RSA 72:11 — Water Works; Flood Control. –

I. Except as provided in paragraph II, property held by a city, town or district in another city or town for the purpose of a water supply or flood control, if yielding no rent, shall not be liable to taxation therein, but the city, town or district so holding it shall annually pay to the city or town in which such property lies an amount equal to that which such place would receive for taxes upon the average of the assessed value of such land, without buildings or other structures, for the 3 years last preceding legal process to acquire the same, or other acquisition thereof, the valuation for each year being reduced by all abatements thereon; but any part of such land or buildings from which any revenue in the nature of rent is received shall be subject to taxation; such payments shall be paid to the collector of taxes of the town or city in which such property lies upon notification from him, and such payment shall be made on or before December 1 in each year; provided, however, that after such acquisition the valuation thus established shall be subject to change, as to make such value proportional with the assessed value of other property in the town which is subject to taxation, so that such payment will not exceed its proportion of the public charge in that year. Any city or town aggrieved by the payment in lieu of taxes on such property shall have the same right of appeal as a taxpayer may have.
II. (a) Alternatively, the governing body of a city, town, or district holding property described in paragraph I may enter into an agreement with the governing body of the city or town in which the property is located for payments in lieu of taxes with respect to the subject property. In the absence of such an agreement, the property shall be subject to the provisions of paragraph I. Notwithstanding any agreement entered into under this paragraph, any portion of the land or buildings from which revenue in the nature of rent is received shall remain subject to taxation as provided in paragraph I.
(b) No voluntary agreement entered into under this paragraph shall be valid for more than 5 years, however, any such agreement may be renewed or amended and restated for any number of consecutive periods of 5 years or less.