Weed Cutting: Q & A from the waterways
Updated: Sep 20
Weed cutting is a critical element of canal maintenance, helping to keep UK waterways clear and healthy. It requires the work of an expert, and those tasked with clearing weeds typically face long days in the sweltering summer heat.
We caught up with Simon Higton, Helmsman at The Rothen Group, to look at a typical day removing duckweed from the waterways.
What does a day of work typically look like for you?
During the warmer summer months, my days are typically spent clearing duckweed from the surface of canals. I generally start early morning, because as the day moves along the waterways get busier, and mid-morning traffic in particular can slow progress down. Ultimately, a big part of collecting duckweed is to keep the canals clear and easy to navigate along, so the earlier in the day we can get this done, the better it is for everybody.
The day can be long, especially as I always try to ensure any maintenance or re-fuelling of the boat is done prior to finishing. This means I can make a start straight away the next morning.
Where in the UK do you do weed clearance?
Last year I was based mostly in central London – in Little Venice, up to Kensal Green, as well as covering some of Camden too. It’s a great way to see the city, and although it can get busy at times, everyone is really friendly and appreciative of the work we do.
Growth of duckweed can be fairly localised, but it is so fast that by mid-summer the work is intense. It’s important to keep the UK waterways clear across both urban and rural areas, as it grows so fast that it’s a constant battle to keep up!
Why is it important to keep the waterways clear?
It’s possible to navigate through a small patch of duckweed, but when it really starts to take hold it becomes a challenge. Even just pushing a boat through an overgrown section, where the weed can sometime be upwards of a foot thick, is almost impossible. The other issue for boats is that engines are very often cooled used the canal water itself. This process uses a filter, which can become clogged if there is duckweed floating in the water, ultimately leading to mechanical problems.
Duckweed can also be bad for the water itself, because it causes large volumes of rubbish to get stuck and block the canal. Combined with deoxygenating the water due to sheer quantity of weed, it will lead to genuine environmental issues if not controlled.
How often does it need to be done?
During the winter, you generally won’t see any duckweed because it is too cold. When things start to warm up – from April and May onwards – you see patches beginning to form, and this intensifies throughout summer, before slowing again in late September.
When temperatures are at their warmest, you can almost see duckweed grow over the course of a day. In July, this can mean revisiting the same patch of water several times a week, just to keep on top of things.
What kind of equipment do you use to collect the duckweed?
We use a custom-built boat specifically designed to collect duckweed. There is a large conveyer belt mounted to the front, which we hydraulically lower into the water to collect the weed. Once the hopper is full, we can reverse the belt to offload the contents into the hold of a larger hopper, ready for transport away from the canal.
We also used a Conver, which is a hydraulically-powered boat with a small digger arm on the front. This enables us to attach a basket for scooping up weed, or a cutting arm for processing large rafts of penny wort, which is a different type of weed.
What was the biggest challenge for you last summer?
The sheer volume of weed that was growing during the hotter months meant it was a bit of a logistical headache. Trying to predict where growth would be biggest, based on weather forecasts, and deciding how much manpower would be needed to remove it, is always quite difficult.
There are also a number of other weed-cutting operatives that you have to work alongside to ensure you’re being as productive as possible. Fortunately, we had an incredible team, and that meant we could keep the waterways clear, even at their busiest.
You’ve mentioned you’re supported by other canal users, are they generally thankful and understanding of the work you do?
We’ve received nothing but praise from the boating community, which is massively appreciated and serves as good motivation during those long working days! I think there is an understanding that weed can be a big problem if left to its own devices, and even for those not on the canal, the smell can be very unpleasant if it starts to rot and die.
The most vocal support actually came from the active commercial boaters who work along the stretch from Little Venice to Camden. We managed to hold back the major duckweed growth and keep waterways open for business, and as many of these companies rely on the canal for their summer trade, this was crucial.
Despite the long hours, it’s a wonderful way to spend the summer. We get to see the friendly faces of those using the canals every day, and keep our beautiful and important waterways clear and healthy as a result.
For more information on weed clearance, please visit: https://www.therothengroup.co.uk/