Flooding prone areas have to be well built and should have proper methods in place to deal with them. Areas with a stopbank have a higher 100-year flood level since the water has resistance due to the stopbank. Due to the presence of clouds and rains the internal runoff area is present which redirects water towards the internal ponding. The stopbank contains a floodgate and a berm. Their purpose is to allow/deny the flow of water towards the internal pond. When the floodgate opens the water flows towards the internal pond. The berm is used as a lock for the floodgate. This maintains an adequate internal pond water level that doesn't reach the house floor, therefore avoiding floods.
In contrast to areas with a stopbank, the margin between the 100-year ponding level and the house floor level is 300m(freeboard area) in areas with no stopbank. The level of river/drain water level is lower here since there is no stopbank present to provide resistance that increases the water level. The houses are elevated higher in this case as there is no direct control over the flood level, so an adequate margin is preferred.
In summary, the areas which have rainfalls and excessive water due to rains should contain a stopbank to control the water level and could have houses lower to the ground. Whereas, areas with no stopbanks should have houses elevated higher since there are no control measures for water level.
Flooding prone
areas
have to
be
well built
and should have proper methods in place to deal with them.
Areas
with a
stopbank
have a higher 100-year flood
level
since the
water
has resistance due to the
stopbank
. Due to the presence of clouds and rains the
internal
runoff
area
is present which redirects
water
towards the
internal
ponding
. The
stopbank
contains a floodgate and a berm. Their purpose is to
allow
/deny the flow of
water
towards the
internal
pond.
When
the floodgate opens the
water
flows towards the
internal
pond. The berm is
used
as a lock for the floodgate. This maintains an adequate
internal
pond
water
level
that doesn't reach the
house
floor,
therefore
avoiding floods.
In contrast
to
areas
with a
stopbank
, the margin between the 100-year
ponding
level
and the
house
floor
level
is
300m
(freeboard
area)
in
areas
with no
stopbank
. The
level
of river/drain
water
level
is lower here since there is no
stopbank
present to provide resistance that increases the
water
level
. The
houses
are elevated
higher
in this case
as there is no direct control over the flood
level
,
so
an adequate margin
is preferred
.
In summary, the
areas
which have rainfalls and excessive
water
due to rains should contain a
stopbank
to control the
water
level
and could have
houses
lower to the ground. Whereas,
areas
with no
stopbanks
should have
houses
elevated higher since there are no control measures for
water
level
.