
570
1.5
0.625
268.3
A11.14
Low - Medium Resid.
80%
0.75
0.7
1.04
0.83
3630
1,986
1.5
0.625
934.6
A11.15
Collector Road
90%
0.83
0.7
1.47
1.32
3630
3,087
1.5
0.625
1,452.8
A11.16
Bluff Park
15%
0.26
0.7
0.83
0.12
3630
557
1.5
0.625
262.0
A11.17
Low Density Resid.
60%
0.60
0.7
4.84
2.90
3630
7,398
1.5
0.625
3,481.2
-
A11.3
Collector Road
90%
0.83
0.7
0.65
0.59
3630
1,365
1.5
0.625
642.4
-
A11.5
Collector Road
90%
0.83
0.7
0.61
0.55
3630
1 1,281
1.5
0.625
602.9
A11.6
Bluff Park
15%
0.26
0.7
1.02
0.15
3630
684
1.5
0.625
322.0
A11.7
Collector Road
90%
0.83
0.7
0.68
1 0.61
3630
1,428
1.5
0.625
672.0
A11.8
Medium Density Resid.
1 80%
1 0.75
0.7
3.06
2.45
3630
5,843
1.5
0.625
2,749.8
A11.9
Collector Road
90%
0.83
0.7
0.83
0.75
3630
1,743
0.50
0.50
1,743.1
A8.2
Bluff Park
15%
0.26
0.7
0.94
0.14
3630
631
1.5
0.625
296.7
TOTAL
65.37%
0.64
0.7
22.94
15.00
3630
37,411
1.5
0.625
17,605.0
Bioretention With Underdrains Green Streets
(Biotreatment) I ( Bioretention w/ Underdrains)
Drainage
Area ID
Land Use Type
%
impervious
Runoff
Coefficient
Design
Storm
Depth
in
Drainage
Area (ac)
Impervious
Area (ac)
Unit
Conversion
Treatment
Required
DCV (ft')
Ponding
Depth (ft)
Depth
Filtered
(ft)
Footprint
z
Needed (ft)
Ponding
Depth (ft)
Depth
Filtered
(ft)
Footprint
Needed
(ft2)
Length
Required
6' Wide
total ft
Length
Required
(each
side. f
Approx.
Length
Avail. (ft)
Lowlands Tributary - West of Bluff Rd. (Storm Drain D
C10
Off -site Contribution
90%
0.83
0.7
0.88
0.79
3630
1,848
1.5
0.625
869.7
C11
Off -site Contribution
90%
0.83
0.7
1.06
0.95
3630
2,226
1.5
0.625
1,047.6
C12.1
Arterial Road
90%
0.83
0.7
1.10
0.99
3630
2,310
0.50
0.50
2,310.2
C13.1
Collector Road
90%
0.83
0.7
0.55
0.50
3630
1,155
1.5
0.625
543.6
C13.2
Open S ace /Trails
15%
0.26
0.7
3.72
0.56
3630
2,495
1.5
0.625
1,174.3
C14
Collector Road
90%
0.83
0.7
0.83
0.75
3630
1,743
1.5
0.625
820.3
C15
Interpretive Parks
0%
0.15
0.7
4.82
0.00
3630
1,856
1.5
0.625
873.2
C3.1
Arterial Road
90%
0.83
0.7
2.39
2.15
3630
5,019
0.50
0.50
5,019.3
C3.2
Medium Density Resid.
80%
0.75
0.7
2.66
2.13
3630
5,079
1.5
0.625
2,390.3
C3.3
Collector Road
90%
0.83
0.7
0.68
0.61
3630
1,428
1.5
0.625
672.0
C4.1
Mixed Use /Residential
80%
0.75
0.7
8.42
6.74
3630
16,079
1.5
0.625
7,566.4
C4.2
Arterial Road
90%
0.83
0.7
1.72
1.55
3630
3,612
0.50
0.50
3,612.2
C4.3
Collector Road
90%
0.83
0.7
0.60
0.54
3630
1,260
1.5
0.625
593.0
C4.4
Low - Medium Resid.
80%
0.75
0.7
1.13
0.90
3630
2,158
1.5
0.625
1,015.4
C4.5
Collector Road
90%
0.63
0.7
0.53
0.48
3630
1,113
--
0.50
0.50
1,113.1
C5.1
Medium Density Resid.
80%
0.75
0.7
3.20
2.56
3630
6,111
1.5
0.625
2,875.6
C5.2
Collector Road
90%
0.83
0.7
0.98
0.88
3630
2,058
0.50
0.50
2,058.1
C5.3
Low - Medium Resid.
80%
0.75
0.7
1.39
1.11
3630
2,654
1.5
0.625
1,249.1
C6.1
Collector Road
90%
0.83
0.7
0.37
0.33
3630
777
1.5
0.625
365.7
C6.2
Collector Road
90%
0.83
0.7
1.06
0.95
3630
2,226
1.5
0.625
1,047.6
C6.3
Low- Medium Resid.
80%
0.75
0.7
1.47
1.18
3630
2,807
1.5
0.625
1,321.0
C6.4
Low- Medium Resid.
80%
0.75
0.7
2.24
1.79
3630
4,277
1.5
0.625
2,012.9
-
C6.5
Collector Road
90%
0.83
0.7
0.28
0.25
3630
588
1.5
0.625
276.7
C7.1
Low Density Resid.
60%
0.60
0.7
3.96
2.38
3630
6,053
1.5
0.625
2,848.2
C7.2
Collector Road
90%
0.83
0.7
1.26
1.13
3630
2,646
0.50
0.50
2,646.2
C7.3
Bluff Park
15%
0.26
0.7
0.76
0.11
3630
510
1.5
0.625
239.9
C8.1
Collector Road
90%
0.83
0.7
1.68
1.51
3630
3,528
1.5
0.625
1,660.3
C8.2
Low Density Resid.
60%
0.60
0.7
4.58
2.75
3630
7,000
1.5
0.625
3,294.2
C9
Bluff Park
15%
0.26
0.7
1.11
0.17
3630
745
1.5
0.625
350.4
TOTAL
66.29 ° /a
0.65
0.7
55.43
36.74
3630
91,362
1.5
0.625
42,994.0
Lowlands Tributary - East of Bluff Rd. Storm Drain E
C12.2
IMixed Use /Residential
80%
0.75
0.7
5.11
4.09
3630
9,758
1.5
0.625
4,591.9
Lowlands Tributary - Storm Drain F
611.1
Mixed Use /Residential
80%
0.75
0.7
4.57
3.66
3630
8,727
1.5
0.625
4,106.7
(Biotreatment) (Bioretention w/ Underdrains)
Drainage
Area ID
Land Use Type
%
impervious
Runoff
Coefficient
Design
Storm
Depth
in
Drainage
Area (ac)
Impervious
Area (ac)
Unit
Conversion
Treatment
Required
DCV (ft')
Ponding
Depth (ft)
Depth
Filtered
(ft)
Footprint
Needed (ft)
Ponding
Depth (ft)
Depth
Filtered
(ft)
Footprint
Needed
W)
Length
Required
6' Wide
Length
Required
(each
Approx.
Length
Avail. (ft)
Green Streets - Total (includes areas above)
A11.1
Arterial Road
90%
0.83
0.7
0.57
0.51
3630
1,197
0.50
0.50
1,197.1
199.5
99.8
274.0
A11.9
Arterial Road
90%
0.83
0.7
0.83
0.75
3630
1,743
0.50
0.50
1,743.1
290.5
145.3
470.0
A19.1
Arterial Road
90%
0.83
0.7
1.09
0.98
3630
2,289
0.50
0.50
2,289.1
381.5
190.8
420.0
A19.3
Arterial Road
90%
0.83
0.7
1.58
1.42
3630
3,318
0.50
0.50
3,318.2
553.0
276.5
550.0
A19.5
Arterial Road
90%
0.83
0.7
2.93
2.64
3630
6,153
0.50
0.50
6,153.4
1,025.6
512.8
795.0
A19.7
Arterial Road
90%
0.83
0.7
2.52
2.27
3630
5,292
0.50
0.50
5,292.3
882.1
441.0
822.0
A7.5
Arterial Road
90%
0.83
0.7
1.9
1.71
3630
3,990
0.50
0.50
3,990.3
665.0
332.5
700.0
C5.2
Arterial Road
90%
0.83
0.7
0.98
0.88
3630
2,058
0.50
0.50
2,058.1
343.0
171.5
475.0
C4.5
Arterial Road
90%
0.83
0.7
0.53
0.48
3630
1,113
0.50
0.50
1,113.1
185.5
92.8
274.0
C3.1
Arterial Road
90%
0.83
0.7
3.39
3.05
3630
7,119
0.50
0.50
7,119.5
1,186.6
593.3
859.0
C4.2
Arterial Road
90%
0.83
0.7
1.72
1.55
3630
3,612
0.50
0.50
3,612.2
602.0
301.0
460.0
C7.2
Arterial Road
90%
0.83
0.7
0.63
0.57
3630
1,323
0.50
0.50
1,323.1
220.5
110.3
350.0
C12.1
Arterial Road
90%
0.83
0.7
1.1
0.99
3630
2,310
0.50
0.50
2,310.2
385.0
192.5
440.0
1311.3
Arterial Road
90%
0.83
0.7
2.21
1.99
3630
4,641
0.50
0.50
4,641.3
773.6
386.8
1,310.0
D3.2
Arterial Road
90%
0.83
0.7
2.72
2.45
3630
5,712
0.50
0.50
5,712.4
952.1
476.0
1,470.0
Al2.9
Collector Road
90%
0.83
0.7
1.17
1.05
3630
2,457
0.50
0.50
2,457.2
409.5
204.8
647.0
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XVI -2b
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Potential Areas of Erosion, Habitat, &
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Channel Type
— Earth (Unstable)
— Earth (Stabilized)
— Stabilized
Tidel Influence
= <= Mean High Water Line (4.28')
Water Body
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0 Dam
jr1 Lake
Reservoir
Forest Areas
Cleveland National Forest
Other Lands
Airport/Military
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NEWPORT BANNING RANCH EXHIBIT Z: Rational Method Hydrology Map for Proposed Condition
t.0i
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FUSCOE
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APPENDIX B
NOTICE OF TRANSFER OF RESPONSIBILITY
NOTICE OF TRANSFER OF RESPONSIBILITY
WATER QUALITY MANAGEMENT PLAN
Newport Banning Ranch
Tentative Tract Map 17308
Submission of this Notice Of Transfer of Responsibility constitutes notice to the City of Newport Beach
that responsibility for the Water Quality Management Plan ( "WQMP ") for the subject properly identified
below, and implementation of that plan, is being transferred from the Previous Owner (and his /her
agent) of the site (or a portion thereof) to the New Owner, as further described below.
Previous Owner/ Previous Responsible Party Information
Company/ Individual Name:
Contact Person:
Street Address:
Title:
City:
State:
ZIP:
Phone:
II. Information about Site Transferred
Name of Project (if applicable):
Title of WQMP Applicable to site:
Street Address of Site (if applicable):
Planning Area (PA) and/
or Tract Number(s) for Site:
Lot Numbers (if Site is a portion of a tract):
Date WQMP Prepared (and revised if applicable):
New Owner/ New Responsible Party Information
Company/ Individual Name:
Contact Person:
Street Address:
Title:
City:
State:
ZIP:
Phone:
IV. Ownership Transfer Information
General Description of Site Transferred to New General Description of Portion of Project/ Parcel
Owner: Subject to WQMP Retained by Owner (if any):
Lot/ Tract Numbers of Site Transferred to New Owner:
Remaining Lot/ Tract Numbers Subject to WQMP Still Held by Owner (if any):
Date of Ownership Transfer:
Note: When the Previous Owner is transferring a Site that is a portion of a larger project/ parcel
addressed by the WQMP, as opposed to the entire project /parcel addressed by the WQMP, the
General Description of the Site transferred and the remainder of the project/ parcel no transferred shall
be set forth as maps attached to this notice. These maps shall show those portions of a project/ parcel
addressed by the WQMP that are transferred to the New Owner (the Transferred Site), those portions
retained by the Previous Owner, and those portions previously transferred by Previous Owner. Those
portions retained by Previous Owner shall be labeled as "Previously Transferred ".
V. Purpose of Notice of Transfer
The purposes of this Notice of Transfer of Responsibility are: 1) to track transfer of responsibility for
implementation and amendment of the WQMP when property to which the WQMP is transferred from
the Previous Owner to the New Owner, and 2) to facilitate notification to a transferee of property
subject to a WQMP that such New Order is now the Responsible Party of record for the WQMP for
those portions of the site that it owns.
VI. Certifications
A. Previous Owner
I certify under penalty of law that I am no longer the owner of the Transferred Site as described in
Section II above. I have provided the New Owner with a copy of the WQMP applicable to the
Transferred Site that the New Owner is acquiring from the Previous Owner.
Printed Name of Previous Owner Representative:
Title:
Signature of Previous Owner Representative:
Date:
New Owner
I certify under penalty of law that I am the owner of the Transferred Site, as described in Section II
above, that I have been provided a copy of the WQMP, and that I have informed myself and
understand the New Owner's responsibilities related to the WQMP, its implementation, and Best
Management Practices associated with it. I understand that by signing this notice, the New Owner is
accepting all ongoing responsibilities for implementation and amendment of the WQMP for the
Transferred Site, which the New Owner has acquired from the Previous Owner.
Printed Name of New Owner Representative:
Title:
Signature:
Date: