Relationships Between the Hydrology, Hydrochemistry, and Ecosystem Characteristics of Urban Headwater Streams in Central Ohio

Headwater streams in urban areas are subject to a variety of physical, chemical, and biological stresses. In addition to being completely or partially buried, they are subject to channelization and other physical alterations that change their natural hydrology. Storm culverts bring contaminants including road salt and fertilizer runoff, and groundwater inputs are often contaminated by leaky sewer pipes or legacy chemicals from industry. These alterations to the physical and chemical environment, along with the introduction of invasive species, can have significant ecosystem impacts, reducing species diversity and abundance.

To assess the role of urbanization on the hydrology, chemistry, and biology of urban headwater streams we sampled 13 streams around Columbus, Ohio. The streams range from minimally impacted (entire length within a state park) to entirely urban. For each stream we selected a 100 - 200 m reach and measured discharge and stream chemistry at the upstream and downstream locations of the reach and then assessed the fish population within the reach. Several reaches had characteristics of a gaining stream, a few were identified as losing reaches, and the rest showed no significant change in discharge. Chloride concentrations correlated strongly with % urban land cover, as expected in an area with heavy road salt application. However nutrient patterns of carbon and nitrogen did not show as strong a correlation with urbanization, suggesting other controls beyond land cover. Planned further work involves comparing stream response to storm water input.