  In this work we aimed to describe the three-dimensional morphology and
kinematics of the molecular gas of the water-fountain nebula IRAS 16342-3814.
In order to do this, we retrieved data from the ALMA archive to analyse it
using a simple spatio-kinematical model. We used the software SHAPE to
construct a three-dimensional spatio-kinematical model of the molecular gas in
IRAS 16342-3814. By reproducing the intensity distribution and
position-velocity diagram of the CO emission from the ALMA observations we
derived the morphology and velocity field of the gas. We used CO(1-0) data to
support the physical interpretation of the model. A spatio-kinematical model
that includes a high-velocity collimated outflow embedded within material
expanding at relatively lower velocity reproduces the images and
position-velocity diagrams from the observations. The high-velocity collimated
outflow exhibits deceleration across its length, while the velocity of the
surrounding component increases with distance. The morphology of the emitting
region; the velocity field and the mass of the gas as function of velocity are
in excellent agreement with the properties predicted for a molecular outflow
driven by a jet. The timescale of the molecular outflow is estimated to be
~70-100 years. An oscillating pattern was found associated to the high-velocity
collimated outflow. The oscillation period of the pattern is T~60-90 years and
its opening angle is ~2 degrees. The CO (3-2) emission in IRAS 16342-3814 is
interpreted in terms of a jet-driven molecular outflow expanding along an
elongated region. The position-velocity diagram and the mass spectrum reveal a
feature due to entrained material that is associated to the driving jet. It is
likely that the jet in those objects has already disappeared since it is
expected to last only for a couple of hundred years.
