8. Physical modifications and morphology

This section describes measures for a range of physical modifications as a result of different areas of activity and development to the water environment.

Morphology describes the physical characteristics of water environments, including both landforms and the processes that creates and modifies them. Morphology is a term used in river basin management planning and along with hydrology is known as hydromorphology. Morphology is important for physical habitat, managing flood risk and erosion, and biodiversity. A functioning morphology can help catchments adapt to climate change and other pressures, but also it is important to understand the risk posed by a changing landscape.

It is important that waters and their surrounding landscapes are managed to help improve the morphological condition to help protect and improve the ecology and ecosystem functions. This is done by managing the pressures acting on morphology, restoring the impacts from existing (legacy) physical modifications and managing the impacts from new activities. New development opportunities to seek opportunities to not only protect, but also enhance or restore waters, providing overall net gain.

Section 8.3 provides an overview of mechanisms used to mitigate the impacts from physical pressures, and to enhance and restore the morphology of waters, often lost because of existing and historic modifications. The mechanisms identified relate to the following areas of activity and development – they focus primarily on mechanisms to manage morphology but include reference to hydromorphology where relevant:

  • navigation
  • development
  • land drainage
  • flood and coastal erosion risk management
  • dredging, disposal and development in estuaries (transitional waters) and coastal waters
  • other controls, plans and programmes

Along the coast and within estuarine waters, port and harbour authorities have a general duty to exercise their functions with regard to nature conservation and other related environmental considerations. There may also be specific duties that are only applicable to individual port and harbour authorities, which are set out in local legislation such as harbour revision orders. Harbour authorities are also public bodies for the purposes of the WFD Regulations.

This is also the case for inland navigation authorities, which have general environmental duties as well as more specific duties that may be set out in local legislation. The Canal & River Trust is the largest United Kingdom navigation authority. The Environment Agency is also a navigation authority and the second largest with 1010km of primarily river navigations in England.

The Green Blue is a joint programme by the Royal Yachting Association and British Marine. It helps the boating community reduce their impact on coastal and inland waters by raising awareness, supporting practical projects and offering easy to follow advice. It has been very successful in influencing boat users, marinas and boatyards to adopt good environmental management and trial innovative solutions; and has also made a significant contribution to reducing the spread of invasive non-native species.

The majority of England’s inland navigation authorities also require compliance with the common minimum standards of the Boat Safety Scheme as a requirement of boat licensing or registration.

The Boat Safety Scheme is owned jointly by the Canal & River Trust and the Environment Agency and is a public safety initiative aimed at helping reduce the risks of fire, explosion, carbon monoxide poisoning and pollution on small craft and so keeping visitors to the waterways, as well as navigation authority staff safe.

The work is done by promoting fire safety, carbon monoxide and pollution avoidance advice to help boat owners keep themselves and their crews safe as well as periodic examination of fuel systems, gas systems, electrical systems and appliances. Boats need to comply with common, minimum standards of construction and equipment and undergo an examination every 4 years.

8.2 Development

Under the planning system local councils and other planning authorities must consider environmental protection and enhancement when assessing development proposals, including those in the marine environment (see section 8.6). The statutory processes of Sustainability Appraisal (incorporating Strategic Environmental Assessment), Habitats Regulations Assessment and individual Environmental Impact Assessment processes (or other relevant assessments) provide a means of screening potential impacts of plans, programmes and individual proposals. Further information is provided in the Planning Practice Guidance supporting the National Planning Policy Framework.

By law, any planning application for development has to be determined against policies in the Development Plan for the area, unless material considerations indicate otherwise. These considerations include the National Planning Policy Framework which states that the planning system should contribute to conserving and enhancing the natural environment by:

  • protecting and enhancing valued landscapes, sites of biodiversity or geological value and soils
  • Providing net gains for biodiversity, contributing to the government’s commitment to halt the overall decline in biodiversity, including by establishing coherent ecological networks that are more resilient to current and future pressures
  • preventing new and existing development from contributing to, being put at unacceptable risk from, or being adversely affected by, unacceptable levels of soil, air, water or noise pollution or land instability; development should, wherever possible, help to improve local environmental conditions such as water quality, taking into account relevant information such as river basin management plans

The Planning Practice Guidance draws attention to the requirements of the WFD Regulations and highlights that local planning authorities should have regard to river basin management plans in exercising their functions. The guidance provides further information on how planners should take account of impacts on the water environment in Local Plans and planning applications, with reference to the WFD Regulations.

To achieve this, the guidance advises that local planning policies will need to consider water supply, waste water and water quality issues, including:

  • how to help protect and enhance local surface and ground waters that allow new development to proceed
  • the type and location of new development where an assessment of the potential impacts on water bodies may be required

The guidance provides further information on the consideration of planning applications where there are water quality or supply issues.

Where the assessment indicates that the development will have a significant adverse impact on water quality, the proposed development will only be acceptable in terms of the WFD Regulations in the circumstances set out in the river basin management plan.

The consideration of any hydromorphological impacts is likely to be particularly important where new development requires new or changed flood defences or improved coastal defences as these can often be designed to combine improving ecological quality with providing recreation facilities (‘green infrastructure’) for the local community.

8.3 Influencing the final planning decision

Under planning law, an application for planning permission must be determined in accordance with the development plan for the area, unless material planning considerations indicate otherwise. The Environment Agency is a statutory consultee for local plans and is also a consultation body is also a consultation body for developments requiring Environmental Impact Assessment. The Environment Agency’s advice, including on the measures in the river basin management plan, is therefore important in informing local plan policies and land allocations that will provide the basis for future decision on planning applications.

Under the provisions of the Town and Country Planning (Development Management Procedure) (England) Order 2015, the Environment Agency is a statutory consultee for several types of planning application related to statutory duties on flood risk, protection of land and water quality, waste regulation and fisheries. This is an important mechanism for informing planning decisions which can improve the hydromorphological condition of water bodies, where appropriate, and help influence development proposals which have the potential to cause deterioration of a water body. Planning conditions can be proposed to mitigate flood risk, water quality and ecological impacts of proposed development and the Environment Agency already work with local planning authorities and developers to achieve these aims.

National Policy Statements for Nationally Significant Infrastructure Projects in the energy, waste, water and transport sectors ensure that Secretaries of State take account of WFD Regulations objectives when issuing Development Consent Orders.

Some developments may have to be assessed against the requirement to prevent deterioration in ecological status or potential and will have to comply with regulation 19 (New Modifications) of the WFD Regulations. Planning Practice Guidance and National Policy Statements provide more guidance on this. The river basin management plan records decisions that are justified using regulation 19.

The mechanisms for managing development and hydromorphological pressures are as follows.

Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 2017:

  • requires an Environmental Impact Assessment for certain activities (listed in the Schedules to the regulations) to determine the likelihood that a proposed project (development or other activity) will have significant environmental effects
  • consenting authorities can modify or reject proposals that would significantly impact on hydromorphological conditions and can secure additional conservation gains as a condition of project approval

Environmental Assessment of Plans and Programmes Regulations 2004:

  • ensures the environmental implications are considered before certain plans and programmes are adopted; The strategic environmental assessment process is integrated throughout the development of a plan or programme, notably during data gathering, feasibility of options, development of the preferred option, and monitoring its implementation
  • the Environment Agency is a consultation body to Environmental Assessments (Strategic Environmental Assessments and Environmental Impact Assessments) produced by other public bodies and developers

Town and Country Planning (Development Management Procedure) (England) Order 2015 establishes the Environment Agency as a statutory consultee for several types of planning application related to Environment Agency’s statutory duties on flood risk, protection of land and water quality, waste regulation and fisheries.

Town and Country Planning Act 1990, Planning and Compulsory Purchase Act 2004 (as amended); Planning Act 2008 (as amended); Planning policy provided in National Planning Policy Framework (NPPF), 2021 and guidance in supporting Planning Practice Guidance (PPG), 2019; National Policy Statements (NPSs) Planning and Compulsory Purchase Act 2004 s3:

  • establishes the sustainable development duty of spatial planning and establishes the principles of and need to produce local plans
  • in England, the National Planning Policy Framework expects that all major developments, and development in areas at risk of flooding, should incorporate sustainable drainage systems unless there is clear evidence that this would be inappropriate
  • conditions can be attached to development permission to require the use of sustainable drainage systems where appropriate, and to ensure ongoing maintenance. Planning agreements (s.106) may also be required

8.4 Land drainage

The Environment Agency has the power to carry out various actions on main rivers to cleanse, repair or otherwise maintain existing watercourses. It has the power to improve any existing watercourse or drainage by deepening, widening, straightening, raising or otherwise improving, or by removing or altering mill dams, weirs or other obstructions. It has the power to make any new watercourse or drainage or do any other act required for the efficient drainage of any land. Local authorities and Internal Drainage Boards have similar powers to act on ordinary watercourses.

These powers cannot be used to undertake works for the sole purpose of improving the physical condition or conservation interest of rivers, although in some cases it can be possible to realise these benefits additionally.

The Natural Environment and Rural Communities Act 2006 gave the Environment Agency amended byelaw-making powers to ensure that the broader effects of drainage systems on the environment can be considered when considering flood risk matters under byelaws. The Environmental Permitting Regulations for flood risk activities were introduced in 2016 to replace parts of the byelaws for works requiring permission, and as a result, development of new byelaws is not currently being pursued.

The Natural Environment and Rural Communities Act 2006 provide similar byelaw-making powers to local authorities and Internal Drainage Boards. This power could be used by these authorities to redraft their byelaws to help reduce impacts in ordinary watercourses.

8.4.1 Dredging and land drainage

The Environment Agency’s Environmental Permitting regime regulates the flood and environmental impacts of dredging activities on a main river. Dredging on ordinary watercourses for the purposes of land drainage, flood risk management or navigation in ordinary watercourses may require an ordinary watercourse consent from the Local Authority or Internal Drainage Board. In all cases the Environment Agency advises that the dredging work adheres to good practice guides.

Mechanisms for managing land drainage are as follows.

Environmental Permitting (England and Wales) Regulations 2016:

  • the Environment Agency had regulatory control (through flood defence consenting under section 109 Water Resources Act 1991) of the construction, alteration or repair of structures in, over or under any main river, they are now regulated under the Environmental Permitting regime
  • power is also given to the Environment Agency to alter or remove any unauthorised works and recover the costs of this
  • conditions can be imposed only in relation to the time and way work can be carried out
  • where the main river is an estuary, main river dredging may also require a marine licence unless carried out by harbour authorities for navigation under their own powers

Water Resources Act 1991, s165, Land Drainage Act 1991 s14(2):

  • empowers Environment Agency to maintain or improve existing drainage works or to construct new works on a main river
  • power also extends to maintain, improve or construct drainage works for the purpose of defence against sea water or tidal water
  • work can only be undertaken to improve flow conveyance and ensure the efficient working of the drainage system, though other conservation benefits may also be achieved
  • equivalent powers are conferred upon Internal Drainage Boards and local authorities through section 14(2) of the Land Drainage Act 1991

  • any work carried out by third parties that may impact on flow conveyance is subject to a land drainage consent from the relevant authority (Environment Agency, Internal Drainage Board or local authority) – see below

Water Resources Act 1991 s107 provides the Environment Agency power to serve a notice in regard to main river to ensure that necessary works to improve flow conveyance are carried out, or to undertake the works and recover reasonable costs.

Land Drainage Act 1991, s21 and s25 provides Internal Drainage Boards and local authorities with powers to serve a notice in regard to ordinary watercourses to ensure that necessary works to improve flow conveyance are carried out, or to undertake the works and recover reasonable costs.

Land Drainage Act 1991, s23 provides local authorities and Internal Drainage Boards with regulatory control (through land drainage consenting) of the erection, raising or otherwise altering of mill dams, weirs or other like obstructions to flow:

  • written consent is also required for the erection or alteration of any culvert that is likely to affect the flow in ordinary watercourses

Water Resources Act 1991, Schedule 25 as amended by s100 Natural Environment and Rural Communities Act 2006 provides power to the Environment Agency to make byelaws necessary for the efficient working of any drainage system and for regulating the effects of any drainage system on the environment.

Land Drainage Act 1991s 66 as amended by s100 Natural Environment and Rural Communities Act 2006. Confers byelaw-making powers on Internal Drainage Boards and local authorities that are deemed necessary for the efficient working of the drainage system and for regulating the effects of any drainage system on the environment. The powers for Internal Drainage Boards only extend to ordinary watercourses.

Environmental Impact Assessment (Land Drainage Improvement Works) Regulations 1999 requires an Environmental Impact Assessment for certain activities (listed in the Schedules of the Regulations) to determine the likelihood that a proposed project (development or other activity) will have significant environmental effects. Consenting authorities can modify or reject proposals that would significantly impact on hydromorphological conditions and can secure additional conservation gains as a condition of project approval.

8.5 Flood and coastal erosion risk management

Under the Flood and Water Management Act 2010, the Environment Agency, lead local flood authorities, district councils, internal drainage boards, water and sewerage companies, and highway authorities have a duty to co-operate in undertaking their flood risk management duties.

An integrated approach to managing water provides the opportunity to better protect communities from flooding, help manage drought risk and realise wider environmental benefits. To achieve this we should look to increase the number of water management schemes within and across catchments.

The National Flood and Coastal Risk Management Strategy for England includes a commitment to ‘mainstream the use of nature based solutions’ to provide ‘climate resilient places’. The Flood and Coastal Erosion Risk Management (FCERM) Strategy Road Map FCERM Strategy Roadmap to 2026 (publishing.service.gov.uk) also links specifically with the river basin management process, as follows:

Measure 1.4.4: From 2021 investments in flood and coastal projects by risk management authorities will help to achieve objectives in river basin management plans and contribute to the government’s aim for 75% of waters to be close to their natural state as soon as practicable.

As part of the Budget in March 2020, the government announced a flood and coastal erosion risk management programme of £5.2 billion over the 6 years from 2021 to 2027. For this new investment programme, the ‘partnership funding’ arrangements, which determine the level of government funding available to projects, has been updated. This includes changes that provide more funding for flood schemes which use flood and coastal risk management measures that provide a range of environmental benefits. A new Environment Statutory Allowance (replacing the Environmental Support Fund) has also been agreed to provide funding to rectify environmental damage resulting from historic FCERM projects.

The environmental outcomes provided by the flood and coastal erosion investment programme, including the length of watercourses enhanced, are routinely reported by the Environment Agency. Flood and coastal risk management strategies and projects are assessed against river basin management plan objectives and in many cases need a number of consents and permissions where environmental impacts are considered.

The government has committed to reform local flood risk management planning so that every area of England will have a more strategic and comprehensive plan that drives long-term local action and investment by 2026. In July 2021, Defra announced it would set up an advisory groupto provide recommendations, advice and views to inform future policy. Defra has set out that future local flood risk management plans should support a catchment-based approach, considering all sources of flood risk and the potential for action across the whole of an area, upstream and downstream, by a variety of bodies. A series of advisory group meetings concluded in June 2022 and Defra is now considering next steps.

8.5.1 Floods Regulations

The Flood Risk Regulations 2009 require the assessment of the risk of flooding, mapping of its potential impacts and the planning of objectives and measures to reduce potential and significant flood risk. The plans should have a focus on human health, cultural heritage, the environment and economic activity.

Lead local flood authorities also prepare local flood risk management strategies under the Flood and Water Management Act 2010.

8.6 Dredging, disposal and development in estuaries, coastal and marine waters

Alongside the terrestrial planning system, there is a system of marine planning and marine licensing for regulating development and other activities in the marine area. In broad terms, this comprises the area within estuaries and rivers to the extent of tidal influence.

The Marine Policy Statement provides the high-level policy context for marine licensing and marine planning and is supplemented by 11 marine plans covering all English marine waters. The Marine Management Organisation is responsible for producing the marine plans. This follows a similar approach to terrestrial plans – setting the direction for decision making at a more local level to lead to efficient and sustainable use of marine resources.

The Marine Management Organisation is also responsible for marine licensing in England. Amongst other things, a marine licence is likely to be required for the construction, alteration or improvement of any works; for the deposit of substances or objects from vessels; for the removal of substances or objects from the seabed; and dredging. Certain exemptions can also apply, for example, harbour authorities are often able to undertake dredging under their own powers without a licence.

Natural England are the only statutory consultee for marine licencing. However, Defra have issued guidance on the bodies that should be considered primary advisors and regularly consulted by the Marine Management Organisation.

The Marine Management Organisation is also responsible for determining applications for harbour orders. These are a form of statutory instrument which create or amend legislation governing harbour authorities. Amongst other things, they can give harbour authorities power to undertake development and dredging.

The Environment Agency also has a regulatory role in estuarine and coastal waters through mechanisms such as flood risk assessment permits, environmental permitting (to 12 nautical miles, although its role in relation to pollution control in, and permitting of discharges to, water extends only to 3 nautical miles) and abstraction licensing (in tidal rivers, bays, creeks and arms of the sea).

Both the Marine Management Organisation and the Environment Agency have adopted the coastal concordat. This sets out the important principles for coordinating the consenting process for coastal development. One principle encourages authorities to dispense with consents where appropriate. The Environment Agency can dispense with flood defence consenting in favour of marine licensing when satisfied that the terms of the marine licence would provide adequate mitigation for flood risk.

Mechanisms for managing development, dredging and disposal in estuaries, coastal and marine waters are as follows.

Marine and Coastal Access Act 2009:

  • controls the deposit or removal of any substance or object in, on or under the sea bed including below the mean high water springs mark and in any tidal river to the extent of the tidal influence, from a vehicle, vessel, aircraft, marine or land-based structure or floating container
  • the construction, alteration or improvement of any works either in or over the sea or on or under the seabed and any form of marine dredging
  • requires implementation of marine plans and marine conservation zones

Marine Works (Environmental Impact Assessment) Regulations 2007 (as amended):

  • requires an Environmental Impact Assessment for certain activities (listed in the Schedules of the Regulations) to determine the likelihood that a proposed project (development or other activity) will have significant environmental effects

Harbour revision and empowerment orders:

  • controls the dredging and other activities carried out by harbour authorities within a set area associated with a port or marina

Harbour Works (Environmental Impact Assessment) Regulations 1999:

  • requires an Environmental Impact Assessment for certain activities (listed in the Schedules of the Regulations) to determine the likelihood that a proposed harbour and associated activities will have significant environmental effects

The Marine Licensing (Exempted Activities) Order 2011;

  • contains a list of exempt activities

In determining marine licence applications, the Marine Management Organisation must consider the need to protect the environment. This may include consideration of physical changes and morphology. Marine licences and harbour orders may also be subject to the same statutory assessment processes as the terrestrial system, such as environmental impact assessment. Conditions can then be used to mitigate adverse impacts.

As public bodies, the Marine Management Organisation must also have regard to the river basin management plans and any supplementary plans in exercising their functions. This includes assessing and determining marine licence and harbour order applications. Harbour authorities undertaking activities under their own powers must also have regard to river basin management plans.

Important environmental considerations for regulators are potential hydrological effects, interference with other marine activities, possible turbidity, noise, drift of fine materials smothering seabed flora and fauna, habitat loss and impact to designated conservation areas. In this way new physical modifications can be assessed to see if they will cause deterioration of the hydrological and morphological conditions. This will also highlight opportunities to make improvements, where this is possible.

Like terrestrial areas, many estuaries and coastal waters have environmental designations and protected sites which must be considered in assessing any consent application. This includes all Marine Protected Areas (Special Areas of Conservation, Special Protection Areas, Ramsar sites, Marine Conservation Zones and Sites of Special Scientific Interest). These additional protections may also help to achieve the environmental objectives of the river basin management plans. Under the Maintenance Dredging Protocol some harbour authorities have produced baseline documents to review whether activities will impact on local protected sites. These assessments can also incorporate the environmental objectives of the river basin management plans in addition to protecting hydromorphological conditions.

United Kingdom Marine Policy Statement states that dredged material should not be accepted for disposal where appropriate opportunities exist to reuse and recycle. This is also in line with The Waste (England and Wales) Regulations 2011 waste hierarchy. Restoring estuarine and coastal habitats with dredged sediment should be considered where practical. Restoring these habitats will contribute to river basin management plan objectives by re-naturalising coastal fringes, improving estuarine and coastal water quality, as well as providing many other multiple benefits for people and nature.

8.7 Other plans, programmes and controls

The management of activities with potential to affect hydromorphological conditions is relevant to many different sectors of industry. Consequently, managing hydromorphological pressures requires an integrated catchment management approach. The sections below list other relevant mechanisms for managing hydromorphological pressures.

Salmon and Freshwater Fisheries Act 1975, Part II:

  • requires that new obstructions to the passage of salmon and migratory trout (or the raising or repair of existing obstructions) be fitted with appropriate fish passes where notice (under section 9) is served to require these works to be undertaken
  • section 2(4) of this Act makes it an offence to wilfully disturb any river or lake bed, bank or shallow on which any spawn or spawning fish may be

Eels (England and Wales) Regulations 2009:

  • enables Environment Agency to serve notice to require removal of an obstruction to eel migration or installation of an eel pass
  • from 1 January 2015 required all water intakes (taking more than 20 cubic metres per day) and outfalls to be screened to prevent entrainment of eel unless exempted by Environment Agency notice

Water Act 2003, s 3 and 4:

  • empowers the Environment Agency to license existing unlicensed impoundments or remove or else modify existing unlicensed impoundments where necessary for the protection of the environment by serving notice under section 4

Water Resources Act 1991 sections 161ZA and ZB:

  • allows for service of notice or taking action in relation to ‘harm’ to the physical condition of surface waters
  • harm is defined as an adverse impact on any hydromorphological quality element that is likely to prevent achievement of WFD Regulations environmental objectives
  • Environment Agency use of these powers, which came into effect in December 2009, must explicitly be linked to the achievement of WFD Regulations environmental objectives

Conservation Habitats and Species Regulations 2017 (as amended). See section 2.6.1 for more information.

Wildlife and Countryside Act 1981, s28G:

  • places a duty on public bodies in exercising their functions to take reasonable steps to further the conservation and enhancement of the special features of Sites of Special Scientific Interest
  • limited geographical application

Wildlife and Countryside Act 1981, s28J:

  • gives Natural England powers to put in place a management scheme to conserve or restore the flora, fauna, geological or geophysical features of Sites of Special Scientific Interest
  • may need Environment Agency (or other drainage authority) consent for the works
  • limited geographical application

Wildlife and Countryside Act 1981 s 28K:

  • gives Natural England powers to serve a management notice to ensure that conservation or restoration works are implemented
  • empowers Natural England to carry out the works itself and recover the costs from the owner or occupier
  • may need Environment Agency (or other drainage authority) consent for the works

Measures to control diffuse pollution have significant potential to prevent deterioration of hydromorphological conditions, and to restore water bodies to a more natural condition. These mechanisms are discussed in section 7.

Various Environment Agency plans and strategies can also be used to target the mechanisms outlined in this section, including:

  • fisheries action plans
  • salmon action plans

  • eel management plans
  • national trout and grayling strategy
  • sea trout and salmon fisheries strategy
  • Biodiversity 2020: a strategy for England’s wildlife and ecosystem services
  • species action plans
  • habitat action plans
  • local biodiversity action plans
  • water resources strategy

Many restoration and enhancement projects are undertaken in partnership with, or in some cases solely, by Natural England and other conservation bodies such as the rivers trusts. Many projects are undertaken through voluntary agreements at local level.