Something to think about is the quality of your soil. Clay/sand that was used for your dam is likely devoid of any nutrients and is probably acidic, since it was dug up from deep below what is now the pond. If you invest in some ag lime and spread it on your dam, it will help neutralize the soil so grass can more readily get started. If any runs into the pond, you're only helping the pond.

Fertilizer will help also, but then you've got to contend with possible algae issues, but most new ponds typically need a bump to get the phytoplankton blooms to start, so in that respect, it may not be a bad thing.

Regardless, you have to make sure the soil is capable of sustaining plant growth. IMO, liming will give you the best bang for your buck before you seed. Then scatter some straw (not hay) over it to retain moisture and reduce erosion.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!