An assessment of agricultural stream designs used in maintenance operations in Quebec
In agricultural watersheds, many meandering rivers were straightened and several rectilinear ditches were added to the drainage network in order to evacuate water as quickly as possible in the spring to improve farm productivity. The design of these modified channels was not based on natural river dynamic concepts, which include both discharge capacity and sediment transport, and thus need to be maintained frequently as they tend to adjust by eroding their banks and returning to a sinuous pattern. The objectives of this research project are to provide a critical analysis of several existing agricultural channel designs in the Montérégie region (Quebec) and to propose alternative solutions which would require less maintenance in the future and which may result in improved water quality in agricultural watersheds. Numerical modelling and field data will be used to better understand flow dynamics and sediment transport in these modified channels, and to make suggestions for improvements in the channel design.