Concepts of River Renovation

Logo: Five Rivers Environmental Contracting Ltd

As World River’s Day approaches, it seems fitting that CJS asked me to write an article about my work on rivers. As part of the project management team at Five Rivers Environmental Contracting Ltd. I am at the forefront of seeing the best, but unfortunately also some of the worst, rivers in our country. You might be shocked to know that only 14% of water bodies in England are in good ecological status [1].

Although we can take measurements of rivers in other ways (physical and chemical) it’s really down to the ecology in a river; what can live and thrive in a watercourse, that gives us an indication of river health. In particular, invertebrates, macrophytes and fish species. Unfortunately, these freshwater species have seen an 83% decline since 1970 - faster than any other type of habitat [1].

We’ve made considerable changes to our waterways over the centuries – straightened, dammed, dredged, lined with concrete, harnessed their power, overfished them, dumped waste in them and abstracted from them. No wonder they could be doing better! So, what can we do to improve our unhealthy, ecologically poor, declining rivers? As something I aim to answer for a job every day, I’ve come to learn a few things about river restoration… or at least that’s what we have called it before. But can we really restore a river to what it once was? In short, I believe not, and so I’d like to introduce the term river renovation.

We can’t take our watercourses back to their original form – we’ve built houses, roads, entire towns and cities at major confluences. Take the Thames for one - home to our capital city, and Salisbury - the town where I work, is at the confluence of five main rivers! We’ve heavily managed surrounding farmland and moved ditches to drain land to make it suitable for grazing livestock or growing crops. But we can renovate and make ‘home improvements’ on our rivers in order to bring back the natural river processes, here’s a few ways how:

1    Remove barriers – fish like to swim!

Only 1% of rivers in England, Scotland and Wales are free of artificial barriers [1]. So many in the industry work tirelessly every year to open up, ease or provide fish passage in our watercourses. I’ve had involvement in fish easement projects; incorporating new bypass channels, Larinier passes and low-cost baffles. What we once thought of as flood management is now recognised as a problematic obstacle for fish. Where heritage reasons make weir and dam removal in this country difficult, bypass channels for fish to migrate upstream are critical in ensuring they can complete their lifecycle, in particular salmonid species and the European Eel.  

2    Connect water back to the land – flooding can be a good thing!

I am not referring to the extreme weather conditions we are seeing more of due to climate change, but to the seasonal bank topping of water out the channel onto the surrounding floodplain.

The problem is that we’ve built on a lot of our floodplains and this makes flood events a little bit inconvenient. But our wetland areas, ponds and backwaters in the floodplain are crucial habitats that we need to create more of - not only for an array of species, but also as a physical feature to help store excess water and slow it down – alleviating flooding downstream and creating a natural cleaning process of our water as sediment falls out of suspension and plants filter out harmful chemicals. More than 85% of wetlands that were present in 1700 had been lost by 2000 [1] – a sobering figure of just how little natural flood management we are now missing out on due to loosing this habitat.

3    Work with stakeholders – it will make your life easier!

Ok, so this one is not a physical renovation feature, but it plays a big role… Landowners want the best for their land, and rightly so. Getting them on-board with large scale river changes can be tricky. More times than I can count, projects have been delayed, postponed or completely fallen through due to the discontent of a stakeholder. Involving all interested parties can help make them engaged with the renovation, ease the working environment on site and even make them invest in the project when they see benefits for them and wider society.

Having stakeholder involvement shares knowledge. This is a powerful tool to influencing river renovation elsewhere, increases perception of ecosystem services and encourages people to take responsibility for their actions on the land. Working with farmers to improve land management techniques for example is vitally important at a time where soil is being lost at 10 times the rate that it’s being created1. I’m not saying you can win them all, but most people just want to know what’s going on and will be much more receptive when they do!

I hope you enjoyed this short article introducing the idea of river renovation rather than restoration. Water is a finite resource on this planet and fresh water is particularly scarce. We are lucky to have as much of the wet stuff as we do, living at this temperate latitude – let’s look after the watercourses and they’ll continue to support our societies too!

by Sophie Hocart BSc, PFQ, Grad CIEEM – Assistant Project Manager for Five Rivers Environmental Contracting Ltd.

1 Statistics from 35 Rivers Trusts in 2018

One of my first projects: the multi-award-winning River Bulbourne before and after river renovation – restoring natural process looks great! (Photos courtesy of Five Rivers).

New channel creation: our understanding of these process now allows us to create them from scratch! Just like we did here on the Hampshire Avon in Chisenbury (Photos courtesy of Wiltshire Wildlife Trust)

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