Nutrient neutrality has become an essential consideration in UK planning, ensuring that new developments do not add harmful nitrogen or phosphorus pollution to sensitive water bodies. This concept emerged in response to protected wetland habitats suffering from excess nutrients, which fuel algae growth and deplete oxygen in waterways. In practice, nutrient neutrality means a project mitigates any nutrient load it would otherwise introduce. This blog post provides a concise update on nutrient neutrality policy and practice, with a focus on North-West England, particularly Cheshire, where several catchments are affected. We review recent national policy developments (including changes in law and guidance) and regional requirements, and offer practical advice for developers and land promoters on achieving nutrient neutrality and navigating the planning system.

Recent National Policy Changes (Post‑2022)

In recent years the UK government has tightened policies to address nutrient pollution from new developments. Following a 2018 European court ruling, Natural England issued guidance in 2019 (and expanded it in March 2022) advising local planning authorities to only approve new housing developments that are “nutrient neutral” in certain sensitive catchments. Natural England warned that extra wastewater from new homes could significantly worsen conditions in habitats already suffering excess nitrogen or phosphorus. In effect, this means any additional nutrient load from a project must be fully offset so that no harm is caused to protected wetlands and water bodies.

National policy has continued to evolve. The Levelling Up and Regeneration Act 2023 introduced a new duty on water companies to upgrade wastewater treatment works by 2030 in designated “sensitive” catchments where protected sites are in unfavourable condition. This is intended to reduce nutrient pollution at source over time. The government initially sought to relax the Habitats Regulations via the Act (proposing that councils assume new development’s wastewater has no adverse effect), but that amendment was subsequently rejected in the House of Lords. Instead, efforts have focused on mitigation measures – including support for nutrient credit schemes. Natural England launched a Nutrient Mitigation Scheme in 2022 to allow developers to purchase “nutrient credits” and fund off-site mitigation, helping to satisfy neutrality requirements.

Cheshire’s Nutrient Neutrality Catchments

In North West England, several areas in Cheshire are now subject to nutrient neutrality rules. Key affected sites include Rostherne Mere Ramsar, West Midlands Mosses SAC (a Special Area of Conservation encompassing several peat mosses, e.g. Wybunbury Moss), and Oak Mere SAC. These freshwater habitats have been designated as being in “unfavourable” condition due to elevated nutrient levels. Both Rostherne Mere and the West Midlands Mosses are impacted by excess nitrogen and phosphorus, whereas Oak Mere’s primary nutrient concern is phosphorus enrichment. New developments within the catchments draining to these protected wetlands must therefore be screened for nutrient impacts. If a project would contribute additional nitrates or phosphates (for example via wastewater or runoff), mitigation will be required so that the net nutrient load is neutral.

Implications for Developers and Land Promoters

For developers and land promoters in affected parts of Cheshire, nutrient neutrality has become a critical factor in the planning process. Local planning authorities now require nutrient budget assessments for new housing or other overnight accommodation proposals within these catchments. Using Natural England’s calculators and methodology, developers must quantify the likely increase in nitrogen and/or phosphorus from their development and compare it to the site’s current nutrient output (e.g. previous land use). The Habitat Regulations mean that if a scheme is predicted to add nutrient pollution, planning permission cannot be granted unless that increase is offset by appropriate mitigation measures. In practical terms, applicants are expected to demonstrate a nutrient neutral or betterment outcome, often by securing mitigation that removes an equivalent amount of nutrients from the catchment. These requirements have significant impacts on project timelines and costs. In some areas, authorities have had to pause approving new developments (“moratoria”) until workable mitigation solutions are in place. Developers have argued that nutrient neutrality rules have led to delays in essential housing delivery and added complexity to obtaining consent.

Land promoters must account for potential nutrient mitigation when bringing sites forward, such as the need to set aside land for treatment ponds or to contribute to off-site mitigation schemes affecting site capacity and viability. Early consideration is essential, undertaking nutrient surveys and engaging with environmental consultants at an early stage will help identify feasible mitigation options before submitting a planning application. By proactively addressing nutrient impacts, developers can avoid last-minute objections and ensure compliance with both national policy and local plan requirements.

Mitigation Strategies for Nutrient Neutrality

A range of mitigation strategies can be employed to achieve nutrient neutrality. Common approaches include:

• On-site solutions: Incorporating sustainable drainage systems (SuDS) and treatment features within the development to capture and remove nutrients. Examples include constructed wetlands, reed beds, or infiltration basins that absorb nitrates and phosphates before water leaves the site. Upgrading private wastewater treatment facilities or using advanced phosphorus removal technology on-site can also reduce nutrient discharges at source.

• Off-site mitigation: Partnering with landowners or environmental bodies to deliver nutrient reductions elsewhere in the same catchment. This often involves creating or restoring natural habitats that absorb nutrients, e.g. funding the creation of woodlands, wetlands or buffer strips along watercourses. Another off-site tactic is changing agricultural practices (such as taking nutrient-intensive farmland out of production or altering fertiliser use) to lower the overall nutrient runoff in the catchment. Developers can enter into agreements to sponsor such measures as offsetting for their projects.

• Nutrient credit schemes: Purchasing nutrient “credits” through accredited schemes to offset the development’s nutrient output. Under these schemes, each credit represents a quantified nutrient reduction achieved by a strategic mitigation project. For example, Natural England’s Nutrient Mitigation Scheme allows developers to buy credits which fund the creation of new wetlands or woodlands that will remove nutrients from waterways. Some local authorities and private providers are also establishing nutrient credit banks or trading platforms. By buying into a credit scheme, a developer secures an evidence-backed mitigation contribution, and receives a certificate to use in their Habitats Regulations Assessment. This can be an efficient solution when on-site options are limited, though credits can be costly and availability may be limited in certain areas.

Recommendations for Navigating Planning & Compliance

To manage nutrient neutrality requirements effectively, developers and land promoters should consider the following steps:

• Confirm catchment status early: Check at the outset whether your site falls within a nutrient neutrality catchment (e.g. those draining to Rostherne Mere, West Midlands Mosses, Oak Mere, etc.). If so, factor this into project timelines and due diligence.

• Conduct a nutrient budget assessment: Use the approved Natural England nutrient calculator for the relevant catchment to calculate your development’s nutrient budget. This will quantify any mitigation needed and should be done before a planning application is submitted.

• Engage with authorities and experts: Consult early with the local planning authority and Natural England. Seek specialist hydrologist or ecologist input to devise a robust mitigation strategy that will satisfy Habitats Regulations requirements. Early dialogue can ensure that your mitigation proposals (on-site design changes or off-site schemes) are acceptable in principle.

• Explore mitigation options proactively: Identify potential on-site design measures to reduce nutrient output (such as SuDS features or improved wastewater technology). Simultaneously, investigate off-site opportunities, for example, nearby land that could be used for tree planting or wetland creation. Where available, consider purchasing nutrient credits from trusted schemes if they align with your project’s needs.

• Stay informed on policy updates: Nutrient neutrality policy is evolving. Remain up-to-date with national and local developments, such as the planned wastewater treatment upgrades by 2030 and any new government initiatives or funding for mitigation. Being aware of these changes can help in planning phasing for larger schemes (for instance, if later phases might benefit from future infrastructure improvements). Monitor announcements from Defra, Natural England, and your local authority so you can adjust your strategy in line with the latest guidance.

At Hex we utilise our specialist knowledge and experience to rigorously address nutrient neutrality from the start, helping developers in Cheshire and across the North-West navigate the complexities of the planning system. Hex Land Partners advises maintaining a proactive and evidence-led approach, demonstrating nutrient neutrality not only ensures regulatory compliance, but also contributes to the protection of our region’s precious wetlands and water environments.