The stream then turns south-southwest for several tenths of a mile, entering Scott Township and crossing Pennsylvania Route 107, which it begins to flow alongside.

[1] Rush Brook joins the Lackawanna River 25.24 miles (40.62 km) upriver of its mouth.

[5] The peak annual discharge of Rush Brook has a 10 percent chance of reaching 840 cubic feet per second.

The peak annual discharge has a 0.2 percent chance of reaching 4600 cubic feet per second.

[5] The corridor of Rush Brook is largely undisturbed, except for its lower reaches, which are in Jermyn.

[3] From a spur of US Route 6 downstream to its mouth, Rush Brook's stream banks have been stabilized and/or channelized.

As it enters the residential part of Jermyn, the stream flows through gabbion baskets and concrete floodwalls.

A beaver dam is located at the inflow of the Rush Brook Reservoir and creates a wetland system.

[6] Rush Brook was entered into the Geographic Names Information System on August 2, 1979.

[8] A concrete tee beam bridge carrying Lincoln Avenue over Rush Brook was constructed in 1930.

A prestressed box beam or girders bridge carrying Pennsylvania Route 107 was constructed across the stream in 1931 and repaired in 1984.

[12] The old New York, Ontario and Western rail line crosses Rush Brook.

In the early 2000s, the Lackawanna River Watershed Conservation Plan proposed creating a pedestrian bridge along the rail line over the stream.

The conservation plan also recommended allocating a tract of land at the stream's mouth for use as a greenway linking to the Lackawanna River Heritage Trail.

[3] Rush Brook flows through Pennsylvania State Game Lands Number 307.

[14] Wild trout naturally reproduce in the creek from the Rush Brook Reservoir downstream to its mouth, a distance of 1.79 miles (2.88 km).

[15] In its upper reaches, Rush Brook tends to have a stable riparian buffer consisting of native trees and understory.