Case study:West Lexham Rehabilitation Project - Revision history

Hazel Wilson at 14:33, 23 October 2015

2015-10-23T14:33:52Z

← Older revision		Revision as of 14:33, 23 October 2015
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	\|Name=West Lexham		\|Name=West Lexham
	\|WFD water body code=GB105033047791		\|WFD water body code=GB105033047791
			\|WFD water body name=Nar to confl with Blackborough Drain
	\|Pre-project morphology=Single channel, impounded, straightened		\|Pre-project morphology=Single channel, impounded, straightened
	\|Reference morphology=Single channel, Pool-riffle, Sinuous,		\|Reference morphology=Single channel, Pool-riffle, Sinuous,

JoshRRC at 15:00, 27 August 2015

2015-08-27T15:00:09Z

← Older revision		Revision as of 15:00, 27 August 2015
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	}}		}}
	{{Site		{{Site
	\|Name=West Lexham		\|Name=West Lexham
			\|WFD water body code=GB105033047791
	\|Pre-project morphology=Single channel, impounded, straightened		\|Pre-project morphology=Single channel, impounded, straightened
	\|Reference morphology=Single channel, Pool-riffle, Sinuous,		\|Reference morphology=Single channel, Pool-riffle, Sinuous,
	\|Heavily modified water body=No		\|Heavily modified water body=No
	\|Protected species present=No		\|Protected species present=No

NickRRC at 13:53, 18 October 2013

2013-10-18T13:53:57Z

← Older revision		Revision as of 13:53, 18 October 2013
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	{{Case study subcatchment		{{Case study subcatchment
	\|Subcatchment=Nar		\|Subcatchment=Nar to confl with Blackborough Drain
	}}		}}
	{{Site		{{Site

SFW Rob at 18:16, 6 September 2013

2013-09-06T18:16:02Z

← Older revision		Revision as of 18:16, 6 September 2013
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	The effect of centuries of impoundment has been to create a sluggish/non-existent flow in the river upstream with the resultant deposition of thick layers of mud. Pools were created by widening the channel locally. To help keep the pools clear in the future, the channel was narrowed upstream. Due to the extreme depth of soft mud, narrowing was achieved by pushing in one side of the existing river edge with the back of the bucket, and the void created behind this was filled with the arisings from creating the pools. Four pools and upstream ‘runs’ were created, with the run formed upstream of the second pool from the top having a small amount of gravel spread on the bed – this was won from the bed of the river in the pool downstream.		The effect of centuries of impoundment has been to create a sluggish/non-existent flow in the river upstream with the resultant deposition of thick layers of mud. Pools were created by widening the channel locally. To help keep the pools clear in the future, the channel was narrowed upstream. Due to the extreme depth of soft mud, narrowing was achieved by pushing in one side of the existing river edge with the back of the bucket, and the void created behind this was filled with the arisings from creating the pools. Four pools and upstream ‘runs’ were created, with the run formed upstream of the second pool from the top having a small amount of gravel spread on the bed – this was won from the bed of the river in the pool downstream.
	}}		}}
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	{{Case study subcatchment		{{Case study subcatchment
	\|Subcatchment=Nar		\|Subcatchment=Nar
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	{{Monitoring documents}}		{{Monitoring documents}}
	{{Monitoring documents end}}		{{Monitoring documents end}}
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	{{Additional Documents}}		{{Additional Documents}}
	{{Case study documents		{{Case study documents
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	{{Additional links and references footer}}		{{Additional links and references footer}}
	{{Supplementary Information}}		{{Supplementary Information}}
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NickRRC at 16:09, 5 September 2013

2013-09-05T16:09:18Z

← Older revision		Revision as of 16:09, 5 September 2013
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	{{Case study status		{{Case study status
	\|Approval status=~~Draft~~		\|Approval status=Approved
	}}		}}
	{{Location		{{Location

Ascarr at 13:34, 17 May 2013

2013-05-17T13:34:32Z

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	\|Invasive species present=No		\|Invasive species present=No
	}}		}}
	{{Project background}}		{{Project background
			\|Project started=2011/02/28
			\|Project completed=2011/03/04
			}}
	{{Motivations}}		{{Motivations}}
	{{Measures}}		{{Measures}}

Ascarr at 13:32, 17 May 2013

2013-05-17T13:32:12Z

← Older revision		Revision as of 13:32, 17 May 2013
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	}}		}}
	{{Project overview		{{Project overview
	~~\|Project title=West Lexham Rehabilitation Project~~
	\|Status=Complete		\|Status=Complete
	\|Themes=Habitat and biodiversity		\|Themes=Habitat and biodiversity
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	\|Main contact forename=Nigel T.H.		\|Main contact forename=Nigel T.H.
	\|Main contact surname=Holmes		\|Main contact surname=Holmes
	\|Multi-site=No		\|Partner organisations=River Restoration Centre, Environment Agency, Norfolk County Council, Natural England,
			\|Multi-site=Yes
			\|Project picture=West lexham.png
			\|Picture description=site location of works
			\|Project summary=A half day work to remove the impounding influence of a weir, and in the channel upstream four pools and runs were dug. A second weir, between two bridges c35m downstream of the one shown in the images, was also removed. This structure had minimal impact on habitat, but was an impediment to easy migration of fish etc. wishing pass upstream.

			The structure within the meadow that was impounding the Nar upstream had some archaeological interest. For this reason there was a ‘watching brief’ from Norfolk County Council to ensure there was no damage done to any known existing interest features, and to record anything else of interest should this be revealed during the removal of the impounding structure. To minimise damage to the historical elements of the bridge, the concrete ‘boards’ were removed with great care, leaving the central pillar and upper lintel in place, yet drawing the bed down to the required level.

			The effect of centuries of impoundment has been to create a sluggish/non-existent flow in the river upstream with the resultant deposition of thick layers of mud. Pools were created by widening the channel locally. To help keep the pools clear in the future, the channel was narrowed upstream. Due to the extreme depth of soft mud, narrowing was achieved by pushing in one side of the existing river edge with the back of the bucket, and the void created behind this was filled with the arisings from creating the pools. Four pools and upstream ‘runs’ were created, with the run formed upstream of the second pool from the top having a small amount of gravel spread on the bed – this was won from the bed of the river in the pool downstream.
	}}		}}
	{{Case study subcatchment		{{Case study subcatchment

Ascarr at 13:25, 17 May 2013

2013-05-17T13:25:19Z

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	\|Approval status=Draft		\|Approval status=Draft
	}}		}}
	{{Location}}		{{Location
			\|Location=52.719391912920244, 0.7207900285720825
			}}
	{{Project overview		{{Project overview
	\|Project title=West Lexham Rehabilitation Project		\|Project title=West Lexham Rehabilitation Project

Ascarr at 13:23, 17 May 2013

2013-05-17T13:23:07Z

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	{{Image gallery end}}		{{Image gallery end}}
	{{Additional Documents}}		{{Additional Documents}}
			{{Case study documents
			\|File name=NAR Spring 2011 - as built project report.pdf
			\|Description=River Nar Rehabilitation summary report by Nigel Holmes
			}}
	{{Additional Documents end}}		{{Additional Documents end}}
	{{Additional links and references header}}		{{Additional links and references header}}
	{{Additional links and references footer}}		{{Additional links and references footer}}
	{{Supplementary Information}}		{{Supplementary Information}}

Marinela at 11:05, 9 April 2013

2013-04-09T11:05:04Z

← Older revision		Revision as of 11:05, 9 April 2013
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	\|Subcatchment=Nar		\|Subcatchment=Nar
	}}		}}
	{{Site}}		{{Site
			\|Name=West Lexham
			\|Pre-project morphology=Single channel, impounded, straightened
			\|Reference morphology=Single channel, Pool-riffle, Sinuous,
			\|Heavily modified water body=No
			\|Protected species present=No
			\|Invasive species present=No
			}}
	{{Project background}}		{{Project background}}
	{{Motivations}}		{{Motivations}}