After a day of traveling...
So, if you can find crawdads that have eggs, a few installed will yield a good population to start the pond, but if you miss that time of spring just bucket stock your crawdads as you can find them. I can't really recommend a stocking number, but I can tell you what I did, right, wrong, or indifferent.
I stocked FHM's in April after the pond hit full pool after renovation then added crawdads (virile) from the creek. Some I trapped while others I netted. All in all I put about 300 crawdads in the 1/4 acre pond over the course of the summer and had a lot of peaceful trips down the ankle deep creek with a bucket and a net. Once the crawdads went in they disappeared to rarely be seen. The FHM's reproduced while the crawdads stayed hidden. My thought was if I added too many crawdads that some would just "walk away" to find greener pastures. So far all is good. Plant life is teaming, clarity is normal for my location at 2 to 3 foot depending. We did see a monster craw (5 incher) while digging the trench for the aeration lines so that was exciting because I did not put any in that big. My pond has about 80 to 90 feet of the dam lined with stones that are about 3 feet wide, mostly in the water at full pool.
Here's a pic of what I did. Notice some of the "veins" of rocks extending down into the deeper parts. These are just in case the water level falls badly. If so, the crawdads have some refuge.
Disclaimer: I really don't know how many crawdads have stayed, how much they like the habitat, or how long they will last, BUT I had a lot of fun doing it!
