Academic Advisory Panel - 4 March 2024 - Water scarcity and excess advisory note

This advisory note has been prepared by the Academic Advisory Panel (AAP) in response to a policy need to increase understanding of the contributions that land managers, farmers, and crofters can make to improving flooding and water scarcity resilience, and to inform the development of the Flood Resilience Strategy. This note summarises discussion held during the AAP meeting on the 4 March 2024. The work on the Resilience of Scottish Catchments to Climate Change and Flood Risk Management conducted by the Scottish Environment Protection Agency (SEPA) was presented to the Panel. The discussion focussed on identifying agricultural activities that exacerbate risks of water scarcity or flooding, exploring how agriculture can improve resilience to those risks, and determining the most effective methods to ensure the adoption of beneficial measures while avoiding harmful ones.

 

Key summary of the discussion

Soil organic matter is fundamental to understanding and managing water scarcity and excess. Soil organic matter determines how much water is held within soil, and rates of water infiltration. Vegetation cover is also vital as it contributes to soil organic matter production and protects soils from erosion. Poor soil management, damage to peatlands, and reductions in vegetation cover diminish soil’s capacity to store or filter water, by degrading soil organic matter. Soil degradation increases overland flow of water during storms, exacerbates soil erosion, and risk of flooding and water pollution. Low soil organic matter, lack of water storage facilities and inadequate on-farm water management increases business vulnerability to drought events. Water abstraction from rivers puts pressure on freshwater ecosystems.

However, many problems can be mitigated by practices that restore soil organic matter and degraded peatlands, and improve water storage and water use efficiency on-farm. Development of impactful resilience strategies requires systems approaches that recognize that water is dynamic in space and time. An integrated catchment-scale response to restoring peatland headwaters, making space for rivers, enriching mineral soils, and slowing down water flow is necessary to achieve the desired cumulative effects for hydrological resilience. Systems water management requires a range of support such as long-term financial incentives, regulatory frameworks, and provision of guidance and training. Recognizing that all farmers and crofters have a role to play and/or are at risk is important, even if flooding/scarcity does not affect them directly now.

Key discussion points:

1. Which agricultural activities exacerbate risks of water scarcity or flooding in agriculture and for wider society:

• Certain cultivation practices can diminish soil’s capacity to store or filter water, reduce soil organic matter, or channel flows leading to increased water runoff. Examples include leaving soils uncovered for prolonged periods of time, unnecessary ploughing, ploughing up and down the hill rather than with the contour of the land, and absence of field boundaries and buffer strips containing vegetation like grassland, scrub, hedges or trees. Activities that lead to soil compaction, such as trampling, excessive heavy machinery traffic, overgrazing, and high animal stocking rates, can also encourage surface flow rather than infiltration and increase the likelihood of flooding.
• The focus on maintaining soil cover on steep gradient fields is of particular importance. Good practices, such as ploughing with contour, may not be possible in cases where the gradient increases risk of tipping to an unacceptable level. Some root-crops such as root vegetables or potatoes can increase soil damage and erosion, particularly if grown on slopes. Consideration should be given to removing steep gradient hills from crop production in catchment areas associated with a high risk of flooding.
• High concentration of vegetable crops in limited areas, such as Fife and Tayside, results in high water demands across a limited number of catchments. This exacerbates issues during water scarcity periods, necessitating the suspension of water abstraction licenses. Crop diversification is recommended.
• Degradation of upland and peatlands landscapes in some areas, due to suboptimal management practices, has diminished water retention capacity in those headwater regions. Consequently, the accelerated release of water contributes to downstream flooding during high flow, water quality issues, and less resilient flow during water scarcity periods.
• Extensive on-farm drainage, channel straightening and the construction of hard standings can accelerate discharge rates and amplify peak flows during intense rainfall. This acceleration in flow may elevate the flood risk and diffuse pollution downstream.
• Suboptimal on-farm water usage, characterised by insufficient water storage or recycling, over reliance on mains supply and abstractions, excessive irrigation, unmonitored livestock watering, overflowing water troughs and potential over production of water-intensive outputs contribute to water scarcity issues.

2. How agriculture can improve resilience to water scarcity and flooding in both agriculture and for wider society:

• Building soil organic matter is important, as it significantly impacts soil water drainage and retention capacity, thereby enhancing crop resilience against flooding and drought events. Implementing practices that promote good soil structure, such as minimising soil compaction, adjusting stocking rates in periods of drought, reducing soil crust, limiting on field traffic in wet conditions, minimising tillage, soil catching and protecting hillslopes is essential. Maintaining soil cover through methods like earlier drilling of winter crops, cover cropping, intercropping, or leaving stubble should be considered aiming for near 100% coverage, particularly during winter season. Crop diversification or adjusting crop types, such as using grass as a more flood tolerant option than cereals, may be necessary. Lighter animals and native breeds may be required to support soil structure. Multi-species swards can better support drought resilient grazing.
• Upland and peatland restoration are also important for enhancing resilience to weather events and can provide additional benefits such as improved water quality, biodiversity and carbon storage.
• The existing farm drainage should be managed to meet farm water requirements. Manipulating drainage through drain blocking or breaking in-field drainage can aid restoring wetland areas or increasing water storage capacity in fields with naturally high water tables. Installing cross drains in strategic locations and sediment traps can safeguard on-farm road infrastructure, capture run off, and protect nearby water bodies.
• Practice of good on-farm water management should be promoted among farmers and crofters. Each farm should:
  • measure its annual water usage and monitor soil organic matter
  • implement actions to enhance water storage, such as restoration of peatlands, creation of wetlands, reservoirs, or water lagoons, recycling greywater
  • adopt modern technologies for water efficiency and resilience (e.g., trickle irrigation, soil moisture sensors, water trough sensors, drought-resistant crop, and grassland varieties)  
• Planting woodlands on farms, appropriate riparian planting along riverbanks, and restoration of natural flood plains can offer range of benefits for natural flood management. These include slowing the rate of water passing through the farm, reducing soil erosion, decreasing the quantity of silt affecting waterbodies, and mitigating nutrient and pesticide runoff and pollution. Additionally, such practices can enhance the stability of river banks, support increased biodiversity and carbon storage.
• An integrated catchment-scale response is necessary to achieve the desired cumulative effects. Management of a watercourse should aim to slow down water flow, make space for rivers, and implement an integrated approach across the full contributing drainage area for a watercourse. Farmers and crofters should be encouraged to manage their common catchment for resilience, and policy should explore how to balance effort against reward. For instance, upstream localized actions, e.g. on peatlands, can improve the hydrological experiences of farms and communities in the downstream areas. Improvement measures should be tailored to the specific needs of individual areas based on to their ecosystems, topography, land use and soil types.

3. What are the best ways to ensure adoption of beneficial measures and avoidance of harmful ones.

• There is a need to increase farmer and crofter awareness of how flooding and drought can directly impact their business and the reasons for taking steps to mitigate these issues. The changing climate and associated water scarcity and flooding have the potential to increase adverse impacts on a wide range of issues. Drier conditions can increase the risk of wildfires. Increased temperature and humidity levels will cause more heat stress on animals. Wetter soils can elevate the incidence of parasites such as liver fluke leading to increased use of chemicals, which in turn can cause resistance to treatment and have environmental impacts. Winter flooding may also result in a higher pest and disease burden in crops. Water quality can be negatively affected by flooding as soil run off can cause contamination issues. Businesses located in high risk areas may be at risk of financial losses.
• Recognising that all farmers and crofters have a role to play, even if flooding does not affect them directly now, is important. Awareness of flood risk maps for the present and the next decades should be increased among farmers and crofters in affected areas, along with information on benefits of slowing water down, practices that improve resilience, and importance of routinely implementing them. The gap between expert advice and common understanding on subjects such as river dredging should also be addressed. Climate change will expand impacts across much of Scotland.
• Systems thinking by policymakers, analysts, researchers and stakeholders is essential for developing impactful policy strategies. Policy trade-offs or points of conflict may arise between different ecosystem services or land uses. Resolving these issues requires strategic prioritisation and spatial planning at catchment scale. Measures that positively impact larger environmental goals and a broad range of policies such as Net Zero Targets, Biodiversity Strategy, Climate Change Adaptation Programme should be prioritised.
• Range of tools such as financial incentives, regulatory frameworks such as Controlled Activities Regulations (CAR), and provision of guidance, information, and training are required to develop effective water scarcity and flooding strategies. For example:
  • incentives may need to take the form of grant-aid for capital investments or (conditional) payments to adhere to management prescriptions and proscriptions,
  • compensation for change of agricultural land use from a productive service (crops) to a regulating service (flood plain) may be required,
  • agricultural policy discussions should encompass consideration of risk management tools, including private insurance as well as mitigation activities, 
  • Government should consider charging water abstraction for irrigation, so the full cost of water is clear and multiple ecosystem services are considered. There are potential challenges for charging around property water rights and licensing processes.
  • awareness of water-related risks and options for managing them needs to be raised with farmers/crofters, with guidance on best management practices and new technologies through appropriate knowledge exchange routes.
• Grants for the establishment of water reservoirs should be readily available. Currently, grant application deadlines are very short, creating additional restrictions for farmers and crofters. Extending deadlines would improve ease of access to funds and, consequently, benefit water management practices.
• Payments for flood storage services ideally need to be long-term commitments, possibly spanning over 30 years. Fundings routes should be established, both through private and public funding. Enforcing the need for water storage through regulatory controls may inadvertently lead to the displacement of farming in sectors with low profitability due to additional financial burden.

Lessons on sustainable financing and systems approach to optimising land use should be sought. Actions funded through Environmental Land Management (ELM) schemes, Agricultural Transition Plan, European Green Financing, or Edinburgh Blue Green Network are some of examples worth considering.