Raising a levee around the NSW town of Deniliquin has cost $15.8 million and will prevent an estimated $85 million of flood losses.

The 17km barrier was officially opened last week, after work that started in the 1990s was completed last year.

Deniliquin Mayor Lindsay Renwick says the town has a long history of flooding and the upgrade will protect 3300 properties from a one-in-100-year event.

The council and state and federal governments paid for the work.

MP for Farrer Sussan Ley says the levee is an example of disaster mitigation having a direct impact on a community’s resilience.