See the Latest Water Quality Monitoring Data from the FoRR Monitoring Team!

FoRR took to the river on August 21 to monitor three sites in the Reedy River watershed. Our sites include the following:

Site #1: Reedy River just downstream of Swamp Rabbit Cafe

Site #2: A small tributary of the Reedy River in Falls Park 

Sit #3: Reedy River on Mauldin Road upstream of ReWa's headquarters

The pH results for August were consistent with our findings in July, with sites only showing small decreases from last month’s results. 

The air and water temperatures for August’s sampling event increased again, but with much smaller margins of increase than last month. The air temperatures at all three sites ranged from 24C to 27C and the water temperatures ranged from 23C to 24C. This month’s results show an average air temperature increase of 0.83C and 0.33C increase in water temperatures across all three sites. The overall average air temperature was 25.67C (compared to 24.83 last month) and the overall average water temperature was 23.5C (compared to 23.17 in July). 

August’s dissolved oxygen (DO) results remained fairly consistent across the three sites, with both Mauldin Road and Swamp Rabbit Cafe showing slightly increased DO levels (this is a good thing!) and Falls Park showing a slight decrease. Mauldin Road’s DO levels increased by 1.0 mg/L and Swamp Rabbit Cafe’s DO increased by 0.5 mg/L. Falls Park, on the other hand, decreased by 1.0 mg/L to only 5.4 mg/L. We noted low flow at the Falls Park location. This site is on a tributary to the Reedy River instead of on the River itself like our other two sites. Low water flow can contribute to low DO levels since one of the ways oxygen is introduced to stream water is through turbulent or “well-mixed” areas in the streams that “stir” oxygen into the water (known as riffles). When there is very little turbulence or mixing, on the other hand, it becomes difficult for oxygen to become incorporated into the water, resulting in lower levels of dissolved oxygen. We can infer that this is one factor contributing to the lower DO levels in Falls Park this month and the main reason that the other two sites do not show the same DO level decrease this month. The average of the DO results at all three sites is 6.37 mg/L, up 0.17 from July’s average DO level. 

The E. coli bacteria results were much higher in August than they were in July. July’s results ranged from only 200-267 cfu/100mL at all three sites, whereas August’s results ranged from 367-467 cfu/100mL. Swamp Rabbit had the lowest bacteria count this month at 367 cfu/100mL, Falls Park came in at 400 cfu/100mL, and Mauldin Road had 467 cfu/100mL. While these results are higher than the “high” threshold of 349 cfu/100mL, and certainly higher than our results in recent months, they fortunately do not exceed the “problematic” threshold of 1,000 cfu/100mL. Many other volunteers within the Reedy Watershed have also been registering higher-than-usual bacteria levels while sampling this month. Sometimes, even with the flow levels being somewhat low overall, the flashy summer storms can cause untreated waste to be introduced into the water system during periods of flash flooding or when large amounts of runoff are introduced to the river at once. This could be the case due to the high frequency of afternoon storms with large amounts of rain falling very quickly in the last month. In addition to flashy storms introducing new bacteria, low flow periods can cause the levels of bacteria in the water to appear more concentrated due to the lesser volume of water present to dilute the bacteria. We are keeping a close eye on any potential “hot spots” where bacteria may be entering our waters and will continue to report back if we identify any issues. We hope to see E. coli levels return to normal (under 349 cfu/100mL) next month. 

This month's turbidity remained fairly consistent with last month’s results. Falls Park and Mauldin Road showed no change again and both had levels of 5 NTUs, the same turbidity reading we measured in June and July. Swamp Rabbit Cafe decreased to 5 NTUs as well, down 2 NTU’s from last month’s result of 7 NTUs. This means the water was fairly clear at all three locations this month. 

August's results and the SC state standards are included for comparison below. All results were within SC state standards. 

August 2023 Monitoring Results: