Thanks for all the responses and input, its greatly appreciated. Im hoping the test holes next year will help out greatly. Am I correct in thinking that monitoring these holes will in essence tell me how a pond at this location would fluctuate, granted no severe weather changes? This area is wet (frogs/tadpoles) almost all year even in the summer. Is this a good indication that I would not have to dig down incredibly far to maintainable depth? Im hoping that a spill way could be designed to drain right into the detention area since it's been designed to slowly release water into an adjacent irrigation ditch.