[2] The ponds are at an elevation of 230 feet (70 m) and after flowing briefly to the north east, the stream follows a more southerly direction, running parallel to the A176 Noak Hill Road for approximately 1.3 miles (2.1 km).

To the west of Crays Hill it is crossed by the A129 Southend Road, and another stream, flowing northwards from springs and lakes in Gloucester Park Basildon joins it.

A public footpath runs along the left bank of the river from the bridge at Castledon Road,[4] and forms part of a nature trail.

The river turns to the south and is separated from the railway station by allotment gardens and Wickford Junior School.

It starts at springs in Northlands Park, Basildon, and is also fed by water from a large lake, which was constructed in the 1970s to collect floodwater from developments at Fryerns and Chalvedon.

Downstream of the railway bridge, the Crouch is crossed by Lower Southend Road, where the concrete channel ends and the river becomes more natural again.

[5] It continues to the south of Runwell and forms the northern border of Wickford Memorial Park, after which it is crossed by the Crouch Valley railway.

The present mill building dates from the late 18th century, and is built of bricks with a red tiled roof.

[8] Just upstream of it is a former granary and drying kiln, built of red brick and dating from the early 19th century.

Its western boundary is defined by Fenn Creek, which begins as a stream called Rettendon Brook rising near Hanningfield Reservoir and is tidal below the point where it is crossed by the A132 road.

[4] Bridgemarsh Island was protected by a sea wall built in 1736, and could be reached from Althorne by a causeway which was accessible at low tide.

[10] Passing along Cliff Reach, the river arrives at Creeksea and Burnham-on-Crouch on the north bank,[12] where Burnham Yacht Harbour provides facilities for visiting boats.

Baltic Wharf is a commercial port, where timber and steel are imported, some of it from Riga in Latvia, with two vessels regularly plying that route.

[17] A passenger ferry operates between Essex Marina and Burnham town quay every day except Wednesdays during the summer months.

[19] In 2006, the Department for Environment, Food and Rural Affairs (DEFRA) created 284 acres (115 ha) of new saltmarsh and intertidal mud flats.

[19] In order to deliver over 3 million tonnes of earth, Crossrail built a temporary jetty in the river, where ships arrived between August 2012 and March 2015, and the sea walls were breached on 11 July 2015.

The route to Billericay would have been around 7.5 miles (12.1 km) long, and 29 locks were proposed, in order to negotiate the difference in height of 181 feet (55 m).

The statutory documents were submitted to Essex County Council on 30 November 1825, but the amount of trade likely to use the canal could never have justified the expense of so many locks, and no more was heard of the scheme.

Local people from the parish of Rettendon petitioned the Lord of the Manor, Thomas Fitch of Danbury, for permission to build a mill on the north bank of the river in 1765.

When it was built, the mill was situated on the south bank, and was therefore in the parish of Rawreth, where the Lord of the Manor was St John College, Cambridge.

Some negotiation was required with Thomas Finch, in order to place stakes, piles and boards on the north bank of the river, for which £5 had to be paid four times a year.

The authority, created via the Crouch Harbour Act 1974, is run not-for profit and funded by dues levied on vessels kept on the river.

Its tasks include passing and enforcing bylaws that regulate use of the river, providing pilotage and buoying/marking the navigable channels.

There are several components that are used to determine this, including biological status, which looks at the quantity and varieties of invertebrates, angiosperms and fish.

Like many 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.