Five mornings a week, Saima Azeem helps her children wash and prepare for school. But this week has been different: She has had to use her few bottles of drinking water to get them ready.

"It's been a difficult morning. I'll have to schedule my chores according to the new water supply timing," the mother of four said in an interview.

Faced with fast-depleting groundwater supplies, Lahore — Pakistan's second-biggest city — this week began rationing water and instituting a range of new conservation measures.