Upon the declaration of a water supply emergency as provided in § 15-603, the Mayor is authorized to call on all water consumers to employ voluntary water conservation measures to limit or eliminate non-essential water uses including, but not limited to, limitations on the following uses:
(a) Sprinkling of water on lawns, shrubs or trees (including golf courses);
(b) Washing of automobiles;
(c) Use of water in swimming pools, fountains and evaporative air conditioning systems; and
(d) Waste of water.