South East Rivers Trust (& the Wandle Trust)

Balsam bashing: Hogsmill River: July 2013

As part of Defra’s initiative to improve rivers across south London (and indeed nationwide) we recently secured funding from the Catchment Restoration Fund for habitat improvements on our sister chalkstream, the Hogsmill, which rises in Ewell and enters the Thames in Kingston near the Rose Theatre.

Before any improvement works can take place, something needed to be done about the enormous amounts of Himalayan balsam growing on the banks.


So, on a sweltering Sunday, and with the blessing of Thames Water on whose site we would be carrying out the balsam removal, 20 of us were admitted through the gates of the sewage treatment works in Lower Marsh Lane.

Having signed us in at the office, Kristine Boudreau, the Hogsmill Nature Reserve Manager, gave us all an induction briefing, and after we had collected our hard hats and hi viz vests, we walked from the building to the site where we were going to begin our work.


Discarding our hats and hi viz vests, we used ladders to get access to the river and began two tasks:  pulling up the balsam, and  removing rubbish, the presence of which was made all the more baffling because the Hogsmill, unlike the Wandle, is not easily accessible.

Hippo and builders’ bags full of balsam stems were dragged up the bank by Roger and JOB, and barrowed away to an ever increasing pile.  Alongside it, we began to stack the rubbish.

Positively gasping in the 30 degree heat by 1 o’clock, we donned our hard hats and hi viz vests once again and walked back to the office where, in the conference room, Jo had prepared tea, coffee, cheese scones and muffins.  It was quite strange to be inside for our refreshment break, but great to have hot and cold running water and kitchen and lavatory facilities!

Ellora, our youngest volunteer that day, declared in true Great British Bake Off fashion that the muffins were ‘light and fluffy’.

Back we trekked across the treatment works for our afternoon shift.


Gideon and Robin decided to tow a couple of half barrels upstream, taking photographs of the graffiti under the bridge…

… and exploring the twin tunnels under Berrylands station.

Finally, mindful of bio-security, we carried out ‘check-clean-dry’ to prevent any spread of invasive species by our equipment, particularly waders and Wellies which had been worn in the water, but also the trugs, ropes, tools and the tyres on the wheelbarrows.

It was easiest to make sure all waders were cleaned while people were still in them…

… and we ensured we’d removed all the mud from them first in order for the spray disinfectant to be effective.

Before we departed, we had a look at where we had been working, and felt that we had at least made a small dent in some of the Himalayan balsam!

Thanks to:  Abi, Andy, Chris, Ellora, Gideon, Jo H, Jo S, John L, John O’B, Jonny, Kristine, Martin, Neil, Nick, Robin, Roger, Rory, Toby and Thomas

Who removed:   1 shopping trolley, 1 push chair, 1 push chair frame, 1 bucket, 1 wheelbarrow without a wheel, 1 plastic crate, 1 bicycle wheel, 1 inner tube, 1 garden chair frame, 2 bicycles, 2 motorbikes, several bin bags of light litter, plus a couple of tonnes of Himalayan balsam.

This event was supported by Thames Water