Martin Cray from the Wye & Usk Foundation updates us on how a charity duck race on the River Usk exposed serious problems, from low flows to compacted soils - learn how the Wye & Usk Foundation is restoring rivers and tackling climate impacts.
READY, STEADY, GO!
As crowds covered the bridge and lined the banks of the Usk, the annual Crickhowell Rotary duck race started to resemble a comedy sketch. Instead of cheering on the sight of 1,600 plastic ducks racing 100m down-stream to the waiting nets, the ducks stayed steadfastly in a row – at the start line.
Despite the surreal pace of the event, there actually was a nail-biting finish (relatively speaking). The leading duck, that had been several metres ahead for the vast majority of the race, stalled with barely 10 meters to go, at the exact moment half a dozen other ducks on the opposite side of the river found some water that was actually moving and ‘streaked’ past to the delight of the crowd.
As the winner was announced, and prizes awarded to the holders of the lucky tickets, the glacial pace of the flow and the ankle deep level of the river was not lost on the crowd. Most commented that it was down to the incredibly dry and warm summer and that was probably attributable to climate change.
What they might not have realised is that, in this particular instance, whilst the low flow certainly wasn’t helped by a summer that seemed more like Casablanca than Crickhowell, it was actually the lack of rain in March that was the major culprit.
WATER FLOWS
Summer flows are not just affected by the amount of rain falling over the summer months. They are ‘underpinned’ by base flow from the geology which is recharged by the winter and early spring rains that soak through the ground, accumulate in aquifers and is subsequently released into the river over the following months.
However, we have a huge problem in both the Wye and the Usk catchments because compacted soil is unable to absorb the rain events and instead it runs straight into the river causing huge silt build ups and, even worse, increasing the severity of floods. If it has run off fast, it is not available in the following months when rain is much less likely.
In the Usk, the St Maughan’s Aquifer that underlies the headwaters is shallow and the rocks discharge faster than most. This means November rain has already mostly discharged by the time you get to May. It is the late winter/early spring rain that loads aquifers for the summer, and late winter is when our headwaters are most compacted.
PREVENTION BETTER THAN CURE
We believe prevention is better than cure: a lot of the farming practices which result in problems like compacting the soil are motivated by economic models outside of the farmers’ control. So we have advisors out in the field helping farmers utilise schemes which benefit the rivers and the local environment.
We have boots on the ground managing projects like under-sowing maize, finding and breaking plough pans, tree planting, wild meadow creation, wetlands creation, habitat restoration and installing features that hold and check run off during heavy rain.
These are all patches on the root issue, and we are setting up markets that will move funds towards managing the land better to harness the incredible ability of soil to absorb rainfall. These will reduce soil and nutrient loss and transform the response of our rivers to rainfall.
They will slow the discharge, reducing flood peak, and ensure more rain goes into the groundwater so that spring and summer flows are less reliant on rainfall. We know that late winter floods, low spring flows and excessive soil loss are causing the problems with our fish and ranunuculus populations.
This is how we are transforming the catchments and mitigating the impacts of climate change.
We need to fundamentally change the systems in place because unless we do, if it doesn’t rain in March, or if it does but runs off, then the river will almost run dry and you really won’t have much trouble keeping your ducks in a row!
