Controlled Drainage – Area Landowners Taking Interest 

The Upper Thames River Conservation Authority (UTRCA) has been actively involved in controlled drainage projects over the past several years.  

What is controlled drainage? In much of Southwestern Ontario, crops grown on fine-textured and poorly drained soils require artificial drainage for optimum crop production. A dual-purpose subsurface drainage system can drain away excess water in wet periods and hold water for crop use in dry periods. Additionally, holding water in the soil profile can help keep some nutrients from escaping through the tile system. Controlled drainage utilizes in-line water level control gates installed along the tile lines to allow for free drainage or to block water flow and raise groundwater to a desired level. Typically, the gates are removed for planting and harvesting needs and installed at other times of the year. 

The first installation within the Upper Medway Creek subwatershed was installed over five years ago on a very flat field. This project has been monitored by Agriculture and Agri-Food Canada staff, and a report on findings is expected in 2023.  

This past year, we took the technology further by designing and installing a controlled drainage project on the UTRCA Demonstration Farm near Thorndale. This project is laid out on a sloping field with the tile runs on the contour and control gates at 450 mm vertical spacing. We will begin monitoring this field in 2023. Since most farmland in the watershed has slopes, if this approach proves to be practical, it must be suited to slopes of up to 3%. 

More recently, there has been interest by landowners in modifying or retrofitting existing tile drainage systems to provide crops with water during dry periods and decreasing the amount of nutrients escaping through the tile system. Controlled drainage was a “hot topic” at the London Farm Show as well as at the two Landowner Workshops held this March in Ilderton and Mitchell. Len Duynisveld, a nearby farmer, worked with stewardship staff and McCutcheon Farm Drainage to modify their tile drainage system with very positive results. Find out more about Len’s comments in the LEADS: Duynisveld Enterprises Video.