Making a case for wetland inventory

Illegal agricultural drainage is difficult to enforce without a wetland map, says Ducks Unlimited

Finding a wetland in North Dakota is easy — a lot easier than in Saskatchewan.

In North Dakota, one can visit the U.S. Fish and Wildlife Service website at www.fws.gov/wetlands/Data/Mapper.html and find the map that colour codes wetlands in the United States.

Someone who wants to identify wetlands on a specific quarter section of land can zoom in on the map and find the wetlands, both big and small, identified for that field.

The same task is more challenging in Saskatchewan.

A Ducks Unlimited Canada website at maps.ducks.ca/cwi has a map of Canada that shows where a wetland inventory is in progress or complete.

The white regions on the map represent areas that haven’t been mapped.

Southern Saskatchewan is mostly white because only 17 percent of the wetlands in the province’s agricultural region have been formally catalogued.

“The National Wetland Inventory exists for all of the U.S., so they have their baseline inventory. And they have a status and trends program, as well,” said Lyle Boychuk, manager of GIS and inventory programs for Ducks Unlimited Canada on the Prairies.

“They’re quite a bit ahead of us, in terms of inventory.”

The lack of an inventory of the millions of potholes and sloughs in southern Saskatchewan creates problems because wetlands are disappearing.

Many people blame illegal agricultural drainage, and the provincial government introduced new drainage rules in September.

However, it’s difficult to enforce wetland drainage regulations if authorities don’t know the wetland exists.

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“We’ve mapped a lot of wetlands, but we’ve only scratched the surface. There remains a lot of unmapped areas,” said Michael Champion, head of industry and government relations for Ducks Unlimited in Saskatchewan.

“The smaller, half acre, one acre or five acres, we don’t have a full understanding of where they all are.”

The Ducks Unlimited website shows similar progress in Alberta; only a fraction of its agricultural land has been mapped.

Manitoba has inventoried a higher percentage of its wetlands, particularly in the western half of the province.

Boychuk said Ducks Unlimited and the Saskatchewan Water Security Agency are having success in certain regions. Ducks Unlimited has identified several key areas for waterfowl habitat and hopes to complete an inventory of those regions in five years.

However, the mapping progress is intermittent, depending on funding. A stable financial commitment is needed.

The cost is not prohibitive, said Boychuk.

“About $6 to $7 million…. It is doable,” he said.

“It’s been done all over the world, but it’s a huge gap here (in Canada) because it hasn’t been made a priority.”

Mapping wetlands is mostly a matter of manpower.

Boychuk said the province took aerial photos of southern Saskatchewan from 2008-11. Money is now needed to hire staff to interpret the photographs.

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Photo interpreters look at stereo images, or three-dimensional pictures, to identify depressions and wetland vegetation on a field.

“You can obviously see water … vegetation heights and you can see depressions in 3D,” Boychuk said.

“You’re actually viewing a stereo model (of the wetland).”

Field tests have proven that photo interpretation is reliable.

“We were never below 90 percent confidence on our mapping … in terms of, are we collecting all the wetlands, are we calling non-wetlands, wetlands.”

The lack of a comprehensive inventory forces scientists and regulators in Saskatchewan to extrapolate data to estimate broad trends such as wetland loss.

The approach has limited power.

“(You need) publicly accessible data, in the regulatory process, for example, in cases of disputes,” Boychuk said. “It always works out that wherever you have data, (it’s) right next door is where you need it.”

WSA spokesperson Patrick Boyle said Saskatchewan is changing its policies and approach to drainage.

“As part of that, we … are working with pilot projects in the southeastern part of the province … to understand how to develop policy out of those (pilot projects),” he said. “One of those policies … is wetland policy for agricultural land.”

Boyle said the province, in collaboration with Ducks Unlimited, is making progress on a wetland inventory.

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