I sent an emails to USGS about both topic. I just got a reply back about the water pressure issue.
"Greetings,
Thanks for your email. I looked at the text on that page and I've done some revising - pretty much taking out discussion about water pressure and pipe size. It just mentions water pressure more in relation to gravity and how the pipes are reduced in size as they go through town.
Okay, I hope this helps."
So apparently some people listen to connstructive criticism :-)