<p>KARACHI, Pakistan This is a city of more than 20 million people, and most of them don't pay their water bills. To get its predominantly Muslim customers to pay up, the Karachi Water and Sewerage Board has begun playing the religion card.</p><p>"Have you ever wondered if you've paid for the water you are using to perform wuzu?" it asked customers recently in a text message sent to their mobile phones. Wuzu is the washing Muslims need to do before praying five times a day. That's a lot of water. Only one-tenth of Karachi pays its water bills. That could be a lot of guilt.</p><p>The text message was one of 200,000 the water board has sent in an experiment that began in January. Not all of the messages have moral undertones. Some merely tell customers to keep an eye out for their next bill and remind them to pay before the due date. Others contain tips on how to save water. Often, the texts alert customers about water supply disruptions and breakdowns something that happens regularly in Karachi, with its aging and inadequate water infrastructure.</p><p>For the KWSB, a struggling agency that only computerized its billing in 2007, these messages represent a small but significant step toward a new openness with customers. An overwhelming majority of people in Karachi carry mobile phones. Texting, also known as SMS messaging, is ubiquitous among rich and poor alike.</p><p><a href="http://www.theatlanticcities.com/politics/2014/03/can-text-messaging-solve-karachis-incredible-unpaid-water-bill-problem/8720/">Keep reading...</a></p>