  This work presents novel findings that broadens our understanding of the
amount of water that can be transported to Earth. The key innovation lies in
the combined usage of Smoothed Particle Hydrodynamics (SPH) and $N$-body codes
to assess the role of collision fragments in water delivery. We also present a
method for generating initial conditions that enables the projectile to impact
at the designated location on the target's surface with the specified velocity.
The primary objective of this study is to simulate giant collisions between two
Ceres-sized bodies by SPH near the $\nu_6$ secular resonance and follow the
evolution of the ejected debris by numerical $N$-body code. With our method 6
different initial conditions for the collision were determined and the
corresponding impacts were simulated by SPH. Examining the orbital evolution of
the debris ejected after collisions, we measured the amount of water delivered
to Earth, which is broadly 0.001 ocean equivalents of water, except in one case
where one large body transported 7\% oceans of water to the planet. Based on
this, and taking into account the frequency of collisions, the amount of
delivered water varies between 1.2 and 8.3 ocean's worth of water, depending on
the primordial disk mass. According to our results, the prevailing external
pollution model effectively accounts for the assumed water content on Earth,
whether it's estimated at 1 or 10 ocean's worth of water.
