Case study:Pymmes Park Wetlands
Project overview
Status | Complete |
---|---|
Project web site | |
Themes | Environmental flows and water resources, Flood risk management, Habitat and biodiversity, Monitoring, Social benefits, Water quality, Urban |
Country | England |
Main contact forename | Ian |
Main contact surname | Russell |
Main contact user ID | |
Contact organisation | London Borough of Enfield |
Contact organisation web site | http://enfield.gov.uk/ |
Partner organisations | London Borough of Enfield, Friends of Pymmes Park, Thames21 |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
The Moore Brook, is a lost river, which drains a catchment area of roughly 350 hectares and flows from Winchmore Hill to Edmonton (Pymmes Park Lake) passing through Firs Farm Recreation Ground. As it drains a large catchment, the Moore Brook picks up a large amount of urban runoff contaminated with phosphates, nitrates, heavy metals, hydrocarbons and oils from footpaths and roads. It has been culverted since the 1950’s, and as a result has been prone to plumbing misconnections. This pollution accumulates throughout the catchment causing problems further downstream when it enters Pymmes Park Lake, and is particularly prominent during periods of dry weather. The London Borough of Enfield highlighted that the ongoing complaints from the smell and pollution of the lake required a holistic approach in managing. This lake directly outfalls into Pymmes Brook, one of the most polluted tributaries of the River Lea.
The London Borough of Enfield and Thames Water took on large scale project to resolve possible misconnections in the catchment. 800 misconnections were resolved, but to manage residual pollution from road runoff and additional misconnections a series of cascading wetland cells to capture dry weather flows, immobilise and filter pollutants from the stream before it entered the lake were introduced.
A total catchment of 294Ha is treated by the four cascading wetland cells. 216Ha of this catchment passes through the Firs Farm Wetlands, which introduces a “first treatment phases” upstream of the Lake. A total of 0.6Ha of wetlands has been constructed across the Moore Brook Catchment, in Pymmes Park and Firs Farm. As a result, Pymmes Park Wetlands filters around 85% of all dry weather flows entering the lake.
Monitoring surveys and results
London Borough of Enfield has compiled pollution records and water quality data from the past, and has been collecting water quality data on Biological Oxygen Demand, Suspended Soilds and Nutrients for three years.
A Water Quality monitoring programme is now in place with Thames21, measuring parameters such as:
- Dissolved Oxygen and Biological Oxygen Demand
-Nutrients (nitrates, phosphates and ammonia)
- Faecal Coliforms
Lessons learnt
Image gallery
Catchment and subcatchmentSelect a catchment/subcatchment
Catchment
Subcatchment
Other case studies in this subcatchment: Firs Farm Wetlands
Site
Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
|