Eddie,
I went to the local Soil & Water Conservation office when I built my pond. They came out & took core samples & shot the lines. I didn't use them after that.
What I read on the NC State site said any dam over 25' or if it backs up more than 10 ac or if there are dwelings, roads etc below the dam an engineer is needed. This was in 04 & the cost of an engineer was going to be $10,000.
If the spring stays wet all year & you can keep it in shallow water it might be worth the chance to try to utilize it. There is also the posibllity of sealing it off.
Get & read the book suggested .. best money you'll ever spend, & take some pic's of the area to post on here & ask questions then.
