Legal Definitions - prior-use doctrine

The prior-use doctrine is a legal principle that generally prevents a government agency from taking or acquiring property that is already being used for a public purpose by another government entity or public body. This doctrine ensures that land already dedicated to serving the public good is protected from being seized for a *different* public use, unless a specific law has been passed to explicitly authorize such a taking.

In essence, it means that one public use cannot easily override or displace another existing public use without clear legislative approval, often requiring a higher standard of justification.

• Example 1: City Park vs. State Highway

  Imagine a state transportation department plans to build a new highway that would cut directly through a significant portion of a city-owned public park. The park is already serving a public purpose by providing recreation and green space for residents. Under the prior-use doctrine, the state transportation department would generally be prevented from simply condemning and taking the parkland for the highway. To do so, the state legislature would likely need to pass a specific law authorizing the taking, perhaps after determining that the highway's public benefit unequivocally outweighs the park's existing public use.

• Example 2: School Athletic Fields vs. Municipal Water Treatment Plant

  Consider a municipal water authority that needs to expand its water treatment plant due to population growth. The most suitable adjacent land is currently owned by the local school district and used for athletic fields, which serve the public purpose of education and student recreation. The prior-use doctrine would prevent the water authority from easily acquiring these athletic fields through eminent domain. The water authority would typically need specific legislative authorization, or demonstrate that the new public use is absolutely essential, cannot be located elsewhere, and that the legislature intended to allow such a displacement of an existing public use.

• Example 3: Public University Land vs. County Jail Expansion

  Suppose a county government wants to expand its overcrowded jail and identifies a parcel of land owned by a state public university, currently used for agricultural research and student training. This university land is already dedicated to a public purpose (education and research). The prior-use doctrine would mean the county cannot simply take this university land for the jail expansion. The county would need explicit legislative approval from the state, or demonstrate that the new public use is of such paramount importance and necessity that it is authorized to override the existing public use, which is a high legal bar to meet.