HomeMy WebLinkAbout2019-09-16 - EIR - Hydrology and Water Quality (Adams Streeter)15 Corporate Park | Irvine, CA 92606 | 949-474-2330
Draft Environmental Impact Report:
Section VII – Hydrology and Water Quality
Project Name:
Bayside Family Resort
Newport Beach CA
Prepared for:
Newport Bayside Resort, LLC
10250 Constellation Blvd. Suite 1750
Los Angeles, CA 90067
09.16.2019
Prepared by:
Felix Gonzalez
fgonzalez@adams-streeter.com
HYDROLOGY AND WATER QUALITY
This report discusses the potential impacts of the proposed project to hydrology and water quality conditions in the City of
Newport Beach. The terms hydrology and water quality are defined as the study of earth’s water and its movement in relation
to land and surface water pollution and associated regulations/practices to manage surface water quality, respectively. This
report is based on information and conclusions contained in the following studies
Preliminary Hydrology Report: Bayside Family Resort, prepared by Adams Streeter Civil Engineers, dated
September 16, 2019
Preliminary Water Quality Management Plan: Bayside Family Resort, prepared by Adams Streeter Civil Engineers,
dated September 16, 2019
REGULATORY SETTING
FEDERAL:
Safe Drinking Water Act
The Federal Safe Drinking Water Act regulates drinking water quality nationwide and gives the US Environmental Protection
Agency (EPA) the authority to set drinking water standards, such as the National Primary Drinking Water regulations, which
protect drinking water by limiting the levels of specific contaminants that can adversely affect public health. All public water
systems that provide service to 25 or more individuals must meet these standards. Water purveyors must monitor for
contaminants on fixed schedules and report to the EPA when a maximum contaminant level (MCL) is exceeded. MCL is the
maximum permissible level of a contaminant in water that is delivered to any user of a public water system. Contaminants
include organic and inorganic chemicals (e.g., minerals), substances that are known to cause cancer, radionuclides (e.g.,
uranium and radon), and microbial contaminants (e.g., coliform and E. coli). The MCL list typically changes every three years
as the EPA adds new contaminants or revises MCLs. The California Department of Public Health’s Division of Drinking Water
and Environmental Management is responsible for implementation of the Safe Drinking Water Act in California.
Clean Water Act
The Federal Water Pollution Control Act (or Clean Water Act [CWA]) is the principal statute governing water quality. The basis
of the CWA was enacted in 1948 and was called the Federal Water Pollution Control Act, but the Act was significantly
reorganized and expanded in 1972. "Clean Water Act" became the Act's common name with amendments in 1972. In 1987,
the Clean Water Act was further amended to require that the U.S. Environmental Protection Agency (USEPA) establish
regulations for permitting municipal and industrial storm water discharges under the NPDES permit program. Final
regulations regarding storm water discharges were issued on November 16, 1990, and required that municipal separate storm
sewer system (MS4) discharges and industrial (including construction) stormwater discharges to surface waters be regulated
by a NPDES permit and also gave the EPA authority to implement pollution control programs, such as setting wastewater
standards for industry. The statute’s goal is to completely end all discharges and to restore, maintain, and preserve the
integrity of the nation’s waters. The CWA regulates direct and indirect discharge of pollutants; sets water quality standards
for all contaminants in surface waters; and makes it unlawful for any person to discharge any pollutant from a point source
into navigable waters unless a permit is obtained under its provisions. The CWA mandates permits for wastewater and
stormwater discharges; requires states to establish site-specific water quality standards for navigable bodies of water; and
regulates other activities that affect water quality, such as dredging and filling wetlands. The CWA funds the construction of
sewage treatment plants and recognizes the need for planning to address nonpoint sources of pollution. Section 402 of the
CWA requires a permit for all point source (a discernible, confined, and discrete conveyance, such as a pipe, ditch, or channel)
discharges of any pollutant (except dredge or fill material) into waters of the United States.
National Pollutant Discharge Elimination System
Under the National Pollutant Discharge Elimination System (NPDES) program (under Section 402 of the CWA), all facilities
that discharge pollutants from any point source into waters of the United States must have a NPDES permit. The term
“pollutant” broadly applies to any type of industrial, municipal, and agricultural waste discharged into water. Point sources
can be publicly owned treatment works (POTWs), industrial facilities, and urban runoff. (The NPDES program addresses
certain agricultural activities, but the majority are considered nonpoint sources and are exempt from NPDES regulation.)
Direct sources discharge directly to receiving waters, and indirect sources discharge to POTWs, which in turn discharge to
receiving waters. Under the national program, NPDES permits are issued only for direct, point-source discharges. The National
Pretreatment Program addresses industrial and commercial indirect dischargers. Municipal sources are POTWs that receive
primarily domestic sewage from residential and commercial customers. Specific NPDES program areas applicable to municipal
sources are the National Pretreatment Program, the Municipal Sewage Sludge Program, Combined Sewer Overflows, and the
Municipal Storm Water Program. Nonmunicipal sources include industrial and commercial facilities. Specific NPDES program
areas applicable to these industrial/commercial sources are: Process Wastewater Discharges, Non-process Wastewater
Discharges, and the Industrial Storm Water Program. NPDES issues two basic permit types: individual and general. Also, the
EPA has recently focused on integrating the NPDES program further into watershed planning and permitting (USEPA 2012).
The NPDES has a variety of measures designed to minimize and reduce pollutant discharges. All counties with storm drain
systems that serve a population of 50,000 or more, as well as construction sites one acre or more in size, must file for and
obtain an NPDES permit. Another measure for minimizing and reducing pollutant discharges to a publicly owned conveyance
or system of conveyances (including roadways, catch basins, curbs, gutters, ditches, man-made channels, and storm drains)
designed or used for collecting and conveying stormwater is the EPA’s Storm Water Phase II Final Rule. The Phase II Final Rule
requires an operator (such as a city) of a regulated small municipal separate storm sewer system (MS4) to develop,
implement, and enforce a program (e.g., best management practices [BMPs], ordinances, or other regulatory mechanisms)
to reduce pollutants in post-construction runoff to the city’s storm drain system from new development and redevelopment
projects that result in the land disturbance of greater than or equal to one acre. The MS4 permit for the part of Orange County
in the Santa Ana Regional Water Quality Control Board’s (RWQCB) jurisdiction, Order No. R8-2009-0030, was issued by the
Santa Ana RWQCB in 2009. The City of Newport Beach Public Works Department is the local enforcing agency of the MS4
NPDES permit.
Federal Antidegradation Policy
The Federal Antidegradation Policy was released in 1968 and was included in the USEPA’s first Water Quality Standards
Regulation. The Antidegradation Policy represents a three-tiered approach to maintaining and protecting water quality. First,
all existing beneficial uses and levels of water quality necessary to protect those uses must be preserved and protected from
degradation. Second, water quality must be protected in areas where the quality cannot support the prorogation of fish,
shellfish and wildlife. Third, the policy provides special protection of waters for which the ordinary water quality criteria are
not sufficient. These waters are called “outstanding National Resources Waters” and have been designated as unique or
ecologically sensitive. If an activity is going to be allowed to degrade or lower the quality (in situations where existing water
quality is higher than that needed to maintain established beneficial uses), the Antidegradation Policy requires that the
proposed projects meet the following criteria:
The activity is necessary to accommodate important economic or social development in the area.
Water quality is adequate to protect and fully maintain existing beneficial uses.
National Flood Insurance Act
The National Flood Insurance Act of 1968 established the National Flood Insurance Programs, which is based on the minimal
requirements for floodplain management and is designed to minimize flood damage within Special Flood Hazard Areas. The
Federal Emergency Management Agency (FEMA) is the agency that administers the program. Special Flood Hazard Areas
(SFHA) are defined as areas that have 1 percent chance of flooding within a given year, also referred to as the 100-year flood.
Flood Insurance Rate Maps were developed to identify areas of flood hazards within a community
STATE:
Porter-Cologne Water Control Act
The Porter-Cologne Act also known as the California Water Code, Section 7 was created in 1969 and is the law that governs
the water quality regulation in California. It was established to be a program to protect the water quality as well as the
beneficial uses of water. This act applies to surface water, groundwater, wetlands and both point and nonpoint sources of
pollution. There are nine regional water boards and one state water board that has resulted from this act. The act requires
the adoption of water quality control plans that contain the guiding policies of water pollution management in California.
Each RWQCB must formulate and adopt a Water Quality Control Plan “Basin Plan” for its region. The Basin Plan must conform
to the policies set forth in the Porter-Cologne Act and established by the SWRCB in its State Water Policy. The Basin Plan
establishes beneficial uses for surface and groundwater in the region and sets water quality standards to protect those
beneficial uses.
The City of Newport Beach is in the Santa Ana River Basin, Region 8, in the Newport Bay Watershed. The water quality control
plan for the Santa Ana River Basin (8) was updated in 2008. This basin plan gives direction on the beneficial uses of the state
waters in Region 8; describes the water quality that must be maintained to support such uses; and provides programs,
projects, and other actions necessary to achieve the standards in the basin plan.
State Antidegradation Policy
Under the State’s Antidegradation Policy (as set forth in SWRCB Resolution No. 6816), whenever the existing quality of waters
is better than what is needed to protect present and future beneficial uses, such existing quality must be maintained. This
State policy has been adopted as a water quality objective in all the State’s Basin Plans. The State policy establishes a twostep
process to determine if discharges with the potential to degrade the water quality of surface or groundwater will be allowed.
The first step requires that, where a discharge would degrade high quality water, the discharge may be allowed only if any
change in water quality would:
Be consistent with the maximum benefit to the people of the State;
Not reasonably affect present and anticipated beneficial uses of such water;
Result in water quality that is not less than that which is prescribed in State policies (i.e., Basin Plans).
The second step (as set forth in SWRCB Resolution No. 68-16) states that any activity resulting in discharge to high-quality
waters is required to use the best practicable treatment or control of the discharge necessary in order to avoid the occurrence
of pollution or nuisance and to maintain the “highest water quality consistent with the maximum benefit to the people of the
state”. The State policy applies to both surface and groundwater, as well as to both existing and potential beneficial uses of
the applicable waters.
NPDES Program
The NPDES permit program is administered in the State of California by the RWQCBs, and was first established under the
authority of the Clean Water Act to control water pollution by regulating point sources that discharge pollutants into “Waters
of the U.S.”. If discharges from industrial, municipal, and other facilities go directly to surface waters, those project applicants
must obtain permits. An individual NPDES permit is specifically tailored to a facility. A general NPDES permit covers multiple
facilities within a specific activity category such as construction activities. A general permit applies the same or similar
conditions to all dischargers covered under the general permit. There are nine RWQCBs in the State of California. These
boards have the mandate to develop and enforce water quality objectives and implementation plans within their regions.
The project site is located within the jurisdiction of the Santa Ana RWQCB.
General Construction Permit
The SWRCB has issued a statewide general NPDES Permit and Waste Discharge Requirements (WDRs) for storm water
discharges from construction sites. Under this General Construction Permit, discharges of storm water from construction
sites with a disturbed area of one or more acres are required to either obtain individual NPDES permits for storm water
discharges or be covered by the General Construction Permit. Each applicant under the General Construction Permit must
file a Notice of Intent (NOI) with the RWQCB and ensure that a Storm Water Pollution Prevention Plan (SWPPP) is prepared
prior to grading. Terms of the SWPPP must be implemented during construction with the primary objective of the SWPPP
being to reduce or eliminate pollutants in storm water discharges from construction activities.
In 1999, the SWRCB issued and subsequently amended the General Construction Storm Water Permit (Water Quality Order
99-08-DWQ), which governs discharges from construction sites that disturb one acre or more of surface area. Again, on
September 2, 2009, the SWRCB adopted a new General Construction Permit that substantially alters the approach taken to
regulate construction discharges through (1) requiring the determination of risk levels posed by a project’s construction
discharges to water quality and (2) establishing numerical water quality thresholds that trigger permit violations. These new
permit regulations took effect on July 1, 2010.
Municipal Storm Water Permitting (MS4 Permit)
The State’s Municipal Storm Water Permitting Program regulates storm water discharges from MS4s. MS4 Permits were
issued in two phases. Phase I was initiated in 1990, under which the RWQCBs adopted NPDES storm water permits for
medium (serving between 100,000 and 250,000 people) and large (serving more than 250,000 people) municipalities. As part
of Phase II, the SWRCB adopted a General Permit for small MS4s (serving less than 100,000 people) and non-traditional small
MS4s including governmental facilities such as military bases, public campuses, and prison and hospital complexes (WQ Order
No. 2003-0005-DWQ).
California Coastal Act
The California Coastal Commission (Coastal Commission) is responsible for protecting water quality in coastal environments
through implementation of the California Coastal Act of 1976, specifically sections 30230 and 30231. These water quality
provisions provide a broad basis for protecting coastal waters, habitats and biodiversity associated with new development
and redevelopment projects. To meet the objectives of Sections 30230 and 30231, the Coastal Commission supports a multi-
pronged approach to water quality management, which includes implementing site-design, source-control, and treatment-
control BMPs and low impact development (LID) features. New development and redevelopment projects that are within
the Coastal Zone are required to apply for a Coastal Development Permit through the Coastal Commission or local jurisdiction
prior to construction. As part of the Coastal Development Permit process, projects must demonstrate water quality
protection with the implementation of site-design, source-control, and treatment-control BMPs.
California Ocean Plan
The Water Quality Control Plan for Ocean Waters of California (Ocean Plan), amended through 2001, establishes beneficial
uses and water quality objectives for waters of the Pacific Ocean along the California coast outside enclosed bays, estuaries,
and coastal lagoons. The Ocean Plan establishes water quality objectives, discharge prohibitions, and management guidelines
for safeguarding the Pacific Ocean’s water quality.
Regional
Basin Plan
As indicated above, the project site is located within the Santa Ana RWQCB’s jurisdiction. The Water Quality Control Plan for
the Santa Ana River Basin (Santa Ana River Basin Plan) designates beneficial uses and water quality objectives for water bodies
in the region. Narrative water quality criteria contained in the Basin Plan cover a range of both organic and inorganic
constituents for both surface and groundwater; the Santa Ana River Basin Plan prohibits the degradation of water quality in
a manner that would adversely impact a water body’s designated beneficial uses. The Basin Plan incorporates applicable
portions of a number of national and statewide water quality plans and policies, including the California Water Code and the
Clean Water Act. For certain designated surface water bodies and groundwater management zones, specific numeric water
quality objectives have been established for a range of constituents. These water quality criteria apply within receiving waters
and do not apply directly to runoff. Within the project area, there are no water bodies (or groundwater management zones)
for which numeric objectives have been established.
The Santa Ana RWQCB defines a beneficial use for surface waters in the region as “one of the various ways that water can be
used for the benefit of people and/or wildlife.” Beneficial uses, along with specific water quality criteria, comprise water
quality standards for surface (navigable) waters as defined by Section 303 of the federal Clean Water Act (33 United States
Code [USC] §1313). Under the Porter-Cologne Water Quality Control Act (California Water Code §§13050 et seq.), these
concepts are separately considered as beneficial uses and water quality objectives. Beneficial uses and water quality
objectives are to be established for all “Waters of the State”, both surface and subsurface groundwater.
There are 23 beneficial uses defined statewide; of these, 19 are recognized within the Santa Ana Region. One additional
beneficial use—Limited Warm Freshwater Habitat—is unique to the Santa Ana Region, bringing the total number of beneficial
uses recognized in the Santa Ana Region to 20. The 20 beneficial uses include the following: MUN: municipal and domestic
supply; AGR: agricultural supply; IND: industrial service supply; PROC: industrial process supply; GWR: Groundwater
Recharge; NAV: navigation; POW: hydropower generation; REC1: water contact recreation; REC2: noncontact water
recreation; COMM: commercial and sport fishing; WARM: warm freshwater habitat; LWARM: limited warm freshwater
habitat; COLD: cold freshwater habitat; BIOL: biological significance; WILD: wildlife habitat; RARE: rare, threatened, or
endangered species; SPWN: spawning, reproduction, and development; MAR: marine habitat; SHEL: shellfish harvesting; EST:
estuarine habitat. The beneficial uses identified for Upper and Lower Newport Bays are listed in the Existing Conditions
section below.
Orange County Storm Water Program 2003 Drainage Area Management Plan (DAMP)
Section 402(p) of the Clean Water Act, as amended by the Water Quality Act of 1987, requires that municipal NPDES Permits
include requirements (1) to essentially prohibit non-storm water discharges into municipal storm sewers and (2) to control
the discharge of pollutants from municipal storm drains to the maximum extent practicable. In response to this requirement,
the Orange County Drainage Area Management Plan (DAMP) was developed in 1993, which has been updated several times
in response to requirements associated with NPDES permit renewals. The City is a permittee covered by the requirements
of this permit. The main objectives of the Orange County DAMP are to fulfill the Permittees’ commitment to present a plan
that satisfies NPDES permit requirements and to evaluate the impacts of urban storm water discharges on receiving waters.
Orange County DAMP elements include: (1) the establishment of public outreach and educational programs, management
strategies, and inter-agency coordination; (2) continuing participation in the Regional Research/Monitoring program that is
being conducted with the neighboring counties, the Southern California Coastal Waters Research Project, and three Southern
California Regional Boards; (3) the establishment of BMPs aimed at managing project-induced hydrologic effects; and (4) the
improvement of water quality throughout the region.
Areas of Special Biological Significance
Areas of Special Biological Significance are areas designated by the SWRCB for the protection of sensitive marine species or
biological communities from undesirable alterations in natural water quality. Pursuant to recent revisions to the California
Public Resources Code (PRC), Areas of Special Biological Significance are now included within the areas classified as “State
Water Quality Protection Areas” where marine species and biological communities are protected from “undesirable
alteration[s] in natural water quality” (PRC §36700[f]). The two closest Areas of Special Biological Significance to the project
site include the Irvine Coast Marine Life Refuge Areas of Special Biological Significance, located offshore and about seven
miles south, and the Newport Beach Marine Life Refuge, also offshore and about five miles to the south.
Local
City of Newport Beach Council Policy Manual
The City of Newport Beach Council Policy Manual stipulates Policies L-18 and L-22 for the protection of water quality within
the City, both of which are intended to minimize dry-weather runoff and runoff from small rain events to improve water
quality-limited receiving waters, the near-shore ocean environment, and Newport Bay’s water quality. Policy L-18 is entitled
“Protection of Water Quality: Drainage – Public Rights-of-Way.” Policy L-22 is entitled “Protection of Water Quality: Water
Quality Management Plans for New Development and Redevelopment.”
Policy L-18 states that “Whenever possible, runoff should be retained on private property to prevent the transport of these
pollutants… Reduction, detention or diversion of runoff can benefit property owners through water conservation and reuse
of water that would otherwise drain to the City’s street drainage system and our harbors, bays and oceans.
Policy L-22 states that the opportunity to reduce the impacts of runoff that would otherwise drain to the City’s street drainage
system and our harbors, bays, and ocean. At the time of submittal of an application for a new development or redevelopment
project, an applicant shall submit [a] Water Quality Management Plan (WQMP) to the City. The WQMP’s purpose is to
minimize to the maximum extent practicable dry weather runoff and runoff from small storms (less than 3/4″ of rain falling
over a 24-hour period) during construction and post construction from the property”.
City of Newport Beach Municipal Code
The City of Newport Beach Municipal Code contains policies relevant to water quality management, specifically to control
storm water runoff from development sites. Section 14.36.040, Control of Urban Runoff, requires new development and
redevelopment projects to comply with the DAMP as well as conditions and requirements established by the Community
Development Department or Building Department to reduce or eliminate pollutants in storm water runoff from a project site.
Local Implementation Plan (LIP)
The City’s Local Implementation Plan (LIP) was prepared as part of a compliance program pursuant to the Third Term NPDES
Permit. The LIP presents the actions, activities and programs undertaken by the City, as well as current activities and
programs, to meet the requirements of the NPDES Permit and to improve urban water quality. Although the LIP is intended
to serve as the basis for City compliance during the five-year period of the Third Term NPDES Permit, the LIP is subject to
modifications and updates as the City determines necessary, or as directed by the Santa Ana RWQCB.
The LIP, in conjunction with the County DAMP, is the principal policy and guidance document for the City’s NPDES Storm
Water Program. Sections A.7.0 and A.8.0 of the LIP address new development and significant redevelopment controls for
incorporating BMPs into environmental compliance requirements. The LIP also addresses construction requirements for
sedimentation and erosion control, as well as onsite hazardous materials and waste management.
On May 22, 2009, the Santa Ana RWQCB re-issued the MS4 Permit for the Santa Ana Region of Orange County (Order R8-
20090030). Reissuance of the fourth term of this permit resulted in changes to the 2003 DAMP and City of Newport Beach
LIP and storm water program. This updated Fourth Term permit includes new requirements pertaining to hydromodification4
and low impact development (LID) features associated with new developments and redevelopment projects. Following the
permit adoption, the County of Orange, as the Principal Permittee, prepared a new 2011 Model WQMP that incorporates
feasibility criteria for LID and hydromodification requirements. Following the Santa Ana RWQCB’s approval of the 2011 Model
WQMP, the City will be required to update their LIP and storm water programs and incorporate the new 2011 Model WQMP
into their discretionary approval process for new development and redevelopment projects.
One component of the New development section of the City’s LIP is the provision to prepare a WQMP for specified categories
of development aimed at reducing pollutants in post-development runoff. Specifically, a project-specific WQMP includes
Santa Ana RWQCB approved BMPs, where applicable, that address postconstruction management of storm water runoff
water quality. This includes operation and maintenance requirements for all structural or treatment control BMPs required
for specific categories of developments to reduce pollutants in post development runoff to the Maximum Extent Practicable
(MEP). The categories of development that require preparation of a project-specific WQMP include:
All significant redevelopment projects, where redevelopment is defined as the addition of 5,000 square feet (sf) or
more of impervious surface on an already developed site;
New development projects that create 10,000 sf or more of impervious surface (collectively over the entire site)
including commercial, industrial, residential housing subdivisions, mixed use, and public projects;
Automotive repair shops;
Restaurants where the land area of development (including parking areas) is 5,000 sf or more;
Hillside developments on 5,000 sf or more, which are located on areas with known erosive soil conditions or where
the natural slope is 25 percent or more;
Developments of 2,500 sf or more located within, directly adjacent to (within 200 feet), or discharging directly into
receiving waters within Environmentally Sensitive Areas (ESA) such as areas designated in the Ocean Plan as Areas
of Special Biological Significance or water bodies listed on the Clean Water Act Section 303(d) list of impaired water
bodies;
Parking lots with 5,000 sf or more of impervious surface, or with 15 parking spaces or more exposed to urban storm
water runoff;
Streets, roads, highways and freeways of 5,000 sf or more of paved surface, which shall also incorporate USEPA
guidance contained within “Managing Wet Weather with Green Infrastructure: Green Streets” in a manner
consistent with the MEP standard; and
Retail gasoline outlets of 5,000 sf or more with a projected average daily traffic of 100 vehicles or more per day.
As required by the City’s municipal ordinances on storm water quality management, a project’s WQMP must be
submitted to the City for approval prior to the City issuing any building or grading permits. As the project site drains
directly to Upper Newport Bay, which is impaired on the 303(d) list and is considered an ESA, the project is subject to the
requirements of the City’s WQMP. This includes meeting any new requirements of the updated MS4 Permit and
associated LIP. Projects that fall into the categories of development listed above that require preparation of a project-
site specific WQMP are referred to as Priority Projects.
EXISITING CONDITIONS
REGIONAL DRAINAGE:
The project site is located within the Newport Bay watershed, which drains approximately 152.02 square miles to the Pacific
Ocean within southern Orange County. The watershed encompasses all waters draining to Newport Bay. The project site is
located within the Upper Newport Bay sub-area of the Newport Bay watershed.
LOCAL DRAINAGE:
The project site is located at the Newport Dunes on APN 988-13-243 at the end of Bayside Drive off of the Pacific Coast
Highway. The project site is approximately 14.3 acres. Under existing conditions, the project site consists of a boat storage
area and a dredging stockpile. An existing driveway, boat storage, and parking lot are located along the north and west
boundaries of the project site. The west and south side of the project site are bounded by an existing RV parking area. A
stretch of the beach at Newport Dunes lagoon forms the easterly side of the project site.
The existing site drainage is generally south to north with existing storm drain pipes and catch basins collecting the runoff
and directing the flows east to Newport Bay. The existing parking lot, vacant area and boat storage parking are generally flat
with mild slopes of 0.5% to 1.0% and carry the surface runoff to low points whereby catch basins intercept and convey the
flows to storm drain pipes. These flows are then conveyed via below grade storm drain pipes to Newport Bay. The dredging
stockpile area varies in height from approximately 5’ below adjacent ground to approximately 15’ above adjacent ground
with irregular piles within the area. Drainage from the stockpile area is mostly contained within the fenced area with the
exception of outward facing slopes that drain to adjacent parking lots or the beach area.
Local geology of the Newport Dunes lagoon consists of Tertiary marine sediments of the Monterey and Capistrano formations,
which underlie Quaternary alluvium and marine terrace deposits of the back bay. Soils on-site generally consist of artificial
fill ranging from silty sands, san with trace silt to sand. Existing beneath the artificial fill, the native alluvium soils varied from
fluvial and dune sands to silts and clays from the back bay bottom. Ground water was encountered at depths between 8-16
feet and varied in depth depending upon the boring elevation and the prevailing tidal influences at the time the reading was
made.
Due to the presence of shallow groundwater, on-site infiltration of stormwater runoff is considered infeasible. The proposed
drainage is to mimic the existing patterns, which are generally south to north. Under the final site conditions, the project site
will connect to the existing surrounding storm drain system at 2 distinct locations. Each drainage point is associated with
tributary onsite areas known as a Drainage Areas. A Drainage Area is a collection of subareas in which the accumulated
stormwater runoff is conveyed (by sheet flow or subsurface drainage systems) to a specific discharge point. Due to the
extensive site improvements proposed, the total drainage subareas will increase from seven, under the existing conditions,
to thirty. The following is description of the proposed Drainage Areas which can be found illustrated on the Hydrology Map
located in Appendix A of the Hydrology Report: Drainage Area 1 consists of subareas 1A-1N and 7.95 acres of the site,
Drainage Area 2 with subareas 2A-2B for a total of 0.43 acres and Drainage Area 3 consisting of subareas 3A-3N and 5.91
acres. The north and west parking lots as well as the north and west ends of the hotel comprise of Drainage Area 1. Storm
water runoff generated from this Drainage Area converges in the center of the site via below grade storm drain systems and
filters through a biofiltration device, which satisfies post construction water quality requirements, before discharging east
into and existing storm drain line located on N Bayside Drive. Drainage Area 2 which only comprises of two subareas totaling
0.43 acres, is located on the east boundary of the site. The 1.75 CFS of runoff generated by a 25yr storm event will be captured
by a series of curb adjacent catch basins and onsite drain inlets and will converge with the runoff from Drainage Area 1,
upstream of the biofiltration unit, before sharing the same discharge point on N. Bayside Drive. Drainage Area 3 comprises
the balance of the site which encompasses the east parking lot as well the hotel grounds located between the lagoon and the
south façade of the hotel. The surface runoff will sheet flow to proposed catch basins then continue to east to the second
and furthest south discharge point. Upstream of the discharge point, roof stormwater runoff will converge with the site runoff
and will filter through a second biofiltration unit before connecting to the back of an existing catch basin along N Bayside
Drive which outlets to the Newport Bay (Upper Ecological Reserve) and then ultimately into the Pacific Ocean. Sizing and
specifications regarding the biofiltration systems and post-construction Best Management Practices for compliance with
stormwater treatment requirements can be found in the attached Preliminary Water Quality Management Plan Report.
Table 1.1 Existing Flowrates
Area ID Area
(Acres)
Flow (CFS)
2-Year 10-Year 25-Year 100-Year
1A 2.93 4.39 7.92 9.46 12.10
2A 2.41 3.61 6.51 7.78 9.95
3A 1.22 1.75 3.15 3.77 4.82
4A 1.38 1.97 3.69 4.44 5.74
5A 1.30 2.26 4.21 5.04 6.52
6A 1.40 2.10 3.94 4.74 6.12
7A 3.65 4.73 8.93 10.76 13.90
TOTAL 14.29 20.81 38.35 45.99 59.15
Table 1.2 Proposed Flowrates
Area ID Area
(Acres)
Flow (CFS)
2-Year 10-Year 25-Year 100-Year
1A 1.18 1.79 3.23 3.85 4.93
1B 0.16 0.24 0.43 0.51 0.66
1C 0.21 0.30 0.55 0.66 0.84
1D 0.10 0.14 0.25 0.30 0.39
1E 0.14 0.19 0.35 0.42 0.54
1F 0.09 0.12 0.22 0.26 0.34
1G 0.35 0.45 0.83 1.00 1.29
1H 0.34 0.43 0.79 0.95 1.23
1I 0.69 0.85 1.57 1.89 2.43
1J 1.43 2.41 4.35 5.19 6.65
1K 0.80 1.33 2.39 2.86 3.66
1L 1.01 1.61 2.93 3.50 4.50
1M 1.23 1.88 3.44 4.12 5.29
1N 0.22 0.24 0.45 0.55 0.7
SUBTOTAL
Area 1 7.95 11.98 21.78 26.06 33.45
2A 0.16 0.31 0.56 0.67 0.86
2B 0.27 0.46 0.87 1.04 1.35
SUBTOTAL
Area 2 0.43 0.77 1.43 1.71 2.21
3A 0.12 0.24 0.44 0.52 0.67
3B 0.57 1.10 0.57 2.37 3.06
3C 0.74 1.29 2.36 2.82 3.65
3D 0.35 0.61 1.12 1.33 1.73
3E 0.28 0.49 0.89 1.07 1.38
3F 0.23 0.38 0.70 0.84 1.09
3G 0.56 0.93 1.72 2.06 2.66
3H 0.49 0.82 1.50 1.80 2.33
3I 0.67 1.04 1.94 2.32 3.02
3J 1.08 1.62 3.03 3.65 4.74
3K 0.11 0.17 0.31 0.37 0.48
3L 0.20 0.30 0.56 0.67 0.88
3M 0.11 0.17 0.31 0.37 0.48
3N 0.40 0.46 0.87 1.05 1.36
SUBTOTAL
3 5.91 9.62 16.32 21.24 27.53
TOTAL 14.29 22.37 39.53 49.01 63.19
Water Quality
Water quality impairments for Upper Newport Bay and Lower Newport Bay, and Total Maximum Daily Loads (TMDLs) for
pollutants for which each of those two water bodies are listed, are shown in Table 1.3 Upper Newport Bay Water Quality
Impairment.
Table 1.3 Upper Newport Bay Water Quality Impairments
Water Body Contaminant TMDL Status
Upper Newport Bay
Chlordane 5A – 2019
Copper 5A – 2007
DDT 5A – 2019
Metals 5A – 2019
Nutrients 5B – Completed
PCBs 5A – 2019
Indicator Bacteria 5B – Completed
Sediment Toxicity 5A – 2019
Sedimentation/Siltation 5B - Completed
FLOOD PLAIN MAPPING:
The project site can be found on published Flood Insurance Rate Map (FIRM) Number 06059C0382J, dated December 3, 2009
and the majority of the site is located in Zone X, which is used to identify base floodplains of lesser hazards, such as areas
protected by levees from the one percent annual flood, or shallow flooding areas with average depths of less than one foot
or drainage areas less than one square mile. A small portion of the site (the east boundary) is located within Zone AE which
indicates special flood hazard areas subject to inundation by the 1% annual chance flood. The base flood elevation along this
portion of the site is set to 9 MSL.
ENVIRONMENTALLY SENSITIVE AREAS:
As discussed above in the Areas of Special Biological Significance section, the project site is not located within 200 feet of an
Environmentally Sensitive Area (ESA) or Areas of Special Biological Significance (ASBS).
THRESHOLDS OF SIGNIFICANCE
In accordance with the County’s Environmental Analysis Checklist and Appendix G of the State CEQA Guidelines, the project
would result in a significant water quality impact on the environment if the project would:
HWQ-1 Violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or
ground water quality.
HWQ-2 Substantially decrease groundwater supplies or interfere substantially with groundwater recharge
such that the project may impede sustainable groundwater management of the basin.
HWQ-3 Substantially alter the existing drainage pattern of the site or area, including through the
alteration of the course of a stream or river or through the addition of impervious surfaces, in a manner which would:
1. Result in a substantial erosion or siltation on- or off-site.
2. Substantially increase the rate or amount of surface runoff in a manner which would result in flooding on
or offsite.
3. Create or contribute runoff water which would exceed the capacity of existing or planned stormwater
drainage systems or provide substantial additional sources of polluted runoff.
4. Impede or redirect flood flows.
HWQ-4 In flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation.
HWQ-5 Conflict with or obstruct implementation of water quality control plan or sustainable groundwater management
plan.
ENVIRONMENTAL IMPACT ANALYSIS
HWQ-1 Analysis Conclusion:
Construction and operation of the project would comply with all applicable regulatory requirements regarding water
quality and implementation of the project design features, including BMPs as part of the project’s WQMP would
ensure that construction and operational water quality impacts are less than significant.
Impacts Associated with Construction:
Water Contaminates
As previously discussed, construction related stormwater pollution occurs when debris, chemicals, sediment or other
pollutants are washed into storm drains and flows into water bodies. To reduce the risk of water degradation, the project will
implement a SWPPP specifying BMPs for minimizing stormwater pollution from construction activities. The SWPPP (with
associated BMPs) is considered protective of water quality during construction and would, therefore, prevent a substantial
violation of water quality standards and minimize the potential for contributing additional sources of polluted runoff during
construction of the project. This would ensure that the potential for discharge of stormwater from construction sites that
may affect beneficial uses of receiving waters and water quality standards, where applicable, would not be substantial.
Furthermore, compliance with regulatory requirements would ensure that construction of the project would not result in the
exceedance of water quality standards during construction, including TMDL limits applicable to Upper and Newport Bay.
Based on the above, construction-related impacts would be less than significant.
Erosion and Sediment Control
During construction, the project site would be subject to ground disturbing activities such as removal of the existing structures
and pavement, excavation and grading, foundation and installation of infrastructure. These activities would expose soils and
potentially allow erosion and sediments to enter into runoff. To address these risks, the following erosion control and
sediment BMPs are examples of what will be implemented during grading activities and site preparation:
Gravel Bag Berm
A gravel bag berm is a series of gravel-filled bags placed on a level contour to intercept sheet flows. Gravel bags
pond sheet flow runoff, allowing sediment to settle out, and release runoff slowly as sheet flow, preventing erosion.
The gravel bags, coupled with construction fencing, will surround the project site to reduce the risk of pollutants
discharging into the local storm drain system. Special consideration will be emphasized in the placement of the
bags along the southern project boundary due to the adjacency to lagoon.
Street Sweeping
Street sweeping and vacuuming includes use of self-propelled and walk-behind equipment to remove sediment from
streets and roadways and to clean paved surfaces in preparation for final paving. Sweeping and vacuuming prevents
sediment from the project site from entering storm drains or receiving waters.
Storm Drain Inlet Protection
Every storm drain inlet receiving runoff from unstabilized or otherwise active work areas will be protected. Inlet
protection will be used in conjunction with specified erosion and sediment controls to prevent sediment-laden
stormwater and non-stormwater discharges from entering the existing storm drain system and discharging directly
to the bay.
Stabilized Construction Entrance and Exit
A stabilized construction access is defined by a point of entrance/exit to a construction site that is stabilized to reduce
the tracking of mud and dirt onto public roads by construction vehicle. Limiting the point of ingress and egress to
the site allows for better sediment tracking control.
Non-Stormwater Controls
In addition, non-stormwater BMPs will also be implemented to mitigate pollutants and contaminates generated by general
construction activities. These temporary BMPs include but are not limited to the prevention of accidental disposal of rinse or
wash waters or materials on pervious or impervious site surfaces or into the storm drain system or directly into the bay. Given
the nature of construction activities associated with non-stormwater BMPs, logistical measures can be considered when
determining the placement or designated areas for the BMPs. Given the site’s proximity to Back Bay, construction activities
and their corresponding BMPs (stockpiling, concrete wash areas, vehicular staging, etc) will be located the furthest away from
the shoreline as possible. Current proposed locations are situated adjacent to southwest property line, nearest to the existing
RV resort. The following non-stormwater BMPs are examples of what will be implemented:
Illicit Connection- Illegal Discharge Connection
Frequent site inspections for evidence of illicit connections, illegal dumping or discharges.
Vehicle and Equipment Cleaning
Washing of vehicles in such a manner as to prevent non-stormwater discharges to surface waters or MS4 drainage
systems. This will include designating an appropriate site-specific area for staging needs as indicated above.
Vehicle and Equipment Fueling and Maintenance
Prevention of oil, grease, or fuel from leaking into the ground, storm drains or surface waters. Site equipment and
fueling activities will be performed in appropriately in designated areas. When possible, equipment maintenance
activities shall be performed at an offsite facility.
Impacts Associated with Post Construction:
Stormwater discharge is generated by rainfall that runs off the land and impervious surfaces such as paved streets, parking
lots, and rooftops. Stormwater discharge may include pollutants of concern, which are those that are expected to be
generated by future development pursuant to the legislative approvals and that could impact stormwater. During operation
of the project, pollutants of concern within runoff may include, but are not limited to; suspended solids/sediment, nutrients,
heavy metals, pathogens (bacteria/virus) pesticides, oil and grease, toxic organic compounds, and trash and debris. Expected
pollutants of concern are described below:
Nutrients
Nutrients are inorganic substances such as nitrogen and phosphorous. The primary sources of these substances in
urban runoff are fertilizers and eroded soils. Excessive discharge of nutrients to water bodies and streams causes
eutrophication, where overgrowth of aquatic plants and algae can lead to excessive decay of organic matter in the
water, loss of oxygen in water and eventual death of aquatic organisms.
Pathogens (Bacteria/Virus)
Bacteria and viruses are microorganisms that thrive under certain environmental conditions. Water contamination
by animal or human fecal wastes and contamination by excess organic wastes are common causes of proliferation
of these microorganisms. Water containing excessive bacteria and viruses can alter the aquatic habitat and harm
humans and aquatic life.
Pesticides
Relatively low concentration of the active ingredients in pesticides can be toxic in water. Excessive or improper use
of pesticides can cause toxic contamination in runoff.
Suspended Solids/Sediment
Sediments are solid materials that are eroded from the land surface. Sediments can increase the turbidity
(cloudiness) of water, clog fish gills, reduce spawning habitat, lower survival rates of young aquatic organisms,
mother bottom dwelling organisms, and suppress aquatic vegetation growth.
Heavy Metals
Metals of concern as water contaminants include cadmium, chromium, copper, lead, mercury, and zinc. Lead and
chromium have been used as corrosion inhibitors; metals are also raw materials used in nonmetal products such as
fuels, adhesives, and paints. At low concentrations naturally occurring in soil, metals may not be toxic. However,
certain metals at higher concentrations can be harmful to aquatic life and to humans. Humans can be impacted
from groundwater contaminated with metals. Metals can become concentrated in fish and shellfish, and can
subsequently harm humans who consume those animals. Environmental concerns have already led to restrictions
on some uses of metals.
Trash and Debris
Trash and debris, such as paper, plastic, polystyrene foam, aluminum, and biodegradable organic matter such as
leaves, grass cuttings, and food waste, may significantly impair aquatic habitat and the recreational value of a water
body. In addition, trash impacts water quality by increasing biochemical oxygen demand.
Toxic Organic Compounds
Organic compounds are carbon based. Commercially available or naturally occurring organic compounds are found
in pesticides, solvents, and hydrocarbons. Organic compounds at certain concentrations can be hazardous to life or
health. Toxic levels of solvents and cleaning compounds can be discharged to storm drains during cleaning and
rinsing operations.
Oil and Grease
Oil and grease in water bodies decrease the aesthetic value as well as water quality. One of the greatest sources of
oil and grease is leakage from motor vehicles.
The SWRCB Municipal NPDES Storm Water Permit for the County of Orange and the Incorporated Cities of Orange County
requires applicants to prepare a WQMP to manage post-construction storm water runoff associated with development. The
proposed project is considered a “Priority Project” as it includes the addition and replacement of more than 5,000 square
feet of impervious surfaces on an already developed site. A Preliminary WQMP has been prepared for the project in
accordance with the Countywide Model WQMP Technical Guidance Document (May 2011) for purposes of this CEQA analysis
to identify appropriate stormwater BMPs and water quality management practices to be implemented during operation of
the project. The PWQMP includes both source control and treatment control BMPs, as well as site design BMPs. A Final
WQMP will be prepared, as a submittal requirement for precise grading permit, and reviewed by the City Engineer. The
WQMP will address the final site configuration and design features and recommend appropriate LID, structural and
nonstructural BMPs and mandate maintenance and inspection responsibilities.
Based on the 2011 Model WQMP requirements, the LID performance criteria applicable to priority projects, such as this
project, requires a project to infiltrate, harvest and use, or biotreat/biofilter (in that hierarchal order) the 85th percentile, 24-
hour storm event. LID BMPs must be designed to retain, onsite, (infiltrate or harvest and use) storm water runoff up to 80
percent average annual capture efficiency. According to the Model WQMP, if it is not feasible to meet LID performance
criteria through retention and/or biotreatment provided on-site or at a subregional/regional scale, then treatment control
BMPs shall be provided onsite or offsite prior to discharge to waters of the US. Sizing of treatment control BMP(s) shall be
based on either the unmet volume after claiming applicable water quality credits, if appropriate. The following LID summary
provides a brief description of each BMP and its feasibility to the project site:
Infiltration LID BMP
Infiltration BMPs are LID BMPs that capture, store and infiltrate stormwater 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, biofiltration without underdrains, drywells, permeable pavement
and underground infiltration galleries.
Due to the highwater table measured onsite, implementation of infiltration BMPs is considered infeasible for this project.
Following the hierarchy of treatment, harvest and reuse follow in importance and has been analyzed for applicability.
Rainwater Harvesting BMP
Rainwater Harvesting and reuse is a LID BMP that captures and stores storm water runoff for later use. The BMP is 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 aboveground 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.
Harvest and Use BMPs are not feasible on the project site based on the minimum harvest demand thresholds described in
the 2011 Model WQMP. The demand threshold is determined by comparing the minimum irrigation area required based on
conservation landscape design to the proposed project irrigated area. The total proposed landscaping is less the minimum
irrigation area calculations.
Biotreatment BMPs
Biotreatment BMPs are 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 (through 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, ionexchange, 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. The following biotreatment BMPs would be utilized on-site for water
quality treatment:
Bioretention with underdrains
A combination of proprietary bioretention units (Modular Wetlands or equivalent) and biofiltration planters with underdrains
shall be integrated within the landscaping areas (where feasible) and will filter/treat runoff from the proposed buildings and
hardscape prior to discharging into the storm drain system. The above systems were selected based on their ability to treat
the project’s pollutants of concerns to a medium or high effectiveness, in accordance with the Model WQMP Technical
Guidance Document.
Modular Wetlands are structural media filtration device that also utilize bioretention processes for storm water treatment
(functional equivalents are also acceptable). Modular Wetland units feature a specially designed media filter mixture within
a below-grade concrete box. The filter media is designed to capture and filter pollutants during the first-flush storm event,
while biological processes degrade, metabolize, detoxify, and volatilize the pollutants during and between storms. Currently,
three Modular Wetlands units are designated onsite. The Post Construction WQMP Exhibit (located in the included
Preliminary WQMP) indicates Drainage Management Area F (DMA-F) as 5.9 acres – the area bounded by the southern building
edge and Back Bay. Two MWS units, one measuring 8’x24’ and the other 8’x8’ will work in conjunction to intersect the
required discharge flows and treat the runoff accordingly prior to discharging into the existing storm drain located on N
Bayside Drive. DMAs A-C which total 4.01 acres similarly will converge to a singular discharge point located on N Bayside Drive
but will also utilize a second 8’x24’ MWS for treatment purposes.
Biofiltration planters with underdrains are plant-based biotreatment systems that typically consist of a ponding area, mulch
layer, planting soils and plants. As storm water passes down through the planting soil, pollutants are filtered, adsorbed,
biodegraded and sequestered by the soil and plants. Underdrains collect the treated water and return it back into the storm
drain system. The final remaining 3.95 acre DMA-D consists of the northern parking lot and perimeter landscaping. The
grading in this area will be such that stormwater runoff will sheetflow into the center planted aisles which will be designed
as biofiltration planters. The underdrains will capture the treated stormwater and reconnect to the main storm drain system
which discharges east onto N Bayside Drive.
Source Control BMPs
In addition to LID BMPs, Source Control BMPs will be implemented to further reduce the potential for stormwater runoff and
pollutants from coming into contact with one another. Source Control BMPs are defined as any administrative action, design
of a structural facility, usage of alternative materials, and operation, maintenance, inspection, and compliance of an area that
aims to eliminate or reduce stormwater pollution. Source Control BMPs are required within all new development and
significant redevelopment projects regardless of whether the project is a Priority Project or a Non-Priority Project, including
those identified in an applicable regional or watershed program, unless they do not apply due to the project characteristics.
The following Structural and Non-Structural Source Control BMPs will be implemented to minimize the potential for
pollutants from entering into the site runoff and are numbered for purposes of the Orange County Stormwater Program and
Model WQMP, followed by a cross-reference for the CASQA BMP Handbook reference number in parenthesis.
• S1: Provide Storm Drain System Stenciling and Signage (CASQA BMP Handbook SD-13)
The developer will be responsible for the stenciling of all catch basins to include a legible message such as “No
Dumping - Drains to Ocean” or an equally effective phrase. The Owner will be responsible for maintaining and
replacement of signage when necessary.
• S3: Design Trash Enclosures to Reduce Pollutant Introduction (CASQA BMP Handbook SD-32)
All trash and waste shall be stored in containers that have lids or tarps to minimize direct precipitation into the
containers. The site operator shall ensure trash is stored properly and does not come into contact with runoff.
• S4: Use Efficient Irrigation Systems and Landscape Design (CASQA BMP Handbook SD-12)
The owner/operator will be responsible for the installation and maintenance of all common landscape areas utilizing
similar planting materials with similar water requirements to reduce excess irrigation runoff. The owner/operator
will be responsible for implementing all efficient irrigation systems for common area landscaping including but not
limited to provisions from water sensors and programmable irrigation cycles. The irrigation systems shall be in
conformance with water use efficiency guidelines.
• S13: Wash Water Controls for Food Preparation Areas
All wash water from food prep areas will be controlled and proper staff training conducted by the site operator. Food
preparation facilities shall meet all health and safety, building and safety and any other applicable regulations, codes
requirements.
• N1: Education for Property Owners, Tenants and Occupants
Educational materials and training will be provided to property owners, residents and tenants, including education
materials and restrictions to reduce pollutants from reaching the storm drain system.
• N2: Activity Restrictions
The owner shall develop activity restrictions (via CC&Rs or equivalent) that include language to restrict activities that
have the potential to create adverse impacts on water quality. Activities include but are not limited to: the handling
and disposal of contaminants, trash management and litter control, irrigation and landscaping practices, fertilizer
applications and household waste management practices, prohibition of vehicle washing on-site, prohibiting washing
or hosing of walkways and driveways, etc.
• N3: Common Area Landscape Management (CASQA BMP Handbook SC-73)
Management programs will be designed and implemented by the Owner, which will maintain all the common areas
within the project site (via landscape contractor). These programs will cover how to reduce the potential pollutant
sources of fertilizer and pesticide uses, utilization of water efficient landscaping practices and proper disposal of
landscape wastes in accordance with City requirements.
• N4: BMP Maintenance
The owner will be responsible for the implementation and maintenance of each applicable nonstructural BMP, as well
as scheduling inspections and maintenance of all applicable structural BMP facilities through its landscape contractor
and any other necessary maintenance contractors.
• N11: Common Area Litter Control (CASQA BMP Handbook SC-60)
The operator will be responsible for performing trash pickup and sweeping of littered common areas on a weekly
basis or whenever necessary.
• N12: Employee Training
All employees of the property and any contractors will require training to ensure that employees are aware of
maintenance activities that may result in pollutants reaching the storm drain.
• N14: Common Area Catch Basin Inspection (CASQA BMP Handbook SC-74)
All private catch basins will be maintained and cleaned by the operator. All public catch basins will be maintained by
the City of Newport Beach. These activities will be done prior to the rainy season, no later than October 1st of each
year.
• N15: Street Sweeping Private Streets and Parking Lots (CASQA BMP Handbook SC-43, SC-70)
The operator shall be responsible for the street sweeping of all drive aisles and parking areas within the project
quarterly, and prior to the rainy season, no later than October 1st of each year.
HWQ-2 Impact Analysis Conclusion:
The project would maintain existing drainage patterns which ultimately convey runoff into Upper Newport Bay. No natural
drainage features exist on the site. The project site is developed under existing conditions and as such that it does not currently
function as a significant groundwater recharge site. All disturbed areas would be paved or landscaped with native and/or
tolerant landscaping consistent with City and California Coastal Commission Guidelines. The project’s impact on sustainable
groundwater management are less than significant.
In regards to the depths of groundwater within the project site, construction dewatering may be required. Should
groundwater be encountered that would require dewatering, the project would apply for coverage and adhere to the
monitoring and reporting program under Order No. R8-2009-0003. Under these conditions, the dewatering operations
outlined by the Best Management Practice, “NS-2” of the California Stormwater BMP Handbook would be implemented for
testing and discharging.
Implementation of the regulatory requirements would ensure that dewatering activities would not result in the exceedance
of water quality standards during construction, including TMDL limits applicable to Upper and Lower Newport Bay. Based on
the above. Construction-related dewatering impacts would be less than significant.
HWQ-3 Impact Analysis Conclusion:
On-or Off-site Erosion, Siltation and Flooding Effects
The project would be designed to maintain existing drainage patterns of the site. Post development runoff would be consistent
with applicable regulatory requirements and the postproject site would not result in significant hydrology impacts
downstream such that siltation, erosion or flooding would occur on or offsite. Furthermore, the project would not create or
contribute runoff water which would exceed the capacity of existing or planned stormwater drainage. Impacts regarding
changes in drainage patterns and stormwater flows would be less than significant.
As discussed in the Existing Conditions section above, the entire site currently drains into the Upper Newport Bay utilizing
existing points of connections to the City storm drain system or, (as seen in the Pre-Construction Hydrology Map located in
the included Preliminary Hydrology Study) discharges directly into the Bay via surface flow onto the beach such as drainage
areas 4A-6A. The project proposes to alter the onsite drainage characteristics but would ultimately maintain and conform to
the overall existing drainage patterns in which the site would convey its runoff directly into the Upper Newport Bay. Prior to
discharging into the Bay, all on-site flows would converge into the onsite storm drain system and be intercepted upstream of
each discharge point by biofiltration units, known as Modular Wetlands, for filtration and treatment of the low flows. The
following table is a summary of the Pre and Post Hydrologic conditions for the 2yr, 10yr, 25yr and 100yr storm events:
Table 1.4 Pre and Post Condition Hydrologic Summary
Condition Flow (CFS)
2-Year 10-Year 25-Year 100-Year
Pre-Condition 20.81 38.35 45.99 59.15
Post-Condition 22.37 39.53 49.01 63.19
*see tables 1.1 and 1.2 for further details
With implementation of the proposed drainage system, as shown in the referenced Preliminary Hydrology Study, the net
change under the proposed conditions compared to existing conditions during a 25- and 100year storm events would be less
than 7% increase of total runoff. Based on the existing public storm drain capacities, the 7% increase in site runoff is within
tolerance of the existing system therefore, would have less than a significant hydrologic impact to the surrounding area.
The Preliminary WQMP for the project also included an analysis as to whether any hydrology conditions of concern (HCOC)
would occur on the site with respect to downstream flooding, erosion and siltation 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 present concerns for the physical and biological degradation of streams. The North Orange County
requirements state that HCOC’s 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.
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.
Per Table 1.4 above, the HCOC conditions increased in runoff generated from the 2yr storm event by 7%, however per Section
XVI.3 - “North Orange County Hydromodification Susceptibility Maps” of the North Orange County Technical Guidance
Documents, the project site is located adjacent to the Upper Newport Bay, a tidally influenced area which is a
hydromodification exempt zone (see exhibit in section II.3 of the WQMP).
Impede or Redirect Flood Flows
The proposed project building elevation and surrounding site elevations are considerably higher than the nearest FEMA
established flood elevation therefore project will not impede or redirect existing floodplain flows.
As previously indicated above, all but a narrow sliver of the easterly site boundary is located in the FEMA “Zone X” which is a
low risk designation. The remaining portion is located in “Zone A/E” which has a 1% chance of flooding with an elevation
established at 9 MSL. The proposed building elevation has been established at 20 MSL and the lowest elevation within FEMA
established inundation area has been set at 10 MSL, one foot higher than the flood elevation. Because every portion of the
project is located above the flood hazard area, no impact related to the existing floodplain will occur.
HWQ-4 Impact Analysis Conclusion:
Risk Release of Pollutants due to Project Inundation in Flood Hazard, Tsunami, or Seiche Zones
Impacts regarding the risk release of pollutants due to project inundation flood hazard, tsunami, or seiche zones would be less
than significant. Refer to the following study for further details, Coastal Hazard and Sea Level Rise Discussion for the Newport
DunesResort Hotel, 1131 Back Bay Drive, Newport Beach, Orange County, California dated December 4. 2017 by GeoSoils, Inc.
HWQ-5 Impact Analysis Conclusion:
Conflict with or Obstruct Implementation of Water Quality Control Plan or Sustainable Groundwater
Management Plan
The proposed project will implement a sitespecific water quality control plan which solely addresses stormwater runoff
generated from the proposed improvements. All proposed LID and Source Control BMPs are project specific and are
designed to function independently of the any existing BMPs located within the surrounding developments. The
implementation of the WQMP will not affect the surrounding developments or prohibit future improvements from
implementing site specific WQMP plans.
Regarding sustainable groundwater management plans, due to the depth of groundwater onsite, minor amounts of
groundwater seepage may be present at the bottom of the deepest portions of the building foundation system. However,
the volume of any displaced groundwater would be minor. Construction of the proposed project would not substantially
deplete the groundwater or interfere with future groundwater recharge such that there would be quantifiable reduction in
aquifer volume or groundwater table level. Impacts related sustainable groundwater management plans would be less than
significant.
CUMULATIVE IMPACTS
HYDROLOGY AND DRAINAGE
Cumulative projects would have the potential to affect hydrology and drainage of the area. The projects would contribute
storm water flows to the local and regional storm water system and drainage facilities. However, each individual project
would be required to submit individual analyses for review and approval prior to issuance of grading or building permits.
Each analysis must illustrate how peak flows generated from each related project site would be accommodated by the City’s
existing and/or proposed storm drainage facilities. Future projects would also be required to comply with existing water
quality standards, implement site-specific improvements, and include BMPs as necessary. Therefore, overall cumulative
impacts would be less than significant.
WATER QUALITY
Development of the proposed project, along with related cumulative projects, would result in increased potential for short-
term construction and long-term operational water quality impacts within the area. However, the proposed project would
adhere to NPDES requirements and implement a SWPPP with specific BMPs. Additionally, the project would include the
preparation and implementation of a project-specific WQMP, which would further reduce operational water quality impacts.
Therefore, the project impacts would not be cumulatively considerable, and impacts in this regard are less than significant.
REFERENCES
Adams Streeter Civil Engineers. 2018, July 5. Preliminary Water Quality Management Plan (WQMP): Newport Dunes, 1131
Backbay Dr, Newport Beach, CA
Adams Streeter Civil Engineers. 2018, July 5. Preliminary Hydrology Report: Newport Dunes, 1131 Backbay Dr, Newport
Beach, CA
US Environmental Protection Agency (USEPA). 2012, September 26. Water Permitting 101.
http://www.epa.gov/npdes/pubs/101pape.pdf.
California Department of Conservation: Tsunami inundation map for emergency planning
http://www.conservation.ca.gov/cgs/geologic_hazards/Tsunami/Inundation_Maps/Orange/Documents/Tsunami_Inundatio
n_NewportBeach_Quad_Orange.pdf
State Water Resources Control Board (SWRCB). 2010 303(d) List of Water Quality Limited Segments
https://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2010.shtml?wbid=CAE801140001999032309080
3