Article 1399 of the French General Tax Code
I. – All real estate, whether built or unbuilt, must be taxed in the commune in which it is located. II. – However, for the basis of assessment of property tax on built properties, the rental value of the motive power of waterfalls and their facilities used by licensed hydraulic companies or with a power greater than 500 kilowatts is divided between the communes in whose territory the watercourses used…