Loudoun Water encourages customers to be proactive, make a plan, and know what to do in the event of an emergency. A water emergency can be any event that may disrupt the normal supply of clean water to a customer’s home. Having access to clean water in an emergency for basic needs like drinking, cooking and hygiene is vital. Learn more about what you and your family can do to prepare for potential water emergencies. Learn how to shut off a main water valve Prepare an emergency water supply Water container storage and cleaning Prevent frozen pipes Report an emergency: Always report problems like damaged waterlines to Loudoun Water immediately. Our emergency after-hours number is 571-291-7878.