14. Black Fan Lagoon

Theme: Water Quality, Habitats and Wildlife


  • That water quality, temperature and river bed quality are such that they support chalk stream ecology

Project description

To ensure that Black Fan Lagoon does not pollute the Mimram

Black Fan lagoon is a holding pond for waste water before it is discharged into the Mimram at Tewinbury. It is important that the lagoon does not act as a source of pollution - oil, silt and algae – which could be discharged directly into Mimram.


To help check this, one of the Riverfly Monitoring sites is at outflow from Blackfan into the Mimram.


In addition, no organisation will yet admit to ownership of Blackfan Lagoon. However the Environment Agency did get Thames Water (the most likely owners) to clear a pollution outflow in 2014.


Grid reference: TL25361378
Project lead: Welwyn Garden City Society
Project partners: Friends of the Mimram
Contact for more information: This email address is being protected from spambots. You need JavaScript enabled to view it.
Black Fan Lagoon

Design by LTD Design Consultants and build by Garganey Consulting.