(4) 2035 LQ General Plan - Chapter IV (11.19.13)
Chapter
IV
ENVIRONMENTAL
HAZARDS
NOISE
SOILS
AND
GEOLOGY
FLOODING
AND
HYDROLOGY
HAZARDOUS
MATERIALS
NOISE
IV-‐1
NOISE
PURPOSE
The
Noise
Element
addresses
the
City’s
current
and
future
noise
environment.
As
the
City
and
its
Sphere
of
Influence
continue
to
develop,
additional
development
will
generate
noise
from
many
sources,
ranging
from
air
conditioning
units
to
automobiles.
This
Element
identifies
areas
where
noise
levels
are
expected
to
reach
unacceptable
levels,
and
provides
policies
and
programs
which
will
assure
that
noise
levels
do
not
negatively
impact
the
community.
Government
Code
Section
65032(f)
requires
that
cities
evaluate
their
noise
environments,
address
the
potential
hazards
associated
with
high
noise
levels
and
set
standards
for
acceptable
and
unacceptable
noise
levels.
The
City
is
also
allowed
to
set
standards
for
noise
under
the
California
Environmental
Quality
Act
(CEQA).
These
standards
can
help
the
City
identify
projects
which
could
significantly
impact
noise
levels,
and
require
that
the
projects
lower
their
noise
levels.
The
Noise
Element
is
most
closely
related
to
the
Land
Use
and
Circulation
Elements.
In
the
case
of
the
Land
Use
Element,
the
location
of
uses
which
create
more
noise
–
such
as
commercial
shopping
centers
–
can
impact
noise
levels
in
residential
neighborhoods,
schools
and
other
“sensitive
receptors.”
The
Circulation
Element
is
closely
tied
to
the
Noise
Element
because
the
noise
created
by
traffic
is
and
will
continue
to
be
the
single
largest
source
of
noise
in
the
City.
The
distribution
and
smooth
flow
of
traffic,
therefore,
is
critical
to
the
City’s
noise
environment.
BACKGROUND
Noise
is
defined
as
an
unwanted
sound
and
can
have
serious
physiological
and
psychological
effects
on
people,
ranging
from
the
disturbance
of
sleep
to
hearing
loss.
In
order
to
prevent
these
negative
effects,
a
number
of
tools
are
available
to
cities,
particularly
when
they
consider
new
development
proposals.
NOISE
IV-‐2
The
changes
in
air
pressure
which
result
in
sound
are
most
often
measured
in
decibels
(dB).
That
measurement
is
further
modified
by
the
A-‐weighted
decibel
scale
(dBA),
which
gives
less
weight
to
very
low
and
very
high
sounds,
consistent
with
the
way
a
human
ear
reacts
to
sound.
A
conversation
between
two
people
measures
about
60
dBA,
while
construction
equipment
can
register
at
110
dBA.
Most
people
cannot
identify
an
increase
in
sound
of
less
than
3
dB,
and
the
structure
of
the
human
ear
causes
us
to
perceive
that
a
sound
that
is
10
dB
higher
than
another
is
twice
as
loud.
The
chart
below
illustrates
loudness
and
its
subjective
impact
on
people.
The
amount
of
noise
in
a
community
at
any
given
time
is
called
the
ambient
noise
level.
It
consists
of
the
total
of
all
noise
sources
–
traffic,
birdsong,
conversations
and
other
noises
–
at
any
given
time
during
the
day.
There
are
two
classifications
of
the
sources
of
noise:
line
sources,
which
include
traffic
noise;
and
point
sources,
which
are
fixed
sources
such
as
air
conditioners.
Both
sources
can
be
affected
by
surrounding
conditions.
“Soft
site”
conditions,
such
as
vegetation,
absorb
noise
and
reduce
its
potential
impact.
“Hard
site”
conditions,
such
as
walls
and
buildings,
can
block
noise
but
can
also
cause
it
to
reverberate.
In
addition,
distance
reduces
noise
levels
–
a
doubling
of
the
distance
NOISE
IV-‐3
between
a
person
and
a
noise
source
reduces
noise
by
about
4.5
dBA.
Soft
and
hard
site
conditions
and
distance
are
all
used
to
determine
the
level
of
noise
that
reaches
the
human
ear
from
the
source.
Noise
Sources
in
La
Quinta
In
La
Quinta,
traffic
noise
is
the
most
common
source
of
noise.
The
level
of
noise
from
traffic
is
directly
affected
by
the
mix
of
vehicles
on
the
road
–
when
heavy
trucks
make
up
a
larger
share
of
the
traffic,
traffic
noise
is
higher
than
when
traffic
is
composed
entirely
of
automobiles.
Also
contributing
to
noise
levels
are
commercial
activities,
including
air
compressors
and
commercial
compactors,
landscaping
maintenance
equipment,
and
daily
activities.
In
the
Sphere
of
Influence,
aircraft
noise
from
operations
at
the
Jacqueline
Cochran
Regional
Airport
can
also
affect
the
noise
environment.
Although
not
a
heavily
used
airport,
takeoff
and
landing
operations
can
impact
the
residential
land
uses
in
the
Sphere.
As
the
City
and
the
Sphere
of
Influence
areas
build
out,
and
traffic
levels
increase,
ambient
noise
levels
can
also
be
expected
to
go
up.
Careful
planning
is
required
to
assure
that
residents
are
not
negatively
affected.
Noise
Sensitivity
The
term
“sensitive
receptor”
is
used
to
identify
land
uses
which
are
more
impacted
by
noise
than
others.
They
include
residential
uses,
schools
and
libraries,
hospitals
and
nursing
homes.
Moderately
sensitive
uses
include
parks
and
golf
courses,
hotels
and
motels.
The
location
of
uses
which
are
sensitive
to
noise
in
relation
to
noise
generators,
such
as
shopping
centers
and
airports,
must
be
considered
in
the
Land
Use
Map.
Community
Noise
Equivalent
Level
(CNEL)
California
Health
and
Safety
Code
Section
46026
establishes
standards
for
local
noise
ordinances
to
help
identify
appropriate
noise
levels
for
various
land
uses.
It
uses
the
Community
Noise
Equivalent
Level
(CNEL),
which
averages
noise
levels
over
a
24-‐hour
period.
The
CNEL
scale
is
weighted
to
recognize
that
noise
is
more
evident
during
the
more
quiet
evening
and
nighttime
periods.
Because
the
ambient
noise
level
is
lower
in
the
evening
and
at
night,
sounds
appear
to
be
louder.
The
CNEL
scale
has
been
used
to
develop
acceptable
ranges
of
noise
for
a
broad
range
of
land
uses,
ranging
from
single-‐family
homes
to
industrial
uses.
Acceptable
noise
levels
under
this
model
increase
as
NOISE
IV-‐4
the
sensitivity
of
the
land
use
decreases,
so
that
louder
noise
environments
are
considered
acceptable
at
shopping
centers,
and
more
quiet
noise
environments
are
required
for
hotels.
Existing
Noise
Levels
The
primary
source
of
noise
in
the
City
and
Sphere
is
traffic.
In
order
to
determine
noise
levels
throughout
the
City
and
Sphere,
a
noise
analysis
was
conducted
for
this
General
Plan
(it
is
included
in
its
entirety
in
the
Appendix
of
the
General
Plan
EIR).
This
analysis
includes
the
monitoring
of
noise
levels
at
20
locations.
Table
IV-‐1
shows
the
results
of
24-‐hour
monitoring
at
seven
locations,
while
Table
IV-‐2
shows
the
current
short-‐term
noise
levels
at
13
additional
locations.
NOISE
IV-‐5
Table
IV-‐1
Existing
24-‐Hour
Noise
Levels
at
Monitored
Locations
Receptor
Location
Description
Time
Of
Measure-‐
ment
Primary
Noise
Source
Hourly
Noise
Levels
(Leq
dBA)
Daily
Noise
Levels
(dBA
CNEL)
L1
Located
north
of
Westward
Ho
Drive
at
La
Quinta
Park
across
from
the
La
Quinta
High
School
baseball
fields.
February
2-‐3,
2011
Traffic
on
Westward
Ho
Drive,
Park
Activities,
Activities
at
La
Quinta
High
School
44.9
-‐
63.6
60.2
L2
Located
north
of
Highway
111
on
southern
portion
of
the
commercial
center
west
of
La
Quinta
Drive.
February
2-‐3,
2011
Traffic
on
Highway
111
50.4
-‐
64.1
65.3
L3
Located
near
the
Washington
St.
and
Via
Marquessa
intersection
adjacent
to
the
existing
medical
offices.
February
2-‐3,
2011
Traffic
on
Washington
Street
58.1
-‐
71.6
72.7
L4
Located
north
of
the
Coachella
Drive
and
Eisenhower
Drive
intersection
at
the
Legacy
Villas
of
La
Quinta.
February
2-‐3,
2011
Traffic
on
Eisnhower
Drive,
Ambient
47.6
-‐
56.1
59.3
L5
Located
next
to
the
Crab
Pot
Restaurant
on
Avenida
La
Fonda
in
"The
Village".
February
2-‐3,
2011
Traffic
on
Ave.
La
Fonda,
Ambient
within
"The
Village"
43.1
-‐
65.4
58.9
L6
Located
northeast
of
the
52nd
Avenue
and
Jefferson
Street
intersection
at
land
uses
proposed
as
multi-‐family
residential.
February
2-‐3,
2011
Traffic
on
52nd
Ave.
and
Jefferson
St.
48.7
-‐
60.3
62.2
L7
Located
on
the
northeast
corner
of
the
intersection
of
Jackson
Street
and
50th
Avenue
near
the
existing
single-‐
family
homes.
February
2-‐3,
2011
Traffic
on
Jackson
St.
52.6
-‐
72.6
71.4
The
noisiest
locations
monitored
for
a
24-‐hour
period
are
on
Washington
Street
in
the
City
and
Jackson
Street
in
the
Sphere
of
Influence.
These
noise
levels
can
be
attributed
to
vehicular
traffic
on
NOISE
IV-‐6
Washington
and
Jackson
Streets.
The
Daily
Noise
Level
represents
the
average
noise
level
occurring
throughout
the
entire
day.
The
Hourly
Noise
Level
represents
noise
levels
measured
during
one
particular
hour.
In
some
cases,
the
hour
measured
may
have
been
affected
by
an
unusually
loud
event
(heavy
trucks
passing
by)
or
temporarily
noisy
condition
(rush
hour).
Where
this
occurs,
the
Hourly
Noise
Level
can
exceed
the
Daily
Noise
Level.
Table
IV-‐2
below,
illustrates
the
existing
noise
levels
monitored
for
10
minutes
at
each
location.
The
table
shows
that
the
noisiest
locations
are
on
major
roadways
in
the
City.
Table
IV-‐2
Existing
Short-‐Term
Noise
Levels
Receptor
Location
Description
Time
Of
Measure
-‐ment
Primary
Noise
Source
Noise
Levels
(Leq
dBA)
Noise
Levels
(dBA
CNEL)
S1
Located
100
feet
from
the
Washington
Street
centerline
north
of
the
Fred
Waring
Drive
intersection.
3:00
p.m.
Traffic
on
Washington
Street
66.1
68.4
S2
Located
near
the
Jefferson
Street
and
Fred
Waring
Drive
intersection
at
an
existing
Walgreens.
3:17
p.m.
Traffic
on
Jefferson
St.
and
Fred
Waring
Dr.
69.3
72.9
S3
Located
near
the
Eisenhower
Health
center
east
of
the
Washington
Street
centerline.
3:43
p.m.
Traffic
on
Washington
Street
69.3
71.6
S4
Located
near
the
La
Quinta
Unified
School
District
Offices
at
the
intersection
of
48th
Avenue
and
Dune
Palms
Road.
4:11
p.m.
Traffic
on
Avenue
48
66.5
67.1
S5
Located
approximately
100
feet
east
of
the
Jefferson
Street
centerline
north
of
the
50th
Avenue
intersection
at
the
existing
commercial
center.
10:27
a.m.
Traffic
on
Jefferson
St.
64.3
68.0
S6
Located
50
feet
east
of
the
centerline
in
the
front
yard
of
51915
Avenue
Bermudas
across
from
the
community
park
south
of
the
52nd
Avenue
intersection.
11:12
a.m.
Traffic
on
Avenue
Bermudas
66.2
71.3
NOISE
IV-‐7
Table
IV-‐2
(cont’d)
Existing
Short-‐Term
Noise
Levels
Receptor
Location
Description
Time
Of
Measure
-‐ment
Primary
Noise
Source
Noise
Levels
(Leq
dBA)
Noise
Levels
(dBA
CNEL)
S7
Located
south
of
52nd
Avenue
at
the
Cahuilla
Desert
Academy
School.
11:55
a.m.
Traffic
on
52nd
Avenue
62.0
66.6
S8
Located
adjacent
to
the
single-‐family
homes
near
the
intersection
of
Avenue
Bermudas
and
Calle
Arroba.
11:29
a.m.
Traffic
on
Avenue
Bermudas
59.2
64.3
S9
Located
east
of
Madison
Street
at
the
Troon
Way
intersection
near
the
existing
single-‐family
homes.
1:10
p.m.
Traffic
on
Madison
Street
64.4
67.5
S10
Located
100
feet
west
of
the
Harrison
Street
centerline
south
of
the
Airport
Blvd.
intersection.
12:16
p.m.
Traffic
on
Harrison
Street
62.1
65.7
S11
Located
north
of
50th
Avenue
centerline
at
the
existing
Boy
and
Girls
Club.
10:46
a.m.
Traffic
on
50th
Avenue
57.7
61.5
S12
Located
50
feet
east
of
the
Monroe
Street
centerline
south
of
the
60th
Avenue
intersection
and
the
existing
residential
uses.
12:40
p.m.
Traffic
on
Monroe
Street
60.4
64.0
S13
Located
100
feet
west
of
the
Jefferson
Street
centerline
between
52nd
and
54th
Avenue
at
the
proposed
residential
uses.
1:30
p.m.
Traffic
on
Jefferson
Street
66.7
71.0
NOISE
IV-‐8
Table
IV-‐3
Land
Use
Compatibility
for
Community
Noise
Environments
Land
Uses
CNEL
(dBA)
50
55
60
65
70
75
80
Residential
-‐
Single
Family
Dwellings,
Duplex,
Mobile
Homes
A
B
C
D
Residential
–
Multiple
Family
A
B
C
D
Transient
Lodging:
Hotels
and
Motels
A
B
C
D
School
Classrooms,
Libraries,
Churches,
Hospitals,
Nursing
Homes
and
Convalescent
Hospitals
A
B
C
D
Auditoriums,
Concert
Halls,
Amphitheaters
B
C
Sports
Arenas,
Outdoor
Spectator
Sports
B
C
Playgrounds,
Neighborhood
Parks
A
C
D
Golf
Courses,
Riding
Stables,
Water
Recreation,
Cemeteries
A
C
D
Office
Buildings,
Business,
Commercial
and
Professional
A
B
D
Industrial,
Manufacturing,
Utilities,
Agriculture
A
B
D
Source:
California
Department
of
Health
Services,
“Guidelines
for
the
Preparation
and
Content
of
the
Noise
Element
of
the
General
Plan,”
1990
A
Normally
Acceptable:
With
no
special
noise
reduction
requirements
assuming
standard
construction.
B
Conditionally
Acceptable:
New
construction
or
development
should
be
undertaken
only
after
a
detailed
analysis
of
the
noise
reduction
requirement
is
made
and
needed
noise
insulation
features
included
in
the
design
C
Normally
Unacceptable:
New
construction
is
discouraged.
If
new
construction
does
proceed,
a
detailed
analysis
of
the
noise
reduction
requirements
must
be
made
and
needed
noise
insulation
features
included
in
the
design.
D
Clearly
Unacceptable:
New
construction
or
development
should
generally
not
be
undertaken.
NOISE
IV-‐9
La
Quinta
Municipal
Code
Section
9.100.210
of
the
City’s
Municipal
Code
governs
noise
control
in
the
City.
The
current
noise
standards
allow
noise
levels
of
60
dBA
from
7
AM
to
10
PM,
and
50
dBA
from
10
PM
to
7
AM
for
noise
sensitive
uses;
and
75
dBA
from
7
AM
to
10
PM,
and
65
dBA
from
10
PM
to
7
AM
for
nonresidential
land
uses.
This
standard
is
more
stringent
than
the
CNEL
standard
and
can
be
modified
by
City
Council.
The
Ordinance
also
addresses
short-‐term
noise
levels
and
places
restrictions
on
the
length
of
time
unacceptable
noise
levels
can
be
maintained.
It
also
addresses
temporary
noise
levels,
such
as
construction
noise,
and
restricts
the
hours
when
such
noise
can
occur
to
the
less
sensitive
daytime
hours.
Anticipated
Future
Noise
Levels
The
Noise
Impact
Analysis
predicts
noise
levels
throughout
the
City
and
the
Sphere
of
Influence
at
build
out
of
the
General
Plan.
These
are
shown
in
Table
IV-‐4,
below,
and
addressed
in
greater
detail
in
the
General
Plan
EIR.
Table
IV-‐4
Build
Out
Noise
Levels
Road
Segment
CNEL
at
100
Feet
(dBA)
Distance
to
Contour
(Feet)
70
dBA
CNEL
65
dBA
CNEL
60
dBA
CNEL
55
dBA
CNEL
Washington
St.
n/o
Fred
Waring
Dr.
72.7
152
327
705
1,519
Washington
St.
btwn
Fred
Waring
&
Miles
73.3
165
356
766
1,650
Washington
St.
btwn
Miles
&
Hwy
111
72.5
148
318
685
1,476
Washington
St.
btwn
Hwy
111
&
Avenue
48
73.0
158
341
736
1,585
Washington
St.
btwn
Avenue
48
&
Eisenhower
Dr
72.3
142
306
658
1,418
Washington
St.
btwn
Eisenhower
Dr
&
Avenue
50
71.7
129
278
599
1,290
Washington
St.
btwn
Avenue
50
&
Calle
Tampico
70.9
115
248
534
1,150
Eisenhower
Dr.
btwn
Washington
St
&
Avenue
50
68.1
74
160
346
745
Eisenhower
Dr.
btwn
Avenue
50
&
Calle
Tampico
66.6
59
128
275
593
Avenida
Bermudas
btwn
Calle
Tampico
&
Avenue
52
59.1
RW
RW
87
188
Avenida
Bermudas
btwn
Avenue
52
&
Calle
Durango
63.6
RW
80
173
372
Adams
St.
btwn
Westward
Ho
Dr
&
Hwy
111
66.6
60
129
277
597
NOISE
IV-‐10
Table
IV-‐4
(cont’d)
Build
Out
Noise
Levels
Distance
to
Contour
(Feet)
Road
Segment
CNEL
at
100
Feet
(dBA
70
dBA
CNEL
65
dBA
CNEL
60
dBA
CNEL
55
dBA
CNEL
Adams
St.
btwn
Hwy
111
&
Avenue
48
66.8
61
132
284
613
Dune
Palms
Rd.
btwn
Westward
Ho
Dr
&
Hwy
111
65.5
50
108
232
500
Dune
Palms
Rd.
btwn
Hwy
111
&
Avenue
48
66.7
60
129
278
598
Jefferson
St.
n/o
Fred
Waring
70.4
107
230
496
1,068
Jefferson
St.
btwn
Fred
Waring
&
Miles
71.8
132
284
613
1,320
Jefferson
St.
btwn
Miles
&
Westward
Ho
Dr
72.2
141
304
654
1,409
Jefferson
St.
btwn
Westward
Ho
Dr
&
Hwy
111
72.2
140
302
651
1,402
Jefferson
St.
btwn
Hwy
111
&
Avenue
48
72.1
139
299
645
1,389
Jefferson
St.
btwn
Avenue
48
&
Avenue
50
72.7
151
326
702
1,513
Jefferson
St.
btwn
Avenue
50
&
Avenue
52
71.1
119
256
551
1,186
Jefferson
St.
btwn
Avenue
52
&
Avenue
54
70.7
111
239
516
1,112
Madison
St.
btwn
Avenue
50
&
Avenue
52
70.4
107
231
497
1,071
Madison
St.
btwn
Avenue
54
&
Airport
Blvd
72.0
136
292
629
1,355
Madison
St.
btwn
Airport
Blvd
&
Avenue
58
70.8
113
244
527
1,134
Madison
St.
btwn
Avenue
58
&
Avenue
60
68.2
76
164
354
762
Monroe
St.
btwn
Avenue
52
&
Avenue
54
70.4
106
228
492
1,060
Monroe
St.
btwn
Avenue
54
&
Airport
Blvd
70.6
110
237
510
1,099
Jackson
St.
btwn
Avenue
54
&
Airport
Blvd
70.0
101
217
467
1,006
Jackson
St.
btwn
Airport
Blvd
&
Avenue
58
70.2
103
221
476
1,026
Jackson
St.
btwn
Avenue
58
&
Avenue
60
69.5
93
199
429
925
Jackson
St.
btwn
Avenue
60
&
Avenue
62
68.3
77
166
358
770
Van
Buren
St.
btwn
Avenue
52
&
Avenue
54
70.0
101
217
467
1,006
Van
Buren
St.
btwn
Avenue
54
&
Airport
Blvd
69.0
86
185
399
859
Van
Buren
St.
btwn
Airport
Blvd
&
Avenue
58
69.3
90
195
419
904
Van
Buren
St.
btwn
Avenue
58
&
Avenue
60
69.4
91
196
422
908
Van
Buren
St.
btwn
Avenue
60
&
Avenue
62
65.8
52
113
243
523
Harrison
St.
btwn
Airport
Blvd
&
Avenue
58
73.7
176
378
815
1,756
Avenue
44
e/o
Washington
St
72.0
136
292
629
1,356
Miles
Ave.
e/o
Washington
St
66.6
59
127
274
590
Hwy
111
e/o
Washington
St
75.4
230
496
1,068
2,301
Hwy
111
e/o
Adams
St
74.2
191
411
885
1,906
NOISE
IV-‐11
Table
IV-‐4
(cont’d)
Build
Out
Noise
Levels
Distance
to
Contour
(Feet)
Road
Segment
CNEL
at
100
Feet
(dBA
70
dBA
CNEL
65
dBA
CNEL
60
dBA
CNEL
55
dBA
CNEL
Hwy
111
e/o
Dune
Palms
75.2
223
481
1,036
2,233
Avenue
48
e/o
Washington
St
67.0
64
137
295
635
Avenue
48
w/o
Jefferson
St
70.0
100
215
464
999
Avenue
50
e/o
Washington
St
64.4
RW
91
197
424
Avenue
50
w/o
Jefferson
St
67.0
63
136
294
634
Avenue
50
e/o
Jefferson
St
69.7
96
207
447
962
Calle
Tampico
btwn
Eisenhower
Dr
&
Avenida
Bermudas
61.9
RW
62
134
289
Calle
Tampico
btwn
Avenida
Bermudas
&
Washington
St
64.7
RW
95
204
440
Avenue
52
w/o
Washington
St
66.7
60
130
280
603
Avenue
52
w/o
Jefferson
St
70.1
102
220
475
1,023
Avenue
52
e/o
Jefferson
St
69.7
95
206
443
955
Avenue
52
e/o
Madison
St
69.2
88
190
410
883
Avenue
54
e/o
Jefferson
St
69.9
98
212
457
984
Avenue
54
w/o
Madison
St
62.4
RW
67
145
312
Airport
Blvd.
e/o
Madison
St
67.3
66
141
304
656
Avenue
58
w/o
Monroe
St
63.8
RW
83
179
386
Avenue
58
e/o
Monroe
St
66.0
54
117
252
542
Avenue
60
e/o
Madison
St
64.9
46
99
213
460
Avenue
60
e/o
Monroe
St
65.3
RW
105
226
488
Avenue
62
btwn
Madison
St
&
Monroe
St
64.3
42
90
195
419
Avenue
62
e/o
Monroe
St
67.5
68
146
314
677
Avenue
62
e/o
Jackson
St
63.7
RW
82
178
383
Avenue
62
e/o
Van
Buren
St
60.1
RW
47
102
220
Most
new
residential
development
on
General
Plan
roads
will
be
located
between
35
and
65
feet
from
the
center
line
of
the
street
(depending
on
the
type
of
road
on
which
the
project
is
located).
Based
on
Table
IV-‐4,
in
order
to
achieve
a
noise
level
of
65
dBA
CNEL
or
less,
noise
analysis
will
be
required
at
most
locations
to
assure
that
a
project’s
design
includes
noise
protection.
NOISE
IV-‐12
Managing
Noise
Levels
Site
planning
and
design
standards,
including
the
use
of
buffer
zones,
building
orientation,
walls,
and
landscaping
between
sensitive
land
uses
and
roadways
are
the
most
common
and
easiest
ways
to
lessen
noise
levels.
As
new
noise-‐sensitive
projects
are
developed
next
to
noisy
roads
throughout
the
City,
noise
impact
analyses
should
be
part
of
the
approval
process
to
assure
that
the
noise
environment
within
the
projects
is
acceptable.
These
analyses
will
be
individually
tailored
to
address
each
site
and
will
provide
noise
attenuation
best
suited
to
the
particular
situation
faced
by
each
project.
Such
analysis
is
critical
to
assuring
good
quality
of
life
for
City
residents.
The
most
effective
way
to
reduce
noise
is
by
installing
a
solid
barrier;
however,
noise
barriers
can
have
limitations.
To
reduce
noise
levels
by
5
dBA,
a
vegetative
barrier
must
be
at
least
15
feet
high,
100
feet
wide,
and
dense
enough
to
completely
obstruct
the
line-‐of-‐sight
between
the
noise
source
and
receiver.
For
a
block
wall
to
effectively
decrease
traffic
noise
levels
by
5
dB,
it
must
be
high
and
long
enough
to
block
the
view
of
the
road.
Construction
Noise
Most
construction
projects
require
the
use
of
heavy
equipment.
Heavy
equipment
can
generate
noise
ranging
from
68
dBA
to
over
100
dBA
at
a
distance
of
50
feet.
For
every
doubling
of
distance,
the
noise
level
is
reduced
by
about
6
dBA.
Heavy
equipment
operating
close
to
existing
sensitive
receptors,
however,
can
create
unacceptable
noise
levels
for
short
periods
of
time.
The
City
has
adopted
a
noise
ordinance
which
limits
construction
activities
in
order
to
reduce
the
potential
for
intrusive
noise
during
evenings,
weekends
and
holidays.
Future
development
proposals
should
be
required
to
analyze
construction
noise
if
the
project
is
proposed
next
to
existing
sensitive
receptors.
Airport
Noise
The
Jacqueline
Cochran
Regional
Airport
is
located
immediately
east
of
the
Sphere
of
Influence
and
accommodates
business
and
private
air
traffic.
In
the
future,
it
is
likely
that
activity
at
the
airport
will
increase.
One
of
the
airport’s
runways
is
constructed
on
a
north-‐south
axis,
which
results
in
the
bulk
of
the
noise
occurring
north
and
south
of
the
runway,
as
shown
in
Exhibit
IV-‐1.
The
other
runway
lies
on
a
northwest-‐
southeast
axis,
and
noise
contours
along
this
runway
are
limited
to
the
immediate
vicinity
of
the
runway.
The
airport’s
noise
levels
are,
therefore,
not
expected
to
impact
areas
west
of
Harrison
Street,
which
defines
the
eastern
edge
of
the
City’s
Sphere
of
Influence.
NOISE
IV-‐14
Bus
Stops
and
Bus
Routes
SunLine
Transit
Agency
operates
bus
routes
in
the
City.
The
current
routes
are
focused
on
Highway
111
and
Washington
Street,
and
they
connect
to
other
routes
which
provide
for
regional
travel
throughout
the
Valley.
As
the
City
and
the
region
grow,
demand
for
transit
service
will
increase,
and
SunLine
is
likely
to
expand
its
services
in
the
City.
Transit
buses
can
have
a
negative
noise
impact
–
their
brakes
and
engines
can
be
louder
than
typical
car
noise,
and
their
acceleration
from
bus
stops
can
be
noisy
if
the
stop
is
located
next
to
residential
development.
As
additional
bus
routes
are
developed,
and
sensitive
uses
are
proposed
next
to
bus
routes,
noise
analysis
will
be
needed
to
assure
that
transit
activities
do
no
raise
noise
levels
beyond
the
City’s
standards.
Truck
Routes
The
City
limits
truck
routes
by
maintaining
an
official
truck
route
map.
Although
the
map
is
updated
periodically,
it
generally
limits
truck
routes
to
major
roadways.
Although
heavy
trucks
occasionally
use
local
streets
to
access
delivery
addresses,
their
presence
on
major
roadways
does
not
significantly
change
the
existing
or
future
noise
environment.
As
with
bus
routes,
the
City
will
need
to
monitor
future
development
of
sensitive
receptors
on
major
roadways
to
assure
that
truck
noise
does
not
raise
noise
levels
beyond
the
City’s
standards.
Groundborne
Vibration
Groundborne
vibration
most
commonly
results
from
construction
equipment,
train
trips
and
heavy
truck
traffic.
Unlike
noise,
there
is
no
established
standard
to
measure
vibration.
Most
groundborne
vibration
in
La
Quinta
is
from
construction
activity
and
heavy
trucks,
since
there
are
no
train
tracks
in
the
City
or
its
Sphere
of
Influence.
In
the
long
term,
it
is
not
expected
that
additional
sources
of
vibration
will
develop
in
the
City.
Construction
equipment
and
heavy
trucks
can
cause
limited
and
short-‐duration
vibrations;
however,
groundborne
vibration
is
not
expected
to
affect
the
City
signifi cantly.
PLANNING
FOR
THE
FUTURE
In
general,
the
City’s
current
land
use
patterns
buffer
sensitive
land
uses
from
high
noise
levels.
However,
as
the
City
and
Sphere
grow
in
the
future,
noise
impacts
will
need
to
be
carefully
considered.
This
is
particularly
true
of
any
area
where
Mixed
Use
development
is
considered
–
along
Highway
111
or
in
the
Village
–
where
there
may
be
NOISE
IV-‐15
less
room
to
buffer
residential
uses
from
commercial
activities.
Careful
consideration
of
each
future
project
will
be
required
to
assure
that
compatibility
is
maintained.
The
City’s
ongoing
efforts
to
preserve
the
quality
of
life
for
all
its
residents,
present
and
future,
must
include
the
protection
of
a
quiet
noise
environment.
GOALS,
POLICIES
AND
PROGRAMS
GOAL
N-‐1
A
healthful
noise
environment
which
complements
the
City’s
residential
and
resort
character.
Policy
N-‐1.1
Noise
standards
in
the
City
shall
be
consistent
with
the
Community
Noise
and
Land
Use
Compatibility
scale
described
in
this
Element.
Program
N-‐1.1.a:
Propose
to
City
Council
an
amendment
to
the
Municipal
Code
(Section
9.100.210)
to
allow
65
dBA
CNEL
for
sensitive
land
uses.
Program
N-‐1.1.b:
Ensure
that
City
Building
Code
standards
include
interior
noise
level
standards
that
are
consistent
with
the
Community
Noise
and
Land
Use
Compatibility
scale.
Policy
N-‐1.2
New
residential
development
located
adjacent
to
any
roadway
identified
in
Table
IV-‐4
as
having
a
build
out
noise
level
in
excess
of
65
dBA
shall
continue
to
be
required
to
submit
a
noise
impact
analysis
in
conjunction
with
the
first
Planning
Department
application,
which
demonstrates
compliance
with
the
City’s
noise
standards.
Policy
N-‐1.3
New
non-‐residential
development
located
adjacent
to
existing
residential
development,
sensitive
receptors
or
residentially
designated
land,
shall
be
required
to
submit
a
noise
impact
analysis
in
conjunction
with
the
first
Planning
Department
application,
which
demonstrates
that
it
will
not
significantly
impact
the
adjacent
residential
development
or
residential
land.
NOISE
IV-‐16
Program
N-‐1.3.a:
Provide
accommodation
for
special
events
in
the
public
interest,
such
as
concerts
and
festivals,
which
may
temporarily
exceed
the
maximum
allowable
decibel
level.
Policy
N-‐1.4
All
Mixed
Use
projects
shall
be
required
to
submit
a
noise
impact
analysis
in
conjunction
with
the
first
Planning
Department
application,
which
demonstrates
compliance
with
the
City’s
noise
standards.
Policy
N-‐1.5
All
noise
impact
analysis
will
include,
at
a
minimum,
short-‐term
construction
noise
and
noise
generated
by
the
daily
operation
of
the
project
at
build
out.
Policy
N-‐1.6
The
City
may
require
remedial
noise
control
plans
and/or
improvements
for
areas
experiencing
noise
in
excess
of
adopted
City
standards.
Program
N-‐1.6.a:
Remedial
improvements
will
be
included
in
the
Capital
Improvement
Program.
Policy
N-‐1.7
Noise
impact
analysis
shall
be
included
in
all
City
Capital
Improvement
Plan
(CIP)
and
developer-‐required
roadway
widening
projects
to
demonstrate
compliance
with
City
noise
standards.
Policy
N-‐1.8
Maintain
a
truck
route
plan
restricting
truck
travel
to
arterial
roadways.
RELATED
GOALS
As
described
above,
this
Element
relates
to
others
in
this
General
Plan.
The
following
Goals
and
their
associated
policies
and
programs
are
closely
related
to
those
of
this
Element.
GOAL
LU-‐1:
Land
use
compatibility
throughout
the
City.
GOAL
LU-‐3:
Safe
and
identifiable
neighborhoods
that
provide
a
sense
of
place.
GOAL
OS-‐2:
Good
stewardship
of
natural
open
space
and
preservation
of
open
space
areas.
NOISE
IV-‐17
THIS
PAGE
INTENTIONALLY
LEFT
BLANK
SOILS
AND
GEOLOGY
IV-‐19
SOILS
AND
GEOLOGY
PURPOSE
The
Soils
and
Geology
Element
assesses
the
physical
characteristics
of
the
planning
area
and
the
community’s
overall
safety.
This
element
relates
to
a
variety
of
other
General
Plan
elements,
including
Land
Use,
Circulation,
Housing,
Economic
Development,
Public
Facilities,
Emergency
Services,
and
Water,
Sewer
and
Other
Public
Utilities.
Many
of
the
issues
addressed
in
this
element
also
directly
relate
to
those
considered
in
the
Flooding
and
Hydrology
Element.
California
Government
Code
and
Public
Resources
Code
require
the
inclusion
of
a
General
Plan
element
addressing
seismic
safety
issues.
As
set
forth
in
Government
Code
Section
65302(g),
the
General
Plan
is
required
to
consider
the
need
to
protect
the
community
from
unreasonable
risks
from
seismically
induced
hazards,
including
surface
rupture,
groundshaking,
ground
failure,
seiching,
dam
failure,
subsidence,
and
other
geologic
risks.
The
City
lies
within
the
most
severe
seismic
shaking
zone,
Zone
4,
as
defined
in
Chapter
2-‐23,
Part
2,
Title
24
of
the
Administrative
Code.
Jurisdictions
in
Zone
4
must
identify
all
potentially
hazardous
or
substandard
buildings,
and
programmatically
mitigate
potential
hazards
associated
with
such
structures.
BACKGROUND
Geologically,
the
planning
area
is
diverse
and
relatively
young.
It
is
subject
to
a
variety
of
complex,
on-‐going
geologic
and
seismic
processes
and
hazards,
including
continuing
uplift
of
the
San
Jacinto
and
Santa
Rosa
Mountains
to
the
west,
and
seismic-‐related
subsidence
(gradual
settling)
of
the
Coachella
Valley.
SOILS
AND
GEOLOGY
IV-‐20
The
following
discussions
summarize
the
soil
types
and
conditions,
and
associated
geotechnical
and
seismic
hazards
that
should
be
considered
in
future
planning
for
La
Quinta.
This
discussion
is
intended
to
provide
an
overview;
additional
technical
information
and
specific
mitigation
measures
are
provided
in
the
Environmental
Impact
Report
for
this
General
Plan.
Seismic
Hazards
Most
of
Southern
California
is
located
at
the
boundary
between
the
North
American
and
Pacific
tectonic
plates,
which
are
moving
past
each
other
at
varying
rates.
The
boundary
between
these
two
plates
is
marked
by
the
San
Andreas
Fault,
which
occurs
approximately
4
miles
north
of
the
City.
Approximately
60
to
70
percent
of
the
plate
movement
occurs
along
the
San
Andreas
Fault.
The
remainder
is
distributed
among
other
faults
within
the
San
Andreas
system
and
those
associated
with
the
Eastern
California
Shear
Zone.
The
southern
California
region
and
the
planning
area
are,
therefore,
in
an
area
susceptible
to
strong
seismic
activity.
Measuring
Seismic
Events
The
seismic
energy
released
when
an
earthquake
occurs
is
measured
in
terms
of
intensity
and
magnitude.
The
intensity
of
ground
shaking
is
determined
by
several
factors,
including
the
earthquake’s
magnitude,
distance
from
the
epicenter,
and
soil
and
rock
composition.
Seismologists
have
used
a
variety
of
scales
to
measure
earthquakes.
Modern
Mercalli
Intensity
(MMI)
scale
is
the
most
common
measure
of
seismic
intensity.
It
defines
earthquakes
in
terms
of
damage
along
a
continuum
of
12
levels,
based
on
observable
damage
to
structures
and
human
responses
to
earthquakes.
Seismic
Moment
(Mw)
Measure
is
currently
favored
by
seismologists,
and
correlates
earthquake
size
to
the
amount
of
energy
released
when
a
fault
ruptures.
A
one-‐point
increase
in
magnitude
represents
a
32-‐fold
increase
in
energy.
Maximum
Probable
Earthquake
(MPE)
is
the
largest
earthquake
likely
to
occur
on
a
fault
or
fault
segment
within
a
specified
time
period.
MPE
is
used
to
prepare
engineering
or
emergency
plans,
to
develop
design
parameters
and
safe
construction
practices,
and
to
prepare
policies
and
programs
regarding
potential
earthquake
hazards
and
impacts.
SOILS
AND
GEOLOGY
IV-‐21
Maximum
Magnitude
Earthquake
(Mmax)
is
a
value
assigned
by
the
California
Geological
Survey
which
represents
the
highest
magnitude
earthquake
a
fault
is
capable
of
producing
based
on
physical
limitations,
such
as
the
length
of
the
fault
or
segment.
Major
Faults
Affecting
the
Planning
Area
Potential
hazards
associated
with
earthquakes
can
range
from
significant
property
damage,
to
the
loss
of
public
services
and
facilities,
to
the
loss
of
life.
Strong
ground
shaking
has
the
greatest
potential
to
result
in
severe
impacts
in
La
Quinta.
Ground
shaking
may
cause
other
hazards
such
as
landslides,
structural
damage
or
destruction,
liquefaction,
and
settlement.
Such
events
can
also
result
in
fires,
hazardous
materials
releases,
and
disruption
of
essential
facilities
and
services
such
as
water,
sewer,
gas,
electric,
drainage,
and
transportation.
Flooding
can
result
from
dam
or
water
tank
failure.
The
most
significant
faults
with
the
potential
to
affect
the
General
Plan
area
are
described
below
and
illustrated
in
Exhibit
IV-‐2.
San
Andreas
Fault
Zone:
considered
the
“Master
Fault”
in
Southern
California
based
on
frequency
and
magnitude
of
earthquakes
and
influence
over
seismic
hazards
in
the
area.
Passes
approximately
4
miles
northwest
of
the
General
Plan
area.
Extends
approximately
690
miles,
from
the
Salton
Sea
to
Cape
Mendocino
in
northern
California.
Last
major
earthquake
on
the
southern
portion:
Fort
Tejon
(1857),
magnitude
8.0;
the
largest
earthquake
reported
in
California.
Southern
San
Andreas
fault
estimated
to
have
a
59%
probability
of
causing
an
earthquake
of
at
least
magnitude
6.7
in
the
next
30
years.
Maximum
Magnitude
Earthquake
(Mmax)
potential
in
La
Quinta:
7.7
to
8.0
earthquake.
Shaking
intensity
could
range
from
moderate
to
strong
and
would
be
expected
to
result
in
moderate
to
heavy
damage,
especially
to
buildings
that
are
older
or
poorly
constructed.
San
Jacinto
Fault
Zone:
historically,
the
San
Jacinto
fault
has
produced
more
large
earthquakes
than
any
other
fault
in
southern
California.
None
have
been
as
large
as
the
1857
and
1906
earthquakes
on
the
San
Andreas
fault.
SOILS
AND
GEOLOGY
IV-‐22
Located
south
of
the
planning
area.
Comprises
the
western
margin
of
the
San
Jacinto
Mountains
via
a
series
of
closely
spaced
faults.
Extends
approximately
175
miles,
intersecting
with
the
San
Andreas
fault
in
San
Bernardino;
continues
south
of
the
U.S./Mexico
border
as
the
Imperial
fault.
Most
recent
surface-‐rupturing
earthquakes
occurred
in
1968
along
the
Coyote
Creek
segment
and
in
1987
along
the
Superstition
Hills
segment.
All
segments
of
the
San
Jacinto
fault
have
an
average
of
31%
probability
of
rupturing
between
1994
and
2024.
Burnt
Mountain
Fault:
one
of
several
of
the
other
Eastern
Mojave
Shear
Zone
faults.
Unknown
until
1992,
when
a
ground-‐surface
rupture
occurred
along
a
3.1-‐mile-‐length
of
this
fault
(most
likely
during
a
large
aftershock
of
the
Landers
earthquake).
Extends
approximately
13
miles.
Approximately
15
miles
north
of
La
Quinta
at
nearest
point.
Considered
capable
of
producing
a
magnitude
6.0
to
6.5
earthquake.
Elsinore
Fault
Zone:
major
right-‐lateral
strike-‐slip
fault
of
the
San
Andreas
fault
system
in
southern
California.
Extends
approximately
190
miles,
from
northern
Baja
California
to
the
Los
Angeles
Basin.
Divided,
from
south
to
north
into
seven
segments.
Closest
Elsinore
segment
to
La
Quinta,
approximately
39
miles
west
of
La
Quinta.
Probability
of
rupturing
in
a
magnitude
6.7
earthquake
in
the
next
30
years
approximately
11%.
SOILS
AND
GEOLOGY
IV-‐24
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SOILS
AND
GEOLOGY
IV-‐25
Seismically
Induced
Geotechnical
Hazards
Seismically
Induced
Ground
Shaking
Seismically
induced
ground
shaking
is
the
most
potentially
significant
geotechnical
hazard
to
the
La
Quinta
area.
As
discussed
above,
large
earthquakes
along
regional
faults,
including
the
San
Andreas
and
San
Jacinto
fault
zones,
have
the
potential
to
generate
moderate
to
severe
ground
shaking
in
the
planning
area.
Factors
that
determine
the
effects
of
ground
motion
and
the
degree
of
structural
damage
that
may
occur
include:
Intensity
of
the
earthquake.
Distance
between
epicenter
and
site.
Soil
and
bedrock
composition.
Depth
to
groundwater.
Presence
of
ridge
tops
(may
result
in
higher
localized
accelerations).
Building
design
and
other
criteria.
Local
agencies
use
a
variety
of
tools
to
assure
seismic
safety
in
structures,
including
the
California
Building
Code
and
Unreinforced
Masonry
Law.
These
are
further
discussed
under
Mitigation
of
Earthquake
Hazards,
below.
Liquefaction
Liquefaction
occurs
when
ground
shaking
of
relatively
long
duration
and
intensity
over
0.2
g
occurs
in
areas
of
loose,
unconsolidated
soils
with
relatively
shallow
groundwater
depths
(50
feet
or
less).
The
sudden
increase
in
water
pressure
in
pores
between
soil
grains
may
substantially
decrease
soil
shear
strength.
This
creates
a
condition
where
soil
takes
on
the
qualities
of
a
liquid
or
a
semi-‐viscous
substance.
Liquefaction
can
result
in
ground
settlement,
ground
undulation,
lateral
spreading
or
displacement,
and
flow
failures.
Structures
may
sink
or
tilt
as
bearing
capacity
decreases,
causing
substantial
damage.
Areas
where
both
shallow
groundwater
and
soils
that
are
susceptible
to
liquefaction
occur
include
the
southeastern
part
of
the
city
and
the
entire
eastern
Sphere
of
Influence
area.
Liquefaction
potential
in
this
area
ranges
from
moderate,
where
groundwater
is
30
to
50
feet
below
the
surface,
to
high,
where
groundwater
is
found
30
feet
or
less
below
the
surface.
Exhibit
IV-‐3,
Seismic
Hazards,
shows
areas
of
liquefaction
susceptibility
in
the
planning
area.
SOILS
AND
GEOLOGY
IV-‐26
Landslides
and
Rockfall
Landslides
and
rockfall
can
occur
when
unstable
slope
conditions
are
worsened
by
strong
ground
motion
caused
by
seismic
events.
Conditions
that
lead
to
landslide
vulnerability
include
high
seismic
potential;
rapid
uplift
and
erosion
that
creates
steep
slopes
and
deeply
incised
canyons;
folded
and
highly
fractured
rock;
and
rock
with
silt
or
clay
layers
that
are
inherently
weak.
Rockfall
and
rockslides
are
also
common
on
very
steep
slopes.
Landslides
have
been
recorded
after
periods
of
heavy
rainfall,
and
rockfall
has
been
associated
with
slope
failure
during
drier
periods.
Areas
where
development
is
located
below
hillsides,
mountain
slopes
and
steep
canyon
walls
are
considered
most
susceptible
to
rockfall.
This
includes
much
of
the
Cove
and
the
southwestern
edge
of
the
City,
which
is
surrounded
by
mountains
comprised
of
granitic
rock.
Exhibit
IV-‐3,
Seismic
Hazards,
illustrates
where
the
highest
potential
exists
for
slope
instability.
Seismically
Induced
Settlement
Seismically
induced
settlement
can
occur
when
strong
ground
shaking
causes
soils
to
become
more
tightly
packed,
collapsing
pore
spaces,
and
reducing
the
soil
column
thickness.
Soils
that
are
loose
and
unconsolidated,
as
is
typical
of
young
alluvial
and
wind-‐deposited
soils,
are
especially
subject
to
this
risk.
Fill
may
also
be
susceptible
if
not
properly
compacted
during
construction.
Areas
where
these
soils
(mapping
units
Qa,
Qa/Ql
and
Qs)
predominate
are
shown
on
Exhibit
IV-‐4,
Geologic
Map,
and
include
much
of
the
valley
floor
throughout
the
northern
Sphere
of
Influence,
the
urban
core
of
the
City,
and
the
eastern
corporate
limits
and
Sphere-‐of-‐
Influence.
SOILS
AND
GEOLOGY
IV-‐28
PAGE
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SOILS
AND
GEOLOGY
IV-‐29
Seiche
Seiches
are
standing
wave
oscillations
(sloshing)
that
occur
in
enclosed
or
partially
enclosed
water
bodies
of
shallow
to
moderately
shallow
depth.
Seiches
may
occur
in
reservoirs,
lakes,
ponds,
and
swimming
pools.
Seiche
waves
typically
associated
with
seismic-‐induced
ground
shaking
are
less
than
2
feet
high,
although
seiches
over
6.5
feet
have
been
reported.
In
the
planning
area,
there
are
numerous
lakes,
ponds,
and
reservoirs
that
may
be
subject
to
seiches
as
a
result
of
ground
shaking.
These
include
Lake
Cahuilla,
recharge
basins
in
the
southeastern
portion
of
La
Quinta,
and
smaller
golf
course
lakes
and
detention
basins.
Potential
damage
may
also
occur
from
seiches
in
water
storage
reservoirs.
Regulatory
Mitigation
of
Earthquake
Hazards
The
State
of
California
enacted
the
Alquist-‐Priolo
Earthquake
Fault
Zoning
Act
in
1972
to
mitigate
the
hazard
of
fault
rupture
by
prohibiting
structures
intended
for
human
occupancy
from
being
located
across
the
trace
of
an
active
fault.
It
requires
the
State
Geologist
to
define
"Earthquake
Fault
Zones"
along
faults
that
show
evidence
of
active
surface
displacement.
The
Act
prohibits
local
jurisdictions
from
granting
development
permits
for
certain
types
of
development
on
sites
within
an
Earthquake
Fault
Zone
until
a
geologic
investigation
demonstrates
they
are
safe
from
surface
displacements
from
future
faulting.
There
are
no
Alquist-‐Priolo
zoned
faults
in
the
City
of
La
Quinta
or
its
Sphere
of
Influence.
The
closest
zoned
fault
is
the
San
Andreas
fault
to
the
north
of
the
city
(also
please
see
Exhibit
IV-‐2,
Faults
and
Historical
Seismicity
Map).
The
State
enacted
the
Seismic
Hazards
Mapping
Act
(SHMA)
in
1990.
It
addresses
non-‐surface
earthquake
hazards
such
as
strong
ground
shaking,
liquefaction
and
seismically
induced
landslides.
It
is
intended
to
minimize
loss
of
life
and
property
by
identifying
and
mitigating
seismic
hazards.
The
California
Geological
Survey
(CGS)
is
primarily
responsible
for
its
implementation.
CGS
is
required
to
provide
local
governments
with
seismic
hazard
zone
maps
that
identify
areas
subject
to
liquefaction,
earthquake-‐induced
landslides
and
other
ground
failures,
also
known
as
“zones
of
required
investigation.”
When
construction
projects
fall
within
these
areas,
site-‐specific
geological
hazard
investigations
are
required
by
the
SHMA.
SOILS
AND
GEOLOGY
IV-‐30
There
are
currently
no
State-‐issued,
official
seismic
hazard
zone
maps
for
La
Quinta
or
its
Sphere.
The
Seismic
Retrofitting
and
Unreinforced
Masonry
Law
was
enacted
by
the
State
in
1986,
and
requires
all
cities
and
counties
in
zones
designated
as
Seismic
Zone
4
to
identify
potentially
hazardous
unreinforced
masonry
(URM)
buildings
in
their
jurisdictions.
In
2006,
the
City
inventoried
URMs
and
reported
there
were
seven
historic
URMs
in
the
City.
Of
these,
five
have
been
retrofitted
in
compliance
with
the
City’s
mandatory
mitigation
program.
One
was
to
be
demolished,
and
one
had
neither
been
mitigated
nor
showed
progress
towards
mitigation.
Both
are
adobe
structures
located
on
the
grounds
of
the
La
Quinta
Resort.
The
City
Building
Department
has
reported
that
the
unmitigated
URMs
are
vacant
and
are
not
being
used.
Soils
There
are
seven
types
of
soil
units
that
have
been
mapped
in
the
planning
area:
1. Alluvial
sand
and
gravel
of
the
Whitewater
River
(Qg)
2. Windblown
sand
(wind-‐lain
dune
sand)
(Qs)
3. Interbedded
lacustrine
(clay
of
valley
areas)
(Ql)
4. Alluvial
deposits
(sand
of
valley
areas)
(Qa)
5. Alluvial
fan
sand
and
gravel
deposits
(Qf)
6. Landslide
deposits
(Qls)
7. Quartz
diorite
(hard
crystalline
rock)
(Qd)
The
locations
of
these
soils
in
the
planning
area
are
shown
on
Exhibit
IV-‐4,
Geologic
Map
of
the
Study
Area.
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AND
GEOLOGY
IV-‐32
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SOILS
AND
GEOLOGY
IV-‐33
Hazards
Associated
with
Soils
Landslides
and
Slope
Instability
Slope
failure
can
occur
on
steep
slopes,
and
development
at
their
base
is
at
risk
of
landslides,
surficial
failures,
soil
slip,
debris
flow,
and/or
rockfall.
The
planning
area
includes
significant
areas
of
hillside
terrain,
such
as
those
associated
with
the
Santa
Rosa
National
Monument.
Areas
subject
to
these
hazards
include
many
of
the
more
developed
areas
in
the
City,
which
are
surrounded
on
three
sides
by
mountains
that
pose
rockfall
hazard.
Earthquakes,
periods
of
intense
rainfall,
or
human
activities
associated
with
construction,
such
as
grading
and
blasting,
can
increase
these
hazards.
Compressible
Soils
Compressible
soils
are
geologically
young,
unconsolidated
soils
of
low
density
that
tend
to
compress
under
the
weight
of
proposed
fill
embankments
and
structures.
In
the
General
Plan
area,
areas
most
likely
to
contain
compressible
soils
include:
Valley
areas,
which
include
young
soil
deposits
associated
with
modern
and
pre-‐historic
floodplains,
including
the
Whitewater
River,
which
are
overlain
with
wind-‐blown
deposits
and
alluvium;
Hillside
areas,
especially
at
the
base
of
natural
slopes,
and
within
canyon
bottoms
and
swales;
Deep
fill
embankments,
normally
those
more
than
about
60
feet
deep,
which
may
compress
under
their
own
weight.
Collapsible
Soils
Collapsible
soils
are
associated
with
sediments
that
have
recently
accumulated
in
arid
or
semi-‐arid
environments,
including
soils
commonly
associated
with
alluvial
fan
and
debris
flow
sediments
deposited
during
flash
floods,
which
are
typically
dry
and
contain
tiny
voids.
Under
some
conditions,
significant
settlement
can
occur
rapidly,
even
under
relatively
light
loads.
Irrigation,
especially
near
building
foundations,
or
a
rise
in
the
groundwater
table
can
lead
to
differential
settlement
of
buildings
or
structures,
causing
walls
and
foundations
to
crack.
SOILS
AND
GEOLOGY
IV-‐34
In
the
General
Plan
area,
this
hazard
may
pose
a
localized
risk
where
young
alluvial
and
wind-‐deposited
sediments
occur.
The
La
Quinta
Engineering
Department
has
prepared
a
bulletin
(available
on
the
City’s
website)
that
identifies
portions
of
the
General
Plan
area
that
are
susceptible
to
collapsible
soils.
The
bulletin
establishes
supplemental
guidance
for
preparing
site-‐specific
geotechnical
reports
as
they
pertain
to
collapsible
soils.
Expansive
Soils
Expansive
soils
are
soils
containing
fine-‐grained
materials
such
as
silts
and
clays
in
varying
amounts.
With
changes
in
moisture
content,
clay
minerals
can
shrink
or
swell,
creating
pressure
that
may
affect
structures
or
other
surface
improvements.
In
the
General
Plan
area,
soils
on
the
valley
floor
include
alluvial
sand
and
gravel
with
fine-‐grained
lakebed
deposits
such
as
silts
and
clays.
Once
graded,
the
expansion
characteristics
of
these
soils
can
vary
widely.
Engineered
fills
that
include
expansive
soils
near
the
finished
surface
may
result
in
damage.
Corrosive
Soils
Corrosive
soils
occur
as
a
result
of
various
complex
electrochemical
and
bacteriological
processes
between
soil
and
buried
metallic
structures,
such
as
water
mains
or
elements
within
building
foundations.
Reactions
depend
on
a
variety
of
factors,
including
structure
type
and
soil
characteristics.
Valley
areas
may
contain
sediments
that
are
corrosive
to
metallic
objects,
such
as
reinforcing
steel
and
pipelines.
Ground
Subsidence
Subsidence
is
generally
caused
by
human
activity,
such
as
the
extraction
of
groundwater,
oil
or
gas
in
sediment-‐filled
valleys
and
floodplains.
Natural
forces,
such
as
earthquake
movements,
can
also
result
in
subsidence.
Regional
subsidence
can
result
in
earth
fissures,
sinkholes
or
depressions,
and
surface
drainage
disruption.
It
can
cause
damage
to
pipelines,
canals,
levees,
wells,
buildings,
roadways
and
railroads
and
other
improvements.
In
the
presence
of
clay
and
silt,
removal
of
groundwater
can
cause
irreversible
subsidence
and
surface
fissures
and
cracks.
The
only
recorded
fissures
in
the
Coachella
Valley
occurred
in
La
Quinta
in
1948,
near
the
base
of
the
Santa
Rosa
Mountains,
at
the
south
end
of
the
SOILS
AND
GEOLOGY
IV-‐35
City.
Fissures
and
differential
displacement
are
more
likely
to
occur
at
the
edge
of
the
Valley
floor,
where
it
meets
the
mountains.
Monitoring
conducted
by
the
US
Geological
Survey
(USGS),
CVWD
and
others
shows
that
subsidence
rates
in
the
Coachella
Valley
have
been
increasing
rapidly
over
the
past
several
decades.
CVWD
has
implemented
a
variety
of
measures,
such
as
groundwater
recharge,
imported
water,
and
water
conservation
techniques
and
programs
to
minimize
the
extraction
of
groundwater.
Erosion
Erosion
is
influenced
by
a
variety
of
factors:
climate,
topography,
soil
and
rock
types,
and
vegetation.
During
intense
storms,
high
rates
of
erosion
can
occur
as
soil
and
rock
in
the
foothills
travel
to
the
valley
floor.
Risk
of
erosion
is
increased
by
wildfires,
which
strip
slopes
of
vegetation
and
leave
them
susceptible
to
erosion.
In
the
planning
area,
canyon
bottoms
and
areas
within
the
valley
that
contain
unconsolidated
soils
are
most
vulnerable.
Human
activities
hasten
natural
erosion,
as
they
remove
protective
vegetation,
alter
natural
drainage
patterns,
and
compact
soils.
Cut
and
fill
slopes
may
be
more
susceptible
than
naturalized
slopes.
Development
also
reduces
the
surface
area
available
for
water
to
percolate,
thereby
increasing
risk
of
flooding
and
downstream
sedimentation.
In
La
Quinta
and
Riverside
County,
development
plans
for
new
projects
must
incorporate
temporary
and
permanent
erosion
control
measures.
All
development
projects
over
one
acre
in
size
must
obtain
coverage
under
the
City’s
General
Construction
permit,
which
includes
preparation
of
a
Stormwater
Pollution
Prevention
Plan
(SWPPP)
and
Best
Management
Practices
(BMPs)
for
pre-‐,
during
and
post-‐
construction
erosion
prevention
and
control.
Wind
Erosion
Wind
transports
and
re-‐deposits
soil,
thereby
damaging
land
and
natural
vegetation.
Wind
erosion
commonly
occurs
in
areas
that
are
flat
and
bare,
dry
and
sandy,
or
in
areas
with
loose,
dry,
finely
granulated
soil.
Effects
of
wind
SOILS
AND
GEOLOGY
IV-‐36
erosion
include
soil
loss
and
the
deterioration
of
soil
structure,
dryness,
loss
of
nutrients
and
productivity,
air
pollution,
and
sediment
transport
and
deposition.
Many
areas
in
the
Coachella
Valley
are
subject
to
varying
levels
of
hazards
associated
with
wind-‐blown
sand.
A
variety
of
conditions
that
are
conducive
to
creating
and
transporting
sand
exist
in
the
valley,
including
the
orientation
of
hill
and
mountain
masses,
nature
of
the
bedrock,
location
of
the
Whitewater
River
floodplain,
slope
and
orientation
of
the
valley
floor,
and
the
hot,
arid
climate
and
sparse
vegetation.
Wind
and
wind-‐blown
sand
can
result
in
damage
to
structures
and
cars,
poor
visibility,
road
closures,
and
general
degradation
of
air
quality.
Health
problems
associated
with
wind
and
blowing
sand
include
allergies
and
respiratory
irritation,
eye
infections,
and
skin
disorders.
The
Coachella
Valley
region
is
particularly
affected
by
particulate
matter
less
than
10
microns
in
diameter,
known
as
PM10,
that
can
directly
irritate
lung
tissues
and
result
in
serious
health
problems.
The
Coachella
Valley
State
Implementation
Plan
(adopted
2003)
has
been
effective
in
reducing
the
concentration
of
PM10
in
the
valley.
(Please
refer
to
the
Air
Quality
Element
for
more
information
on
PM10.)
Except
for
protected
areas
near
the
base
of
the
Santa
Rosa
Mountains,
most
of
the
planning
area
is
located
within
an
active
Wind
Erosion
Zone.
Sediments
subject
to
erosion
underlie
the
northern
portion
of
the
City.
Please
see
Exhibit
IV-‐5,
Wind
Erosion
Susceptibility
Map.
NOTES
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r -I
L J TERRA NOVA®
Planning It Research, Inc.
City of La Quinta General Plan
Wind Erosion Susceptibility Map
La Quinta, California
Legend
Wind Erodibility Rating
Very high
High
Moderate
Low
Not rated or not available
Weather Station
La Quinta City Boundary
/ La Quinta Sphere of Influence
N 6000 0 6000
Feet
W+
E 2000 0 2000
Mew.
$ Scale: 1:72,000
Base Map: USGS Topogmphic Map from SurelMAI'S RASTER, 1997.
Source: modified from NaWral Resources Conservation Service Wind
Emdibiity Group - Riverside County, Coachella Valley Area.
Earth
Consultants
International 9t
project Number: 3004
Date: 2010
Exhibit
IV -5
l
r -I
L J TERRA NOVA®
Planning It Research, Inc.
City of La Quinta General Plan
Wind Erosion Susceptibility Map
La Quinta, California
Legend
Wind Erodibility Rating
Very high
High
Moderate
Low
Not rated or not available
Weather Station
La Quinta City Boundary
/ La Quinta Sphere of Influence
N 6000 0 6000
Feet
W+
E 2000 0 2000
Mew.
$ Scale: 1:72,000
Base Map: USGS Topogmphic Map from SurelMAI'S RASTER, 1997.
Source: modified from NaWral Resources Conservation Service Wind
Emdibiity Group - Riverside County, Coachella Valley Area.
Earth
Consultants
International 9t
project Number: 3004
Date: 2010
Exhibit
IV -5
SOILS
AND
GEOLOGY
IV-‐38
PAGE
NUMBER
SPACER
-‐
PULL
FROM
DOC
SOILS
AND
GEOLOGY
IV-‐39
PLANNING
FOR
THE
FUTURE
Local
seismic
and
geotechnical
conditions
will
continue
to
necessitate
careful
land
use
planning
to
protect
the
health
and
safety
of
residents
and
their
property.
The
implementation
and
enforcement
of
regulations
and
guidelines
such
as
the
Alquist-‐Priolo
Earthquake
Fault
Zoning
act,
CEQA
Statutes
and
Guidelines,
California
Building
Code,
City
zoning
ordinance,
and
other
applicable
legislation
will
help
manage
hazards
discussed
in
this
Element.
As
development
in
the
area
continues
to
occur,
it
will
be
increasingly
important
for
the
City
to
closely
coordinate
with
state,
regional
and
county
agencies
to
update
information
databases
of
geotechnical
and
seismic
conditions
in
the
region.
Through
the
development
review
process,
the
City
must
ensure
that
development
proposals
are
subject
to
comprehensive
geotechnical
and
safety
assessments
prior
to
approval,
and
that
all
necessary
mitigation
measures
are
implemented.
Public
education
will
continue
to
be
an
important
means
to
inform
residents
on
how
to
reduce
potential
losses
from
geotechnical
hazards
while
preparing
for
possible
future
disaster
scenarios.
GOALS,
POLICIES
AND
PROGRAMS
GOAL
GEO-‐1
Protection
of
the
residents’
health
and
safety,
and
of
their
property,
from
geologic
and
seismic
hazards.
Policy
GEO-‐1.1
The
City
shall
maintain
and
periodically
update
an
information
database
and
maps
that
identify
local
and
regional
geologic
and
seismic
conditions.
Program
GEO-‐1.1.a:
The
City
shall
periodically
confer
with
the
California
Division
of
Mines
and
Geology,
Riverside
County,
neighboring
communities,
and
other
appropriate
agencies
to
improve
and
routinely
update
the
database.
Policy
GEO-‐1.2
The
City
shall
continue
to
require
that
development
in
areas
subject
to
rockfall,
landslide,
liquefaction
and/or
other
geotechnical
hazards
described
in
this
Element,
prepare
detailed
geotechnical
analyses
that
SOILS
AND
GEOLOGY
IV-‐40
include
mitigation
measures
intended
to
reduce
potential
hazards
to
less
than
significant
levels.
Policy
GEO-‐1.3
The
City
shall
require
that
development
in
areas
subject
to
collapsible
or
expansive
soils
conduct
soil
sampling
and
laboratory
testing
and
implement
mitigation
measures
that
minimize
such
hazards.
Program
GEO-‐1.3.a:
The
Building
and
Safety
Department
shall
review
and
determine
the
adequacy
of
soils
and/or
other
geotechnical
studies
conducted
for
proposed
projects
and
enforce
the
implementation
of
mitigation
measures.
Policy
GEO-‐1.4
The
City
shall
require
that
all
new
structures
be
built
in
accordance
with
the
latest
adopted
version
of
the
Building
Code.
Policy
GEO-‐1.5
The
City
shall
continue
to
require
that
structures
that
pose
a
safety
threat
due
to
inadequate
seismic
design
are
retrofitted
or
removed
from
use,
according
to
law.
Policy
GEO-‐1.6
The
City
shall
coordinate
and
cooperate
with
public
and
quasi-‐public
agencies
to
ensure
that
major
utilities
continue
to
be
functional
in
the
event
of
a
major
earthquake.
Program
GEO-‐1.6.a:
The
City
shall
maintain
working
relationships
and
strategies
between
the
Public
Works
Department,
utility
providers,
and
other
appropriate
agencies
to
strengthen
or
relocate
utility
facilities
and
take
other
appropriate
measures
to
safeguard
major
utility
distribution
systems.
RELATED
GOALS
As
described
above,
this
Element
relates
to
others
in
this
General
Plan.
The
following
Goals,
and
their
associated
policies
and
programs,
are
closely
related
to
those
of
this
Element.
GOAL
FH-‐1:
Protection
of
the
health,
safety
and
welfare
of
the
community
from
flooding
and
hydrological
hazards.
SOILS
AND
GEOLOGY
IV-‐41
THIS
PAGE
INTENTIONALLY
LEFT
BLANK
FLOODING
AND
HYDROLOGY
IV-‐43
FLOODING
AND
HYDROLOGY
PURPOSE
The
Flooding
and
Hydrology
Element
describes
potential
drainage
and
flooding
hazards
in
the
City
and
its
Sphere
of
Influence,
as
well
as
the
future
potential
for
major
flooding.
Other
General
Plan
elements
are
related
to
Flooding
and
Hydrology.
The
Soils
and
Geology
Element
is
the
most
closely
related,
as
the
City’s
flooding
patterns
are
controlled
by
its
soils
and
geology.
Other
related
elements
include
Hazardous
Materials
and
Circulation.
The
Land
Use
Element,
by
which
land
uses
such
as
open
space,
developed
areas,
and
essential
public
facilities,
are
designated
and
located
is
also
affected
by
flooding
issues.
There
are
a
number
of
State
regulations
and
policies
that
require
the
City
and
local
and
regional
agencies
(including
the
Coachella
Valley
Water
District
and
Riverside
County
Flood
Control
and
Water
Conservation
District)
to
analyze
and
provide
protection
from
flooding
hazards
in
the
community.
The
joint
planning
of
area-‐wide
drainage
plans
affecting
local
jurisdictions
is
required
by
Chapter
73
of
the
Statutes
of
California
(1939).
Government
Code
Section
8401(c),
also
known
as
the
Cobey-‐Alquist
Flood
Plain
Management
Act,
mandates
local
government
planning,
adoption
and
enforcement
of
land
use
regulations
for
flood
plain
management.
The
Cobey-‐Alquist
Act
also
sets
forth
requirements
for
state
financial
assistance
for
flood
control
measures.
Mapping
of
areas
susceptible
to
dam
inundation
is
established
by
California
Government
Code
Sections
8589.5
and
65302(g).
BACKGROUND
The
desert
climate
of
the
Coachella
Valley
is
generally
characterized
by
mild
winters
and
hot,
dry
summers.
However,
the
proximity
of
mountain
ranges,
including
the
San
Jacinto
and
Santa
Rosa
Mountains,
and
FLOODING
AND
HYDROLOGY
IV-‐44
associated
climatic
zones
affect
regional
conditions.
Flooding
can
result
from
rapid
melting
of
mountain
snowpack,
as
well
as
occasional
intense
thunderstorms.
The
latter
occur
most
frequently
during
the
winter
months,
between
November
and
April,
but
may
also
happen
as
monsoon
storms
during
the
summer
and
early
fall
(July
through
September).
Storms
are
generally
of
short
duration
but
may
result
in
several
inches
of
rainfall
in
localized
areas.
Surrounding
mountains
average
over
25
inches
annually,
as
compared
with
3
inches
in
the
Valley,
including
the
La
Quinta
planning
area.
Even
when
the
Valley
does
not
receive
rain,
runoff
from
mountain
slopes
can
cause
flooding,
as
well
as
mud
and
debris
flows.
Rapid
rainfall
can
quickly
saturate
dry
soils,
impeding
percolation
and
increasing
runoff.
Hydrological
Conditions
and
Flood
Hazards
The
valley
floor
is
comprised
of
a
broad,
gently
sloping
basin
formed
by
alluvial
fans
which
have
been
created
from
the
deeply
chiseled
mountain
canyons
of
the
Santa
Rosa
Mountains,
the
Whitewater
River
floodplain,
and
sediments
of
prehistoric
lakes.
Much
of
the
development
in
the
City
and
its
Sphere
occurs
on
the
valley
floor,
including
that
portion
which
lies
along
the
base
of
the
Santa
Rosa
Mountains
in
the
western
portion
of
the
City.
Flooding
is
a
recurring,
natural
event.
Floodplains
are
meant
to
carry
excess
waters
during
flooding.
Floodplains
can
also
be
useful
for
a
variety
of
human
uses,
such
as
agriculture
and
water
supply.
However,
flooding
becomes
a
hazard
when
man-‐made
structures
encroach
into
floodplains.
Worldwide,
floods
are
among
the
most
destructive
and
costly
of
all
natural
disasters,
resulting
in
more
deaths
per
year
than
any
other
geologic
hazard.
There
are
two
primary
classifications
of
flooding
that
occur
in
the
planning
area:
flash
floods
that
occur
along
natural
or
man-‐made
channels,
and
sheet
flooding
across
the
valley
floor.
Flash
floods
are
brief
but
result
in
high
water
volumes
and
velocities.
Because
mountain
slopes
are
comprised
of
impervious
rock,
little
percolation
occurs,
and
waters
collect
and
flow
rapidly
into
channels
on
the
valley
floor.
These
flows
can
convey
large
amounts
of
debris
including
mud,
sand
and
rock.
FLOODING
AND
HYDROLOGY
IV-‐45
When
either
flood
control
channels
do
not
exist,
an
existing
channel’s
capacity
is
exceeded,
or
channels
are
impacted
by
debris
or
structures,
storm
waters
travel
across
the
valley
floor,
creating
the
condition
known
as
sheet
flow.
Buildings,
sidewalks,
parking
lots,
and
roadways
reduce
the
area
available
for
natural
infiltration
of
storm
water.
Water
that
formerly
would
have
been
absorbed
may
run
off
if
new
development
does
not
provide
effective
storm
handling
systems.
Given
that
surrounding
mountain
slopes
generally
receive
greater
levels
of
rainfall,
development
downstream
of
canyons
and
at
the
base
of
mountains
may
be
at
particular
risk.
Stream
Flow
and
Flood
Hazard
There
are
no
perennial
rivers
or
streams
in
La
Quinta.
Although
well-‐
defined
in
the
mountains,
on
the
valley
floor
most
natural
drainage
channels
disperse
into
braided,
ephemeral
streams
and
areas
of
sheet
flow.
The
Whitewater
River
is
the
main
watercourse
in
the
valley.
It
collects
a
watershed
of
more
than
1,000
square
miles,
draining
runoff
from
the
San
Bernardino,
Little
San
Bernardino,
San
Jacinto
and
Santa
Rosa
Mountains.
From
its
source
near
the
San
Gorgonio
Pass,
it
flows
southeasterly,
ultimately
ending
at
the
Salton
Sea.
Throughout
the
City,
the
Whitewater
is
conveyed
through
a
man-‐made
channel
known
as
the
Coachella
Valley
Stormwater
Channel.
Based
on
historical
records
collected
by
the
Army
Corps
of
Engineers,
multiple
large
flood
events
occurred
in
the
Whitewater
River
basin
throughout
the
1800s.
There
were
also
damaging
floods
throughout
the
20th
century,
with
more
recent
ones
occurring
in
1965,
1966,
1969,
and
1976.
The
maximum
flood
of
record
occurred
in
1965
in
the
lower
Coachella
Valley,
where
flood
flows
exceeded
10,000
cubic
feet
per
second
(cfs).
FLOODING
AND
HYDROLOGY
IV-‐46
Flooding
is
typically
defined
in
terms
of
the
“100-‐year
flood.”
The
100-‐
year
flood
is
the
level
of
flood
water
expected
to
be
equaled
or
exceeded
every
100
years,
on
average.
In
other
words,
it
has
a
one
percent
probability
of
occurring
in
a
given
year.
Seismically
Induced
Flooding
Flooding
can
occur
when
water
retention
and
storage
structures
fail
as
a
result
of
earthquakes.
Such
structures
may
include
dams,
levees,
and
above-‐ground
water
tanks.
Dam
Failure
The
California
State
Water
Code,
Division
3,
contains
safety
statutes
governing
dams.
The
California
Office
of
Emergency
Services
has
determined
that
the
City
of
La
Quinta
is
not
at
risk
from
potential
inundation
from
any
existing
dams.
Levee
Failure
The
Coachella
Valley
Stormwater
Channel,
the
Coachella
Canal
and
Lake
Cahuilla
are
protected
by
levees.
In
the
event
of
a
severe
earthquake,
there
is
potential
for
lateral
spreading
of
foundation
soils.
Lateral
spreading
is
a
condition
where
underlying
soils
move
sideways
as
a
result
of
strong
ground
shaking
(also
see
Soils
and
Geology
Element)
and
underlying
soils
becoming
liquefied
or
fractured.
Under
these
conditions,
levee
systems
could
sustain
damage
or
fail
entirely.
While
there
are
no
existing
engineering
analyses
demonstrating
the
potential
inundation
area
of
the
Coachella
Canal
or
Lake
Cahuilla,
complete
failure
of
these
levees
would
impact
development
directly
downstream.
Portions
of
the
Coachella
Valley
Stormwater
Channel
(Whitewater
River)
are
concrete-‐lined
and
buried
under
sand
for
protection.
These
levees
are
subject
to
erosion
as
well
as
damage
from
strong
ground
shaking
due
to
an
earthquake.
They
are
periodically
maintained
by
CVWD.
They
are
further
discussed
under
Flood
Control
Measures,
below.
The
portion
of
the
Channel
that
passes
through
the
City
between
Jefferson
Street
and
Miles
Avenue
deviates
from
the
natural
watercourse.
Based
on
flood
insurance
studies
conducted
by
the
Federal
Emergency
Management
Agency
(FEMA),
there
is
potential
for
a
“breakout”
along
this
reach
of
the
river
during
a
100-‐year
storm.
Such
a
breakout
could
result
in
50%
loss
of
channel
capacity
and
flooding
within
a
portion
of
the
City’s
northeast
Sphere-‐of-‐Influence,
as
well
as
in
the
cities
of
Indio
and
Coachella.
FLOODING
AND
HYDROLOGY
IV-‐47
Seiching
Ground
shaking
during
earthquakes
can
result
in
seiching,
or
water
sloshing,
in
open
bodies
of
water.
Lake
Cahuilla,
local
canals,
above-‐
ground
storage
tanks,
detention
basins,
and
even
swimming
pools
may
be
subject
to
seiching
during
earthquakes.
Seiching
may
cause
water
to
overtop
or
damage
containment
structures,
resulting
in
inundation
of
downslope
development.
Failure
of
Above-‐Ground
Storage
Tanks
Strong
ground
shaking
can
cause
structural
damage
to
above-‐ground
water
storage
tanks,
particularly
where
tanks
are
not
adequately
braced
and
baffled.
Pipes
leading
to
the
tank
may
be
sheared
off
and
water
released.
The
1992
Big
Bear
and
1994
Northridge
earthquakes
led
to
revised
design
standards
for
steel
water
tanks,
which
now
utilize
flexible
joints
at
connection
points
to
allow
for
movement
in
all
directions.
Hazards
associated
with
damage
to
water
tanks
include
inundation
of
structures
down-‐slope
and
reduction
of
potable
water
supplies
for
emergency
services,
such
as
fire
protection.
Therefore,
evaluating
and
retrofitting
tanks
to
ensure
their
structural
reliability
in
the
event
of
an
earthquake
is
crucial.
Water
supplies
in
reservoirs
should
also
be
kept
at
or
near
capacity.
The
Coachella
Valley
Water
District
(CVWD)
reports
that
there
are
ten
water
reservoirs
in
La
Quinta
with
a
total
capacity
of
44.3
million
gallons.
All
are
constructed
of
welded
steel
to
current
seismic
standards,
as
well
as
those
established
by
the
American
Water
Works
Association.
Bridge
Scour
Scour
occurs
along
roadway
and
railroad
bridges
when
erosion
occurs
and
undermines
foundation
supports
such
as
abutments
or
piers.
In
California,
this
condition
is
addressed
through
a
seismic
retrofit
program
that
includes
inspection
of
bridge
underpinnings.
Washington
Street
and
Jefferson
Street
are
the
two
main
Whitewater
River
crossings
in
the
City;
these
are
all-‐weather
crossings.
Additionally,
construction
of
the
Adams
Street
bridge
over
the
Whitewater
River
began
in
2011
and
is
FLOODING
AND
HYDROLOGY
IV-‐48
expected
to
be
completed
in
late
2013.
This
will
provide
a
third
all-‐
weather
crossing
over
the
channel.
Across
the
La
Quinta
Evacuation
Channel,
the
Eisenhower
Drive
and
Washington
Street
crossings
are
all-‐weather
flood
channel
crossings.
During
and
after
flooding,
the
City
inspects
these
crossings
for
scour
damage.
There
are
also
three
crossings
over
the
Coachella
Branch
of
the
All-‐
American
Canal,
which
is
used
for
irrigation
purposes.
These
occur
at
Avenue
50,
Avenue
52,
and
Jefferson
Street
south
of
Avenue
52.
The
Coachella
Valley
Water
District
(CVWD)
strictly
manages
flows
through
the
canal,
and
it
is
not
used
as
a
flood
control
mechanism.
These
crossings
are
expected
to
remain
passable
during
storm
events;
however,
they
should
be
inspected
periodically.
Regional
Stormwater
Management
The
Riverside
County
Flood
Control
and
Water
Conservation
District
(RCFC)
is
responsible
for
analysis
and
design
of
regional
flood
control
structures.
Regional
facilities
are
those
that
collect
runoff
from
areas
outside
the
City,
including
surrounding
mountains,
and
are
managed
by
the
Coachella
Valley
Water
District
(CVWD).
CVWD
is
empowered
with
broad
flood
control
management
responsibilities,
which
include
planning,
maintenance
and
construction
of
improvements
for
regional
facilities.
In
the
planning
area,
regional
facilities
include
the
Coachella
Valley
Stormwater
Channel
(Whitewater
River),
the
La
Quinta
Evacuation
Channel,
the
Bear
Creek
System,
the
East
La
Quinta
Channel
and
Lake
Cahuilla.
Local
Drainage
Management
The
City
is
responsible
for
maintenance
of
local
facilities,
which
collect
and
convey
runoff
from
local
streets
and
properties
to
regional
channels
and
basins.
The
City
has
recently
updated
its
Master
Drainage
Plan,
which
describes
existing
and
planned
local
facilities.
The
City
utilizes
it
to
manage
and
document
the
location
and
condition
of
existing
stormwater
management
facilities.
It
has
also
been
used
to
obtain
FEMA
Letters
of
Map
Revision
for
some
flood
areas.
Flood
Control
Facilities
The
following
describes
major
flood
control
facilities
in
the
planning
area.
The
locations
of
these
facilities
are
shown
on
Exhibit
IV-‐6,
FEMA
Flood
Zones
and
Flood
Control
Facilities.
FLOODING
AND
HYDROLOGY
IV-‐49
Whitewater
River/Coachella
Valley
Stormwater
Channel
As
previously
discussed,
the
Coachella
Valley
Stormwater
Channel
is
the
principal
drainage
course
in
the
City.
Although
typically
dry,
it
may
become
inundated
during
storm
events.
The
Channel
extends
approximately
50
miles
with
an
average
cross
section
of
260
feet.
It
is
unlined
in
most
locations,
and
portions
of
it
are
protected
by
levees.
This
watercourse
generally
follows
the
recent
historical
natural
river
path,
although
as
noted
above,
it
deviates
from
this
path
through
a
portion
of
the
City.
Levees
along
the
stormwater
channel
are
FEMA-‐classified
as
“Provisionally
Accredited
Levees,”
which
indicates
they
provide
protection
from
the
100-‐year
flood.
CVWD
was
required
to
submit
documentation
demonstrating
the
protection
capabilities
of
these
levees
to
comply
with
requirements
of
Section
65.10
of
National
Flood
Insurance
Program
(NFIP)
regulations
(Title
44,
Chapter
1
of
the
Code
of
Federal
Regulations).
CVWD
met
this
requirement.
Bear
Creek
System
The
Upper
Bear
Creek
System
is
designed
to
manage
runoff
from
the
Santa
Rosa
Mountains.
The
system
is
located
along
the
southerly
and
westerly
edges
of
the
Cove
and
includes
the
Upper
Bear
Creek
Training
Dike,
Upper
Bear
Creek
Detention
Basin,
Bear
Creek,
and
Bear
Creek
Channel.
Runoff
from
a
1.7
square
mile
drainage
area
is
diverted
by
the
dike,
which
directs
it
along
Bear
Creek
to
the
detention
basin.
The
Basin
has
a
storage
capacity
of
752
acre-‐feet.
Outflows
enter
the
Bear
Creek
Channel,
an
approximately
2.5-‐mile
long
channel
with
capacity
to
convey
the
100-‐year
flood.
Smaller
canyons
also
drain
into
the
channel.
Channel
flows
continue
downstream
into
the
La
Quinta
Evacuation
Channel,
ultimately
discharging
into
the
Coachella
Valley
Stormwater
Channel.
The
City
has
applied
to
FEMA
for
accreditation
of
the
training
dike
and
is
awaiting
receipt
of
the
formal
accreditation
letter.
East
La
Quinta
System
This
system
is
located
along
the
southeastern
edge
of
the
Cove
and
is
intended
to
collect
drainage
from
hills
east
and
south
of
Calle
Bermudas.
The
system
is
comprised
of
the
East
La
Quinta
Channel
and
several
detention
basins.
Flows
are
carried
to
the
La
Quinta
Evacuation
Channel.
FLOODING
AND
HYDROLOGY
IV-‐50
La
Quinta
Evacuation
Channel
The
La
Quinta
Evacuation
Channel
extends
approximately
3.5
miles
northeasterly
from
the
Bear
Creek
Channel,
through
developed
areas
of
the
City,
to
the
Coachella
Valley
Stormwater
Channel.
It
is
primarily
intended
to
capture
and
transport
stormwater
from
various
flood
control
systems
in
the
City.
Dikes
In
addition
to
the
Bear
Creek
Training
Dike,
there
are
several
other
dikes
located
near
the
base
of
mountains
in
the
City.
These
have
been
constructed
to
protect
developed
areas
from
runoff
from
mountain
slopes,
and
include
three
dikes
constructed
by
the
Bureau
of
Reclamation:
the
Eastside
Dike,
constructed
to
protect
the
Coachella
Branch
of
the
All-‐American
Canal;
and
Dike
2
and
Dike
4,
which
total
5.2
miles
south
and
southeast
of
Lake
Cahuilla,
respectively,
and
were
built
to
protect
Lake
Cahuilla
and
lands
between
Avenue
58
and
Avenue
66.
Dike
4
is
accredited
by
FEMA;
Dike
2
is
not
yet
accredited.
NOTES:
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i
Deep Canyon Stormwater Cha......
1 j
Coachella Valley
Stormwater Channel
/ La Qui to Resort Channel
Oleander Resery
X levee -
levee
—Coachella
Canal
AO
X
Bear Creek Channel
—x
Avenida Bermudas
7 levee X
East La Quints Channel
Upper Bear Creek
nfi
Deteon Basin
Calle Tecate
Quinta Evacuation
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Detention Basin
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\ \
rA
i x I
x Dike No4
FEMA Flood Zones and
Flood Control Facilities
Explanation
High Risk Mea
Zone that corresponds W the 100 -year flood areas, as determined by
apprmi
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d, usednaledhydraulcanalyseswerenor
`'t t' performed, no base (loud elesarons or depths are shown Mandatory
flood Insurance is reqs red
nu Zone that corresponds to 1001ear shallow flood areas
where average depths are between 1 and 3 feet (usually
fiom shret flow, on sloping tsran)• Mandatory Bond
insurance's rego red
Moderate and Low Risk Area
0 Zone that Corresponds to areas of5myear floor, area of 1Myear need
with average depths of les than 1 has or w ith road nage areas les than
1 square ale, and area proncted by levees fiom 1110,car Rood. No
base flood elevations or depths are shown Flood insurance is available
.. but nm hat red.
Dike X _ x
I
X\
0 Zone that corresponds 0 areas ounde of the 5Wyear Bond. No base
flood elevations or depths areshown. Floodinsurenceisavailable
but nm required.
undetermined Rink area
OZone that corresponds to unstudied areas where food hazards are
de rwh ned, but Bonding is puvble Flopd insurance is available
but net required
awwwaa Dike / La Quinta City Boundary
Levee
Rivero-
stream i- La Qu nla sphere nnnnuenu
• For elevatioaor depths sce original FEMA Flood Insurance Rate Maw
vailabkatthe City, County, orva—1 a.gov.
N Scale: 1:84,000
7000 0 7000
W
E Feet
2 0 2
S EGlometim;
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source: Federal Emergency Maagen,m Agen<r,sac e,rmdiao, neon Irauraree R,re
Map (Pard! Numbs .5Q72sQ 060650241G, OvermUNNO, WK5C2231a
06465Q333G,0K,cC2233G, 0r05Q234G, PY.65CE337G, tistac 39G 0aXsU2.G,
060550261 Q otcasavoccI
W'Inttanh
ema%nal
Consultants
Project Number 3004
- - - Date: 2010
r City of La Quinta General PlanExhibit
JTERRANOVA® FEMA Flood Hazard Zones and Flood Control Facilities
Planning & Research, Inc, La Quinta, California I IV -6
FLOODING
AND
HYDROLOGY
IV-‐52
PAGE
NUMBER
SPACER
-‐
PULL
FROM
DOC
FLOODING
AND
HYDROLOGY
IV-‐53
Flood
Hazard
Mapping
The
National
Flood
Insurance
Act
of
1968
and
the
Flood
Disaster
Protection
Act
of
1973
require
that
the
Federal
Emergency
Management
Agency
(FEMA)
evaluate
flood
hazards
and
provide
affordable
flood
insurance
to
residents
of
communities
where
future
floodplain
development
is
regulated.
To
determine
the
need
for
and
availability
of
federal
flood
insurance,
FEMA
has
developed
Flood
Insurance
Rate
Maps
(FIRMs)
for
many
areas
in
the
United
States.
The
Floodplain
Administrator
for
the
City
of
La
Quinta
is
the
City
Engineer.
Data
compiled
for
La
Quinta
and
its
Sphere
of
Influence
are
shown
on
Exhibit
IV-‐6.
Applicable
flood
zones,
as
shown
on
this
map,
include:
Zone
A:
Areas
of
100-‐year
flood
where
no
base
flood
elevations
or
depths
are
shown.
Requires
flood
insurance.
Zone
AO:
Areas
of
100-‐year
flood
with
average
depths
of
1
–
3
feet,
generally
from
sheet
flow
on
sloping
terrain.
Requires
flood
insurance.
Zone
X:
Areas
of
500-‐year
flood
with
average
depth
of
less
than
1
foot
or
less
than
one
square
mile
drainage
area;
and
protected
by
levees
from
100-‐year
flood.
No
base
flood
elevations
or
depths
are
shown.
Flood
insurance
available,
but
not
required.
Zone
D:
Areas
where
flood
hazards
are
undetermined
but
flooding
is
possible.
Flood
insurance
available,
but
not
required.
As
shown
on
the
map,
areas
within
the
planning
area
that
are
within
the
100-‐year
flood
plain
(Zones
A
or
AO)
include
the
Coachella
Valley
Stormwater
Channel,
the
La
Quinta
Evacuation
Channel,
Bear
Creek
Channel,
and
detention
basins.
Portions
of
the
area
north
and
south
of
the
Coachella
Valley
Stormwater
Channel,
the
entire
Cove
area,
several
areas
south
and
southeast
of
Lake
Cahuilla,
and
a
portion
of
the
City’s
eastern
Sphere
of
Influence
are
within
Zone
X.
Land
Use
Planning
as
a
Flood
Control
Strategy
One
of
the
most
effective
and
direct
means
of
controlling
flooding
and
protecting
lives
and
property
is
through
land
use
planning.
This
may
include
designing
flood
control
structures
so
that
stream
courses
are
left
in
a
naturalized
state
or
developed
as
open
space
for
parks
or
golf
courses.
Portions
of
the
planning
area
are
mapped
within
the
100-‐year
floodplain.
Others
may
be
subject
to
sheet
flow
where
natural
channels
emanating
from
mountain
streams
and
canyons
lose
definition
on
the
valley
floor.
Restricting
the
type
and
location
of
structures
near
major
drainages
can
limit
exposure
of
people,
FLOODING
AND
HYDROLOGY
IV-‐54
structures
and
other
improvements
to
flood
hazards
and
reduce
potential
losses.
Development
should
be
strictly
limited
within
100-‐
year
floodplains
to
uses
that
do
provide
for
human
habitation.
No
critical
facilities
should
be
located
within
floodplains.
Other
Flood
Control
Measures
The
Clean
Water
Act
(CWA)
was
enacted
in
1972
and
was
intended
to
set
goals
for
restoring
and
maintaining
water
quality
through
reduction
of
point-‐source
pollution
by
industry
and
sewage
treatment
facilities.
A
1987
amendment
further
required
that
states
reduce
runoff
into
waterways.
The
National
Pollutant
Discharge
Elimination
System
(NPDES)
implements
these
requirements
by
mandating
the
adoption
of
stormwater
management
plans
and
programs
to
reduce
runoff
of
pollutants
in
storm
water
systems
into
waters
of
the
United
States.
In
California,
the
NPDES
is
administered
by
the
State
Regional
Water
Quality
Control
Board,
which
issues
NPDES
permits
to
local
jurisdictions.
In
Riverside
County,
the
NPDES
is
a
joint
permit
system
among
the
Riverside
County
Flood
Control
and
Water
Conservation
District
(RCFC),
Riverside
County,
CVWD,
and
all
Riverside
County
cities,
including
La
Quinta.
PLANNING
FOR
THE
FUTURE
The
City
of
La
Quinta,
Riverside
County,
and
the
Coachella
Valley
Water
District
have
worked
closely
together
to
proactively
plan
for
and
protect
developed
areas
from
significant
flooding.
Development
within
100-‐year
floodplains
is
limited
to
flood
control
channels,
detention
or
retention
basins,
and
golf
courses
that
dually
serve
as
retention
basins.
New
flood
control
facilities
should
be
designed
to
protect
other
environmental
resources
and
retain
watercourses
in
a
natural
state
or
for
use
as
open
space,
whenever
feasible.
Some
areas
of
the
City
are
still
subject
to
localized
flooding.
These
hazards
should
be
addressed
through
the
continued
enforcement
of
requirements
for
on-‐site
retention
facilities.
FEMA
mapping
also
shows
areas
that
are
considered
subject
to
flooding
from
storms
stronger
than
the
100-‐year
storm.
Moderate
flood
hazards
are
also
mapped
within
undeveloped
areas,
particularly
in
the
Sphere
of
Influence.
However,
in
some
portions
of
the
General
Plan
area,
some
study
areas
are
limited,
and
flood
zone
mapping
is
incomplete.
As
a
result,
there
are
some
areas
outside
of
the
mapped
flood
zones
that
are
likely
to
be
subject
to
flooding.
The
City
should
FLOODING
AND
HYDROLOGY
IV-‐55
coordinate
with
FEMA
and
other
agencies
for
more
complete
mapping
to
define
flooding
hazards.
Seismic
hazards
could
place
storage
tanks,
lakes,
detention
basins,
levees,
dikes
or
other
water
storage
or
retention
facilities
at
risk.
Future
planning
for
new
development
should
consider
the
potential
for
flooding
and
continue
to
limit
or
prohibit
structures
in
areas
subject
to
the
100-‐year
storm.
GOALS,
POLICIES
AND
PROGRAMS
GOAL
FH-‐1
Protection
of
the
health,
safety
and
welfare
of
the
community
from
flooding
and
hydrological
hazards.
Policy
FH-‐1.1
The
City
shall
monitor
and
update
its
2009
Master
Drainage
Plan
every
5
years,
or
as
needed,
to
reflect
changes
in
local
and
regional
drainage
and
flood
conditions.
Policy
FH-‐1.2
The
City
shall
coordinate
efforts
to
update
floodplain
mapping
in
all
areas
of
the
City,
particularly
those
where
potential
flood
impacts
are
not
yet
known.
Program
FH-‐1.2.a:
The
City
shall
coordinate
and
cooperate
with
CVWD
in
the
filing
of
FEMA
applications
to
amend
the
Flood
Insurance
Rate
Maps,
as
necessary.
Policy
FH-‐1.3
The
City
shall
continue
to
implement
development
standards
that
provide
for
a
reduction
in
runoff
from
developed
lands
and
are
consistent
with
local
and
regional
stormwater
management
plans.
Program
FH-‐1.3.a:
New
development
shall
continue
to
be
required
to
construct
on-‐site
retention/detention
basins
and
other
necessary
stormwater
management
facilities
that
are
capable
of
managing
100-‐year
stormwater
flows.
FLOODING
AND
HYDROLOGY
IV-‐56
Policy
FH-‐1.4
The
City
shall
coordinate
with
CVWD
regarding
the
implementation
of
measures
which
protect
bridge
crossings
from
the
scouring
and
erosive
effects
of
flooding.
Program
FH-‐1.4.a:
The
Public
Works
Department
will
work
with
CVWD
to
inspect
bridge
crossings
for
scour
damage
during
and
after
significant
flooding
events.
Program
FH-‐1.4.b:
The
City
shall
coordinate
with
the
appropriate
state
agencies
to
participate
in
the
state’s
bridge
scour
inventory
and
evaluation
program.
Policy
FH-‐1.5
The
City
shall
coordinate
with
CVWD
to
minimize
the
potential
for
the
occurrence
of
inundation
from
levee
or
water
tank
failure,
including
seismically
induced
inundation.
Program
FH-‐1.5.a:
The
City
shall
annually
request
a
status
update
from
the
Coachella
Valley
Water
District
of
their
monitoring
of
the
structural
safety
of
the
levees
around
Lake
Cahuilla
and
along
the
Coachella
Valley
Stormwater
Channel
and
the
La
Quinta
Evacuation
Channel.
Program
FH-‐1.5.b:
The
City
shall
annually
request
a
status
update
from
the
Coachella
Valley
Water
District
of
their
monitoring
of
the
structural
integrity
of
above-‐ground
water
tanks
and
reservoirs,
and
where
needed,
the
implementation
of
bracing
techniques
to
minimize
potential
structural
damage
and/or
failure.
Policy
FH-‐1.6
Major
drainage
facilities,
including
debris
basins,
retention/detention
basins,
and
flood
control
facilities
shall
provide
for
the
enhancement
of
wildlife
habitat
and
community
open
space
to
the
greatest
extent
feasible,
while
still
maintaining
their
functional
qualities.
Policy
FH-‐1.7
New
critical
facilities
shall
not
be
constructed
within
the
boundaries
of
the
100-‐year
flood
plain.
FLOODING
AND
HYDROLOGY
IV-‐57
Policy
FH-‐1.8
Development
within
drainage
areas
and
stormwater
facilities
shall
be
limited
to
recreational
uses
such
as
golf
courses,
lakes,
sports
or
play
fields,
and
similar
uses.
Policy
FH-‐1.9
The
City
shall
periodically
monitor
and
update,
as
needed,
evacuation
routes
to
ensure
safe
ingress
and
egress
for
residents
and
emergency
vehicles
in
the
Cove
and
southern
neighborhoods
in
the
event
of
a
major
flood.
Program
FH-‐1.9.a:
The
City
shall
provide
maps
and
other
information
concerning
evacuation
routes
to
residents
of
the
Cove,
Riverside
County
Fire
Department,
Sheriff’s
Department
and
other
appropriate
agencies.
RELATED
GOALS
As
described
above,
this
Element
relates
to
others
in
this
General
Plan.
The
following
Goals,
and
their
associated
policies
and
programs,
are
closely
related
to
those
of
this
Element.
GOAL
GEO-‐1:
Protection
of
the
residents’
health
and
safety,
and
of
their
property,
from
geologic
and
seismic
hazards.
GOAL
WR-‐1:
The
efficient
use
and
conservation
of
the
City’s
water
resources.
HAZARDOUS
MATERIALS
IV-‐59
HAZARDOUS
MATERIALS
PURPOSE
The
Hazardous
Materials
Element
addresses
the
potential
hazards
associated
with
the
storage,
use,
and
transport
of
hazardous
materials
in
and
through
the
City.
Public
safety
must
be
addressed
in
the
General
Plan,
in
conformance
with
California
Government
Code
65302(g).
Hazardous
materials
represent
one
of
the
issues
associated
with
public
safety.
This
Element
is
closely
related
to
the
Emergency
Services
Element.
The
City’s
first
responders
ensure
public
safety
in
the
event
of
a
hazardous
materials
spill
or
release.
This
response
includes
isolation,
evacuation
(if
warranted),
identification,
containment
and
proper
disposal
of
the
hazardous
materials,
as
well
as
proper
notification
to
other
agencies.
It
is
also
related
to
the
other
components
of
the
Environmental
Hazards
Chapter
–
the
Soils
and
Geology
Element
and
the
Flooding
and
Hydrology
Element.
Finally,
the
location
of
land
uses
which
use,
store,
or
transport
hazardous
materials
ties
this
Element
to
the
Land
Use
Element,
insofar
as
it
is
important
for
the
City
to
assure
that
sensitive
land
uses,
such
as
residences
and
schools,
are
buffered
from
exposure
to
hazardous
materials
to
the
greatest
extent
possible.
BACKGROUND
Hazardous
materials
are
those
chemicals,
oils,
and
other
substances
which
have
the
potential
to
be
toxic.
They
range
from
fertilizers,
pesticides
and
automotive
products,
to
pool
chemicals
and
chlorine
products.
If
hazardous
materials
are
improperly
stored,
used
or
transported,
they
can
be
released
into
the
air,
soil
or
water
and
cause
harm
to
the
City’s
residents,
business
people
and
visitors.
As
a
result,
hazardous
materials
are
highly
regulated,
particularly
in
commercial
and
industrial
applications.
A
number
of
regional,
State
and
federal
agencies
have
responsibility
for
managing
and
regulating
these
materials.
HAZARDOUS
MATERIALS
IV-‐60
At
the
federal
level,
the
Environmental
Protection
Agency
(EPA)
has
primary
responsibility
for
the
regulation
of
hazardous
materials.
The
California
Environmental
Protection
Agency
and
the
Department
of
Toxic
Substances
Control
are
the
primary
State
agencies
which
deal
with
hazardous
materials.
At
the
regional
level,
the
Riverside
County
Department
of
Environmental
Health
monitors
and
regulates
hazardous
materials
use
and
disposal
throughout
the
County,
including
in
the
City
and
its
Sphere
of
Influence.
If
contamination
of
a
water
source
occurs,
the
Regional
Water
Quality
Control
Board
has
enforcement
powers.
The
City’s
Emergency
Services
Division,
Fire
and
Police
Departments
would
be
called
upon
in
the
event
of
a
spill
or
similar
emergency
relating
to
hazardous
materials
within
City
limits
(please
see
the
Emergency
Services
Element
for
further
discussion
of
emergency
services).
In
order
to
coordinate
efforts
relating
to
hazardous
materials
management,
the
County
has
developed
a
Hazardous
Waste
Management
Plan
(HWMP),
which
addresses
the
proper
disposal,
processing,
handling,
storage
and
treatment
of
hazardous
materials.
The
City
has
also
adopted
the
HWMP
and
implements
it
at
the
local
level.
In
the
City,
hazardous
materials
are
limited
to
small
quantity
generators
(those
generating
less
than
1,000
kilograms
of
hazardous
waste
per
month),
ranging
from
individual
households
which
store
cleaning
solutions
and
automotive
products,
to
service
stations
and
medical
clinics,
which
may
store
or
use
larger
quantities
of
hazardous
materials.
Household
hazardous
waste
can
be
disposed
of
properly
through
Household
Hazardous
Waste
disposal
events,
or
at
a
network
of
“ABOP”
facilities
operated
by
the
County
Waste
Management
Department.
An
ABOP
–
or
Antifreeze,
Batteries,
Oil,
Paint
–
facility
is
located
in
Palm
Springs
and
is
open
regularly
to
accept
these
materials,
as
well
as
electronic
waste.
Household
Hazardous
Waste
disposal
events
are
held
periodically
at
varying
locations
throughout
the
County,
including
cities
in
the
Coachella
Valley.
The
most
common
commercial
uses
which
use
hazardous
materials
in
the
City
are
service
stations,
which
not
only
use
and
store
fuels
and
oils,
but
also
operate
underground
storage
tanks,
which
have
the
potential
to
contaminate
soils
and
water
supplies
if
not
properly
maintained.
Other
commercial
users
include
dry
cleaning
operations,
HAZARDOUS
MATERIALS
IV-‐61
pool
cleaning
or
supply
stores,
and
automotive
supply
stores.
Commercial
and
industrial
users
are
responsible
for
meeting
the
requirements
of
the
County
Department
of
Environmental
Health.
These
requirements
include
the
proper
disposal
of
hazardous
materials
through
a
number
of
licensed
contractors
specializing
in
these
materials.
In
the
event
of
a
spill
or
leak
of
hazardous
materials,
initial
response
would
be
made
by
the
closest
fire
engine
company,
followed
by
response
from
a
dedicated
Hazardous
Material
Response
Team
(HMRT).
The
Riverside
County
Fire
Department
operates
a
Hazardous
Materials
Team,
which
operates
throughout
the
County
and
responds
to
incidents
when
necessary.
PLANNING
FOR
THE
FUTURE
As
the
City
and
its
Sphere
of
Influence
build
out,
the
number
of
hazardous
materials
storage
and
use
locations
is
likely
to
increase.
Further,
the
eastern
edge
of
the
Sphere
occurs
immediately
adjacent
to
the
Jacqueline
Cochran
Regional
Airport,
and
commercially
and
industrially
designated
lands
in
that
area
may
include
businesses
which
store,
use
and
transport
airplane-‐related
hazardous
materials.
The
City’s
continued
participation
in
regional
programs
and
coordination
with
County
departments
with
responsibility
for
hazardous
materials
will
be
important
in
the
future.
The
City’s
Emergency
Services
Division
and
City
Hall
facilities
dedicated
to
emergency
management
will
require
expansion
as
population
grows,
to
assure
that
the
City
can
respond
effectively
to
emergencies
relating
to
hazardous
materials.
GOALS,
POLICIES
AND
PROGRAMS
GOAL
HAZ-‐1
Protection
of
residents
from
the
potential
impacts
of
hazardous
and
toxic
materials.
Policy
HAZ-‐1.1
The
storage,
transport,
use
and
disposal
of
hazardous
materials
shall
comply
with
all
City,
County,
State
and
federal
standards.
HAZARDOUS
MATERIALS
IV-‐62
Program
HAZ-‐1.1.a:
Continue
to
coordinate
with
all
appropriate
agencies
to
assure
that
local,
State
and
federal
regulations
are
enforced.
Program
HAZ-‐1.1.b:
Development
plans
for
projects
which
may
store,
use
or
transport
hazardous
materials
shall
continue
to
be
routed
to
the
Fire
Department
and
the
Department
of
Environmental
Health
for
review.
Program
HAZ-‐1.1.c:
The
City’s
Emergency
Services
Division
shall
maintain
a
comprehensive
inventory
of
all
hazardous
waste
sites
within
the
City,
including
underground
fuel
storage
tanks.
Policy
HAZ-‐1.2
To
the
extent
empowered,
the
City
shall
regulate
the
generation,
delivery,
use
and
storage
of
hazardous
materials.
Program
HAZ-‐1.2.a:
All
facilities
which
produce,
utilize,
store
or
transport
hazardous
materials
shall
be
constructed
in
strict
conformance
with
all
applicable
Building
and
Fire
Codes.
Policy
HAZ-‐1.3
Support
Household
Hazardous
Waste
disposal.
Program
HAZ-‐1.3.a:
Continue
to
work
with
the
County
to
assure
regular
household
hazardous
waste
disposal
events
are
held
in
and
around
the
City.
Program
HAZ-‐1.3.b:
Educate
the
City’s
residents
on
the
proper
disposal
of
household
hazardous
waste
through
the
City’s
newsletter
and
by
providing
educational
materials
at
City
Hall.
RELATED
GOALS
As
described
above,
this
Element
relates
to
others
in
this
General
Plan.
The
following
Goals,
and
their
associated
policies
and
programs,
are
closely
related
to
those
of
this
Element.
GOAL
ES-‐1:
An
effective
and
comprehensive
response
to
all
emergency
service
needs.
GOAL
PF-‐1:
Public
facilities
and
services
that
are
available,
adequate
and
convenient
to
all
City
residents.