South Branch Tunkhannock Creek is a tributary of Tunkhannock Creek in Lackawanna County and Wyoming County, in Pennsylvania, in the United States. It is approximately long and flows through Scott Township, Benton Township, North Abington Township, and La Plume Township in Lackawanna County and Clinton Township, Factoryville, and Tunkhannock Township in Wyoming County. The watershed of the creek has an area of . The creek's named tributaries include Trout Brook, Ackerly Creek, and Kennedy Creek. South Branch Tunkhannock Creek is not designated as an impaired waterbody and has relatively good water quality.
The topography of the watershed of South Branch Tunkhannock Creek has been described as "rough and hilly" and the underlying geology consists of interbedded sedimentary rock. There is a gorge with a depth of on the creek at one point. Major land uses in the watershed of South Branch Tunkhannock Creek include forested land and agricultural land. Some natural gas drilling is also done in the watershed. Historical industries in the area included agriculture and summer resorts. The Delaware, Lackawanna and Western Railroad also passed through the creek's watershed.
The main stem of South Branch Tunkhannock Creek is designated as a Trout Stocked Fishery and a Migratory Fishery. The creek has a diverse array of aquatic life and has been stocked with trout. A reach of the creek navigable by canoe and the creek is also a highly popular stream for angling. It passes through Lackawanna State Park.
Course
South Branch Tunkhannock Creek begins in a pond or small lake in Scott Township, Lackawanna County, between Hubbard Mountain and Meyers Mountain. It flows northwest through a valley for several tenths of a mile alongside Pennsylvania Route 247 before crossing that highway. The creek then turns north-northwest for a few miles, flowing alongside Pennsylvania Route 438. It then turns northwest for several tenths of a mile, still following Pennsylvania Route 438, before turning north-northwest for a few tenths of a mile. At this point, the creek gradually turns southwest, crossing Interstate 81, leaving Pennsylvania Route 438 behind, and flowing along the border between Benton Township and North Abington Township. After several tenths of a mile, the creek turns west-northwest for more than a mile, entering Lackawanna Lake, where it receives Kennedy Creek, its first named tributary, from the left.
From the southwestern end of Lake Lackawanna, South Branch Tunkhannock Creek flows northwest for more than a mile before turning west for a few miles and entering La Plume Township. The creek then turns south for several tenths of a mile, briefly flowing along the border between La Plume Township, Lackawanna County and Clinton Township, Wyoming County. It then crosses US Route 6 and receives the tributary Ackerly Creek from the right. The creek then turns west for a few tenths of a mile, exiting La Plume Township and Lackawanna County.
Upon exiting Lackawanna County, South Branch Tunkhannock Creek enters Factoryville, in Wyoming County. Here, the creek flows northwest for several tenths of a mile before entering Clinton Township. Here, it turns southwest and then northwest before meandering west-southwest alongside US Route 6 for a few miles. In this reach, it receives the tributary Trout Brook from the left before turning west, entering Tunkhannock Township, and meandering west-northwest for a few miles. The creek then crosses US Route 6 and after several tenths of a mile, reaches its confluence with Tunkhannock Creek.
South Branch Tunkhannock Creek joins Tunkhannock Creek upstream of its mouth.
Tributaries South Branch Tunkhannock Creek has three named tributaries: Kennedy Creek, Ackerly Creek, and Trout Brook. Kennedy Creek joins South Branch Tunkhannock Creek upstream of its mouth, at Carpenter Town, and drains an area of . Ackerly Creek joins South Branch Tunkhannock Creek upstream of its mouth.
Hydrology In the part of the watershed of South Branch Tunkhannock Creek that is above Factoryville, a total of of streams are classified as impaired. Of these, are impaired by pathogens from an unknown source, are impaired by urban runoff, and are impaired by municipal point source pollution. Some factors causing impacts to the creek's watershed include urban sprawl and poorly managed stormwater. Runoff events are also impacting the floodplains, streambanks, and stream channels in the watershed. However, the creek largely has good water quality. It is not designated as an impaired waterbody.
Near Factoryville, the average annual discharge of South Branch Tunkhannock Creek is . The maximum flow time from the headwaters of the creek to this point is 21 hours and 57 minutes. The average monthly recharge of the creek at Montdale, in terms of percentage of the total annual recharge of the creek, ranges from 1.8 percent in August to 19.2 percent in March. In 1976, the water temperature of the creek near Tunkhannock ranged from .
In the 1960s and/or 1970s, the turbidity of South Branch Tunkhannock Creek near Tunkhannock ranged from 4 to 22 Jackson Turbidity Units. The specific conductance of the creek ranged from 70 to 200 micro-siemens per centimeter. The concentration of suspended solids ranged from . The water hardness of the creek ranged from .
In the 1960s and/or 1970s, the pH of South Branch Tunkhannock Creek near Tunkhannock ranged from 4.6 to 7.6. The concentration of dissolved oxygen ranged from and the carbon dioxide concentration ranged from . The bicarbonate concentration ranged from .
The concentration of albuminoid nitrogen in South Branch Tunkhannock Creek near Tunkhannock was once measured to be the 1970s. The concentration of phosphates ranged from , while the orthophosphate concentration was and the phosphorus concentration ranged from . The concentration of organic carbon was once measured to be . The chloride concentration in the creek's filtered waters in the 1960s and/or 1970s ranged from and the fluoride concentration ranged from in filtered waters. The sulfate concentration ranged from and the silica concentration ranged from . The ammonia concentration in unfiltered waters ranged from less than to and the nitrate concentration in filtered water ranged from .
In the 1960s and/or 1970s, the magnesium concentration in the filtered water of South Branch Tunkhannock Creek near Tunkhannock ranged from less than to , while the calcium concentration ranged from . In 1973, the concentration of barium was once measured to be , the concentration of strontium was , and the beryllium concentration was less than . In the 1960s and/or 1970s, the concentrations of sodium and potassium in the creek's filtered water ranged from and , respectively. In 1973, the lithium concentration was once measured to be . In the 1960s and/or 1970s, the concentration of recoverable iron in the creek's unfiltered water ranged from and the concentration of recoverable manganese ranged from .
In 1973, the concentration of bismuth in South Branch Tunkhannock Creek ranged was found to be less than in one measurement, as were the chromium, germanium, silver, and tin concentrations. The concentrations of molybdenum, vanadium, and gallium were less than . Traces of boron, cadmium, cobalt, copper, lead, and nickel were also observed. The zinc concentration was , the aluminum concentration was , and the titanium concentration was . The zirconium concentration was .
At the Pennsylvania Route 438 bridge near the village of Scott, the peak annual discharge of South Branch Tunkhannock Creek has a 1 percent chance of reaching . Approximately further upstream, it has a 1 percent chance of reaching and at a Pennsylvania Route 438 bridge further upstream, it has a 1 percent chance of reaching . Below a tributary known as South Branch Tunkhannock Creek Tributary J, the peak annual discharge has a 1 percent chance of reaching .
Geography, geology, and climate The elevation near the mouth of South Branch Tunkhannock Creek is above sea level. The elevation of the creek's source is between above sea level. From its upper reaches to an elevation of above sea level, the creek's gradient is . From this point downstream to above sea level, the gradient is only .
The underlying geology of the watershed of South Branch Tunkhannock Creek mainly includes interbedded sedimentary rock. In the upper , upstream of Montdale, the watershed is entirely on shale and sandstone rocks.
The topography of the watershed of South Branch Tunkhannock Creek was described as "rough and hilly" in a 1921 book. The valley of the creek's main stem is surrounded by steep hills and some reaches have alluvial floodplains. Numerous small lakes and swamps dot the watershed. A mountain known as Tunkhannock Mountain is located in the vicinity of the creek. It is linked by Bowman Mountain and Eaton Knob to the North Mountain region, although the three peaks are considerably lower than North Mountain.
The channel of South Branch Tunkhannock Creek is sinuous and flows through glacial drift and rock formations consisting of sandstone. The creek has many rock gardens, cobble riffles, and several rock ledges, including one large one. Additionally, the creek flows through a deep gorge carved through sandstone and shale. In the gorge, the creek carves tubs and potholes and flows through a narrow chasm into a large pool. There is also another chasm in the gorge, where the creek drops . There is also a mushroom-shaped rock outcropping in the gorge. The creek also has some strainers.
The average annual rate of precipitation in the watershed of South Branch Tunkhannock Creek is .
Watershed The watershed of South Branch Tunkhannock Creek has an area of . Upstream of Factoryville, the watershed has an area of . The mouth of the creek is in the United States Geological Survey quadrangle of Tunkhannock. However, its source is in the quadrangle of Carbondale. The creek also passes through the quadrangles of Dalton and Factoryville. The mouth of the creek is located at Bardwell. South Branch Tunkhannock Creek flows in a generally westerly direction, although its route is circuitous.
In the portion of the watershed of South Branch Tunkhannock Creek that is above Factoryville, there are of streams. There are more than twenty named ponds, lakes, and swamps in the watershed of South Branch Tunkhannock Creek. There are also dozens of unnamed ones.
The watershed of South Branch Tunkhannock Creek is mostly in northwestern Lackawanna County and northeastern Wyoming County, although a small corner of it is in southern Susquehanna County. As of 2010, the population of the portion of the watershed above Factoryville is 15,897. In terms of population, the creek's watershed is the fastest-growing area in the Tunkhannock Creek drainage basin. As of 2006, the dominant land uses in this part of the watershed are forested land, which occupies 54.66 percent of the area; and agricultural land, which occupies 32.42 percent of the land area. Other land uses include developed land (5.25 percent), grassland/herbaceous land (3.27 percent), water (1.74 percent), wetlands (1.29 percent), and barren or extractive land (0.09 percent). The creek itself mostly flows through sparsely populated and forested terrain (except for Factoryville), although it flows alongside the busy US Route 6 for a substantial part of its length.
There are three natural gas drilling pads tracked by the Susquehanna River Basin Commission in the watershed of South Branch Tunkhannock Creek upstream of Factoryville. There are no permitted natural gas water withdrawals in this part of the watershed. However, the public water supply includes 56 groundwater withdrawals and no surface water withdrawals. There are 23 National Pollutant Discharge Elimination System sites in the watershed above Factoryville: 19 for wastewater treatment plants, 3 for stormwater, and 1 for industrial purposes.