Small is a relative term.
If you're planning on using the pond as a source for irigation then small becomes bigger.
How much water will you need to retain for your sprinkler system?
Dig the pond big enough to hold that much water.
You can't possibly know if you need a liner until you start digging with something. You could & prob. do have good clay soil to hold water.
At this point there's no need to divert the spring.
There's no need at all to wait for the mud to dry before digging.
After you've figgured out how big a pond you need, check with your local soil & conservation rep. He/she, can give lots of free advise & offer a list of local contractors.
Pond Boss Subscriber & Books Owner
If you can read this ... thank a teacher. Since it's in english ... thank our military!