Hertford Castle Weir
Encyclopedia
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...
located in Hertford
Hertford
Hertford is the county town of Hertfordshire, England, and is also a civil parish in the East Hertfordshire district of the county. Forming a civil parish, the 2001 census put the population of Hertford at about 24,180. Recent estimates are that it is now around 28,000...
near to Hertford Castle
Hertford Castle
Hertford Castle was a Norman castle situated by the River Lea in Hertford, the county town of Hertfordshire, England.-Early history:Hertford Castle was built on a site first fortified by Edward the Elder around 911. By the time of the Norman Invasion in 1066, a motte and bailey were on the site...
and next to Castle Hall.
Its function is to connect the upper River Lea to the canalised section that runs through Hertfordshire
Hertfordshire
Hertfordshire is a ceremonial and non-metropolitan county in the East region of England. The county town is Hertford.The county is one of the Home Counties and lies inland, bordered by Greater London , Buckinghamshire , Bedfordshire , Cambridgeshire and...
, North London
North London
North London is the northern part of London, England. It is an imprecise description and the area it covers is defined differently for a range of purposes. Common to these definitions is that it includes districts located north of the River Thames and is used in comparison with South...
into the River Thames
River Thames
The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...
. The section of the river above Castle Weir is not deep enough to support barge
Barge
A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and need to be towed by tugboats or pushed by towboats...
s or narrow boats
Narrowboat
A narrowboat or narrow boat is a boat of a distinctive design, made to fit the narrow canals of Great Britain.In the context of British Inland Waterways, "narrow boat" refers to the original working boats built in the 18th, 19th, and 20th centuries for carrying goods on the narrow canals...
, but is navigable by row boats, canoes and kayaks.
The weir marks the start of the River Lee Navigation
River Lee Navigation
The Lee Navigation is a canalised river incorporating the River Lea . Its course runs from Hertford Castle Weir all the way to the River Thames at Bow Creek. The first lock of the navigation is Hertford Lock the last being Bow Locks....
. It is overlooked by a function room at the Hertford Castle Hall.
Access
Just off Mill Bridge (B158 road) in the centre of Hertford town, beside the Castle Hall.A small bridge runs from Mill Bridge over the secondary drop to a car park. A step upstream from this bridge allows access to the top of the weir.
Angling
AnglingAngling
Angling is a method of fishing by means of an "angle" . The hook is usually attached to a fishing line and the line is often attached to a fishing rod. Fishing rods are usually fitted with a fishing reel that functions as a mechanism for storing, retrieving and paying out the line. The hook itself...
in the weir pool is possible, but tricky due to pontoon access at the weir pool. Anglers often stand on the stepped weir drops, but this is discouraged due to the damage that is sustained to the weir itself.
Weir setup
Castle Weir has 3 sections:- A vertical 70 cm drop onto a second 30 cm concrete block, situated in a stilling pool. The stilling pool overflows into a tunnel which leads under the road. The 70 cm drop has two electric gates which move vertically in high flows.
- 5 padlocked sluiceSluiceA sluice is a water channel that is controlled at its head by a gate . For example, a millrace is a sluice that channels water toward a water mill...
gates. Rarely used, as these are manually controlled by British WaterwaysBritish WaterwaysBritish Waterways is a statutory corporation wholly owned by the government of the United Kingdom, serving as the navigation authority in England, Scotland and Wales for the vast majority of the canals as well as a number of rivers and docks...
.
- Stepped drop for high flows.
Whitewater use
Kayakers and canoeists regularly use the weir for practicing whitewaterWhitewater
Whitewater is formed in a rapid, when a river's gradient increases enough to disturb its laminar flow and create turbulence, i.e. form a bubbly, or aerated and unstable current; the frothy water appears white...
skills and playboating
Playboating
Playboating is a discipline of whitewater kayaking or canoeing where the paddler performs various technical moves in one place , as opposed to downriver whitewater canoeing or kayaking where the objective is to travel the length of a section of river...
.
- Main drop - Can be run straight or sideways.
- Main drop sluice - Creates a jet which can tail squirts can be performed on. At high flows it makes the weir harder to paddle in, and can cause pinning in the stopper, river right.
- Stilling pool drop - Side-surfing is possible at most flows. Cartwheeling is possible when the pool level raises. Normally about 70 cm deep.
- Side sluice - A wave and stopper forms here, depending on weir pool levels and amount of water coming through the sluice. This water has been constricted by kayakers using concrete blocks to form different features. It can vary from 30–50 cm high wave which can be carved in front-surf, to a shallow retentive pour-over, which is side-surf able.
- Stepped drop - Can be run when river is in spate, very likely to do damage to the weir or your boat when the water flowing over it is less than 3 cm in depth. A small wave and stopper forms at the bottom which can be played on, however, it is very shallow.
See also
- Weirs on the River Lea
- River Lea
- River Lee NavigationRiver Lee NavigationThe Lee Navigation is a canalised river incorporating the River Lea . Its course runs from Hertford Castle Weir all the way to the River Thames at Bow Creek. The first lock of the navigation is Hertford Lock the last being Bow Locks....