2.
Response
to
Comments
2.9
Individual
Responses
to
Comments
from
Organizations
The
FEMA
data
shown
on
Figure
4.H-3
was
used
to
represent
existing
conditions
at
the
Baylands
Project
site,
and
represents
the
best
available
science
for
areas
prone
to
the
100-year
flood.
Areas
subject
to
the
100-year
floods,
however,
do
not
necessarily
include
areas
subject
to
local
ponding.
Mitigation
Measures
4.H-4a,
-4b,
and
-4c
were
based
on
an
understanding
of
areas
with
local
problems
(e.g.,
Levinson
Marsh
and
the
PG&E
property)
and
were
written
specifically
to
require
corrective
measures
to
address
ponding
issues.
As
stated
in
the
Draft
EIR,
raising
the
existing
grade
levels
combined
with
Mitigation
Measures
4.H-4a,
-4b,
and
-4c
which
require
improvements
to
existing
drainage
problem
areas,
adequate
protection
from
flood
hazards
and
ponding
areas
would
be
provided.
As
required
by
Mitigation
Measure
4.H-4a
on
page
4.H-30,
“Drainage
improvements
shall
accommodate
the
100-year
peak
storm
event
within
the
piping
system
and
streets
such
that
building
finished
floor
elevations
provide
a
minimum
of
1-foot
of
freeboard
above
the
100-year
storm
event
hydraulic
grade
line
water
elevation
with
tidal
flow
and
100
years
of
estimated
sea
level
rise.”
In
addition,
the
City’s
standard
conditions
of
approval
for
site-specific
development
requires
that
site
grading
and
drainage
be
designed
to
as
to
avoid
standing
water,
expect
in
basins
specifically
designed
for
that
purpose.
By
ensuring
that
finished
floor
elevations
of
all
proposed
development
are
a
minimum
of
one
foot
above
the
100-year
flood
zone
with
tidal
flow
and
100
years
of
estimated
sea
level
rise,
and
positive
drainage
is
provided,
flooding
impacts
would
be
reduced
to
less
than
significant
levels.
See
for
a
discussion
of
stormwater
monitoring
and
the
use
of
LID
stormwater
features.
FEMA
flood
hazard
maps
are
based
on
100-year
flood
flows.
As
stated
in
the
Draft
EIR
on
page
4.H-5,
the
FEMA
flood
maps
that
were
updated
in
October
2012
were
used
as
a
source
for
the
flood
analysis
in
the
Draft
EIR.
The
sources
listed
for
Figure
4.H-3
are
modified
as
shown
in
Final
EIR
Chapter
3.0
to
reflect
FEMA’s
2012
flood
mapping.
See
Response
As
discussed
on
page
4.H-17,
General
Plan
Policy
155
requires
“regular
maintenance
to
remove
silt
and
debris
from
storm
drain
facilities”
of
which
trash
would
be
included
as
part
of
any
debris
removal.
In
addition,
the
Final
Stormwater
Management
Plan
would
include
requirements
for
operational
maintenance,
which
would
include
BMPs
that
address
removal
of
trash
(as
described
in
Draft
EIR
Mitigation
Measure
4.H-
1c:
“The
SMP
shall
provide
operations
and
maintenance
guidelines
for
all
of
the
BMPs
identified
in
the
SMP,
including
LID
measures
and
other
BMPs
designed
Brisbane
Baylands
Final
EIR
2.9.3-80
May
2015