Ann Berkeley, Evenlode Catchment Partnership Manager
The Smarter Water Catchments (SWC) Initiative, sponsored by Thames Water, was officially launched on 22nd October 2021. The launch took place at Magpie Farm near Chipping Norton where guests and local landowners had the opportunity to visit the farm’s newly constructed wetland complex.
Magpie Farm is situated in the upstream reaches of the Evenlode Catchment where rainwater flows quickly off agricultural land taking valuable nutrients and topsoil with it downstream. A complex of wetland habitats have been constructed to combat this issue as well as providing other benefits. A number of ponds act as sediment traps before the water enters a larger wetland area with a multi-functional design to cater for water treatment, biodiversity, and aesthetics. Downstream from the wetland, hay bales are used to create a greater diversity of flow and habitats for a range of wildlife. By slowing and storing more water on higher ground the scheme also serves as an effective natural flood management scheme.
The project was delivered in partnership between Thames Water, Natural England, Atkins, the landowner, and the Evenlode Catchment Partnership; it has proven to be an excellent example of multi-benefits.
The Smarter Water Catchments Initiative
In the past catchment management projects in the UK have typically been successful in tackling single issues such as pesticides or phosphorus pollution. However, continued increase in competition for water and the intensification of land use has led to a recognition that a more holistic approach to land and water management is required. Indeed, the non-linear, multi-sectoral nature of resource management means that improved collaboration between government, stakeholders, private companies, and local organisations is crucial for multiple benefits to be achieved. The Smarter Water Catchment approach seeks to do just this, bringing people together and drawing on the collective understanding of different partners to tackle multiple challenges that will provide wider benefits on a catchment wide scale.
At present, managing river catchments can often be a fragmented process with responsibilities divided between different organisations, funding mechanisms, and regulatory frameworks. The Smarter Water Catchments Initiative aims to combat some of these issues and build better functioning river catchments by:
1. Recognising catchments as interconnected systems
2. Working with key stakeholders to tackle multiple challenges together
3. Harnessing natural processes wherever possible
4. Capitalising on opportunities for solutions on a catchment scale
These principles and aims can be observed from the projects being delivered in the Evenlode Catchment. Here are some of the highlights:
Natural Flood Management
The Evenlode Catchment Partnership has delivered an award-winning Natural Flood Management scheme on the Littlestock Brook near Milton-under-Wychwood which entails harnessing natural processes to reduce flood risk to local communities. The project involves slowing and temporarily storing overland flows through land management and soft engineering processes to reduce flood risk to downstream communities. In total the natural flood management measures include 15 field corner bunds (which temporarily store 30,000m3 of flood water), 27 leaky woody dams, and 100m of de-culverted watercourse.
To reduce diffuse phosphate and sediment entering Littlestock Brook and improve wildlife habitats, the project also created 14 nutrient retention ponds and 1.1km field margin sediment/nutrient traps, as well as planting 14.4ha of riparian woodland and constructing a new footpath for recreation.
As one of the first NFM projects in the Thames Basin, it increases our understanding of the effectiveness of working with natural processes for flood risk management in a lowland agricultural landscape. Hydraulic modelling results show that the new measures reduce the severity of flooding to 12 properties for a range of flood events. A comprehensive monitoring network of water levels, sediment and nutrient fluxes in heavy-rainfall events has generated detailed evidence on the effectiveness of these features for flood risk and wider ecosystem services of water quality, habitat, and carbon.
Critical to the project’s success has been integrated delivery through the Evenlode Catchment Partnership and local community to address multiple local environmental issues and to empower them to invest in their own catchment-based solutions. The project was selected as the winner of the Climate Resilient Places category in the Flood & Coast Excellence Awards 2021. #
River Restoration
As well as mitigating flood risk, natural processes can be harnessed to provide wider ecosystem benefits. This is being achieved through a collaborative project on the Dorn where the river has been reconnected to its historical floodplain. A series of natural barriers have been installed to control the flow of the river, in much the same way beavers would have done in the past. These natural barriers and scrapes are enabling a rewilding of the landscape by returning the river to the way it would have looked before human interference and bringing important benefits for river health and biodiversity as well as increasing the flood resilience of the catchment. It has been a collaborative project bringing together partners including Atkins, Blenheim Estate, The Environment Agency, and the ECP.
Water Quality and Advocacy
Working together towards a shared vision is crucial in the challenge of improving water quality in the Evenlode Catchment. Poor water quality means that none of the 18 waterbodies in the catchment currently achieve ‘good’ ecological status under the WFD. Phosphorus is the main pollutant; about 65% of which comes from sewage effluent and about 28% from agricultural runoff. The high phosphorus concentration enriches the water and causes algal blooms in the late spring and summer which severely affect the quantity and diversity of macrophytes, invertebrates and fish.
Currently, only the sewage treatment works (STWs) on the Dorn and the Glyme tributaries are equipped with phosphorus stripping capabilities – more investment to upgrade the Catchment’s other STWs with this capability will be vital if the aim of achieving good ecological status in the catchment’s watercourses is to be realised.
Since the launch of the Smarter Water Catchments Initiative the Evenlode Catchment Partnership (ECP) has installed multi-parameter sondes in strategic locations around the catchment. These devices monitor a range of parameters including ammonia, conductivity, dissolved organic matter, turbidity, and tryptophan for coliforms. Using these devices makes it possible to monitor changes in water quality in real time and enhances our ability to build a detailed picture of water quality issues in the catchment. The data captured will be available to the general public through an open-source online portal in the near future.
Catchment-scale solutions necessarily involve bringing together multiple stakeholders behind acommon aim and drawing on the collective expertise and experience available. The North-East Cotswolds Farmer Cluster comprises over 50 farms that together make up a significant portion of the Evenlode Catchment. The cluster aims to deliver landscape-scale regeneration of the farmed environment through collaboration and knowledge exchange. As well as improving soil health, working together on this scale creates the opportunity for linking priority habitats together such as species rich grasslands, wetlands, watercourses, and pollinator corridors.
Riverfly Monitoring
Local communities can be well placed to be the natural guardians of the river environment and in an ideal position to monitor the health of their watercourses. The ECP has been working with the Riverfly Partnership who spearhead an initiative to allow communities and anglers to take action that will help conserve the river environment. Training days are run for members of the public to learn how to identify and monitor riverfly populations on their stretch of river. This initiative provides a simple monitoring technique which participants can use to detect any severe changes in river water quality and puts them in direct communication with the Ecology Contact of the Environment Agency.
Conclusion
The Smarter Water Catchments Initiative is being trialled by Thames Water in three catchments using £3 million seed funding for each catchment over a period of 5 years from 2020 to 2025. These consist of the Evenlode, Chess and Crane catchments.Addition funding has also been secured from the Environment Agency and other partners.By bringing together partnerships of key actors and communities, all working towards a shared vision, creates great potential to deliver long lasting multi-benefit projects. The partnership continues to lobby for adequate investment into upgrading the Evenlode Catchment’s sewage treatment works and for raw sewage spills to be stopped. If this can be achieved, then the outlook for the catchment’s water quality and biodiversity looks brighter.
