Wascana Creek has already spilled its banks in some parks of Regina, but residential areas like this one are high and dry. (CBC)

The rising water in Regina could be worse than previously forecast, the city says.

The city is now preparing for the highest water levels since the big flood of 1974, officials said in a flood update on Friday.

Although a once-in-25-year event was forecast earlier this year, the city is now getting ready for a once-in-50-year event.

While most of the winter snow has melted away inside the city, there's lots of unmelted snow east of Regina that will feed into Wascana Lake and Wascana Creek in the next few days.

That could raise water levels in Wascana Lake another metre to 572 metres above sea level, the highest level since 1974.

The city has dikes in place that are designed to prevent water from reaching homes.

There are also 40,000 sandbags piled up in low-lying areas, with plans for up to 40,000 more.

The city says it will let water spill over the banks of Wascana Creek and as a result, some park areas and pathways will be flooded.

The water levels are expected to peak next week, but that could change depending on the weather.

Snow is expected in parts of eastern Saskatchewan on Friday.