Agriculture

High tech land maps make water management easier

New tool pinpoints best places for water storage


LiDAR will help executive director Armand Belanger find locations for future wetlands in the East Interlake Conservation District.

Armand Belanger is excited to be fighting algae with lasers. As the manager of the East Interlake Conservation District (EICD), Belanger has been busy rolling out a new LiDAR tool that can be used to help municipalities and landowners plan better water management within the district's watersheds.

The Light Detection and Ranging Watershed Project Planning (LiDAR) tool uses lasers mounted on aircraft to create highly accurate elevation maps of the terrain. Those maps show in detail how water drains off the land into waterways and then into Lake Winnipeg.

"This tool will allow us to know exactly where in the watershed to place and implement better land management practices, such as the construction of new wetlands," said Belanger. Wetlands have been proven to be important to preventing excess nutrients from entering the lake and causing massive, destructive algae blooms.

Improving water management practices in the conservation district has been a priority for several years, but until now planners had few means to accurately determine the best locations to adopt practices such as restoring wetlands. Conservation districts have traditionally depended on landowners coming forward on their own to identify potential locations for water storage or drainage solutions.

"Every year, about 10 landowners come to us to ask about retaining water on their properties," said Belanger, adding that the EICD has an open-ended application process for landowners to propose enhancements to their properties such as habitat creation or wetland preservation. "We would go out and survey those properties and may go with one of them every year. But this tool allows us to know exactly where to place these projects, so now we can go directly to the landowners and show them why a wetland makes sense on their land."

Belanger and the EICD received funding from the Growing Assurance program to use the LiDAR tool and its associated software application. It's a technology that can benefit both the environment as well as farmers seeking more information about the drainage on their properties.

"Through Growing Forward 2, we've been working with conservation districts to restore or improve wetlands and increase adoption of other beneficial practices that serve to increase ecological goods and services," said Colleen Wilson, landscape stewardship specialist with Manitoba Agriculture, Food and Rural Development. "If you're slowing down the water you can prevent some of the nutrients from getting into the lake. We're encouraging conservation districts to link up with landowners on projects that can have a lot of public benefit and also potentially private benefit."

Transformative system in the U.S.

Wilson said EICD's LiDAR project was intriguing because it had already been used in the Red River Valley on the American side of the border. She wants to see the technology used to speed up the process of identifying suitable locations and developing good water management practices for the province. It's a system that other conservation districts may soon be clamouring for.

"This system has literally transformed the way we manage water and the way we look at water," said Chuck Fritz, Director of the International Water Institute (IWI) in Fargo, North Dakota. The IWI created the tool with the help of Houston Engineering and put it into use in 2007 to map parts of the Red River Valley in the United States. "We're able to apply best practices to improve water quality in ways we never could before without the data."

Fritz and the IWI made all the maps freely available, which was a boon to area farmers who appreciated the sudden access to excellent maps. He said it is useful for farmers who want to use certain precision agriculture technology and tools. Previously, farmers had to pay significant sums of money for things such as GPS data and elevation maps before using precision agriculture methods to enhance yields. With the maps free and easily accessible, it removes that barrier and allows farmers to begin using technology that was previously out of reach.

But even before farmers make a leap to new precision technology, the LiDAR data is exciting them for more basic land use reasons. Like many parts of the province, the Interlake has suffered a lot of flooding in recent years and farmers need better elevation data to improve drainage.

"It's a great tool for the whole area," said Frode Anderson, a grain farmer in the Bifrost area. "It will be good if we can get a better idea of where the actual flows are and which way the land slopes. As a landowner it will be nice to be able to get a picture of that quarter section and it will tell me exactly how to drain that quarter properly."

What exactly is LiDAR?

LiDAR is the nickname given to the Light Detection and Ranging Watershed Project Planning tool. The tool used by the East Interlake Conservation District was pioneered by the International Water Institute in Fargo, North Dakota for use in mapping the Red River Valley.

The LiDAR tool creates detailed topographical terrain maps showing land elevations. It is ideal for planning water management practices because it provides highly specific details on how water drains off land into watercourses. This gives planners and landowners information they need to enhance water storage features such as wetlands and identify where excess nutrients are running off the land into waterways.

The system uses a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light. Using a laser mounted in an aircraft, data is fed into special software that creates highly accurate high-resolution maps of landscapes. It can even identify levels of phosphorous and nitrogen.

Help against flooding

Belanger appreciates that farmers want to learn how to drain land better, but he's looking for it to help spot areas where farms can store water for longer. It's a balancing act that the technology makes possible. Belanger has already used the system to identify Anderson's farm as one possible site for future water retention projects. They want to expand an existing slough on his property to retain excess water.

"We've been flooded in this area so many times," said Anderson. "It will help if we can hold the water back until the (natural) drainage system can handle these huge rains that we've been getting."

The tool is so accurate that it can accurately map land down to five metre grids. By providing elevations and taking into account culverts, roadways and other obstacles, the tool gives planners a near perfect picture of water drainage over large areas of terrain. It can also provide estimates of nitrogen and phosphorous on the land, which is also vital information when trying to find suitable locations for water quality projects.

"We're the conservation district that is closest to Lake Winnipeg, so we want to lead by example," said Belanger. "Over time, we'll see a reduction in peak flows and be able to better manage those flows. That will help us reduce the nutrients entering the lake which will lead to a reduction of algae."