The area of northern Victoria considered 'at risk' to salinity has grown immensely in just a few years.

In the last four years, authorities say 142,000 hectares have been added to the list of areas deemed to be at risk.

Goulburn-Murray Water says it will undertake more water-table monitoring surveys this year, and the outcome could cause further concern.

James Burkitt, Goulburn-Murray Water's manager of salinity, says the water table has risen by two metres since a drought broke four years ago.

Increased salinity is a frequent by-product of floodwater or a lift in the water table, bringing a range of issues.

Irrigating with excessively salty water can dry out trees, damage and slow the growth of fruit, and lead to significant loss in produce quality and revenue for farmers.

Mr Burkitt said the new water table level could be a basis for future risks, and must be closely monitored.