Connecting fields to the river

By John Boardman, Environmental Change Institute

River pollution is a major problem with few rivers in the UK measuring up to the ‘Good’ standard under Water Framework Directive criteria.  Concerns are about ecological damage, voiced by the angling community, and the costs of purification borne by water companies and therefore consumers.

Pollution comes in many forms – when my grandson (8) swims in the Thames he asks me ‘Will I find a Shopping Trolley?’ In rural England, N and P, pesticides and metaldehyde (slug pellets) are pollutants. Damage to fisheries is often the result of fine sediments coating the beds of former gravel-based streams. Over 70% of fine sediment in watercourses in England and Wales is from agricultural sources.

The problems are acute and challenging in areas of intensive arable farming, an example being the Rother valley in West Sussex (Figure 1). Fertile, easily worked but erodible soils are used to grow winter cereals, maize, potatoes, vegetables, salad crops and asparagus.  Most fields in the low-lying belt near to the river are under crops, some with irrigation adding to the risk of runoff.

Figure 1. The Rother valley and fields with a history of erosion since 1987

Erosion in the form of gullies, rills or wash is a frequent occurrence and we have a database of almost 200 fields with a history of erosion since 1987 (Figure 2). This is based on one-off surveys, remote sensing, including Google Earth, and systematic monitoring of all the fields in the last five years.

Figure 2. Erosion near Petworth on a winter cereal field, February 2014

The threat to the river is not so much a result of high erosion rates (these occur occasionally), as the degree of connectivity between arable fields and the river.  Of the 200 fields about 68% are potentially connected to the river: runoff and sediment reaching the river by various routes (Figure 3). At times of exceptional erosion and during storms it is possible to map routeways and points at which sediment enters the river. This is not a task for the faint-hearted or for modellers. Maps and models are poor predictors of pathways of flow. They tell us little about field boundaries: are they permeable or impermeable?  We also need field evidence for the condition of ditches (cleaned or overgrown?) and the presence of culverts between fields and under roads. This is not to deny the usefulness of technology. Google Earth, when one is fortunate with the date of the image, is brilliant!

Figure 3. Routes from the fields to the river

Understanding patterns of connectivity gives us a chance to design mitigation measures to protect the river. In the Rother valley this is an ongoing challenge because with a predominance of high value crops it is not easy to persuade farmers to adopt less risky land use options. Also, detaining coarse sediment (sand) is not difficult but fine sediment tends to travel with the runoff and reach the river via leaky mitigation measures.

This research has been a co-operative effort. I thank Professor Ian Foster (Northampton), South Downs National Park, the Arun and Rother Rivers Trust, Catchment Sensitive Farming, Southern Water and the Environment Agency for help and data.

Further reading

Boardman, J. 2016. The value of Google Earth for erosion mapping. Catena 143, 123-127

Boardman, J. Vandaele, K., Evans, R., Foster, I.D.L. 2019. Off-site impacts of soil erosion and runoff: why connectivity is more important than erosion rates. Soil Use and Management 35(2), 245-256DOI: 10.1111/sum.12496

Impacts of drought on water intakes for Power Stations

As part of the NERC- Oxford ENDOWS/MARIUS Drought Project, Prof Paul Whitehead and Dr Gianba Bussi have undertaken a water quality modelling study on the River Trent. The aim was to assess the potential impacts of drought on water intakes for Power Stations on the Trent. INCA Flow, N, P Sediments, DO and BOD models were set up for the Trent catchment.  A set of drought scenarios based on the Oxford Weather@home data sets were used to drive the models and assess impacts on flows and water quality. Power plants use river waters for cooling purposes and can be sensitive to droughts and low flows. Water quality is also a concern, due to algal blooms and sediment loads that might clog filters. Paul and Gianba assessed the impacts of droughts on river flow and water quality from the point of view of power plant operation. The INCA (INtegrated CAtchment) water quality model was coupled with the weatrher@home climate model to create a dataset of flow and water quality time series. The results suggest a significant decrease in flows and an increase in phosphorus concentrations, potentially enhancing algal production. Power plants should expect more stress in the future based on the results of this study, due to reduced cooling water availability and decreasing upstream water quality. This issue might have serious consequences also on the whole national power network.

Fig 1: River Trent Topography and INCA Reach Boundaries

Fig 2: Impacts of Climate Change (near future and far future) on distributions of the average concentration of nitrate and phosphorus during droughts (top row) and maximum concentration of nitrate and phosphorus during droughts (bottom row) for the River Trent at the catchment outlet (Reach 10).

See more: Bussi, G., P.G. Whitehead. 2020. Impacts of droughts on low flows and water quality near power stations. Hydrological Sciences Journal, doi: 10.1080/02626667.2020.1724295.

Technological solutions to global challenges

OWN member, Prof Richard Compton, and Profs Rickaby and Bouman, embark on collaborative project to improve monitoring of ocean ecosystems. Read the press release here.

On the move: What drives Somalia’s migration?

Read the blog feature on recent book chapter by OWN member, Lisa Thalheimer here.

How will the COVID-19 pandemic impact food security and virtual water “trade”?

OWN member, Hussam Hussein, writes about the impact of Covid-19 on food security and virtual water trade. Read about it here.

River Nile dam: Reservoir filling up

OWN member, Dr Kevin Wheeler, comments on Ethiopia’s Grand Renaissance dam for the BBC. Read the article here.

Legalising water?

By Associate Professor Bettina Lange

Managing water resources is increasingly governed by an expanding and complex set of legal rules. Ch. 15 of Fisher, Lange and Scotford ‘Environmental Law: Text, Cases and Materials’ (2019, OUP) introduces key provisions of water law applicable in the UK. The chapter discusses the main environmental offence that can be harnessed for sanctioning the pollution of water, and outlines regulatory frameworks for the discharge and abstraction of water, as well as recent developments in drought and flood law. The recently published update for this textbook sets out succinctly the latest developments in the courts’ approach to fining water polluters, the impact of Brexit on environmental, including water law in the UK, as well as on-going developments in relation to the recent core piece of environmental legislation in the UK: The Environment Bill 2019-21.

TEDx Oxford talk on Smart Handpumps

Patrick Thomson is lead researcher for the Smith School’s Water Programme. Patrick’s research focuses on the use of technology to enable institutional change and bring reliable water services to rural communities. To this end, Patrick developed the first Smart hand-pump for water use, the story of which is the subject of this talk. Patrick Thomson is lead researcher for the Smith School’s Water Programme. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at

Watch the talk here.

WaterSciencePolicy Blog launch from WSPM alumni

WaterSciencePolicy launched in May 2020 as in independent initiative by a group of Oxford WSPM Alumni. It serves as a global digital platform to connect the work of academia and the research community – in an blog format – with the opinions of practitioners and activists in the field of water and water-related issues. It was designed as a public space where researchers can contribute to make their academic work more accessible by condensing it into a more concise format and practitioners can share their experience from the field. The platform thrives to be a hub for triggering dynamic discussions, where ultimately science meets policy and management. It is ad-free and open access to provide everyone an independent voice. The aim is to inform with substantiated and explanatory content on the latest developments, facilitating informed discourse and novel insights among an expanding water-curious audience. With an interdisciplinary approach across regions and sectors, the platform disseminates cutting-edge research, original points of view and innovative practices to stimulate critical debate and understanding. WaterSciencePolicy convenes thinkers to discuss why water matters and what are the possible solutions towards living prosperous lives while respecting planetary boundaries.

Do you want to give the world a glimpse into a particular water-related issue you are working on? Do you have exciting research to share? Do you have novel insights or want to challenge existing paradigms? Whether you are a professional, an academic, or a layman, as long as you have something important to say about water, WaterSciencePolicy team is interested in your contribution. Here is how you can submit:

Guidelines for submission: Checklist

  • Your 800-1000 words .docx article, including:
    • short blurb – three bullet point sentences at the beginning of your text to summarize the main ideas of your piece
    • In-text references with hyperlinks (including for diagrams and pictures – unless they are your own)
    • short Bio (up to 50 words) + your LinkedIn & Twitter – if desired
    • Proper spelling and other intricacies with respect to our English Style Guide
  • Pictures and diagrams as separate files
  • square (1:1) profile picture
  • A header image that is most relevant to the content
  • This is it, four points. Now place in a folder, zip it all up and send it to

If you have more questions, have a look at existing articles and make sure to check out the more elaborate submission guidelines for tips and tricks on What makes a good blog here.

Securing access to safe water is more important than ever

OWN member Dr Catherine Fallon Grasham argues that securing safe water is more important now more than ever before. Read about it here.