The Remai Modern Art Gallery is behind schedule and over budget.

A report going to Saskatoon city council's executive committee on Monday details what's happening at the showcase riverbank project.

According to the four-page update, corrections and clarifications to the internal drawings are to blame. The projected cost is now between $87.2 million and $88.4 million. That is $3.5 to $4.5 million higher than expected.

The gallery is now forecast to open in 2017, not next year as projected.

"The change between what the contractor bid on the original drawings versus what the new design condition requires, has resulted in the contractor having to expend additional resources," the report states.

City administration is expected to work on finding ways to cover the shortfall.

The next update will come before the end of the year.