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Natural flood management (NFM) involves measures to restore and protect natural hydrology and geomorphology to minimise flood risk. NFM is promoted as part of the nation's flood resilience response. Government agencies have created national maps of opportunities for specific NFM measure to target available grant aid and encourage landowners and managers to deliver effective NFM measures where most needed. Mapping opportunities within a regulatory framework ensures that measures are targeted towards areas with a presumption of suitability thus minimising the burden of the application process. The viability of NFM depends on the responsible authority and community at risk accepting the proposed measures as both effective and appropriate. Top-down initiatives can fail to meet their targets when landowners and managers feel left out of the decision making and their experiential local knowledge is at odds with the spatial prioritisation derived from national datasets. This interdisciplinary paper assesses the applicability of a technical-based national mapping approach with local stakeholders for identifying opportunities for woodland and runoff management measures to reduce flood risk within the lowland catchments of the West Thames River Basin, in southern England. Farmer surveys supported the technical map in terms of targeting areas of deep clay and silt soils over mudstone as high priority for improved land and soil management to reduce rapid runoff. However, while incentives correctly target the problem areas, farmers desired greater flexibility in choice of NFM measures to reflect local soil knowledge and the sustainability of management practices within farm systems. It is argued that a more integrated and co-designed mapping approach would enhance NFM uptake and thus achieve a greater reduction in downstream flood risk. • This paper assesses the relevance of national maps to identify opportunities for NFM in lowland agricultural catchments. • Farmers' experiential knowledge confirm the map correctly target areas with soils prone to degradation and surface runoff. • The farmers favoured soil-based NFM measures that support continued agricultural use such as cover crops and minimal tillage. • Farmers were resistant to woodland creation incentives and would prefer more support for soil and land management practices. • Our study highlights the need for co-development of NFM incentives to aid delivery of national policy [ABSTRACT FROM AUTHOR]

Field investigations between 2002 and 2011 identified soil structural degradation to be widespread in SW England with 38% of the 3243 surveyed sites having sufficiently degraded soil structure to produce observable features of enhanced surface-water runoff within the landscape. Soil under arable crops often had high or severe levels of structural degradation. Late-harvested crops such as maize had the most damaged soil where 75% of sites were found to have degraded structure generating enhanced surface-water runoff. Soil erosion in these crops was found at over one in five sites. A tendency for the establishment of winter cereals in late autumn in the South West also often resulted in damaged soil where degraded structure and enhanced surface-water runoff were found in three of every five cereal fields. Remedial actions to improve soil structure are either not being undertaken or are being unsuccessfully used. Brown Sands, Brown Earths and loamy Stagnogley Soils were the most frequently damaged soils. The intensive use of well-drained, high quality sandy and coarse loamy soils has led to soil structural damage resulting in enhanced surface-water runoff from fields that should naturally absorb winter rain. Surface water pollution, localized flooding and reduced winter recharge rates to aquifers result from this damage. Chalk and limestone landscapes on the other hand show little evidence of serious soil structural degradation and <20% of fields in these landscapes generate enhanced runoff. [ABSTRACT FROM AUTHOR]