[1] It rises near Tow Law and descends through the Deerness Valley for a distance of 11.6 miles (18.7 km), passing the villages of Waterhouses, Ushaw Moor and Esh Winning.

[2] A recent restoration project has improved the water quality and reduced barriers to fish migration along the Deerness.

[3][4] The River Deerness rises at a spring on the eastern edge of the town of Tow Law, close to the 950-foot (290 m) contour.

[5] Hedleyhill Terrace is located on the north bank, just before the former course of the Deerness Valley Railway approaches from the south and crosses the river.

[5] The line opened in 1858 to serve the coal mines of the region, but following its closure in 1964, it has become the Deerness Valley Railway Path, part of a network of long distance walkways in the Durham area.

[6] The railway bridge was one of two timber trestle viaducts on the branch line, but it was demolished in 1967/68 when the track was lifted, and the path crosses the river on a low level footbridge.

The large village of Esh Winning is located on the north bank, while two tributaries, Crow Gill and Holburn Beck join from the south.

The work involved replacing the steel truss supporting the deck, and diverting utility services which also crossed the river at this point.

[5] Prior to the nineteenth century, the Deerness Valley was sparsely populated, with those who lived in the farms and small villages engaged in agriculture.

In addition to seven types of coal, clay and fireclay were extracted, while at Ushaw Moor and New Brancepeth, deposits of witherite and barites were also exploited.

[12] As the mines opened, the population of the valley increased significantly, with workers arriving from Durham, Cumberland, Northumberland and Westmoreland, as well as from other areas of England and Wales.

There were no facilities for these workers, and the mine owners built housing, initially of wood, but gradually replaced by brick and stone dwellings.

[13] While villages such as Waterhouses were described in glowing terms at the time, noting the garden plots, Miners Institute, school and Co-operative Store, sanitation was an issue, and there were outbreaks of typhoid and scarlet fever in the 1890s.

The total cost of the project was £2.6 million, which included the enlargement of some 980 feet (300 m) of sewer pipes, and the work was carried out by ESH & Stantec and Carlow Concrete.

There were plans to remove the 5-foot (1.5 m) vertical weir at Broadgate, but a 40-inch (1,000 mm) gas main crossing the river a little further upstream would have created a new barrier, and so a bypass channel was built instead.

At Ushaw Moor, erosion beneath the bridge had been addressed in 1933 by building four concrete steps, with no consideration of their effect on fish migration.

A rock ramp was constructed down the steps, with stones and boulders used to create a more natural route for the fish to negotiate the structure.

Like most rivers in the UK, the chemical status changed from good to fail in 2019, due to the presence of polybrominated diphenyl ethers (PBDE) and mercury compounds, neither of which had previously been included in the assessment.