The river flows in a generally north to south direction, passing through Kentmere, Staveley, Burneside, Kendal and Sedgwick.

In 1848, the construction of Kentmere Reservoir was completed, which was designed to ensure that millers had a more regular supply of water to enable their mills to operate throughout the year.

[3] The river is crossed by Low Bridge, which carries a minor road to the settlement of Kentmere, and in then joined by Hall Gill.

Prior to draining, it had provided habitat for algae called diatoms, which formed a layer of diatomite on the bottom of the tarn when they died.

This was in turn replaced by the present bridge, which was designed by the architect Francis Webster to provide easy access to the terminus of the Lancaster Canal, then under construction.

[17] Below the bridge, woodland on the west bank contains the remains of Sedgwick gunpowder works, fed by a long leat from a dam in the river.

[18] After passing under Force Bridge, Sedgwick, on the east bank of the river are the remains of Basingill gunpowder works, which is a scheduled monument.

[19] The river turns to the south-west, and is spanned by a much larger bridge carrying the A590 dual carriageway, before it enters Levens Park.

The River Winster flows into the estuary from the north, just before the Kent enters Morecambe Bay, a vast area of intertidal mudflats and sands.

Around 1800, farms around Kentmere, in the upper reaches of the river, were bought by wealthy outsiders, and efforts were made to improve the land for agriculture.

A committee of ten mill owners plus the major of Kendal was formed, and asked the water engineer John Frederick Bateman to advise on the scheme.

[34] The woollen mill had been bought by Simpson and Ireland in 1834, and they had initially supported the Kentmere Reservoir scheme, but when they realised that they would be paying more than most in rates, due to the fall at their mill being the second highest on the river at the time, they opposed the scheme, and as a consequence, the Act of Parliament which authorised its construction contained a clause limiting their contribution to £15 per year, in order to remove the opposition.

He built a cotton mill in 1770, but changes in the markets made it uneconomic, so it was leased to Hudson and Foster in 1828, who fitted a second-hand paper making machine.

Dockray Hall Mill was fed by a large curved dam to the east of the point where Burneside Road crosses under the railway line.

The leat curved round to the east, and there was a second weir, parallel to the modern river bank, below Gooseholme foot bridge.

The leat ran alongside Natland Road, on the east bank, and the mill buildings were just to the north-east of the sewage treatment works.

[45] A local architect called Francis Webster rented the site from the Lord of the Manor in about 1800, and built a weir and two water mills.

J Chaplow and Sons used the larger building as a workshop after they bought it in 1895, and were described as "haulage contractors, threshing machine proprietors and furniture removers" in 1905.

The site covered 4.9 acres (2.0 ha), and although it is believed to have opened in 1764, research by English Heritage in 2002 suggested that it was not built before 1768 and probably did not start producing gunpowder until 1770.

Wakefields moved to a new site at Gatebeck on the Peasey Beck in 1850, which had more fall, and where flows were augmented by compensation water from Killington Reservoir, which supplied the Lancaster Canal.

It covered some 27 acres (11 ha),[50] and was fed from a weir originally built straight across the river, but subsequently reconstructed in a triangular shape.

The site was reused during the Second World War for the storage of ammunition, and ownership passed to the National Trust in 1950, when they acquired Sizergh Castle and its grounds.

The scheme would have generated 1,250 MWh of electricity per year, which would have been sold to the national grid, with the profits used to fund community projects once the capital costs were repaid.

[54] A Trust was set up to manage the scheme, and a planning application was submitted to the Lake District National Park Authority in August 2009.

The depth of the channel was also increased in places, and a total of 310 thousand cubic yards (240,000 m3) of spoil was removed, which was reused to construct the base of a business park on the south side of Kendal.

As a result of public consultation, plans for flood walls near Abbot Hall Art Gallery and Kendal Parish Church had been modified to be less intrusive.

The work involved replacing around 100 yards (90 m) of stone culvert carrying Dyers Beck with a meandering channel, running into a small wetland area.

[68][69] The river is a designated Special Area of Conservation, covering 269.6 acres (109.12 ha), primarily as an important habitat for the endangered White-clawed Crayfish (Austropotamobius pallipes).

It is a designated watercourse of plain to montane levels, which means that it is characterised by populations of water-crowfoot and water starwort, which can form floating mats of white flowers in the summer.

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), perfluorooctane sulphonate (PFOS) and mercury compounds, none of which had previously been included in the assessment.