A drainage project underway in Huron County could change the way excess water on hilly fields is managed in a way that benefits farmers and the environment.
The Huronview project will feature controlled drainage, where lateral tiles are laid on the contours of the land with gates that can start and stop the flow of water. Gentle terraces are designed to direct water horizontally across a slope, to a grassed waterway, to limit erosion. There will also be a trial to test 15-foot versus 30-foot width between tiles.
Why it matters: It has been more difficult to justify tile drainage in rolling terrain, as slope already provides drainage, although it can also cause erosion. This project looks at new ways of managing tile drainage in several situations.
The project on the 47-acre site is a partnership of many organizations and businesses. The Huron Soil and Crop Improvement Association is leading the project, having rented the farm for the past several years for a minimal price from the County of Huron, which owns the land. The Canadian Agricultural Partnership, the funding mechanism for agriculture for the federal and provincial governments, provided much of the funding. Local drainage contractors include Roth Drainage, KMM Drainage, Williams Drainage and Parker& Parker through the Land Improvement Contractors of Ontario. Plastic tile supply companies are partners and the Ausable Bayfield Conservation Authority is also involved.
The site is part of a 100-acre watershed including adjoining farms and drains into the nearby Bayfield River. There are a couple of wetlands on the property too.
Project planner Jeremy Meiners, of the Illinois-based AGREM LLC., has managed controlled drainage along contours and created terraces throughout the U.S. and in other places in the world.
He says that knowing the goals of a farmer in a drainage project is key. However, the project should be able to both increase yield and help a farmer better manage their soil and nutrients inputs.
“When the goals of growers and the goals of society align, it is a win-win situation,” he said during an open house at the project on June 13.
About 350 farmers, drainage contractors and interested local officials toured the project on yet another gray, cool Saturday, while drainage contractor equipment tiled and levelled the fields.
A farm with some history
The farm, located just outside of Clinton, has been owned by the County of Huron since the 1800s where it once was a home of refuge for the disabled and the poor. Residents worked the land to grow their food. A stone cairn commemorates people who died while living there.
The property is now the home of the Huronview home for seniors, and the offices of Huron County Health Unit.
Behind the buildings is farmland that the county has rented to farmers for three-year terms for generations. Over the last few years the county has partnered with the Huron County Soil and Crop Improvement Association for research.
Combination systems are becoming more common in the U.S. Traditionally, in the southern U.S., they’ve used surface drainage – terracing and grassed waterways and ditches – while in the northern U.S., tile drainage is more common. The trend is to using both where it makes sense. Terracing is at a low slope, so the slope is still workable, but the water runs laterally across the face, to a grassed waterway or a tile inlet, says Melisa Luymes, manager of the Huronview Project for the HSCIA.
She says it’s like downhill skiing. The first time you try it you might head straight down the hill, but then you figure out that it’s better to ski crossways back and forth across the slope.
Meiners says the terraces are at a 1.5 to two per cent slope and especially help during heavy rainfall events when topsoil is washed down the slope.
Hickenbottom inlets, which take surface water into the tile system, can be used to move water from low areas.
A closed-loop system will also work at the Huronview site as there are reservoirs in the form of wetlands that can receive drainage water. Meiners has also installed some biodigester systems where nutrients are captured in woodchips at the end of the tile.
Wetlands can also be used to manage runoff and might be a positive spinoff from the use of more controlled drainage. The best-case scenario is when the captured runoff is used for field irrigation or pumped back into a tile system for subsurface irrigation.
The contoured controlled drainage system installed at Huronview confronts the challenge of gravity when installing drainage.
“Controlled drainage has a serious problem,” says Meiners. “It requires a very flat field.”
Too much slope and the water pressure created in the system will blow out the tile.
Only about three per cent of land is flat enough for traditional controlled drainage. Some has been tried in flat Essex County, but the laterals need to be at a .1 per cent slope in order for it to work. The only way for that to happen on rolling topography is with the tiles laid along the contours at variable depths to maintain the .1 per cent slope. A tile map for contour controlled drainage looks significantly different than a traditional map of a tiled field.
In the controlled drainage section of Huronview, control gates are located at the end of the tile run in each elevation zone. Several different types are on the market, ranging from a manual gate to one that is expected to work with moisture sensors, although Meiners doesn’t think the technology is there yet.
“When the gate is open it is a drainage system. When it is closed you can raise the water table in your farm to a desired level,” says Meiners.
In other words when the land needs to be dry for planting, drain it, then put in the gates to keep the water in the field for the growing plants. Sometimes a high summer rainfall event might mean the need to open the gates. The system requires maintenance.
There’s funding available in the U.S. in some areas for farmers that keep their control gates closed during fertilizer application period to reduce runoff, says Meiners.
The next step is to put water back into the system during dry periods as subsurface irrigation. That’s much tougher in a control system on a slope, although Meiners said if the water was put in at the top of the hill, then it could work.
Three tile drainage trends
Consultant Jeremy Meiners says he’s seeing three main land drainage trends around the world. Portions of all three will be on display at Huronview.
- Combination systems with subsurface and surface drainage in the same field
- Closed loop, where subsurface water is drained to a holding pond, constructed wetland or a bioreactor
- Contour controlled drainage: drainage that can be turned on and off on rolling topography.