Wis. Stat. § 182.005
The articles of a corporation organized in whole or in part to establish, maintain or operate a system of water reservoirs for the purpose of regulating the flow of any river in the state shall guarantee to every owner of water power located below the reservoir system, who does not already own his or her quota of stock, the right at any time to purchase from the corporation at par such a proportional share of all of the capital stock of the corporation as the cubic foot storage fall of the water power of the owner shall be of the sum of the cubic foot storage falls of all water powers benefited by the reservoir system. The cubic foot storage fall of any water power is the product of the height expressed in feet of the head obtained or obtainable by the dam at said power, multiplied by the storage capacity expressed in cubic feet of the reservoirs tributary to such power. The articles shall never be amended so as to withdraw said guaranty.
Wis. Stat. § 182.005