Quantifying Controls on Stormwater Quality in Red Butte Creek
Location
Logan Country Club
Start Date
3-28-2017 4:15 PM
End Date
3-28-2017 4:20 PM
Description
Increased urbanization associated with population growth alters the amount, routing, and quality of stormwater runoff. This study quantifies how these processes interact to influence stormwater runoff from the University of Utah’s Research Park into Red Butte Creek. We focused on two adjacent stormwater outlets, Dentistry and Connor Road, which have sewersheds of 129 acres and 67 acres respectively. From October 2015 to November 2016 we sampled precipitation, stormwater runoff from rooftops, parking lots, roads, and turf grass, and stormwater culverts during 11 storm events. Precipitation depth and culvert discharge data were collected at regular intervals via iUTAH in situ sensors. During storm events the first pulse of stormwater runoff from these urban land covers has 3-30 times higher dissolved organic carbon and 2-3 times higher total dissolved nitrogen concentrations than precipitation. Surprisingly, the first pulse signature observed from runoff directly from urban land covers differs between stormwater culverts. During storm events, stormwater at the Dentistry culvert has elevated levels of solutes during the first flush that decrease over time, presumably due to solute source limitation. Consistent with a quick flushing event, event stormwater discharge at Dentistry culvert ends within 0.5-3 hours following cessation of precipitation. However, after a storm event stormwater discharge at Connor Road decreases to a baseflow rate observed even during long periods with no storm events. This causes the first flush to appear diluted and, as the storm wanes, solute concentrations increase towards concentrations measured in non-storm event. Concentration patterns in base cations suggest that stormwater runoff from Connor Road interacts with shallow subsurface water. These observations demonstrate that adjacent sewersheds with similar land use may exhibit very different hydrological and hydrochemical responses to rainfall. As a result, the amount and quality of stormwater is then affected by both urban land cover how runoff interacts with subsurface structure en route it to the stream.
Quantifying Controls on Stormwater Quality in Red Butte Creek
Logan Country Club
Increased urbanization associated with population growth alters the amount, routing, and quality of stormwater runoff. This study quantifies how these processes interact to influence stormwater runoff from the University of Utah’s Research Park into Red Butte Creek. We focused on two adjacent stormwater outlets, Dentistry and Connor Road, which have sewersheds of 129 acres and 67 acres respectively. From October 2015 to November 2016 we sampled precipitation, stormwater runoff from rooftops, parking lots, roads, and turf grass, and stormwater culverts during 11 storm events. Precipitation depth and culvert discharge data were collected at regular intervals via iUTAH in situ sensors. During storm events the first pulse of stormwater runoff from these urban land covers has 3-30 times higher dissolved organic carbon and 2-3 times higher total dissolved nitrogen concentrations than precipitation. Surprisingly, the first pulse signature observed from runoff directly from urban land covers differs between stormwater culverts. During storm events, stormwater at the Dentistry culvert has elevated levels of solutes during the first flush that decrease over time, presumably due to solute source limitation. Consistent with a quick flushing event, event stormwater discharge at Dentistry culvert ends within 0.5-3 hours following cessation of precipitation. However, after a storm event stormwater discharge at Connor Road decreases to a baseflow rate observed even during long periods with no storm events. This causes the first flush to appear diluted and, as the storm wanes, solute concentrations increase towards concentrations measured in non-storm event. Concentration patterns in base cations suggest that stormwater runoff from Connor Road interacts with shallow subsurface water. These observations demonstrate that adjacent sewersheds with similar land use may exhibit very different hydrological and hydrochemical responses to rainfall. As a result, the amount and quality of stormwater is then affected by both urban land cover how runoff interacts with subsurface structure en route it to the stream.