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Water Cycle Study

Water Cycle Study

The South Downs National Park Authority has commissioned consultants AMEC to undertake a combined Water Cycle Study and Strategic Food Risk Assessment (level 1) to support longer term decisions for housing growth in the area.

The vision for the project is to ensure that housing growth plans are based on sound water service and environmental evidence, and that growth will be supported by sustainable water service infrastructure without impacting on environmental objectives.

Water Cycle Study – Scoping and Outline Report

The Issue

The South Downs National Park Authority (SDNPA) is in the process of developing its Local Plan for the South Downs National Park and this includes the need to provide more homes for the increasing number of people who live here and to support our economic growth. However, more people and more homes means that more water will be required, more homes will need to be connected to the supply and the wastewater distribution systems, and we need to make sure that homes are not built in areas at risk of flooding, or in areas that will increase the risk of flooding for others.

It is the water supply and water sewerage companies that face the challenge of securing water supplies and wastewater services for increasing numbers of people whilst also ensuring they do not cause environmental problems. They do this by adhering to strict regulatory consents which govern how much water they can abstract and when, and how much water of specified water quality they are allowed to discharge back into rivers.

The South Downs National Park is home to major rivers including the Western Rother and Itchen which in turn support valuable aquatic habitats. Our environment is generally in a good condition and we all want it to stay that way. The Environment Agency is responsible for setting the environmental permits which the water companies are required to adhere to. These permits are designed to meet UK and European Union environmental targets.

The water companies develop their assets to supply and treat water balancing demand for services against the permit conditions they must meet. Growth that does not take into consideration the capacity and the constraints of the water services risks water services not being met, environmental damage, or hurried and unsustainable upgrades being made.

South Downs National Park is working in partnership with Portsmouth Water, South East Water, and Southern Water, the Environment Agency, and our neighbouring local authorities to ensure that all the possible risks and concerns are examined and a sustainable solution identified.

Water Cycle Study

A Water Cycle Study is one of a number of strategic studies used by Local Planning Authorities as part of the evidence base for Local Development Frameworks (LDF). The study aims to identify a phased approach for development so that water and infrastructure services can be planned and implemented in line with the growth requirements of the SDNPA. This will take account of the environmental capacity of water bodies, and infrastructure capacity. The study will make recommendations on how development should proceed and what policies are required to deliver the planned growth without compromising, and where possible enhancing, the water environment.

The main aspects considered in a water cycle study are:

  • Water resources – increased demand for water and supply infrastructure
  • Water quality – increased demand for sewerage and other wastewater, requiring collection and treatment.  Treatment capacity and constraints increase risks to surface water quality and the water companies
  • Flood risk – increased hardstanding and increased volumes of water discharging from wastewater treatment works can increase the risk of flooding.  The study will incorporate and build on the Strategic and Area Flood Risk Assessments that have already been completed
  • Sustainable Drainage is desirable and the study will confirm what the options are in this area
  • Integration with adjoining areas (including cumulative impacts of growth)

The Stages

Typically these studies are produced in 3 phases; Scoping, Outline, and Detailed. This project will include Scoping and Outline. The Scoping Study will be delivered in April 2014, with the Outline Study being produced by June 2014.

Scoping: This involves a review of the potential growth sites in relation to the capacity of the existing water infrastructure and environment to identify where there are constraints to growth.

Outline: Where technical and geographic constraints are identified the Outline stage investigates these in more detail to determine the range of solutions and most appropriate options to support the growth plans. Typically this involves re-affirming the need to align growth plans with water company business planning cycles.

The study assesses the requirements for water infrastructure to facilitate development and potential environmental constraints will be identified. Existing information on customer demand for water and sewerage services are used together with water company forecasts to help inform National Park Authority policies relating to water consumption and flood risk.


The Steering Group comprises South Downs National Park Authority, AMEC, Southern Water, Portsmouth Water, South East Water, Environment Agency, and the Lead Local Flood Authorities: West Sussex, East Sussex, Hampshire, and Brighton and Hove City Council.

Further Details

For further information about the project, please contact:

Jeremy Burgess – Landscape and Biodioversity Lead (Water)
South Downs Centre
North Street
GU29 9DH



"The Downs...too much for one pair of eyes, enough to float a whole population in happiness."