Date of Award
Master of Science (MS)
Silver Bow Creek (Blacktail Creek to Warm Springs Creek) is listed as impaired for nitrates, total nitrogen and total phosphorus in the Montana 2014 draft 303(d) list. Blacktail Creek, a head water to Silver Bow Creek, flows approximately 17 miles before joining Silver Bow Creek in Butte, MT. Previous studies have shown that nutrient concentrations in Blacktail Creek are significantly higher than the Montana Department of Environmental Quality (DEQ) target concentrations. In the literature, constructed (treatment) wetlands have been popularly used as an effective Best Management Practice (BMP) to process nutrients from municipal, industrial, and livestock wastewater. While there has been enough research conducted on the effectiveness of constructed (treatment) wetlands in processing nutrients, little research has been conducted on riverine wetlands that are hydrologically connected to streams. For this study we have chosen a historically excavated wetland (KOA wetland) within the flood plain of Blacktail Creek. This study investigates the hydrologic connection between Blacktail Creek and the KOA wetland as well as the nutrients removal potential of the KOA wetland. The hydrologic connection between Blacktail Creek and the riverine wetland was evaluated using two approaches: wetland inundation modeling using HEC-RAS and an analysis of water surface changes. Further validation of the HEC-RAS model is required, but this study found a limited hydrologic connection (both surface and sub-surface) from Blacktail Creek to the KOA wetland. Based on this determination it is likely that the riverine wetland currently offers limited potential for processing of Blacktail Creek’s nutrients. Nutrient sampling of the riverine wetland and adjacent Blacktail Creek during the study has shown that the KOA wetland does not contribute nitrite+nitrate and may actually serve to process nitrogen, but is a potential source of phosphate to the stream. This study is significant as restoration of Blacktail Creek is ongoing and an improved understanding of the hydrologic connection between Blacktail Creek and existing riverine wetlands can potentially aid in meeting target nutrient concentrations.
Ball, Jonathan, "AN ASSESSMENT OF THE HYDROLOGIC CONNECTION BETWEEN BLACKTAIL CREEK AND A RIVERINE WETLAND FOR NUTRIENTS PROCESSING POTENTIAL" (2015). Graduate Theses & Non-Theses. 42.