Cathy:
In addition to the bibliography I've already sent, you may want to
check with the following folk:
Vance Bente - Just completed a restudy of portions of California's San
Antonio de Padua water system downstream from the mission complex.
Edna Kimbro - Involved in a major cultural landscape documentation of
the San Antonio mission area which dredged up some great historical
survey data on the system there.
Julia Costello - Also involved in earlier Army work at Hunter Liggett
which visited and re-recorded elements of the upstream portions of the
San Antonio system.
Drop me a line if you don't have their addresses.
Leo