Slaughter, J.
This case pits a municipality’s power to protect the health and safety of its residents against the utility regulatory commission’s power to impose uniform, statewide standards on regulated public utilities. Our state utility code does not automatically preempt local ordinances that a municipality may want to enforce against a public utility. But the code sweeps broadly and subjects even generally applicable ordinances to the commission’s regulatory oversight to the extent they are “affecting or relating to the service of any public utility”—a phrase under the code with far-reaching scope. Both trial courts and the commission can hear a municipality’s action to enforce an ordinance. But only the commission can decide whether an ordinance implicating a public-utility function is unreasonable. We reverse and remand.
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We hold that the trial court has jurisdiction over Noblesville’s enforcement action against Duke. But only the commission can decide whether Noblesville’s ordinance interferes unreasonably with Duke’s utility functions. The commission “has both the fact-finding expertise and the broader non-local focus necessary to balance [the] competing interests” of public utilities and municipalities in deciding such disputes. Duke Energy Ind., LLC v. Town of Avon, 82 N.E.3d 319, 325 (Ind. Ct. App. 2017). Under our doctrine of primary jurisdiction, the trial court must refer the reasonableness question to the commission.
First, we explain that municipal ordinances presumptively apply to regulated public utilities. Thus, Duke’s blanket assertion that Noblesville has no power to enforce its ordinance against Duke is unfounded. Next, we explain that both the commission and trial court can hear ordinance-enforcement actions generally. But the utility code confers on the commission sole authority to decide whether a local ordinance “affecting or relating to” public-utility service goes too far. That means Noblesville can seek to enforce its ordinance against Duke in the trial court, but only the commission can decide whether the ordinance interferes unreasonably with Duke’s public-utility functions.
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Having determined that state law does not automatically preempt local ordinances affecting public-utility service, we consider next whether the utility code requires the commission to decide any disputed issues or claims here. Applying the code, we hold the trial court can hear Noblesville’s enforcement action, but the action’s merits turn in part on an issue—Duke’s counterclaim—that only the commission can decide. Duke’s demolition of the home and garage and its proposed construction of the new office building and garage involve utility “service”—a term the code defines expansively. These projects fall within the commission’s sphere, and the commission has primary jurisdiction for deciding whether Noblesville’s enforcement of its ordinance against Duke goes too far.
Put differently, if one or more issues are within the agency’s exclusive authority, the trial court must refer at least those issues to the agency, which has primary jurisdiction over them. To “refer” an issue to an agency means the trial court instructs the affected party to “take the issue formally before the appropriate agency.” Id. at 648 (citing Reiter v. Cooper, 507 U.S. 258, 268 n.3 (1993)). In practice, the court can do that in either of two ways.
First, it can dismiss the entire action and refer the parties to the agency…
Or, second, the court can refer only the agency-bound issues while retaining jurisdiction over the action…
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We hold that the commission must decide whether Noblesville’s proposed enforcement of its disputed ordinance against Duke’s demolition and construction projects interferes unreasonably with Duke’s public-utility functions. To be sure, trial courts and the commission have concurrent authority to hear ordinance-enforcement actions generally. But the utility code’s broad language grants only the commission the power to decide whether a municipal ordinance impedes a public utility’s service unreasonably and thus goes too far. Under principles of primary jurisdiction, then, the trial court must refer at least Duke’s counterclaim to the commission and may, in its discretion, refer the entire action, including Noblesville’s claim.
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We hold that Duke’s counterclaim is subject to the commission’s exclusive reasonableness review under sections 8-1-2-54 and 8-1-2-69. Since only the commission has primary jurisdiction to decide whether Noblesville’s ordinance improperly impedes Duke’s utility functions, Duke’s counterclaim belongs to the commission. Whether the commission finds the ordinance reasonable will dictate whether the trial court in turn grants Noblesville’s request to enforce its ordinance against Duke. Thus, the trial court on remand must refrain from ruling on the enforcement claim until the commission decides whether Noblesville’s ordinance is reasonable. See Austin Lakes, 648 N.E.2d at 645. The court also may opt to give the commission primary jurisdiction over the entire action, which consists of Noblesville’s enforcement claim and Duke’s counterclaim.
For these reasons, we hold that whether Noblesville’s disputed ordinance affects or relates to Duke’s public-utility service unreasonably is for the commission to decide. We reverse the trial court’s judgment and remand for further proceedings consistent with our opinion.
Rush, C.J., and Massa, Goff, and Molter, JJ., concur.