Iowa One Call is a FREE public service provided to anyone planning to do construction in Iowa. It marks public and private utilities prior to construction.
You should contact Iowa One-Call any time that you could be disturbing existing underground utilities. Examples include but are not limited to digging, re-grading, or installing fence posts.
Iowa One-Call can be reached toll-free at 1-800-292-8989. They will need to be contacted at least 48 hours (excluding weekends and legal holidays) before you dig.