  We treat energy-momentum conservation laws as particular gauge conservation
laws when generators of gauge transformations are horizontal vector fields on
fibre bundles. In particular, the generators of general covariant
transformations are the canonical horizontal prolongations of vector fields on
a world manifold. This is the case of the energy-momentum conservation laws in
gravitation theories. We find that, in main gravitational models, the
corresponding energy-momentum flows reduce to the generalized Komar
superpotential. We show that the superpotential form of a conserved flow is the
common property of gauge conservation laws if generators of gauge
transformations depend on derivatives of gauge parameters. At the same time,
dependence of conserved flows on gauge parameters make gauge conservation laws
form-invariant under gauge transformations.
