Characterization of Habitat Quality and Hydrology of An Urban Stream Prior to Low-Head Dam Modification, Springfield, Ohio

Buck Creek and its tributary, Beaver Creek, flow through Springfield, OH (pop. 63,000), passing over a series of low-head dams that historically protected utilities and diverted water. The Springfield Conservancy District is exploring recreational enhancements along a continuous seven-mile reach associated with removal or modification of four of the dams. Issues being addressed for federal, state, and city agencies include flood hazards, wetland soils, endangered species, historic properties and sites, combined sewer overflows, and stream integrity. Prior to dam removal, we have conducted an assessment of the stream reach using OEPA's Qualitative Habitat Evaluation Index (QHEI) and locally-derived hydrologic data in combination with data from USGS gaging stations and USACE outflow reports from an upstream flood-control dam and reservoir, the purpose of which is to evaluate the potential for improving stream function during modification of the dams. QHEI values were determined upstream and downstream for each of the four dams. QHEI values do not vary significantly, ranging from 57-67 (out of a maximum of 100), and no trends are apparent, either along the entire reach or between upstream and downstream sites. The scores reflect variability within individual metrics, some better upstream of the lowhead dam, others downstream, but overall are dominated by the substrate metric. The study reach is located in glacial outwash, and D50 of the substrate ranges from medium to coarse gravel. Buck Creek flow is regulated by the upstream flood-control dam and has not exceeded the pre-dam 1.5-yr discharge by even half since its construction, but it has not caused the substrate to be embedded. Over the past year, flow contribution from Beaver Creek has exceeded the pre-dam 1.5-yr discharge of the combined Buck and Beaver Creek at least three times and conditions along most of the study reach indicate the channel substrate was mobilized.