In City of Waco v. Texas Natural Resource Conservation Commission, 83 S.W.3d 169 (Tex. App.-- Austin 2002, pet. denied), the Court held that the district court had jurisdiction to consider the city's request for a declaration that the Texas Natural Resource Conservation Commission (TNRCC) could not grant additional permits in a watershed area until the city complied with federal regulations that were incorporated into state law. Id. at 173.
The City was not attacking an agency order or rule, and the only ground for dismissal that the TNRCC raised was one of ripeness-- "that the controversy was hypothetical and not ripe for adjudication apart from a specific permit application." Id. at 178.
The Court made clear that "the City was not appealing from a specific agency action and was not challenging the validity or application of an agency rule," but rights it alleged it was afforded under federal regulation. Id.
In that context, the Court held that the district court had jurisdiction to consider the city's request for declaratory relief "on a purely legal issue." Id. at 178.