CRNG wrote, on Sat, 28 Jun 2014 07:37:08 -0500:

After reading the (IMO many good) suggestions in this thread, it's
beginning to look like a pretty complex problem.
I wonder how it affects property values?

I suspect that, as long as the water tanks & wells meet the code
of unincorporated Santa Clara County, then the property values are
not adversely affected.

But, I never understood property values anyway, as houses in the
Silicon Valley that are literally a postage-stamp POS habitually
go for well over a million dollars.

Googling for the relevant residential water tank storage standards,
I see a chart on page 4 of this local Fire Department PDF:
http://www.sccgov.org/sites/fmo/docs...r%20012612.pdf
which intimates that my 5,000 gallons is downright puny and is
the first line of the specifications, which seems to indicate that
it's the absolute bare minimum for even a very low hazard fire area:
https://c1.staticflickr.com/3/2935/1...c0e5cb11_b.jpg
And, it's nowhere near what is needed in my very high hazard
fire risk area, so, I must be grandfathered in from decades ago.

This document says that the second tank (which is required) is
for the fire department, but I don't think mine is hooked up
that way (I'll snap some pictures separately):
http://www.sccgov.org/sites/fmo/wate...v%20012512.pdf

Page 6 of this document says I must connect the tanks by 4-inch
steel pipe, which is what I have currently connecting them:
http://www.sccgov.org/sites/fmo/docs...891CFMO-W2.pdf