Big Run

Big Run is a tributary of Weeping Rock Creek. It merges with Weeping Rock at RM 0.43 of Weeping Rock.


2021 sampling sites (A & B)

2021 monitoring data for Big Run site A (Macroinvertebrate Cumulative Index Value rating: excellent)

2021 monitoring data for Big Run site B (Macroinvertebrate Cumulative Index Value rating: good)

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:

FLOW Water Stewards are monitoring Big Run three times a year (spring, summer and fall) at two locations in Shale Hollows park. The Big Run stream winds along a twisting corridor lined by 20- to 40-foot-tall shale cliffs. You can see many remnants of concretions (round rock formations) in the cliffs and along the stream bed. Our citizen scientists monitor water chemistry parameters such as total dissolved solids, conductivity, salinity, hardness, alkalinity, nitrate, phosphates and others. The overall water quality is good, with average total dissolved solids 563 mg/l (just above the desired <500 for healthy streams), conductivity 706 uS, healthy salinity levels of 408 ppm, total hardness 245 ppm and total alkalinity 218 ppm. The nitrates are around 2 ppm which indicates nutrient enrichment, and phosphates are 0 ppm. FLOW water stewards also monitor macroinvertebrate diversity in water and though their results indicate fair to good water quality (SQM index average of 14), volunteers saw mayfly and stonefly nymphs, water pennies larvae, caddisfly and alderfly larvae, and riffle beetles (indicators of good water quality), in addition to scuds, damselfly nymphs, sowbugs and other organisms. Our water stewards' data can be found below in excel spreadsheet named Big Run data.

Big Run monitoring data.xlsx