Progress Report: Land Use and Wetland Drainage Effects on Prairie Water Quality Study

© Centre for Hydrology, University of Saskatchewan, Saskatoon, Saskatchewan, January 2009This report is an update on progress made to the end of December 2008. According to our study plan, we should have completed one summer worth of data collection and made progress in laboratory analytical work. Outlined in the report are data collection methods and progress to date made on our research objective of “determining changes in water quality of streams and impacts to ecosystem function associated with wetland drainage”. Considerable progress toward the research objective was achieved during the reporting period, and overall, the project is on schedule. Smith Creek was broken down into its tributaries (North Fork, South Fork and Thingvalla). Water samples at the outlet and tributaries of Smith Creek were taken on 35 occasions during the spring, summer and fall. Chemical analysis of these samples is 70% complete. The wetland for the drainage experiment was selected and instrumented with an electronic water level recorder and precipitation gauge. A bathymetry survey of the wetland was carried out and used to compute the volume of water stored in the wetland at different water levels. Water chemistry for the wetland was analyzed 29 times during the spring, summer and fall. Preliminary results show concentrations of DOC increased over the spring and early part of the summer as the wetland evaporated. Concentrations then fell to post-snowmelt values during the unusually wet late summer period. The wetland was drained this fall ahead of schedule due to the needs of the landowner. Once drained, the wetland lost 42% of its volume within 22 hours. Preliminary findings were that the drain was a source of TP during the first 2.5 hours and then transitioned to a sink. The Benthic Entomology (BENT Lab) of the Saskatchewan Watershed Authority (SWA) provided a preliminary assessment of the biotic health in the Smith Creek watershed. Sampling was conducted in spring 2008, and the progress of this assessment is as follows: a) Four sites were sampled in the watershed; b) 83% of all samples have been processed and identified; c) to date, a total of 9,669 individuals have been identified, representing 80 taxa; and d) of the samples processed, they are characterized primarily by pollution-tolerant fly larvae, and fast growing non-insect taxa typical of seasonal prairie streams. SWA is now preparing plans for additional assessment in 2009, and further evaluation of 2008 results using a reference condition approach and test site analysis in order to obtain robust measures of ecosystem health in the Smith Creek watershed