utilities capacity study - Exeter and East Devon Growth Point

In August of 2009 the Exeter and East Devon Growth Point Delivery Team appointed WSP Group, a national multi-disciplinary consultancy with offices based locally in Exeter, to carry out a comprehensive Utilities Capacity Study for the extent of the Exeter and East Devon Growth Point area (which includes the whole of Exeter City and strategic development sites in the western part of East Devon) and:

  • The rest of East Devon district
  • A small area to the south west of Exeter in Teignbridge district (identified as area of search 4c in the emerging Regional Spatial Strategy (RSS)

The background to this key study was that the proposed development areas would be built out over a period of approximately 20 - 25 years and would be subject to existing and emerging national planning and local development plan policies, as well as Building Regulations, the Code for Sustainable Homes (CSH) and the incoming Code for Sustainable Buildings (CSB).

A fundamental principle of the energy infrastructure requirements is that everything that the Growth Point Partners look to as part of a future energy strategy should be based on achieving their aspirations for a low or zero carbon economy. To achieve this, the partnership was looking to thoroughly investigate the current and future technologies, particularly combined heat and power (CHP) and other alternative sustainable methods.

Therefore, this study was not viewed as just a conventional utilities provision study but should also draw on the work done by Element Energy in their previous study.

Additionally it had been identified that strategic housing and employment growth could not occur without considered ICT utilities provision and this was included in the Utilities Capacity Study.

Aims and Objectives
The main aim of the study was to identify capacity and future utilities provision including:

  • Alternative sustainable technology
  • Gas
  • Electricity
  • Water supply
  • Surface water
  • Sewerage
  • ICT and telecommunications

For the Growth Point area for the next 20 - 25 years and to provide a comprehensive strategy for the delivery of utilities infrastructure.

The study was tasked with clearly recommending an implementation strategy based on current and future technologies.


In order to achieve these outcomes the following tasks were identified:

  • Identify and prioritise development areas.

A single map shall be produced containing all the development areas that the Client wants included within the study with an indication of their priority with respect to size, importance and timetable

  • Determine demand profiles by utility service.

Domestic GasThe development quanta for each development area shall be determined with reference to the Document List. The areas or units of development shall be classified according to Town and Country Planning use classes. The development quanta shall be time-related with the development profile taken to 2035. This work will need to be done in consultation with each Authority.

The development quanta and its classification shall be agreed with the Client early in the study period and prior to the application of utility demand characteristics against development quanta classification.

Utility demand figures against unit of development by planning classification shall be used to determine the maximum demand of the development.

The demands within a development shall be diversified to produce a realistic demand for that development. Then the demands for developments shall be diversified to produce a realistic demand figure for the whole development area. Whole development areas shall be diversified with adjacent development areas which are likely to share the same source of utility supply. This procedure shall take into account the development programme

The demand profiles shall be discussed with each relevant utility to ensure that the figures are consistent with those used by the utility companies and that any differences are identified and explained.

Demand profiles of each development area taken up to 2035 shall be produced for each development area and for all development areas.

  • Determine capacity profiles for each utility service within study area.

The study shall estimate utility network capacity based upon mapping information received from the utilities, other published information from the utilities, discussions with utility company staff and other experience as appropriate.

These estimates shall be at strategic levels and be consistent with the aim of providing information to inform the utility strategy relating to the development areas individually and collectively.

Long term development statements shall be obtained from each utility supplying the study area.

Capacity profiles for each utility shall be discussed with each utility taking into account natural growth and the utility's long term development plans.

Clearly outline assumptions regarding the capacity and acceptability of existing and new utilities infrastructure (e.g. what phasing of water efficiency in new buildings is assumed, what Code levels are assumed, what update of broadband coverage is assumed)

  • Determine any shortfall in utility network capacity for the development areas and identify where on the network the capacity exists.

The study shall compare demand profiles for the development areas individually and as a whole against capacity profiles for the utility networks and determine any shortfall and when and where it might occur.

The study shall take the capacity analysis into the utility network as far as the primary assets such as water treatment works, pumping stations, electrical/gas grid connections, primary substations, gas pressure reducing stations, governors and local storage facilities, telephone exchanges or Points of Presence.

Establish what is already contained and planned for within the investment programmes of utilities' providers for each utility.

  • Identify budget costs associated with upgrade/reinforcements of utilities' networks to service the individual development areas and development areas together.

Fibre Optic CableThe study shall consider options for increasing utility capacity if required to the development areas individually and collectively. The study shall take into account the development programme to determine the most efficient means of providing capacity to meet the development programme. The study shall take into account the topography of the area to determine the most cost effective means of providing capacity to the development areas.

The cost of upgrades/reinforcements of the utilities' networks shall be determined using up to date unit rates/cost information for the installation of the appropriate apparatus. These costs shall be compared to known costs for similar installations and examples shall be included within the study.

Costs of the installations shall be discussed with the utility networks' owners and/or operators with a view to obtaining the most reliable costs according to how and by whom the required apparatus is installed.

  • Discuss programme of implementation with utility companies and determine realistic timetable to service the development programme.

Having determined the extent of upgrades/reinforcements the study shall consider the programme for implementation through discussions with the relevant utility company. Alternative implementation programmes by third parties shall be considered, such as build by contractor for adoption by utility, and examples of timescales for similar implementation proposals elsewhere shall be included within the study

  • Identify and recommend procurement procedures for making up shortfall in utility capacity for each development and for all development areas together.

Having determined any shortfall in utility capacity and the extent of works required to make up the shortfall, the study shall identify and consider procurement procedures for each and all the developments.

The procurement options should consider capital expenditure, programme of implementation, quality of service, operating expenditure and reliability of long term supplies amongst other considerations.

  • Identify funding options from Local, Regional and Central Government and European Union sources

The financing of infrastructure utilising existing and potential funding sources should be considered, including:

1.    Government grants

2.    Regional Infrastructure Fund

3.    Tax Increment Financing

4.    Private sector finance

5.    S106 / Tariff / Community Infrastructure Levy

The study shall also consider and discuss the advantages and disadvantages of public sector intervention in the procurement process to avoid any delay in the development programme

  • Sustainable Development

The study shall include an overview of the provision of sustainable utility services to augment, or as an alternative to, the conventional sources. The study could consider the work done by Element Energy and at least the following:

1.    Alternative technology, i.e. wind turbines, CHP plant, ground source heat pumps etc.

2.    On site boreholes and water treatment works for potable water.

3.    Re-use of grey water and on-site waste water treatment works including recycling of waste.

4.    The use of waste to provide energy and the potential for waste-to-energy plants in the area in addition to any current proposals.

5.    The study should quantify the contribution made by sustainable utility provision with respect to reduced consumption of utility services.

  • Provide a drawing based record of the major utility apparatus within the development areas.

The development areas will have been agreed with the Client following Section 3 above.

Client: Exeter and East Devon Growth Point Partnership and Teignbridge District Council
Consultant: Gordon Davis, Associate Director, WSP Group