Devon and Cornwall Soils Alliance Lower River Cober – Business Case
Stuart Coleman
1 Introduction
The following report provides a brief business case overview of the findings from the feasibility study area, which is one of nine across the Devon and Cornwall region funded by the Water Environment Grant (WEG). These waterbodies fail the WFD for sediment related issues and these business cases provide evidence as to type and location of soil and sediment issues, degree of farm advice and grant required to support business, regulatory issues/failings and whether current farming practices within the catchment are aligned with inherent land capability.
2 Lower River Cober
1.1 Background
The Lower River Cober is located on Cornwall’s south coast. It is fed by two waterbodies, the Upper River Cober and Carminowe Creek and is approximately 1900ha (Figure 1). During wet weather walk-over surveys the catchment was found to be affected by soil erosion and compaction as well as poaching and run off.
1.2 Deskbased study
The soil type maps and underlying geology maps were the most valued section in this GIS pack; providing useful guidance on the general characteristics of the soils likely to be experienced during the survey; and indeed the problems which might be experienced on them. They formed the initial reference for further desk-based investigation. The water quality and consented discharges maps were also generally useful. However, the habitat maps had limitations due to habitat classification methods and an underestimation of good quality semiimproved grassland.
The main farm sectors found in the lower Cober sub-catchment are:
• Dairy – with significant dirty-water and slurry outputs from the livestock in the yard areas; and a range of grass and fodder-crops, and some cereals, and in one case additional cropping of potatoes;
• Beef - with a range of grass and fodder-crops;
• Vegetable Cropping – mainly via contractors on rented land;
• Horticultural Bulbs - mainly via contractors on rented land;
• Smallholdings – including residential and non-commercial livestock, and horses;
• Woodland – Mainly riparian growth owned by multiple holdings; but also two substantial blocks of woodland owned by the NT Penrose Estate surrounding Loe Pool SSSI; and the Trevarno Estate higher up the catchment including steep ground beside the Trevarno Stream;
• Energy Cropping – there is also a relative newcomer to the Cober catchment generally – rotational growth of crops as feed-stock for an Anaerobic Digestion power- plant in a nearby parish to the north-west of the catchment. It is known that the contractors who own the plant have diversified into this new enterprise in recent years, and are already renting land in the upper Cober with a three year crop rotation of Fodder Beet / Maize / Rye Cereal. This has been proven to be grown in substantial blocks of land; and the non-food use of these crops has led to both untimely harvests and untimely cultivations to fit in with power-plant requirements for fuel. This has led to at least one near-pollution incident (mitigated by a significant buffer-strip in the upper Cober catchment. It is suspected, but yet to be proven, that this energy cropping is moving into the lower Cober catchment; and as such poses a new pressure on soils and adjacent access routes, and a new risk of pollution for local watercourses.
1.3 Literature summary
The EA River Basin Management Plan is really the framework within which CWT already works when engaging in catchment-based projects; so it did not provide much useful information that we did not already know at a sub-catchment scale. The specific data for the River Cober itself is the really useful information.
The Loe Pool Forum is the oldest community-based catchment organisation in the UK; and its series of historic catchment management reports offer a useful insight into the long-term efforts to identify the pollution problems facing Loe Pool SSSI, and mitigate against them. The most recent document produced is the ‘2017 Cober Management Review and 2027 Plan’; which offers a useful overview of a range of issues relating to water quality and ecological functionality in Loe Pool, and flooding problems experienced in the Helston area; with information drawn from multiple sources.
The limitation of the document’s value is that its main focus is on Loe Pool and its immediate environs; and there is limited scope at the time of writing to consider the agricultural management of the wider catchment in detail.
The limited budget and associated time allocation of this project means a thorough read of the documents was not possible.
The Loe Pool Catchment Management Plans do contain useful information, and offer a valuable and publically available resource for exploring the history of environmental problems associated with Loe Pool SSSI and the wider Cober catchment; and the strategies to make improvements
1.4 Fieldwork findings
The Soil Mentor estimated that several farms are impacting the whole catchment, but these are evenly distributed across the catchment. The free draining soils were found to be forgiving of careful agricultural practices. However, the following issues were identified by the Soil Mentor:
- Soil compaction from livestock and farm vehicles were a major source of soil run off;
- Crop types and cropping practices that are prone to run off were observed in the catchment;
- Run-off pathways onto roads/lanes into drains, on-line ditches and bridges were a major contributor to soil entering the watercourse;
- Lack of cover crop/post harvest cultivations on overwintering arable and maize stubbles;
- Late winter cereal sowing.
High suspended-sediment are often witnessed within watercourses in the whole Cober catchment, not just the lower sub-catchment and the problems of soil run-off and diffuse pollution from rented ground are widespread, and not limited to individual fields.
Dirty-water run-off from livestock farming; especially via dairy yards and associated slurry and dirty-water applications to fields; is known to be a non-soil source of phosphate and nitrate pollution entering watercourses leading into Loe Pool SSSI.
1.5 Regulation
The Soil Mentor was asked a series of questions that related to the issues and failings they observed in the catchment. These questions and the Soil Mentor’s responses are outlined in (Table 1, question 2), it was estimated that 100% of the issues could be improved with better enforcement.
1
Of the issues highlighted in the feasibility report, what percentage of these issues would be classed as regulatory failings? E.g. SSAFO, FRFW, X compliance. Please note, this is for the % of issues highlighted, not the % of the whole catchment?
Would better enforcement of current regulations such as FRFW, X-compliance, NVZ work towards improving the issues highlighted?
A general lack of regulatory enforcement is the critical problem throughout the Cober, not just the lower Cober. A better funded EA Environmental and Farm Advisory Team would make our non-regulatory role in delivering the UST project, and the allocation and uptake of various EA diffuse-pollution grants much easier - we need carrot AND stick... but nonstatutory organisations can never provide the stick..!!
1.6 Land capability and landuse type
The observations of the Soil Mentor in the Lower River Cober catchment suggest that there are areas where the farming practices are not aligned to the capability of the land. A particular example was the growing of bulbs in the catchment, which was considered the largest contributor to sediment pollution entering the Penrose stream.
1.7 Solutions and recommendations
The Soil Mentor suggested that any funded initiatives should be supported/underpinned by a number of elements, including:
- Multi-location water sampling, over a number of years which would provide a “proof of concept” that is needed to identify the impact of different crops over the seasons;
- Effective Environment Agency enforcement, in order for the threat of enforcement to be real;
- Comprehensive engagement with farmers, landowners and large veg cropping contractors;
- Experienced farm advisors to help identify the problems and to support in the preparation of a well-planned Countryside Stewardship application;
- Additional EA funding for targeted advise and capital work.
1.8 Estimated cost of remediation
The approximate costs of addressing the pollution issues in the catchment are shown in Table 2.
Farm and Soils Adviser
1 x Part-time (3 x 7.5 hours) x 5 years = £54,000 x 60% = £32,400 x 5 years = £162,000 Water Monitoring and Data Collection Officer 1 x Part-time (2 x 7.5 hours) x 5 years =£45,900 x 40% = £18,360 x 5 years = £91,800
Total £488k (Medium)
1.9 Risks and barriers associated with solutions
No specific risks identified.
1.10 Benefits of change
- Reduce the amount of run-off soil leaving fields and entering watercourses as suspended sediments; the reduction of sediment deposited on gravel-beds in the watercourses with benefit a range of macro-inverts and brown trout, and the higher species which eat them.
- The reduction of soil entering roads and drains and culverts will reduce blockages and associated flooding of property, and the associated risk of traffic accidents and the public cost of drain maintenance.
- The reduction of phosphate associated with the suspended sediments traveling in the watercourses will reduce the building of a nutrient-rich sediment load in Loe Pool SSSI – a major cause of eutrophication in the lake, and a major reason for the waterbody failing its required condition standards under WFD.
- Reduced nitrate leaching through top-soils into the water-table, and in turn entering watercourses and Loe Pool – a major cause of eutrophication in the lake, and a major reason for the waterbody failing its required condition standards under WFD.
- Reduced loss of green-house gases to the atmosphere.
- Improved Natural Flood Management, with reduced peaks of flow at known pinchpoints in the catchment.
- Improved crop performance, with better soil condition and nutrient balance.
- Reduced requirement for inorganic fertilisers.
- Reduced requirement for herbicide use.
- Reduced requirement for cultivating and re-seed pastures to ‘freshen them up’ and tackle pernicious weed problems.
- Improved soil organic-matter.
- Reduced processed drinking-water requirements.
- Improved farmland wildlife within the sub-catchment and beyond.
- Improved knowledge base within the farming sector
- Improved community well-being – more connectedness between the farming sector and the rural and suburban residents.
1.11 Lessons learnt
The general health-risk relating to lockdown precautions hung over everything during 2020 and into 2021; and this did make in-person interviews with new landowners, and free access to their land by an unknown agri-environment consultant challenging. Also, an underestimation of the time each task would take lead to a delay in submitting the report.
Covid 19