Ohio Rev. Code Ann. § 1522.18

The chief of the division of water resources, on the chief's own initiative or upon written complaint by any person, may investigate or make inquiries into any alleged failure to comply with this chapter, any rule adopted under it, any order issued under it, or the terms and conditions of a permit issued under it. The chief or the chief's duly authorized representative may enter at reasonable times on any private or public property to inspect and investigate conditions relating to any such alleged act of noncompliance and, if necessary, may apply to the court of common pleas having jurisdiction for a warrant permitting the entrance and inspection.