In the past, industries in the watershed of Spring Brook included timbering, coal mining, and agriculture.

It flows south for a short distance before meandering west for a few miles, crossing Interstate 380 and entering Spring Brook Township.

On the northern side of that hill, the stream turns south and then northwest, entering the Watres Reservoir.

It eventually bends east and enters the Nesbitt Reservoir after crossing Pennsylvania Route 502.

On the northern side of the reservoir, the stream flows north, receiving the tributary Green Run from the right before turning west-southwest.

A few miles further downstream, it passes through the Spring Brook Intake before exiting Lackawanna County.

It receives the tributary Monument Creek from the left and turns north-northwest for a few miles, flowing alongside Pennsylvania Route 502.

On this stretch, it leaves behind the hills that it flows through, crosses Pennsylvania Route 502, and exits Luzerne County.

It then turns northwest for a few tenths of a mile, crossing US Route 11 before reaching its confluence with the Lackawanna River.

[2] Spring Brook joins the Lackawanna River 3.62 miles (5.83 km) upriver of its mouth.

[2] Panther Creek joins Spring Brook 10.40 miles (16.74 km) upstream of its mouth.

Plank Bridge Creek joins Spring Brook 8.65 miles (13.92 km) upstream of its mouth.

Green Run reaches its confluence with Spring Brook 6.48 miles (10.43 km) upstream of its mouth.

[8] However, a study from the previous year found concentrations of sodium and alkalinity exceeding the threshold for concern.

[10] The peak annual discharge of the stream at its mouth has a 10 percent chance of reaching 5050 cubic feet per second.

[11] The concentration of sodium and potassium (as Na) in Spring Brook ranged from 1.4 to 3.9 milligrams per liter.

[11] The concentration of alkalinity in the waters of Spring Brook between the Watres Dam and the Nesbitt Reservoir is 11 milligrams per liter.

[15] The topography of the watershed of Spring Brook is mainly mountainous, with swampy land in its upper reaches.

[4][8] However, some residential areas, such as Yostville, Maple Lake, and Spring Brook Village are in the stream's vicinity.

[4][12] The Pennsylvania American Water Company owns all four lakes and several hundred acres of the surrounding land.

[1] In the early 1900s, the main industries in the watershed of Spring Brook included coal mining and agriculture.

[4] Spring Brook flooded during Hurricane Diane in 1955, reaching a discharge of 10,300 cubic feet per second (290 m3/s) near Moosic and destroying three homes and inundating the basements and first floors of many others.

[4] A two-span steel stringer/multi-beam or girder bridge carrying Main Street/State Route 3024 over Spring Brook was built in 1956.

[23] Wild trout naturally reproduce in Spring Brook from its headwaters downstream to its mouth.

Still less common are the genera Baetis, Paraleptophlebia, Acroneuria, Stenonema, Nigronia, Agapetus, DoIophilodes, and Optioservus.

Only one individual each of the genera Isonychia, Amphinemura, Cheumatopsyche, Rhycophila, Neophylax, Psephenus, Boyeria, Tabanus, and Cambarus were observed.

[4] The modified Hilsenhoff Biotic Index value of Spring Brook a short distance upstream of the Watres Reservoir is 2.56.

[7] A trail known as the Spring Brook / Wilkes-Barre and Eastern Greenway was proposed in the Lackawanna River Watershed Conservation Plan in 2001.

There are plans for trails on the flood levee at the stream's mouth and on the old Wilkes-Barre and Eastern Railroad corridor.

[4] A stretch of at least 7 miles (11 km) of Spring Brook are navigable by kayaking, paddling, or rafting.