Stony Run (Buffalo Creek tributary)

Stony Run is a tributary of Buffalo Creek in Union County, Pennsylvania, in the United States. It is approximately 3.3 mi long and flows through West Buffalo Township and Buffalo Township. The watershed of the stream has an area of 1.46 sqmi. The stream is impacted by nutrient pollution, sediment, E. coli, and thermal radiation. The watershed mostly consists of forested land and agricultural land. It is designated as a High-Quality Coldwater Fishery and a Migratory Fishery. The stream also has a healthy population of benthic macroinvertebrates.

Course
Stony Run begins in West Buffalo Township. It flows east-southeast through a broad valley that it shares with Rapid Run. After more than a mile, the stream enters Buffalo Township. Here, it turns southeast for several tenths of a mile before receiving an unnamed tributary from the left. It then turns southwest for several hundred feet before turning east-southeast again. After several tenths of a mile, it turns southeast and a few tenths of a mile after that, it reaches its confluence with Buffalo Creek.

Stony Run joins Buffalo Creek 9.68 mi upstream of its mouth.

Hydrology
Stony Run is impacted by nutrient pollution, sediment, E. coli, and thermal radiation.

In 2000, the sediment load of Stony Run was 89897 lb, while in 2008, it was 83827 lb. This equates to less than 100 lb/acre. However, the annual sediment load could in the future be reduced by 68.43 percent to 26467 lb. In 2000, row crops and streambank erosion contributed 46974 and 33173 lb of sediment, respectively. A total of 4438 lb came from hay and pastures, 2710 lb came from low-density urban land, and 2602 lb came from other sources.

In 2000, the load of nitrogen in Stony Run was 8325 lb and in 2008 it was 8231 lb. This equates to between 5 and 10 lb/acre. The annual load of nitrogen could be reduced by as much as 36.17 percent to 3254 lb. In 2000, 2131 lb of nitrogen came from groundwater/subsurface water. Another 483 lb came from row crops and 224 lb came from hay and pastures. 27 lb came from low-density urban land, 15 lb came from septic systems, 2 lb came from streambank erosion, and 79 lb came from other sources.

The phosphorus load of Stony Run in 2000 was 378 lb and in 2008, it was 370 lb. This equates to about 0.4 lb/acre. However, the phosphorus load could be reduced by 46.22 percent to 199 lb per year. In 2000, row crops contributed 64 lb of phosphorus to the stream, while groundwater/subsurface water contributed 53 lb and hay and pastures contributed 22 lb. A total of 4 lb came from low-density urban land, 2 lb came from septic systems, 1 lb came from streambank erosion, and 4 lb came from miscellaneous sources.

Geography and geology
The elevation near the mouth of Stony Run is 505 ft above sea level. The elevation of the stream's source is between 680 and 700 ft above sea level.

There are no fences along any streams in the watershed of Stony Run. However, there could eventually be 1.0 mi of fences. No stream reach in the watershed has stabilization, but up to 4.0 mi could potentially be stabilized. Forest Hill is located near the headwaters of Stony Run.

A debris fan from the late Pleistocene occurs in the vicinity of Stony Run.

Watershed
The watershed of Stony Run has an area of 1.46 sqmi. The stream is entirely within the United States Geological Survey quadrangle of Mifflinburg. There are a total of 4.0 mi of streams within the watershed. Of these, 1.0 mi are on agricultural land. The mouth of the stream is near Cowan.

A total of 61 percent of the watershed of Stony Run is on forested land. Another 32 percent is on agricultural land and 3 percent is on impervious surfaces. The area of land on impervious surfaces could potentially rise to 30 percent. The agricultural land in the watershed includes 195 acre of row crops and 143 acre of hay and pastures.

None of the agricultural land in the watershed of Stony Run is on slopes of more than 3 percent. There are no unpaved roads in the stream's watershed.

The watershed of Stony Run makes up 1 percent of the Buffalo Creek drainage basin.

History
Stony Run was entered into the Geographic Names Information System on August 2, 1979. Its identifier in the Geographic Names Information System is 1188794.

The John Umstead tract, which was located along Stony Run, was surveyed by Thomas Sutherland on May 17, 1770.

In a 2008 report, the watershed of Stony Run was ranked tenth amongst sub-watersheds in the Buffalo Creek drainage basin for restoration priority.

Biology
The drainage basin of Stony Run is designated as a High-Quality Coldwater Fishery and a Migratory Fishery. The stream has a population of benthic macroinvertebrates that has been described as "healthy".

There are 0.2 mi of vegetated riparian buffers along streams in the watershed of Stony Run.

The pathogen load in Stony Run is on the order of 6.842 × 1015 organisms per month. The largest contributor of pathogens is urban areas (6.738 × 1015 organisms per month). Farm animals contribute 1.034 × 1014 organisms per month, septic systems contribute 3.287 × 1011 organisms per month, and wildlife contributes 1.745 × 1011 organisms per month. The pathogen load could in the future be reduced by 1.16 percent to 6.762 × 1015 organisms per month.