Title: Effect of surface inlet type on suspended sediment transported through a subsurface drain tile system Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 15, 2011
Publication Date: October 13, 2011
Citation: Papiernik, S.K., Feyereisen, G.W., Krueger, E.S., Baker, J.M., Wente, C.D. 2011. Effect of surface inlet type on suspended sediment transported through a subsurface drain tile system. Abstracts, 2011 Eastern South Dakota Water Conference, Brookings SD, October 13, 2011, p. 23. Technical Abstract: Throughout the Prairie Pothole Region, subsurface tile and surface inlets are used to remove water from low-lying or poorly-drained soils. Open inlets are being increasingly converted to buried inlets in which perforated tile is placed in a trench of rock (i.e., a French drain) and buried below a layer of soil. We are conducting experiments to evaluate the dynamics of water and nutrient flow in two tile-drained fields. We evaluated the transport of sediment in tile drainage in four consecutive years, three years with open inlets and one year after conversion to buried inlets. Results showed that when open inlets were present, sediment concentrations averaged 310 mg/L for the snowmelt period (February through April) and 170 mg/L during the non-snowmelt period (May through January). Maximum concentrations averaged 1450 mg/L during snowmelt and 5980 during non-snowmelt. In the first year after inlet conversion, sediment concentrations averaged 428 mg/L (maximum 4770 mg/L) during snowmelt and 34 mg/L (maximum 590 mg/L) during non-snowmelt. Disturbance of the soil during the inlet construction may have resulted in no reduction in average or maximum sediment concentration during snowmelt in the first year. After the snowmelt period, maximum and average sediment concentrations were only 10% and 20%, respectively, of the average of the three years prior to inlet conversion. Results for the second year after inlet conversion are currently being analyzed, and sediment loads are being calculated for each year of the study. These results will indicate whether buried tile inlets decrease sediment transport via tile drainage, potentially extending the life of the subsurface tile system and decreasing the outlet concentrations of sediment and associated contaminants.