Water Quality Variability in a Bioswell and Concrete Drainage Pipe, Southwest Lincoln, Nebraska

Abstract The goal of this project is to evaluate the effectiveness of bioswells in protecting water quality from urban runoff. The hypothesis tested in this project is that water in bioswells improves water quality. Water quality in both a bioswell and an underground concrete lined ditch, both containing ground and surface water, were tested for certain water quality parameters. These parameters consisted of: Dissolved Oxygen, pH, water temperature, weather temperature, Total Dissolved Solids, Specific Conductivity, Alkalinity, Total Dissolved Carbon, Chemical Oxygen Demand, and depth and width of the sampling site. An additional contaminant that was looked at was motor oil. This was measured by comparing Total Organic Carbon with Chemical Oxygen Demand. A variety of different methods to measure the water quality parameters were utilized. The concrete site had more stable readings, but much higher water temperatures. However, the bioswell water is mainly from surface water runoff, and the underground concrete lined pipe is from underground water, so the two cannot be directly compared. The bioswell had high readings, especially pertaining to Oxygen Demand, Total Organic Carbon, and Specific Conductivity in early test dates. But, these readings improved as they were filtered though the bioswell. As plant activity increased and the weather began to warm up there were more stable readings. It is concluded that bioswells are an effective way to reduce problems associated with urban runoff pertaining to certain water quality parameters.

Minimun Riparian Buffer Width for Maintaining Water Quality and Habitat Along Stevens Creek

ABSTRACT Riparian buffer zones are important sites of biodiversity, sediment trapping, pollutant removal, and hydrologic regulation that have significant implications for both people and wildlife. Urbanization’s influence on and need for adequate water quality increases the need for careful planning in regards to riparian areas. Wildlife are key components in the ecosystem functions of riparian zones and require consideration in peri-urban planning as well. This study reviews relevant literature to determine the recommended minimum riparian buffer width for maintaining water quality and habitat along Stevens Creek in Lincoln, Nebraska. Only sources that listed a specific purpose related to water quality and habitat for their buffer width recommendations were considered. The study found that the baseline buffer width recommended for Stevens Creek that would be adequate for both water quality maintenance and basic habitat is 50 ft (15 m) per side. This number may be modified based on other factors such as slope, soil particle size, adjacent land use, the presence of certain wildlife communities, stream size, and stream order.