Hogsmill Community Newsletter

Author: Ian Lamont

Hogsmill Community Newsletter

Posted on by Ian Lamont

The Hogsmill Community Newsletter summarises the results of River Monitoring Initiative (RMI) sampling on the Hogsmill, together with other pollution monitoring and river-related activities and events.

The RMI is a national scheme for monitoring the health of rivers. Volunteers undertake regular surveys using a standard net sampling technique to count the number of certain “water quality sensitive” invertebrates.

An overall “score” is then calculated. A sharp fall or a drop below a “trigger” level could indicate pollution. This can then be reported to the Environment Agency (EA) to enable further investigation.

SuDS design and delivery

Posted on by Ian Lamont

When Covid-19 affected our plans for the SuDS in Sutton’s Schools project, the South East Rivers Trust shifted its focus from Education and Engagement to Design and Delivery – increasing the expertise we are able to give on future sustainable drainage systems (SuDS) projects.

The primary objective of any SuDS scheme is to alleviate flood risk – capturing and storing rainwater, reducing pressure on the drainage system.

We worked with schools to deliver clear benefits, whether it be for wildlife, as calm spaces or to enhance the work of particular lessons.

The SuDS in Sutton’s Schools project was managed by the London Borough of Sutton council and our role has been to deliver education and engagement to help schools meet flood relief targets.  The primary aim has been to alleviate flood risk in the Hackbridge area – known as Critical Drainage Area 33.

The SuDS in Sutton’s Schools project was delivered in schools in two phases – using the summer holidays to deliver the bulk of the work.  The first phase was completed in 2019 and, because of delays caused by Covid-19, the second phase was completed in 2021.

Thames Catchment Community Eels Project

Posted on by Ian Lamont

We’re eel-y excited to announce that Thames Rivers Trust in partnership with the South East Rivers Trust, Action for the River Kennet, and Thames21, have been successful in gaining funding to aid the long-term survival of the European eel.

Eels have a spectacular and complex life cycle! European eels spend most of their lives living in Europe’s rivers, including here in the UK. When they are ready to spawn they migrate more than 6,000km across the Atlantic to the Sargasso Sea, where their lifecycle begins again.

Once hatched, the larvae make the incredible journey back across the ocean to our rivers, and develop into young eels, also known as elvers, before swimming upstream.

SERT on tour – delivering a fish passage project on the River Ock

Posted on by Ian Lamont

In September 2020, we successfully installed two fish passes on a weir on the River Ock in Abingdon. The River Ock is a small tributary of the Thames and owes its name to the pre-Saxon word “Ock” meaning young salmon. Salmon were a common sight on the Ock and a staple part of local diets in the middle ages. So why are these migratory majesties no longer present on the river?

Aside from other more global issues, barriers to migration such as the weir at Abingdon would present challenges to upstream migration of all fish species, not just salmon. The weir results in fragmented habitat which in turn can create bottlenecks at varying life stages. As a result, the survival and success of fish is compromised. It was therefore in the river’s best interest to implement fish passage on this weir.

The weir is a standard crump gauging weir, used by the Environment Agency’s Hydrometry and Telemetry’s team to monitor flows in order to help predict downstream flooding and manage abstraction licenses. It is 5.7m long and split into two channels. The left hand channel (as you look downstream) feeds the River Ock and the right hand channel feeds the Sandford Brook. The design of the weir, coupled with the fact that it was a gauging station, added several complexities.

Action on sewage in rivers

Posted on by Ian Lamont

Raw sewage is entering UK rivers on a horrifyingly regular basis, damaging our river ecosystems and putting public health at risk. In 2019 alone, untreated sewage poured into England’s rivers for an astounding 1.5 million hours, over the course of 200,000 separate incidents.

What’s really shocking is that, much of the time, this practice is completely legal.

Across the UK is a network of Combined Sewer Overflows (CSOs). These are essentially Victorian-era relief valves on the sewage treatment infrastructure. If sewage piping, or even a sewage treatment works, is becoming overwhelmed with sewage and rainwater, it is diverted and discharged into a nearby watercourse instead of backing up into homes.

Eat, Sleep, Restore, Repeat

Posted on by Ian Lamont

Our volunteers were incredibly busy back in February 2020, carrying out River Restoration on the Beverley Brook and Wandle.

At the start of 2020, a new group of volunteer River Restorers came together to learn about natural river processes and how heavily modified waterbodies (such as the Beverley Brook) have been altered over time. These changes stop the natural processes which would usually shape a healthy river ecosystem, leaving us with a degraded river that has few, good habitats for wildlife.

Early in 2019, we carried out a large-scale restoration project along 1.3 km of the Beverley Brook through Wimbledon Common. Our River Restorer volunteers came on board to help us extend the work upstream – this time using people power alone!

We worked together to plan and design the work, ready to deliver as a team in mid-February.

Drain misconnections and our rivers

Posted on by Ian Lamont

A guest blog written by Jennifer Connelly

According to the Department for Environment, Food and Rural Affairs, there are still an estimated 150,000 to 500,000 UK homes with misconnected drains. Dodgy pipework or old houses with out of date plumbing can cause wastewater to end up in our rivers and seas, creating serious problems for wildlife. So what are drain misconnections, what causes them and how do they affect our environment?

First rain garden complete

Posted on by Ian Lamont

The weather could not have been better for our planting day at Sutton Council’s Denmark Road Offices, writes Charlene Duncan. This planting day was organised to enable staff members to contribute to the new rain garden. Thanks to the hard work of everyone who came out, the rain garden is now complete!

Nearly 30 members of staff volunteered their time to transform the area in front of the building. It was a great chance for staff to meet people from other departments and to socialise with colleagues.  Staff members gave what time they could, from 20 minutes to more than three hours!  Every contribution was greatly appreciated.

This rain garden is part of our SuDS in Sutton’s Schools project.  It demonstrates sustainable drainage systems (SuDS) to the schools involved in the project and the wider community. SuDS are measures that divert water from the drains to reduce flood risk and improve the quality of water flowing into our rivers.

By waiting until the autumn to plant up the rain garden, we have increased the new plants’ chances of survival.  Planting during this summer’s drought would have meant the plants required a lot of watering.  While a bit of watering is still necessary for the newly planted garden, once established, the water from the offices’ downpipes will be all that is needed.

So, a massive thank you to all volunteers who gave up their time.  And, an extra thank you for those of you who could not give your time but offered moral support and encouragement on the day.  The garden is looking lovely and it’s all down to you.

Now all we need is some rain.

Watch our timelapse video of the rain garden being constructed