Scott Jamison wrote:

Kira:  But the spring didn't come into existence until *after* Hikaru
drowned, so how could Rhi Fa already have draconic blood?

SKJAM!:  Good point.  One possible solution...the original Musk Dynasty
founders used a *different* Nyanniichuan, one which was destroyed by the
time Hikaru came along.  Thus there was a template needing to be
filled...

Or there could be simultaneously a dozen springs of various drowned
human females.  After all, there is both a spring of drowned boy and
a spring of "drowned virtuous man".  That's not even counting the 
Japanese spring of drowned man.  

Kira:  And that brings up the question of whether the monkey-girl that
cursed Herb was just a coincidence after all.

A bit of revenge from a vengeful spirit?