Water

Water is often used to symbolize things in literature. Water is a universal symbol of change and is often present at turning points in a story. Since water is often a sign of life, many times water represents life.  Likewise, water can also represent death (such as dark murky waters). Water can also be up into two categories: fresh water and bad/polluted water. Fresh water can represent good health, and bad water symbolizes bad health. Water can also mean purity and cleansing. It also represents thirst, since people drink water to quench their thirst. 

Rivers

The river is a sign of ease, grace and fluidity; as expressed by its meandering form. Often times it is used to represent the calm beauty of nature. Certain types of rivers are often described as auspicious and healthy.

A fast-flowing river can often be used to symbolize strength, power, sometimes calamity. Calamity can be represented through a disaster, such as the river flooding a nearby town or village.

A slow-flowing river can often be used to symbolize weakness, or sometimes being steady and calm.

It also symoblises that it will last forever, and will never stop.

The Ocean  

The Ocean is a sign of power and strength, dominating all other symbols of water--due to its immensity. All life was ocean-born and life still exists in the ocean; therefore the ocean represents life. Also, the ocean represents mystery. The ocean is known for being unpredictable and uncontrollable, hard to navigate in time of storm and sometimes known for being beautifully calm; always at it's own will or Neptune's (Roman god of the sea). Sometimes, the ocean is referred to as being a tear of God or the sorrow; a place where you leave your bad memories and sadness.  The ocean is also known to symbolize hope, truth, and in some cases, mystery and magic. The ocean's salt can also symbolize being well grounded, or stabilized.

From A Seeker’s Thoughts, blog by Joseph Panek

Rivers - As A Symbol

Symbolically, a River represents the flow of time.   It symbolizes
the natural flow of Nature along with all of her cycles, transitions,
transformations and passageways.

When we stand in the middle of a bridge above a river, and look
down, we experience a powerful, awe-inspiring, hypnotic sensation
as we watch the river flow beneath our feet. Although it is the same
River, it is the continual flow of new Water within that River which
mesmerizes and enchants us. The metaphor, "A lot of water under
the bridge" paints a mental picture of the hypnotic effect of the
passage of Time.

First of all, although a River is composed of Water, it is important
to understand that the River and Its Water are two separate and
distinct essences; they are two separate and distinct principles.
Water is the Feminine Essence which gives birth and nourishes.
The River, on the other hand, is the Masculine Principle which
Impregnates the soil of Mother Earth with Its Water.

Creation myths from numerous cultures speak of a great mountain
from which four Rivers flowed in four different directions. These
Rivers provided the life-giving nourishment for the four cardinal
areas of creation (North, South, East and West).

The twists and turns which are a part of a River's long journey
symbolize the twists and turns which we encounter during our
earthly journey; our incarnation. As with the River, our earthly
journey is not direct. Just as a River must take Time to turn, pause
and aerate Itself, we too must take Time to pause, alter course a
little, and refresh ourselves.

And just like the River, once our pause and refreshment is over we
are then ready to resume the next clear path of our journey. The
River also reminds us that we can only go forward in our life's
Journey. It is when we attempt to go back (live in the past) that we
find ourselves "swimming upstream" in a futile attempt to defy the
natural flow of Nature.

The River, in its long Journey, is symbolic of life in general; and of
our lives in particular. There are periods when the River experiences
turbulent, chaotic and disturbing Times (rapids); there are periods
when It experiences twists, turns and pauses; and then there are
periods when the River flows peacefully, smoothly and calmly.

And finally, just as with each and every one of us, the Time comes
for the River to end its long Journey. This is the moment when the
River passes through its Delta (Change) to be transformed into, and
become part of, the Great Sea. This moment of transition for the
River symbolizes our moment of transformation which occurs when
our long earthly Journey comes to its end. This is the time when we
also change in order to return to, and re-become part of, that Great
Consciousness which we call Divinity. The River, what a great
metaphor for this complex Journey we call life!

In addition to symbolizing the flow of time Rivers also Symbolize Borders,

boundaries, transcendence, Mirrors, the Subconscious, and persistence.

Rivers as Borders: Since the beginning of time rivers have served
as natural borders. Rivers, such as the Mississippi, Colorado and
Delaware serve as borders between states. They can act as borders
between countries in the way that the Rio Grande separates a
portion of the Unites States from Mexico, and as the St. Lawrence
separates a portion of the United States from Canada. Rivers can
also act as a natural Border between countries and continents in
the way that the Ural River creates a natural Border between Asia
and Europe. Natural Borders, created by Nature, separate one
civilization, or realm from another. In this aspect, crossing a River
symbolizes leaving a familiar domain behind in order to enter into,
and experience, an entirely new one.

Rivers as boundaries: Perhaps the best example of a River as
a boundary is Julius Caesar crossing the Rubicon with his army.
Roman law forbade a returning general from bringing his army
into Rome. The general was required to leave his army on the
opposite side of the Rubicon and enter Rome alone. When Julius
Caesar crossed the Rubicon with his army he violated the rules
of Roman generalship and changed the course of history. In this
instance, crossing a River, or crossing the line, represents defiance
boldness and destiny

Rivers as transcendence: Charon, the mythological Greek
boatman, would ferry the souls of the deceased across the River
Styx into Hades.

In a like fashion the bodies of the deceased, after  ritual and
mummification, would be ferried to the West bank of the Nile River
to be interned in Necropolis (the "city of the dead"). Necropolis was
located on the West bank of the Nile River because the Sun sets in
the West as It begins Its underworld Journey which culminates in Its
eventual re-birth the following morning. In this instance, crossing a
River symbolizes "transcending" from a lower form of consciousness
to a higher one, thereby "aspiring" to a higher realm.

Rivers as the Subconscious: Chinese Feng Shui tells us that
the calm section of a River provides the greatest amount of Chi,
or vital energy, and is an ideal place to build a home. Here the
Waters are quiet, peaceful, relaxing and soothing..
It is at this location that the River's Waters are also the deepest.

Symbolically, deep Water represents the subconscious, and
although our Subconscious harbors our greatest fears, it is also
where our deepest thoughts and innermost feelings reside; it
is also the secret underwater workshop of our imagination. It is
this point of the River, where "still waters run deep", that
Symbolizes our spiritual ability to "submerge" ourselves into a
meditative state which enables us to reflect upon the wonder and
beauty which is both high above us and deep within us.

Rivers as persistence: Rivers can carve mountains into canyons.
All it takes is time. The Grand Canyon is an excellent example
of this Divine truth. This aspect of a River serves as a priceless
metaphor which teaches us that, with patience and persistence,
we too can wear away (erode) any obstacles which block our path
or impede our progress.