Weir

From Chester Wiki

It is not clear whether the purpose of the weir at Chester was:

• to enable the river to be crossed, by wading in the few inches of water flowing over it, or
• to better regulate the flow in the river above the weir and help with navigation in the river's upper reaches, or
• to provide a head of water for mills

The first seems the most likely of these as the weir cuts diagonally across the river and therefore the water depth on the "causeway" is generally very shallow. Whatever the reason, the river is tidal below the weir and above relatively constant in level.

The erection of a hydroelectric power plant at the weir on the River Dee in 1913 provided an attractive alternative to extending the existing thermal station. This scheme was the only one in England dealing with both tidal and head waters. The success of the Chester scheme had considerable influence on the decision to construct a similar plant at York when, in 1918, coal stocks became a cause of anxiety. A hydroelectric power station based on the Chester plan was built in 1923 at Linton Lock on the River Ouse and continued in operation until 1962.

Chester's weir boasts another unique feature in that it has a watergate designed to allow the passage of sea/river craft past the weir at exceptional high tides. The watergate is reached by a ladder descending from the Norman Bridge.

It has been described as follows by water-folk thus:

• The Watergate is a totally unique feature in the UK, it consists of a curved flume in the weir crest, normally blocked by a curved bottomed gate. This gate can obviously only be opened when the tide makes a level with the weir and its purpose is to enable increased draught, when going across the weir either for deep draughted (but biased towards round bottom boats)......or for using the weir on lesser Spring tides.

In 2004, a group of intrepid canal folk amply demonstrated that the river above the weir is accessible to boats (and barges) from below. One narrowboat ran upriver as far as a rare barge mooring at Farndon

With the benefit of favourable tides, the Lady Edwina Grosvenor sailed upriver over the weir using the same procedure.