Guidance

Understanding environmental improvements metrics

Published 22 June 2026

Applies to England

1. Introduction

FCERM projects can provide environmental improvements that arise as a by-product of interventions to reduce flood/coastal risk. If your project is approved for early project development, you will need to record these improvements at subsequent reporting stages.

The environmental improvement metrics record these additional environmental benefits. They are:

• OM:4A number of hectares of qualifying habitat created or enhanced
• OM:4B length in kilometres of rivers enhanced

You should include the monetised benefits that come from environmental improvements within the economic benefits. This includes the economic benefits that can be attributed to the improvements recorded under OM:4A and OM:4B and any other significant environmental outcomes.

The environmental benefits reported under OM:4A and OM:4B should be:

• an integrated part of the proposed package of FCERM measures
• a good opportunity to achieve wider Defra outcomes, either by using project resources efficiently or enabling opportunities through partnership with others

You should not count necessary environmental compensation for environmental losses caused or required by your project. The environmental metrics can be reported by large-scale habitat projects, such as those in the Environment Agency’s Habitat Compensation and Restoration Programme.

2. Hectares of habitat created or improved OM:4A

You should record the area of habitat created or improved by the project as OM:4A.

OM:4A captures the number of hectares of habitat created or improved in condition between poor, moderate or good.

OM:4A is for creating or enhancing, or both, the following habitat types:

• intertidal
• woodland
• wet woodland
• wetlands and wet grassland
• grassland
• heathland
• ponds and lakes
• arable land (enhancement only)

Determining habitat condition pre and post scheme will require some judgement. Project teams should refer to the tables below and draw on expert ecological advice.

2.1 Intertidal habitats

These habitats are found between the high and low tide marks. The habitats most commonly associated with FCERM works are salt marshes and mud flats.

Poor condition	Moderate condition	Good condition
Habitat shows signs of damaging management or use (for example, drainage, inappropriate grazing), pollution or obvious and damaging erosion. Few of the species expected for the type of habitat are present.	Natural processes will support the habitat being created or enhanced. Management regime (includes no management where appropriate for the habitat) generally appropriate for the site, but some minor issues are present. Habitat shows signs of physical damage, but its structure is still considered robust and will recover if natural processes are established. For existing habitats, some but not all of the expected species are found on the site and evidence is provided that the habitat will continue to recover within the benefits period of the project. For new habitats, there is evidence that the habitat will establish within the benefits period of the project.	Natural processes are optimal for the type of habitat. Management regime (includes no management where appropriate for the habitat) and the conditions to maintain the habitat are in place, and evidence is provided that this will continue for at least the benefits period of the project. For existing habitats, most of the expected species are found on the site and evidence is provided that the habitat will recover within the benefits period of the project. For new habitats, there is evidence that the habitat will establish or recover within the benefits period of the project.

Table 1: Description of intertidal habitat conditions for OM:4A

2.2 Woodlands and wet woodlands

Vegetation dominated by trees more than 5 m high when mature, which forms a distinct, although sometimes open, canopy (areas of trees with a canopy greater than 20%). This includes felled, young or newly planted woodland. For wet woodland trees are typified by trees associated with wet soils such as alder, birch and willow. There is no minimum size for areas of trees that have the definite characteristics and feel of a woodland and are managed as woodland.

Poor condition	Moderate condition	Good condition
Signs of damaging management (damaged trees, excessive poaching or grazing impacts), high proportion of non-native species and few of the species you would expect to see in the woodland type.	Management regime generally suitable for the site (includes no management where appropriate for the habitat), but a few minor issues may be evident. Trees are of similar age and height structure throughout the woodland. Some standing or fallen deadwood is present. For existing habitats, some but not all of the expected species are found on the site, and evidence is provided that the habitat will continue to recover within the benefits period of the project. For new habitats, there is evidence that the species being planted are appropriate for the habitat and will establish within the benefits period of the project.	Management regime (includes no management where appropriate for the habitat) is optimal for the type of habitat and will continue for at least the benefits period of the project. For existing habitats, most of the expected species are found on the site and a diverse age structure is present or there is evidence that the habitat will recover within the benefits period of the project. For new habitats, there is evidence that the species being planted are appropriate for the habitat and the habitat will establish or recover within the benefits period of the project.

Table 2: Description of woodlands and wet woodland habitat conditions for OM:4A

2.3 Wetlands and wet grassland

Wetlands and wet grassland habitats include, flood plain wetland mosaics, reedbeds and bogs. They are found on flood plains, on the fringes of open water, in valleys, in basin-like depressions, and also around springs and flushes. Often have peat soils present (in either wet, dry or drained state and of any depth). Water regimes may be where the soil is waterlogged, with the water table close to or above the surface for most of the year or where periodic surface water flooding results in a distinctive wet grassland habitat or mosaic.

Poor condition	Moderate condition	Good condition
Site shows signs of damaging management, low water levels (drying out or inappropriate drainage) or poor water quality. Few of the species you would expect to see in the habitat type present.	Management regime generally suitable for the site (includes no management where appropriate for the habitat), with no obvious/known sources of pollution. Water levels vary within expected ranges for the type of habitat. For existing habitats, some but not all of the expected species are found on the site, and evidence is provided that the habitat will continue to recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish within the benefits period of the project.	Management regime (includes no management where appropriate for the habitat) is optimal for the type of habitat and will continue for at least the benefits period. Water quality and quantity is optimal for the type of habitat. For existing habitats, most of the expected species are found on the site, and there is evidence that the habitat will recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish within the benefits period of the project.

Table 3: Description of wetlands and wet grassland habitat conditions for OM:4A

2.4 Grassland

Land under permanent natural or semi-natural grassland, dominated by grassland species with very little (if any) dwarf shrub, wetland or wooded species within the sward. Grassland habitats include lowland and upland grasslands and meadows.

Poor condition	Moderate condition	Good condition
Habitat not managed for biodiversity, low number of the species you would expect to see in the particular type of grassland. Includes habitats managed mainly for amenity purposes.	Habitat in some form of management, but not optimal for the type of grassland. For existing habitats, some but not all of the expected species are found on the site, and evidence is provided that the habitat will continue to recover within the benefits period of the project. Total cover of wildflowers and sedges less than 30%, excluding white clover, creeping buttercup and injurious weeds. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish within the benefits period of the project.	Species-rich grassland of all priority habitat types with appropriate management and most of the expected species found, and there is evidence that the habitat will recover within the benefits period of the project. Wildflower and sedges above 30%, excluding white clover Trifolium repens, creeping buttercup Ranunculus repens and injurious weeds. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish or recover within the benefits period of the project.

Table 4: Description of grassland habitat conditions for OM:4A

2.5 Heathlands

Heathland with at least 25% cover of heathers and other dwarf shrubs, or previously heathland in a degraded state below this. Species typically comprises heathers, gorses, fine grasses, wildflowers, mosses and lichens in a complex mosaic. Habitat covers the full altitudinal range of heathlands.

Poor condition	Moderate condition	Good condition
Shows signs of damaging management that is affecting the habitat. This can be physical damage to the vegetation and includes activities such as excessive poaching, damage from using or storing machinery, burning sensitive areas or unmanaged/excessive public access activities. Includes areas where the heather and dwarf shrub cover is below 25%, but still frequent through the area (fragmented heathland).	Management regime is generally suitable (includes no management where appropriate for the habitat). For existing habitats, some but not all of the expected species are found on the site, and evidence is provided that the habitat will continue to recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish within the benefits period of the project.	Management regime (includes no management where appropriate for the habitat) is optimal for the type of habitat and will continue for at least the benefits period. Most of the expected species are found on the site. Cover of trees and scrub less than 15%, injurious weed cover less than 5%. For existing habitats, there is evidence that the habitat will recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish or recover within the benefits period of the project.

Table 5: Description of heathland habitat conditions for OM:4A

2.6 Ponds and lakes

Lakes generally cover water bodies over 2 ha in area. Expert judgement should be used to decide if a water body between 1 and 2 ha area is described as a pond or as a lake. Ponds generally cover all water bodies up to 1 ha in area. They include sunny or shaded and temporary or permanent ponds at any stage of succession, from newly created ponds to ones that are completely overgrown. They also include scrapes and other temporary ponds, which may be dry at certain times of the year.

Poor condition	Moderate condition	Good condition
Shows signs of damaging management that is affecting the habitat. Water quality is poor (indicated by things like algal blooms and scums, and obvious sources of pollution). Few of the species you would expect to see in the type of pond or lake are present. Unmanaged invasive weeds are present.	Management regime generally appropriate for the site (includes no management where appropriate for the habitat), with no obvious/known sources of pollution. Water levels vary within expected ranges for the type of habitat. For existing habitats, some but not all of the expected species are found on the site, and evidence is provided that the habitat will continue to recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish within the benefits period of the project.	Management regime (includes no management where appropriate for the habitat) is optimal for the type of habitat and will continue for the benefits period. Water quality and quantity is optimal for the type of habitat. For existing habitats, there is evidence that the habitat will recover within the benefits period of the project. For new habitats, there is evidence that the species being introduced are appropriate for the habitat and the habitat will establish or recover within the benefits period of the project.

Table 6: Description of pond and lake habitat conditions for OM:4A

2.7 Arable land

Land under cultivation, includes temporary grass leys.

Poor condition	Moderate condition	Good condition
Intensively managed, cropped annually, few field margins or semi-natural areas.	Cropped annually with moderate levels of field margins and semi natural areas.	Extensively managed, cropped annually with high levels of field margins.

Table 7: Description of arable land habitat conditions for OM:4A

3. Kilometres of river enhanced OM:4B

OM:4B is for projects that enhance the habitats, physical features and natural functioning of watercourses. It includes creating new lengths of watercourses where these work with natural processes and improve the habitat for wildlife.

You should provide evidence in the project business case of how:

• the watercourse will be restored or enhanced
• it will be managed to sustain the change over the duration of benefits period

OM:4B is the total length in kilometres of watercourse created/enhanced in one of 3 categories:

• the comprehensive restoration of natural processes, habitats and the removal of physical modifications (includes creating channels with minor physical modifications that do not inhibit natural river processes)
• the partial restoration of natural processes, habitats and the partial removal of physical modifications (includes creating channels with some physical modifications and partial functioning of natural processes)
• a single major physical or habitat enhancement (for example, bank reprofiling to naturalise the banks or opening up fish passage)

Determining river condition pre and post scheme will require some judgement. You should refer to Table 2 and draw on expert ecological and/or geomorphological advice.

Category	Description
Comprehensive restoration of natural processes, habitats and removal of physical modifications (includes creating new channels with minor physical modifications that do not inhibit natural river processes)	Comprehensive restoration is achieved where habitats are enhanced and all physical modifications (including river engineering structures), which restrict the natural functioning of the river corridor have been removed apart from minor modifications (for example, small outfalls). The modifications do not limit biodiversity or natural river processes: the ability for physical habitat features to form and evolve. A scheme that includes newly cut channels can be considered a comprehensive restoration if reinstating the natural channel planform, for example remeandering a previously straightened section.
Partial restoration of natural processes, habitats and partial removal of physical modifications (includes creating new channels with some physical modifications and partial functioning of natural processes)	A partial restoration of the river channel has been achieved where habitats are enhanced and some of the physical modifications or engineering structures have been removed, altered or minimised to enable partial natural functioning of the river. Natural processes are reinstated to some degree and some physical habitat features are able to form and evolve, but are limited by the ongoing presence of physical modification and/or structures. This can include newly cut channels in which the ‘channel form’ (due to its main use or another pressure) is not natural, but the design enables some degree of natural river processes to operate and physical habitat features to form.
A single major physical or habitat enhancement	In this category only one physical pressure is improved by the project, for example by reinstating natural banks or improving fish passage by removing or modifying structures, Wherever possible, weir modification should provide additional benefits and help restore natural processes. For example, reducing weir heights benefits river processes by lowering artificially raised water levels and reducing the length of channel affected by the ponding effect of the weir. For fish passage, OM:4B benefits may be claimed for the distance to the next physical barrier. Where distances are large, you will need to make a judgement on the length of qualifying benefits.

Table 8: Categories of watercourse enhancement for OM:4B