Nearly one in five Canterbury farmers have failed to comply with their consents to take river and ground water.
ECan regional council figures showed significant non-compliance for the year to the end of June.
Large parts of the region had been in drought for more than a year and rivers and ground water were already running low.
Breaches were for taking more water than a consent allows, faulty water meters and failing to report the amount of water taken.
Farmers with consents to discharge dairy cow effluent were found to be significantly non-compliant in 9 percent of cases.