Update: The post now includes the official text used for the citywide phone alert.
An alert from the South Milwaukee Water Utility …
Due to the unusual depth of frost this year, Water Utility customers are being asked to run their water full flow from a cold water faucet for five minutes, five times per day, until March 1st. This request is to prevent water pipes from freezing.
Residents leaving for an extended period should make sure that their basement is warm and have someone come to your house regularly to run the cold water to make sure your lateral doesn’t freeze.
To prevent your water main from freezing, you may notice a hydrant running in your neighborhood.
From South Milwaukee Water Utility (414) 768-8070.
See http://www.smwi.org
South Milwaukee Blog 
Good advice!