Water levels in Winnipeg and throughout southern Manitoba are starting to recede but will remain high for a couple of weeks, say flood officials. (Bert Savard/CBC)

A preliminary study of contaminants being swept off the land and into Lake Winnipeg as a result of the 2009 flood is not sounding alarm bells yet, say officials.

Floodwaters typically pick up nutrients, waste from sewage lagoons and even hazardous materials, then carry it all into Manitoba's waterways and eventually, the lake.

Dwight Williamson, assistant deputy minister for ecological services with Manitoba Water Stewardship, told CBC News that data collected so far shows the runoff is not as damaging as it was in the flood of 1997.

"We have just started to receive the early parts of our data set back, so it will be a few weeks before we put together the full story," he said.

What his department has seen so far is encouraging, he added.

"Nitrogen levels are a little bit lower than we saw in 1997. Phosphorus levels as well — 20 per cent lower," said Williamson. "So we have also seen quite a reduction in E. coli or bacteria levels in the Red River downstream of Winnipeg relative to 1997."

Williamson said his division is also monitoring the runoff from at least six sewage lagoons. Many of the flood preparations taken in recent years appear to be mitigating environmental damage, he said.

Tax breaks for the flood-affected

The Canada Revenue Agency is giving a break to people who have been hit by this year's flooding.

Those affected are being given an extra month to file a tax return. Spokesperson Emilia Kotris said late filers will likely not be assessed any penalties or interest — provided they can prove their hardship due to the flood.

"I can't say … that at some point they will not have to provide an explanation," said Kotris.

For those whose situation necessitates the late file, penalties and interest on money owing will not start until after June 1, said Kotris.