Latest Presentation on state of aquifiers and flows: Dr. Michael Jones of Thames Water as delivered to Open Meeting FOGB 15th June 2022 Click here
YouTube recording of Thames Valley Flood Scheme Catchment Partnership Meeting 16th August 2021CLICK HERE
THAMES WATER Abstraction of Water from the Baunton Pumping Station. Report 21st July 2021N.B. These reductions were first introduced in 2005 and abstraction ceases when flows drop below 32 Ml/d at the Baunton gauging station. Flows have just reduced in the River Churn to below the flow constraint related to our Baunton abstraction. Therefore we will be turning off the Baunton abstraction within 24 hours. It is interesting that this is very late in the year for this to happen compared to the normal situation when we hit the flow constraint around March time. The reason for it being so late this year was the heavy rainfall in May which led to the recovery of groundwater levels which was very unusual for the time of year but very welcome for water resources if not for flood impacts!
Some homes in Cirencester and villages along the River Churn have suffered flooding this winter, and more have been under threat. The Friends of Gumstool Brook are interested in adequate water flow in local streams in dry, summer weather, but also in protection from excess water during wet, winter conditions. We are a special interest group so have no power to make changes, but we record data, make it available and encourage the various official organisations to work together to manage the watercourses wisely. That management is not an easy task, the various interlinked streams and the Churn affect one another, and keeping everything in balance is a challenge. When heavy rain fills the Churn north of Cirencester the water spreads across the flood meadows and these act as holding reservoirs – up to a point.
Here’s a photo of the Churn passing under the Abbey Way bridge on 27th December, 2020 as you can see, it’s almost up to the underside of the bridge itself.
And this is the field beside the Barton Mill Pound, doing a great job of holding water that would otherwise threaten homes in The Mead and Gloucester Street.
And finally, this is water overflowing from the Mill Pound into the flood meadow, despite a rapidly flowing conduit recently installed to prevent the level ever reaching this point. When rain is heavy and persistent over a period of weeks, this is the inevitable result.
Our hearts go out to everyone suffering from flooding. We will continue to monitor the conditions and influence the decision makers to the best of our ability. Meanwhile, we can all hope for drier weather as this will quickly reduce water levels and get us back to normal.
We wish all our readers a Happy (and flood free) New Year in 2021.
After a wet autumn and winter (2019-2020) in the Thames catchment, experiencing above average rainfall, Spring saw below average rainfall, with May 2020 being the driest May in our 136 year record (Thames Water – Water Situation).
The wet autumn and winter was good for groundwater, with aquifers filling up sometimes to exceptionally high levels, and river flows also being above average. Now across the Thames region, the availability of groundwater in our aquifers is generally at around normal levels for this time of year, and while river flows are below average our reservoir storage is only just below average. The water situation has been similar in the Cotswolds and around Cirencester, with good winter flows in the Daglingworth Stream and River Churn decreasing to much lower flows in June.
As a result of decreasing river flows, and as required by our licence from the Environment Agency, Thames Water’s groundwater treatment works for public water supply at Baunton was switched off as is often the case in the summer; this year switching off in late May. This trend in river flows is consistent with groundwater levels decreasing from exceptionally high to just below normal for the time of year. There are however some exceptions, with groundwater levels in parts of the Cotswolds being notably low for the time of year.
Although the current water resources position is reasonably healthy, our region, like much of the South East, is seriously water-stressed. Every drop we supply to our customers comes straight from the environment and would otherwise be sustaining local wildlife and wetlands and keeping our rivers flowing. Normally, about a third of the water we supply in the Thames region is pumped from natural underground aquifers. The remainder is abstracted from rivers – however, as we move into the summer most of the river water is itself supplied from aquifers, making groundwater a truly vital source.
Over the last couple of months, we’ve seen unprecedented demand in many of our water supply areas. Due to Covid-19 very few people are commuting into central London, which has a separate water supply system, leading to a greatly increased demand across the rest of our region. With so many people at home all day, we’ve seen a massive change in the way water is used and how much is needed. This has been compounded by the unusually warm weather, and the driest May on record, leading to a huge upsurge of interest in gardening and in the usage of paddling pools and hot-tubs during lockdown.
In some areas our customers have been using water faster than we can treat it and pump it through our pipes, leading to low pressure and in some cases, interruptions to supply. These are currently local problems, but if we have a hot, dry summer we could not only struggle to keep up with demand but also see levels dropping faster than normal in our aquifers and reservoirs. We have never before experienced the current pattern of demand for water, and no one is sure what the next few months will look like.
Reductions in demand will have an immediate impact on the environment by reducing the amount of water we must abstract from river and groundwater sources thereby sustaining river flows and ecosystems. To raise awareness, we’ve started a four-week campaign using local radio, digital audio and social media. Through these channels, we’re explaining how water supplies have been impacted in recent months, providing water efficiency tips and asking customers to be more aware of how they use our most precious resource. We hope this, and promoting the water saving tips on our ‘How you can be water smart’ webpage, will prompt a reduction in usage and help us avoid a water shortage in coming months.
A wet winter has been followed by an exceptionally dry and sunny May in 2020. This makes for nice weather but leaves our lovely waterways under threat of ‘drying-up’ later this summer. The Friends of the Gumstool Brook was founded in 2013 as a result of concern about this type of destructive problem.
A photograph below (taken December 2019) of the overflow from the Barton Mill Pound feeding into the water meadows. Built in 2018 it is intended as a natural resistance to flooding downstream by diverting excess waters into the fields where they may more easily dissipate. We are keeping the system under review.
UPDATE 2022 Remedial work urgently required for Summer 2022
This winter has been much wetter than normal; frequent and sometimes heavy rain has filled local streams and the River Churn to unusually high levels for an extended period. The photo shows the water flowing past Cirencester’s outdoor swimming pool on 29th October. The pipe crossing the stream is normally well above the water level, and although no longer covered now, the gap between pipe and water remains unusually small. The water meadows along the course of the Churn have been partially flooded for three months now.
Of course, some winters are wetter than others and that has always been the case. 2019/2020 has not been exceptional in the long-term record, and it’s been good to see water levels consistently high for an extended period when we’ve so often witnessed the Daglingworth Stream completely dry between Stratton and Cirencester in summertime. Will this happen in 2020? We’ll have to wait and see.
Our local watercourses are always fascinating, ever changing, and with some interesting wildlife. If you haven’t done so recently, pick a dry, sunny day and treat yourself to a stroll along the Churn and its associated streams. OpenStreetMap marks most of the smaller paths and shows the water courses clearly, all an easy walk from the Market Place.
The humble sluice gate doesn’t get a lot of attention – unless things go badly wrong. All managed water courses have sluice gates to control the flow, and the Gumstool Brook and its associated channels are no exception.
There is good news this winter. The sluice feeding Barton Mill Pound from the River Churn is open and water is flowing well along the Riverside Walk; excessive levels are prevented by the recently constructed overflow into the water meadow north of Riverside Walk. The Mill Pound and the channel past the outdoor swimming pool are now full, and consistent enough in level that they’re frequented by water voles and a kingfisher. What a delight it is to spot either of these wonderful creatures. Look out for moving, rustling leaves on the bank at dusk (water vole), or a flash of blue during the day (kingfisher).
There’s an important sluice gate from the stream past the swimming pool into the Gumstool Brook between the horse paddock and the back gardens of The Mead, and this remains closed. So despite wet weather and high water levels, the Gumstool Brook is lower than it would be if the sluice was open, and properties in and around the brook are protected from flooding. (Note: the Friends of the Gumstool Brook have no control over these sluice gates; they are managed by various authorities.)