D.C. Mun. Regs. tit. 21, r. 21-105
No person shall open or cause to be opened or assist in opening any fire hydrant under the control of the Mayor of the District of Columbia, except as specifically provided in this section.
Fire hydrants may be opened in the case of actual fire, but only to the extent necessary to combat the fire.
Fire hydrants may be opened by employees of the District of Columbia who are authorized to do so.
The Director of the D.C. Department of Recreation may authorize the use of water from designated fire hydrants for community recreational purposes at no charge to the sponsors of the activity.
Fire hydrants may be opened by other persons who are authorized to do so in accordance with the provisions of § 106.
In cases where Potomac water is needed for construction or other temporary purpose, a permit shall be issued by the Department for the use of fire hydrants, subject to the payment of the prevailing fee and the provisions of § 106.
No person, other than authorized employees of the Department, shall turn off or turn on, or otherwise operate any water valve, cut off, curbcock, or similar control located in public space, except registered plumbers who are authorized to operate curbcocks, cutoffs, or similar controls on consumers services (excluding side valves, three inch (3 in.) and larger, leading from the public water main).
Conviction of a violation of the provisions of this section shall be punishable by a fine of one hundred dollars ($100).
D.C. Mun. Regs. tit. 21, r. 21-105