After skirting south of the built-up area of Harold Hill, the route passes under the Great Eastern Main Line.

From here it is partly non-urban: a large area of flood-plain follows before the Ingrebourne threads between the suburbs of Upminster and Hornchurch.

The river from here is surrounded by public open space: with Gaynes Parkway, the Ingrebourne Valley Greenway and Hornchurch Country Park taking up the area until reaching Rainham.

The Ingrebourne Marshes are a Site of Special Scientific Interest because of the diversity of its wildlife and extensive areas of wetland reeds.

[2] The river forms one of the strategic waterways identified in the Blue Ribbon Network policy in the London Plan.