Chichester Local District Plan 2023: Green corridors and environmental issues, what are they and where will they be?

Following a full council meeting of Chichester District Council on Tuesday, January 24 figures for a new housing target as well as improvements to improvements to two A27 roundabouts in the district.

Following on the discussion, the councillors agreed to put the Plan out to a six week consultation.

The Plan has aimed for a minimum of ten per cent net gain in biodiversity.

Working in partnership with neighbouring authorities, a water neutrality strategy was set out to ensure that development in the north-east of the area would not have ‘an adverse impact’.

The Plan also proposed a series of wildlife corridors to link the South Downs National Park with the harbour and stressed the need to protect corridors where development was planned.

What are the issues?:

Protecting and enhancing the natural landscape of the plan area is a key objective for the Local Plan and due to its coastal nature, safeguarding the coast and views is also important. The natural landscape provides social, environmental and economic benefits which, when appropriately managed, can contribute towards long-term sustainable growth, making space for nature recovery.

In planning for this development, the Local Plan takes account of and seeks to avoid and reduce the impact of development on the plan area's natural landscape, safeguarding areas for climate change adaptation and providing nature-based solutions which protect the natural landscape.

The plan area includes parts of four national landscape areas: Low Weald, Wealden Greensand, South Downs and South Coast Plain. A Strategy for the West Sussex Landscape has been developed by West Sussex County Council (WSCC), which sets a vision for each of these character areas as well as providing landscape guidelines relating to development. Chichester Harbour Conservancy's Chichester Harbour AONB Management Plan (the Management Plan); Chichester Harbour AONB Landscape Character Assessment; as well as the council's adopted Chichester Harbour AONB Joint Supplementary Planning Document (SPD) all provide important guidance for development proposals in the AONB. The Management Plan and SPD are material planning considerations in the assessment of development proposals for land within the AONB. Other studies commissioned as part of developing the Local Plan, such as the Landscape Capacity Study, are important sources of evidence for landscape value and potential impact from development. Natural England also provides important guidance on carrying out landscape character assessments where a planning proposal is likely to impact the natural landscape.

How will the issues be met?

In order to meet the proposed housing growth, CDC are proposing to make sure there will be the necessary infrastructure to support the new development.

Water companies have a statutory duty to treat wastewater resulting from new development. The council will be working closely with these companies, primarily Southern Water but also Portsmouth and Thames Water where relevant, to ensure new development is factored into their future plans.

Wastewater treatment capacity has long been a problem in the south of the district and timely upgrades to infrastructure are required to manage the increased wastewater from our proposed and planned development.

Parts of Chichester Harbour, internationally-designated for its ecology and conservation importance, are assessed to be in an 'unfavourable - declining' condition as a result of a build-up of excess nutrients causing eutrophication (algal growth) harmful to wildlife. Relative to other sources of excess nutrients, such as run-off from surrounding farmland as a result of agriculture, wastewater from new development contributes a small amount of pollution.

It is important that pollution caused by wastewater, as well as other sources, is addressed to reduce harmful impacts and enable recovery of the Harbour. Policies within the proposed Local Plan seek to ensure that there is no net increase, and where possible a net reduction, in nutrients discharged to the Harbour by requiring relevant new development to be nutrient neutral. In addition, a nutrient budget has been prepared to demonstrate that there is sufficient mitigation available (for example through off-setting schemes) for the first 5 years of the plan period.

The approach to nutrient neutrality has been developed with key partners including Southern Water, Natural England, the Environment Agency, and other authorities affected by the issue (including the Partnership for South Hampshire - PfSH).

What is meant by 'water neutrality'?

Natural England has advised us that the abstraction (removal) of water within the Sussex North Water Resource Zone is having a negative impact on the Arun Valley, an internationally protected habitat. To avoid further harm, new development within the zone (within the north of the Local Plan area) must not increase pressure on water resources.

Affected local authorities have worked closely with Natural England, the Environment Agency and Southern Water to produce a joint water neutrality study. The results of the study have informed the water neutrality policy which requires that all new development must be highly water efficient to contribute to achieving water neutrality, where total water use in the supply area after development is equal to or less than before. This may require developments to incorporate water saving fixtures, greywater recycling or rainwater harvesting measures.

How will waste be treated through the plan?:

Ten wastewater treatment works (WwTW) currently serve the plan area. A Water Quality Assessment was prepared in 2018 to help understand the capacity of existing WwTW to accommodate proposed development. This has been supplemented and updated by ongoing discussions with Southern Water and the Environment Agency, published in the form of Statements of Common Ground.

Upgrades to wastewater infrastructure will be necessary to manage the increased wastewater from housing growth over the plan period whilst maintaining and improving the water quality of receiving waters.

Southern Water is preparing a Drainage and Wastewater Management Plan (DWMP) for the Arun and Western Streams area which will consider the options and priorities for the conveyance and treatment of wastewater over the next 25 years. This includes considering the impacts of climate change and the potential need to relocate works affected by sea level rise in future. The DWMP has been used to inform the Local Plan and associated development strategy.

It is noted that both Portsmouth Water and Southern Water have targets to reduce water consumption to 100 litres per person per day (lppd) by 2040, a lower figure than the current most stringent Building Regulation target of 110 lppd. Policy NE19 (Nutrient Neutrality) covers the need for nutrient neutrality in parts of the plan area.

The Water Management and Water Quality policy applies additional restrictions to development in the Apuldram (Chichester) Wastewater Treatment Catchment in order to protect the water environment of Chichester Harbour. The catchment is affected by a high level of groundwater infiltration to the sewer network which has historically led to high winter flows to the treatments works, meaning the storm overflow has been in operation for significant periods of time. The Environment Agency and Southern Water agreed a joint position statement in December 2018, which is a material consideration in determining planning applications in the catchment.