The Lewis Center tributary enters the Olentangy River at RM 18.19. It drains less than 10 square miles in Delaware County. The Ohio EPA monitored this tributary in 1999 at RM 0.10. The results are listed in the table below. This is a perennial stream (flows all year long). The effect of nearly every stressor within the basin was likely made more acute by significantly diminished stream flow within the entire catchment (EPA pg. 59). As classified by the Palmer Drought Severity Index, severe to extreme drought conditions were indicated for the period between July and October 1999 (Ohio DNR 1999) Big Run Preserve is a 75 acre area along Big Run that is within the Delaware County Preservation Parks system. FLOW partnered with Preservation Parks naturalists to conduct a bird survey in July of 2008 for the Ohio Bird Atlas. More information on the park can be found at: http://www.preservationparks.com/parks/brp.asp