Feildes Weir is a weir on the River Lea located near Hoddesdon, Hertfordshire at the confluence of the River Lea and River Stort. The weir marks the start of the Lower Lee. A channel of the man-made River Lee Flood Relief Channel is incorporated into the weir.
The weir has had a complex history of changes to channel control and bypassing over the years. Control was originally exercised by a barrage of gates and sluices.
In 1976, a 29 metres (95 ft) wide thin-plate weir was installed, with three vertical-lift sluices controlling a parallel flood relief channel. Flows average about 4.4 m3/s discharge over the weir; higher flows enter the flood channel.
- From Hoddesdon via A10 road, A1170 road to Dinant Link Road to Rattys Lane.
- From Nazeing via Dobbs Weir Road.
- Pedestrian and cycling access via Lea Valley Walk.