Case study:Enhancement of the River Crouch following a pollution incident

0.00

(0 votes)

To discuss or comment on this case study, please use the discussion page.

Location: 51° 37' 12.15" N, 0° 32' 4.89" E

Edit location

Loading map...

{"format":"googlemaps3","type":"HYBRID","minzoom":false,"maxzoom":false,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":50,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"... further results","default":"","import-annotation":false,"width":"auto","height":"400px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"visitedicon":"","wmsoverlay":false,"zoom":14,"layers":[],"controls":["pan","zoom","type","scale","streetview","rotate"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"resizable":false,"kmlrezoom":false,"poi":true,"cluster":false,"clustergridsize":60,"clustermaxzoom":20,"clusterzoomonclick":true,"clusteraveragecenter":true,"clusterminsize":2,"imageoverlays":[],"kml":[],"gkml":[""],"searchmarkers":"","fullscreen":false,"scrollwheelzoom":false,"showtitle":false,"hidenamespace":true,"template":"Location map popup","userparam":"","activeicon":"","pagelabel":false,"ajaxcoordproperty":"","ajaxquery":"","locations":[{"text":"\u003Cp\u003E\u003Cbr /\u003E\n\u003C/p\u003E\u003Cp\u003E\u003Cb\u003EProject Title:\u003C/b\u003E Enhancement of the River Crouch following a pollution incident\n\u003C/p\u003E\u003Cp\u003E\u003Cb\u003ECountry:\u003C/b\u003E \u003Ca href=\"/wiki/index.php?title=England\" title=\"England\"\u003EEngland\u003C/a\u003E\n\u003C/p\u003E\u003Cp\u003E\u003Cb\u003EProject Status:\u003C/b\u003E Complete\n\u003C/p\u003E\u003Cp\u003E\u003Cb\u003EThemes:\u003C/b\u003E Social benefits\n\u003C/p\u003E\u003Cp\u003E\u003Cbr /\u003E\n\u003C/p\u003E","title":"Enhancement of the River Crouch following a pollution incident","link":"","lat":51.620041614322,"lon":0.53469300270081,"icon":"/wiki/images/a/af/Red_marker.png"}]}

Left click to look around in the map, and use the wheel of your mouse to zoom in and out.

Project overview

Edit project overview

Status	Complete
Project web site	http://www.vimeo.com/106173104
Themes	Fisheries, Habitat and biodiversity, Hydromorphology, Social benefits
Country	England
Main contact forename	Trevor
Main contact surname	Bond
Main contact user ID	User:Tbond
Contact organisation	Environment Agency
Contact organisation web site	http://www.gov.uk/government/organisations/environment-agency
Partner organisations	Basildon District Council, Essex Wildlife Trust
Parent multi-site project
This is a parent project encompassing the following projects	No

A gravel bar formed at the confluence of the River Crouch and Runwell Brook

Project summary

Edit project overview to modify the project summary.

The River Crouch at Wickford Memorial Park is a high priority waterbody that is currently failing to achieve its Water Framework Directive (WFD) objectives for hydromorphology. In addition, the river is failing for a number of water quality elements including dissolved oxygen and phosphates. Following a pollution incident in 2009 and the subsequent court case, Anglian Water Services (AWS) volunteered to commit funding of £15,000 for a restoration project on the stretch of the Crouch immediately downstream of the Memorial Park Bridge. The principle aim of this project was to improve the ecology of the River Crouch at Wickford by employing targeted, low-cost river restoration techniques. More broadly, the project has helped fulfil the objectives of the WFD by focusing on those quality elements for which it is currently failing.

The project involved the installation of several large woody-debris flow deflectors. Because of the high flood risk nature of the upstream town of Wickford, particular care was given to the stability of the features created. A belt and braces approach to the project ensured ecological gains without compromising the flood-risk function of the River Crouch.

Monitoring surveys and results

This case study hasn’t got any Monitoring survey and results, you can add some by editing the project overview.

Lessons learnt

This case study hasn’t got any lessons learnt, you can add some by editing the project overview.

Image gallery

Edit Image gallery

The existing river had a straight planform

The first step in the deflector installation was to dig out a trench in the bank

The second step in the deflector installation is to lower the large woody-debris into the trench

Step three in the deflector installation is to stake and brace the large woody-debris. By linking all the elements together and using screws to fasten the material, the likelihood of structure failure is minimised

The final step is to cover the debris with soil and then repair the bank to its former condition

The deflectors were set at different heights in the water so that they would operate under a range of flow conditions

Catchment and subcatchment Select a catchment/subcatchment Edit the catchment and subcatchment details (affects all case studies in this subcatchment) Catchment River basin district Anglian River basin Combined Essex Subcatchment River name River Crouch Area category 10 - 100 km² Area (km2) Maximum altitude category Less than 100 m Maximum altitude (m) 7777 m <br />0.077 km <br />7,700 cm <br /> Dominant geology Calcareous Ecoregion Great Britain Dominant land cover Improved grassland Waterbody ID GB105037028550 Site Edit site Name River Crouch WFD water body codes GB105037028550 WFD (national) typology Low, Small, Calcareous WFD water body name River Crouch Pre-project morphology Straightened Reference morphology Straightened Desired post project morphology Heavily modified water body No National/international site designation Local/regional site designations Protected species present No Invasive species present Yes Species of interest Dominant hydrology Groundwater Dominant substrate Gravel River corridor land use Urban Average bankfull channel width category 5 - 10 m Average bankfull channel width (m) Average bankfull channel depth category 2 - 5 m Average bankfull channel depth (m) Mean discharge category Mean annual discharge (m3/s) Average channel gradient category Average channel gradient Average unit stream power (W/m2) Project background Edit project background Reach length directly affected (m) 600600 m <br />0.6 km <br />60,000 cm <br /> Project started 2012/12/21 Works started 2014/09/08 Works completed 2013/09/20 Project completed 2014/10/10 Total cost category 10 - 50 k€ Total cost (k€) Benefit to cost ratio Funding sources Anglian Water Cost for project phases Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname Investigation and design Less than 1 k€ Environment Agency Trevor Bond Stakeholder engagement and communication Less than 1 k€ Environment Agency Michael Neale Works and works supervision 10 - 50 k€ Environment Agency Tony Miles Post-project management and maintenance Monitoring Reasons for river restoration Edit reasons for restoration Mitigation of a pressure Pollution incident Hydromorphology Biology Physico-chemical Other reasons for the project Measures Edit Measures Structural measures Bank/bed modifications Bank reprofiling Floodplain / River corridor Planform / Channel pattern Other Woody-debris flow deflectors Non-structural measures Management interventions Social measures (incl. engagement) Interpretation boards Other Monitoring Hydromorphological quality elements Edit Hydromorphological quality elements Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Biological quality elements Edit biological quality elements Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Physico-chemical quality elements Edit Physico-chemical quality elements Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Any other monitoring, e.g. social, economic Edit Other responses Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Monitoring documents Upload monitoring documents Additional documents and videos Upload additional documents Additional links and references Edit links and references Link Description Supplementary Information Edit Supplementary Information