The following sections of the Wisconsin Statutes, and the Wisconsin Administrative Code give the utility authority to gain access to a private property to check/test water meter at a reasonable hour.
Wisconsin Stat. § 196.171 Examination of meters, pipes, fittings, wires and works; entering buildings for.
(1) Any officer or agent of any public utility furnishing or transmitting water, gas or electric current to the public or for public purposes may enter, at any reasonable time, any place supplied with gas, electricity or water by the public utility, for the purpose of inspecting, examining, repairing, installing or removing the meters, pipes, fittings, wires and works for supplying or regulating the supply of gas, electricity or water and for the purpose of ascertaining the quantity of gas, electricity or water supplied.
(2) No officer or agent of a public utility may enter any premises under this section unless the officer or agent:
(a) Was duly appointed by the public utility for the purpose of acting under this section.
(b) Exhibits written authority signed by the president, by a vice president and secretary, or by a vice president and assistant secretary of the public utility. The authority of any officer or agent of a municipally owned public utility shall be signed by the commissioner of public works or by any other official in charge of the public utility.
(3) Any person who directly or indirectly prevents or hinders any officer or agent from entering a premises, or from making an inspection, examination, removal or installation under this section shall be fined not more than $25 for each offense.
A utility may also disconnect service based on Wis. Admin. Code § 185.37. In particular, with regard to entry to premises by utility personnel, the following apply.
Wisconsin Admin. Code § 185.37: Disconnection and refusal of service.
(2) Utility service may be disconnected or refused for any of the following reasons:
(f) Refusal or failure to permit authorized utility personnel access to the base meter;
(h) Failure to comply with Wisconsin statutes, commission rules, or commission orders pertaining to utility service;
(j) Failure to comply with the utility's rules or if the customer uses a device that unreasonably interferes with communications or signal services used for reading meters;