Modern dairies need to address concerns of potential water shortages and environmental contamination of water supplies. Accurate assessments of water usage are needed to improve management, minimize costs, and protect water supplies. In 2004, thirteen meters were installed at key locations on a 1,000 cow dairy to monitor cow and wastewater usage. Data collected from January 1, 2005 through December 31, 2006, indicated that monthly average cow drinking water ranged from 11.6 to 30.6 gallons per cow per day (gal/cow/day) with an average usage of 23.3 gal/cow/day. Wastewater usage ranged from 5.6 to 7.6 gal/cow/day with an average usage of 6.3 gal/cow/day. Monitoring encouraged increased efficiency in water use for washing down the parlor and cleaning equipment and resulted in a savings of 8 million gallons per year from a reduction in the rate of cooling plate water from 42 gallons per minute (gpm) to 16 gpm. Current monitoring of three additional dairies shows similar water usage.