Riverflying the flag for healthy waterways

Riverflying the flag for healthy waterways

Lou Sykes, our Catchment Officer for the River Loddon, has recently recruited volunteers to undergo training for riverfly monitoring on this catchment for the first time. In this blog, she emphasises the importance of this monitoring, details what volunteers should be looking for and puts out a call for more volunteers across our wider river networks.

This year, the Loddon Catchment Partnership is focusing on investigating poor sources of water quality. We at the South East Rivers Trust (SERT) have conducted riverfly volunteer training to educate the public about freshwater invertebrates, as these creatures can serve as indicators of pollution.

Twelve volunteers have completed the riverfly monitoring training and are now regularly conducting surveys on the upper Loddon near Basingstoke to initiate the riverfly regime in this area. They are now part of a nationwide initiative to assess water quality in rivers. By consistently monitoring the river, they can identify reductions in water quality and report potential pollution issues to the Environment Agency.

So, what are Riverflies?

Volunteers checking a river sample
Volunteers checking a river sample for an RMI survey

They are tiny creatures that live in our rivers (hopefully!). Creatures such as mayfly have an evolutionary history going back hundreds of millions of years. They will spend most of their life in the water as nymphs or larvae feeding on plant life or algae.

They do important work, such as keeping things clean or stopping the build up of too much detritus.

Others are predatory and feed on other aquatic invertebrates. Some make cases from leaves, twigs, tiny pebbles and sand, acting as little underwater architects.

Others cling to rocks in faster moving waters. Some create little shelters in rocks and build little nets out of silk which they produce to catch food as it passes by.

Why are riverflies important?

Riverflies are often referred to as the canaries of our rivers as they are excellent biological indicators for monitoring water quality. The canaries reference comes from an era when mining for coal was a prevalent industry in Britain: canaries would be sent down mines before humans to test how toxic the air was. If the birds died, it was not safe for minors to enter.

Similarly, riverflies are sensitive to pollution, so finding them in the water gives us an indication of the state of the river. With Rivers Trust statistics showing that only 15% of rivers in England are rated in good overall health, riverfly monitoring is a valuable way to test the continued health of a stretch of river.

A polluted section of the River Loddon
A polluted section of the River Loddon

Riverflies live comparatively long lives as nymphs or larvae on the riverbed and are relatively localised within the waterway. The types of riverfly you can find vary based on habitat diversity, flow rate, water level and water quality, so you can tell how your river is functioning based on the groups that you find.

Monitoring for riverflies is a nationally important citizen science initiative (known as RMI), developed to monitor the health of rivers and to detect potential pollution events.

The Riverfly Partnership is a network of organisations, representing a wider range of stakeholders from anglers and water course managers to conservationists and relevant authorities that are looking to protect the water quality of our rivers and conserve riverfly habitats.

How  do we survey for riverflies and what are we looking for?

We survey for riverflies using a kick-sweep sample. Essentially, this involves kitting up in a pair of waders, grabbing a net and getting into the stream to ‘kick’ the riverbed and disturb the gravels to knock invertebrates living on them into your net. Your net is also swept through submerged vegetation to capture any invertebrates living in those, too. These, plus a hand search of large rocks or any other items that can’t make it into your net (yes that does occasionally mean the odd shopping trolley) make up the sample you look at.

This goes in a tray on the bank to be analysed, looking to estimate numbers of three key groups of riverflies: the up-wing flies or mayflys (Ephemeroptera), caddisflies or sedges (Trichoptera), and stoneflies (Plecoptera). We also assign freshwater shrimp (Gammarus) to this category too.

What’s next? Sign up to help!

A riverfly monitoring tray
A riverfly monitoring tray helps volunteers count numbers and types of samples

Having empowered our new volunteers on the Loddon, we are looking to expand and recruit more people to help monitor the health of rivers.

We have already lined up more training later this summer, for another group of volunteers on the Loddon catchment, giving more people the thrill of knowing they are contributing to vital data.

But we would like to know if you would like to get involved, across our 12 catchments (click through to a map to find your local river), which covers an area from Reading to Dover and down to Hastings.

Would you like to know more about the creepy crawlies living in your local river and what they show with regards to water quality? Could you spend a few hours each month monitoring a stretch of river?

We are interested in building a picture of potential volunteers, for whom we can design opportunities. Please get in touch on the below form to register your interest, so that we can understand how many people might want to be trained as riverfly monitors and where they are from.

Glorious gravel boosts the Blackwater

Assistant Project Officer Luke Beckett reports on a week-long series of events with volunteers in mid-March, putting gravel into a stretch of a River Loddon tributary to improve conditions for river wildlife.

River Blackwater gravel installation
Some of the gravel was transported by dinghy © South East Rivers Trust

Anglers and conservation enthusiasts were among more than a dozen volunteers who joined us for the exhausting but rewarding task of installing more than 19 tonnes of gravel into the River Blackwater. In joining us earlier this month, they added a vital resource to help nature thrive into a 200 metre stretch of the river in Aldershot.

The newly seeded gravel, which is the final part of our Blackwater Valley river restoration work, will provide improved habitat for macroinvertebrates such as beetles, dragonflies and mayflies. It will also help aquatic plants thrive, as well as increasing spawning habitat for fish.

The River Blackwater at Ivy Road has historically suffered from bank and riverbed modifications. This section of the River Loddon catchment has been widened and deepened, leaving a uniform channel with little variation in water depth.

The channel has lacked flow energy and habitat diversity and subsequently, silt and fine sediments had built up, smothering the riverbed. Moreover, the site is just downstream of the Aldershot sewage treatment plant, which regularly discharges sewage effluent into the channel.

Since 2021, the South East Rivers Trust has worked with support from the Environment Agency and the Blackwater Valley Countryside Partnership, plus local volunteers, to improve this stretch of river.

Installing gravel at River Blackwater
Will the pile of gravel ever go down? © South East Rivers Trust

The in-channel deflectors and berms previously installed have helped to narrow the channel and increase water flow velocity, as well as habitat complexity. The increased velocity has already cleared much of the fine sediments and silt.

The newly-seeded land-based gravel will move around with the natural ebb and flow of the river, settling to form natural river features, such as bars, riffles and deeper pools.

This clean gravel and variety of river habitats is essential for river life: the River Blackwater supports a number of fish species – such as chubb, roach, perch, dace, gudgeon and rudd – all of which should benefit from this improved spawning habitat.

Gravel seeding is not the most glamorous of tasks. This site delivery was no different and was made difficult by the lack of access routes.

 

Raking gravel into the River Blackwater
Raking gravel into the River Blackwater © South East Rivers Trust

Large vehicle access to the river was not possible, which meant a lot of moving wheelbarrows loaded with heavy gravel from our drop off location to the channel itself.

The distance was at least 75 metres and up to 200 metres to push the gravel to the correct places, making this tough physical work. Wader wearing volunteers also had to rake the gravel once in the riverbed, sometimes having taken it to an appropriate location in a dinghy.

It was slow going at times, leaving us questioning whether the gravel pile was even going down! But, after four days, including a lot of rain, not enough sunshine and many teas, coffees and biscuits, the gravel pile was finally gone and the last wheelbarrow and boat load were emptied.

The team took a moment to look over their hard work from Ivy Bridge, where a few curious fish were already checking out the new riverbed, before the heavens opened once again!

This brings our river restoration work at Ivy Road Recreational Ground to a close, but we look forward to returning over the coming months and years to see how the channel responds.

Gravel and brash berms
The final scene: Gravel on the left is complimented by previously installed brash berms on the right © South East Rivers Trust

Going live on the Loddon

The launch of our River Loddon Storymap, on behalf of the catchment partnership, allows residents across the area to see the problems faced by the river and the collective actions of around 20 partners in trying to improve the waterways. Residents can also sign up to join in, as individuals or to join the partnership as a group. Lou Sykes, catchment officer for the Loddon, introduces the new Storymap.

Capturing the work of catchments

The Whitewater, a tributary of the Loddon

Since its inception in 2000 as the Wandle Trust working on one river, the South East Rivers Trust (SERT) has grown exponentially and now cares for and maintains watercourses across 12 catchments in the south east of England.

SERT is also long established in the Beverley Brook and Hogsmill catchments, hosting and chairing the catchment partnerships. These lead a variety of organisations to devise ways to assess the issues faced by rivers and create plans to improve them using the Catchment Based Approach (CaBA).

Our growth is such that we now partially or fully host and chair 11 of the 12 catchment partnerships throughout the south east. This area stretches from the Kent coast to the Sussex coast, meandering through Surrey and encompassing much of Berkshire and north Hampshire.

It is for this latter area, the 680 km2 River Loddon catchment, that SERT has now launched a Storymap, capturing the partners, issues and plans to improve the whole network of watercourses. This will be the first in a series of new Storymaps on various catchments that will be released in 2023, funded by Thames Water.

The ArcGIS Storymap portal is a story authoring, web-based application, that enables an organisation to share maps in the context of narrative text and other multimedia content.

Using this facility, SERT’s catchment partnerships can detail the pressures faced by the river networks and introduce objectives for improving rivers and the surrounding areas, as identified by the partnership.

Bringing different groups together to solve the river’s issues

A scene from the Lyde tributary
A scene from the Lyde tributary

By creating this presence online, the catchment partnership raises awareness and becomes a supportive group, speaking with one voice.  In the case of the Loddon catchment, this brings about 20 different groups together: this better empowers collaborative working and helps to ensure all issues affecting the river are noted, captured and addressed under one umbrella. By working together, the catchment partnership can plan and deliver positive actions that will improve the riparian environment across a whole river network, as opposed to working on sections in isolation.

Leading on the Loddon catchment partnership, SERT brings together people from various local organisations and interest groups including water companies, government bodies, local flood groups and angling clubs.

Giving communities and groups the chance to have their voices heard is crucial to the Catchment Based Approach, empowering them with a sense of ownership as the partnership delivers action on the ground.

The Loddon Storymap allows readers to explore the character of the catchment including its tributaries, outlines the issues facing the river, the actions being taken to address them and how to get involved in actions to protect this vast network of water. The maps on the Storymap are ‘live’, meaning that whenever they receive new data they update automatically. Data comes from a variety of different places, with the latest from the Rivers Trust and the Environment Agency showcasing the issues of the catchment.

Maps capture the issues

Summaries of issues affecting the river range from the general to the specific, such as under water quality. Did you know, for example, that road runoff can carry more than 300 different pollutants which can cause short and long-term damage to watercourses?

Consented discharges on the Loddon
Consented discharges on the Loddon

Meanwhile, one of many bespoke maps details the phosphate status of the river network, which rises from chalk-fed streams in Basingstoke and goes all the way to Reading and stretches across to Aldershot. Another map shows the pollution from waste water. Another details the topical issue of sewage spillages.

The extend to which the catchment is affected by flooding, low flows and abstraction is also outlined, with a warning: “The primary risk of flooding in the Loddon catchment is from rivers – and flooding events are being projected to become more frequent and more severe as the climate changes.”

Flood zones and areas most susceptible to flooding, from both rivers and surface water, are shown in another map.

The site also reports the extent to which physical modifications have impacted river health. Like many rivers, the Loddon has been modified over centuries – straightened, widened or deepened – to improve drainage for land, housing, industry and farming.

Habitat quality
Habitat quality on the Loddon

River habitat quality is also shown, with just one area rated as having a truly diverse habitat, according to River Habitat Survey methods. Many areas across the catchment have good ranges of habitat, but others are rated as poor. Another map outlines the results of fish surveys, compiled as indications of river health, allowing readers to click on specific areas.

The issues section ends with a warning: “The number of people living in Basingstoke, Wokingham, Sandhurst, Fleet and Aldershot is rapidly growing and these towns have multiple areas of new development proposed between 2023-2040.

“The south east of England is in the midst of a water shortage crisis. Growing populations together with our changing climate pose a severe risk to the health of our rivers. Many of the challenges faced by our river catchments are likely to be intensified by the demands of a growing population.“

So what can be done?

Perch at Tice's Meadow
Perch found at Tice’s Meadow in Loddon Rivers Week 2022

A key section of the Storymap is the action plan, outlining “natural processes opportunity mapping” that includes the potential for “floodplain reconnection”, for example lowering artificially incised riverbanks, the potential for riverside woodlands and such opportunities across the wider catchment.

Key priorities are to identify habitat improvements, deliver restoration or enhancements, improve fish passage by tackling barriers, keep rivers cool in the face of a changing climate and tackling invasive species.

It also outlines the benefit of natural capital mapping. “Taking a GIS-based catchment approach to understanding the location, condition and potential of natural assets,” the portal says “allows us to target action to protect water resources and communicate change. This enables us to integrate a catchment-scale nature-based solutions approach with water company plans, catchment partnerships, and landowners.”

Mentioning work that has been carried out on the catchment so far, the portal highlights Loddon Rivers Week, which takes place every September. Last year, residents witnessed instant improvements after taking part in gravel seeding in Hook and installed large woody materials at Tice’s Meadow and Ivy Recreation Ground in Aldershot. Other work on the Loddon involves a long-standing effort to remove Floating Pennywort and creation of the Charvil Meadows backwater in 2020.

Lastly, the Get Involved section prompts people who see issues with their river to report them to the relevant authority, to suggest enhancement protects, join the partnership as a group, volunteer for events or invest in the river by financially supporting enhancement work.

Whatever you want to know about the Loddon, visit the Storymap and get involved!

Making a difference during Loddon Rivers Week

Almost a year to the day that the South East Rivers Trust constructed a backwater on the River Loddon in Charvil Meadows, we were back to do further enhancements as part of Loddon Rivers Week 2021.

This was just one of a series of river work that took place during this celebration of the River Loddon and its tributaries, between 18th-26th September. The work to co-ordinate the week was funded by the Environment Agency.

During the week, volunteers planted native plants to stabilise the banks of the previously constructed backwater, put in gravel to a chalk stream, tackled invasive species and enjoyed learning about bats.

Several partners were involved in the week, including Hampshire and Isle of Wight Wildlife Trust, the Loddon Fisheries and Conservation Consultative, Blackwater Valley Countryside Partnership, Hampshire County Council and Dinton Pastures County Park.