Chakras are centres of energy which govern certain zones of the body; they convey energy between dimensions (or planes of existence) and are centres of subtle forces, the generation of prana (energy) and higher consciousness.
The Svadhistana is located above the Muladhara, at the base of the genital organ or in the centre of the lumbar region.
This chakra is associated with water, symbolised by a half moon and the god Vishnu, sustaining principle of the universe. It is usually red, sometimes white.
It is governed by the goddess Rakini Shakti (or Sakti); she is dark blue, with three red eyes, a bleeding nostril and four arms. She holds a trident, lotus, drum and chisel.
The animal symbol of Svadhistana is a green sea-monster, similar to a crocodile, representing dominion over the sea and hence the unconscious.
It has six petals representing the mental conditions of: neglect, insensitivity, credulity, suspicion, destructiveness and cruelty, as well as frustration, attachment and anxiety. Physically it governs the large intestines, rectum, kidney, bladder, sexual organ and testes. Imbalance in this chakra can be the cause of sexual problems, diabetes, kidney and bladder problems.
Meditation on this chakra will bring mastery of the elements, and relieve a person of egotistic feelings, petty impulses and desires. It helps to develop the qualities of equanimity and placidity of mind, as well as self-confidence and well-being.
See also Chakras: Muladhara
Information source: Energies of Transformation, A Guide to the Kundalini Process, by Bonnie Greenwell PhD.