A public authority may take private property for public use on payment of just compensation. Challenges to the taking itself succeed rarely; the substance of most cases is valuation.
Public use and necessity. Courts are generally deferential, though states vary considerably and several have narrowed the permissible purposes by statute — particularly for transfers to private developers. Procedural defects in the authorisation are a more realistic challenge than the purpose itself.
Just compensation is normally fair market value at the date of taking, based on the highest and best use, which may not be the current use. That single point drives most valuation disputes: land used as a warehouse but zoned and suitable for something more valuable should be valued accordingly.
Partial takings are more complex. Compensation covers the part taken and severance damages to the remainder — loss of access, an awkward remaining shape, changed drainage. Offsets for special benefits to the remainder may apply.
What is usually not compensable varies by state but often includes lost business profits and goodwill, though relocation assistance may be available separately by statute.
For an owner: obtain an independent appraisal early. The condemning authority’s offer is a starting figure, and in these matters the gap between the first offer and the settled figure is frequently substantial.