Case study:Hogsmill Sewage Treatment Works phase 1

From RESTORE
Jump to: navigation, search
0.00
(0 votes)


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


Location: 51° 24' 4", -0° 17' 16"
Edit location
Loading map...
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
Themes Economic aspects, Flood risk management, Habitat and biodiversity, Social benefits
Country England
Main contact forename Toby
Main contact surname Hull
Main contact user ID
Contact organisation Wandle Trust
Contact organisation web site
Partner organisations Natural England, Epsom & Ewell Borough Council
Parent multi-site project
This is a parent project
encompassing the following
projects
No
Hogsmill River Before works

Project summary

Edit project overview to modify the project summary.


Enhance a section of the Hogsmill through the STW by creating marginal and wetland area berms, backwaters and scrapes. This is within a wider wildlife area within the STW, encompassing wildflower grassland, tree planting and visitor interpretation trail and enhancement works to Surbiton Lagoon. Section 106 development gain from planning permission. Original scheme no longer valid so work proposed to the Hogsmill to enhance the channel edge habitat.

Monitoring surveys and results

Edit project overview to modify the Monitoring survey and results.


Photographs pre-works

Lessons learnt

Edit project overview to modify the lessons learnt.


Spring 2013:
A number of large log deflectors that were placed there to attempt to improve flow and scour are currently ineffective due to the over wide channel. The Hogsmill STW phase 2 project will build on this previous work undertaken by Thames Water.

Good population of large fish, probably chub (approx 40-60cm)
Parts of the Hogsmill River support extensive aquatic vegetation and some London rarities such as small pondweed Potamogeton berchtoldii.The upper reaches have a diverse invertebrate community including some species characteristic of chalk streams. Caddisflies and mayflies have been found, as well as the more pollution tolerant beetles, freshwater shrimps and freshwater limpets.


Image gallery


ShowHideAdditionalImage.png


Catchment and subcatchment

Catchment

River basin district Thames
River basin London

Subcatchment

River name Hogsmill
Area category 10 - 100 km²
Area (km2)
Maximum altitude category 100 - 200 m
Maximum altitude (m) 192
192 m
0.192 km
19,200 cm
Dominant geology Calcareous
Ecoregion Great Britain
Dominant land cover Suburban
Waterbody ID GB106039017440



Other case studies in this subcatchment: Bonesgate Phase 2, Elmbridge Meadows, Hogsmill River Connectivity Project, Moor Lane Allotments, River Hogsmill Restoration Project, Three Bridge, Kingston


Site

Name
WFD water body codes GB106039017440
WFD (national) typology
WFD water body name Hogsmill
Pre-project morphology
Reference morphology
Desired post project morphology
Heavily modified water body No
National/international site designation
Local/regional site designations
Protected species present No
Invasive species present No
Species of interest
Dominant hydrology
Dominant substrate
River corridor land use
Average bankfull channel width category
Average bankfull channel width (m)
Average bankfull channel depth category
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

Reach length directly affected (m) 330 m
0.33 km
33,000 cm
Project started 2011/01/01
Works started
Works completed 2011/01/01
Project completed
Total cost category
Total cost (k€)
Benefit to cost ratio
Funding sources Thames Water

Cost for project phases

Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname
Investigation and design
Stakeholder engagement and communication
Works and works supervision
Post-project management and maintenance
Monitoring



Reasons for river restoration

Mitigation of a pressure Riparian development
Hydromorphology
Biology
Physico-chemical
Other reasons for the project Recreation


Measures

Structural measures
Bank/bed modifications Bank reprofiling
Floodplain / River corridor Creation of wetland
Planform / Channel pattern Creation of backwater
Other
Non-structural measures
Management interventions
Social measures (incl. engagement)
Other


Monitoring

Hydromorphological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Biological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

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

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative


Monitoring documents



Additional documents and videos


Additional links and references

Link Description

Supplementary Information

Edit Supplementary Information