1.) Diverting a flowing creek into a pond is perhaps a violation of some federal laws and probably a violation of state law. Some states designate waterways as small as a dashed blue line on a USGS topo map as a stream. Obstructions and diversions in streams are usually legislated pretty heavily.
You probably need to internet search the SC rules. They may start with a simple publication like, "Rules to Build a Pond on Your Land". It will only have the basics, but that may lead you to the more relevant specific rules.
Note - After you do the clearing, I would take good photos and try to document the prior pond. Frequently, the rules may be much different if you are just modifying a pre-existing pond.
2.) How high did the creek run when you got hit by Helene (or a different hurricane)? From the comments above, you can see that if you divert the entire creek to your pond, the outlet of your lake would have to survive your biggest possible flood event. The engineering for that is possible, but gets VERY expensive very quickly.
3.) Does your creek run year round or most of the year? If so, one plan may be to just divert a portion of the creek flow to your pond site. Let the floods keep going down the creek.
750 gpm flow is over 1,000,000 gallons per day. That would add at least 3' to a one acre pond every day.
Many new ponds require many months, or even more than a year for their initial fill up. You can see that you don't need to divert much of the flow to have a nice pond.
Good luck on your new pond project!
