Background
Christy Hamilton and her company, HMI Manufacturing, operate on three parcels of real property in Twin Falls, Idaho, adjacent to Rock Creek Canyon. The City of Twin Falls owns water and sewer lines that run beneath two of those parcels. The water line under the West Parcel was installed in 1918; the sewer line under the East Parcel was installed pursuant to a 1947 easement agreement (known as “Peterman 1”) granted by the then-owners, Isaac and Mabel Peterman. In June 2018, the water line broke near the northeast corner of the HMI Manufacturing building—the same location where it had broken in 1984, 1986, and 2000—causing structural damage and disrupting HMI’s operations.
HMI filed suit against the City and City employee Jon Caton, alleging trespass, nuisance, and related claims. The City defended on the ground that it held valid easements—either express or prescriptive—for both utility lines. Following a two-day bench trial in March 2024, the Twin Falls County District Court dismissed HMI’s claims, finding the City held an express easement for the sewer line (or, in the alternative, a prescriptive easement), and a prescriptive easement for the water line. Final judgment entered December 13, 2024, and HMI timely appealed.
On appeal, HMI argued that the district court misread the Peterman 1 instrument by failing to give effect to all its language and by ignoring a latent ambiguity created by the absence of a referenced “master map.” HMI also contended that the water line’s prescriptive easement was improperly established because the West Parcel was wild, unimproved, and unenclosed at the time of installation—making early use presumptively permissive rather than adverse.
The Court’s Holding
The Idaho Supreme Court affirmed on all issues. On the express easement for the sewer line, the court held that the Peterman 1 instrument adequately described a servient parcel that encompassed the East Parcel. Both parties’ surveyors agreed at trial that the boundary description in Peterman 1 identified a parcel large enough to include the East Parcel; a subsequent parenthetical reference to “Tax #294″—set in smaller type after a period—did not override or replace that boundary description. The court declined to elevate the tax-parcel reference over the operative boundary language, concluding the two were meant to refer to the same land, not to identify a separate, smaller parcel to the south.
On the easement’s location, the court held that the Peterman 1 grant functioned as a blanket (floating) easement because the cited master map could not be located and thus no specific path was established at the time of contracting. Applying its prior holding in Manning v. Campbell, the court concluded that the sewer line’s actual installation under what became the Recycle Center on the East Parcel fixed the easement’s location as a matter of the parties’ course of performance, just as if the location had been formally specified. No evidence was introduced that any alternative sewer line had ever been installed in the area, and HMI’s own surveyor acknowledged no sewer line existed in the Tax #294 parcel. The court further held that the unavailability of the master map did not produce a latent ambiguity; at most it indicated the written agreement was only partially integrated, leaving the omitted term (precise location) available to be clarified by extrinsic evidence of performance. Having affirmed the express easement ruling, the court declined to reach the alternative prescriptive easement theory for the sewer line. On the water line, the court affirmed the district court’s finding of a prescriptive easement supported by clear and convincing evidence of open, notorious, continuous, and adverse use dating to at least 1978.
Key Takeaways
- A blanket or floating easement that does not specify a precise location is fixed in place by the parties’ actual construction and use of the utility—subsequent installation of the line operates as if the location had been “specifically fixed by formal contract.”
- An easement instrument’s reference to an unlocatable collateral document (here, a “master map”) does not create a latent ambiguity; it may render the agreement only partially integrated, opening the door to parol evidence—including course of performance—to supply the omitted term.
- Where a property description contains both a metes-and-bounds boundary description and a tax-parcel identifier that are in tension, courts will harmonize them rather than allow the secondary reference to nullify the primary boundary description.
- Municipal utility lines with decades of documented open use can establish prescriptive easements by clear and convincing evidence even when early written authorization is incomplete or hard to locate.
Why It Matters
This decision offers important guidance for Idaho practitioners who deal with aging utility easements drafted before modern record-keeping standards. It confirms that courts will look to a utility’s actual, uncontested installation and use to fix the location of a vaguely worded or floating easement—providing municipalities and utility providers a reliable path to defend infrastructure that has been in the ground for generations when original documentation is incomplete or missing.
The opinion also reinforces the limits of a “latent ambiguity” argument in easement litigation: a party cannot manufacture ambiguity simply because a referenced map or exhibit is unavailable. Instead, the court will treat the gap as a partial integration issue and allow extrinsic evidence of the parties’ conduct to fill it—which, in practice, tends to favor the party whose use has been long-standing and uncontested.