I was kidding a bit about snakes getting into your water line, But they can if you leave a line open for repair.
I find snakes all the time here. They will find a water leak if you have any, Frogs hang out around water leaks also.
This year looks great for snakes and frogs in Texas and bugs are plentiful. Mice have it rough, but some survive, If the cats don't get them.
That snake with the dots that you seen may have been some sort of water snake. They are very cool.
I have a pond out back and have some very colorful Snakes. They eat my tadpoles. The Big Bull Frogs eat the snakes sometimes. A snake eating a snake is very cool. Mother nature at its best.
I only pick up snakes that I can Identify. Just look into their eyes. Most are safe to handle, Some stink big time when you pick them up. Ken to a Skunk I guess.
Keep us posted on your project, take pictures of any snakes you may find.
Good Luck on your project.