It may be cold outside, but New York City is in some hot water. Last week, the city's water supply hit a 15-year low -- or only about 33 percent of capacity.
Responding to the drought that has hit not only New York, but parts of Pennsylvania, Delaware, and New Jersey as well, the four-state Delaware Water Commission delared a state of emergency Jan. 15 and imposed mandatory conservation. Some 21 million people are affected by the order, which, among other things, bans watering of lawns, shrubs, and noncommercial washing of cars.
This week, New York Mayor Edward I. Koch is expected to order controls of his own, including probably:
* The installation of equipment to reduce water pressure at the tap in homes and offices.
* increasing fines for the illegal use of fire hydrants -- although this step is not expected to take effect until warm weather arrives.
There is also the future possibility, city officials say, that commercial and industrial landlords may be fined for not promptly fixing leak ing waterpipes.