Final Water Resources Management Plan. Non-Technical Summary

Transcription

1 Final Water Resources Management Plan Non-Technical Summary June 2014

2 Sutton and East Surrey Water Non-Technical Summary Introduction In its Final Water Resources Management Plan (), Sutton and East Surrey Water (the Company) presents its preferred plan for maintaining the supply-demand balance in its area of supply for the next 25 years from 2015/2016 to 2039/2040. The describes the measures proposed for meeting growth in demand for water from new and existing consumers, and how we will manage supplies and protect the environment. The Company is a water supply only company which covers an area of 834 km 2 comprising a large proportion of Surrey, and extending into parts of Kent, West Sussex and Greater London. The Company currently provides drinking water to over 675,000 consumers in over 280,000 properties. On average, the total amount distributed each day is 160 million litres which is equivalent to over 60 Olympic swimming pools. 85% of the raw water comes from underground resources (groundwater) and 15% from river sources. The majority of the water supplied by the Company is for domestic household consumption which increases significantly during dry summer periods. At March 2014, 44% of household properties and 88% of non-household properties within the Company s supply area were metered. The Company faces a number of challenges over the next 25 years, characterised by pressures on water availability due to increased demand from new and existing customers, the impacts of climate change, and the need to protect the environment. The area of South East England in which the Company operates has been classified by the Environment Agency (EA) as being under serious water stress. Water resources planning process Water companies have a statutory duty to prepare an updated WRMP every five years. A schematic of the water resources planning process is shown below. The approach used by the Company to develop its is summarised in the following sections. Throughout the process, the Company has actively engaged with its customers and environmental regulators. LCS/ NTS Page 2 of 7 June 2014

3 Sutton and East Surrey Water Supply forecast Buffer for uncertainty (headroom) Demand forecast Baseline supply-demand forecast Surplus Deficit Appraise options Final supply-demand forecast (preferred plan) Customer and stakeholder feedback Baseline supply-demand forecast The Company s forecasts of the demand for the next 25 years consider factors such as population growth, historic trends, customer behaviour with respect to water use, climate change and the inclusion of the Company s current water demand management policies (e.g. reducing leakage and metering). The needs of other water companies in the South East of England have also been taken into account. The quantity of water available to meet the forecast demand has been established by calculating how much can be supplied from each of the Company s sources, taking into account estimates of the impacts of climate change. Predicting water supply and demand in the future is not an exact science and so an allowance, called headroom, is made for uncertainties in the forecasts of supply and demand. This allowance is added to the forecast of demand. The outcome of this work is a baseline forecast of water supply and water demand. The purpose of water resources planning is to see what additional actions (if any) need to be taken to balance the forecasts of supply and demand. Appraisal of options The Company s baseline forecast shows that our existing water sources are insufficient to meet expected demands over all of the 25 year period. This situation is known as a supplydemand deficit. As there is a forecast supply-demand deficit, the Company has looked at a LCS/ NTS Page 3 of 7 June 2014

4 Company options Sutton and East Surrey Water number of ways or options to remove the deficit. The range of options investigated is listed in the figure below. Resource management New / upgrading existing borehole sources Increasing / upgrading water treatment works capacity / capability Increasing reservoir capacity Groundwater storage and recovery schemes Customer-side Installing water saving devices Metering Distribution-side Leakage reduction Third Third party party options options Bulk transfers of treated water from other water companies The options can be grouped into three main types of schemes. Resource management options affect the amount of water available at existing and/or new borehole and river sources. Customer-side options are water demand saving options implemented at customers properties. Distribution-side options look at activities involved in the management of the Company s water supply pipe network, such as reducing leakage from the pipe network. Third party options include the transfer of treated water from a neighbouring water company into the Company s water supply network. In considering the range of options, the Company has been guided by: a) Government policy priorities which require water companies to take a long-term perspective, reduce the demand for water, consider water scarcity and environmental damage, and look at options for sharing water resources; and b) Customer preferences which include fixing leaks, using metering as the fairest way to charge, better storage solutions and resilience of water supply. The views and priorities of our customers were obtained during an 18-month customer engagement programme that included questionnaires, telephone interviews, and face-to-face discussions. The options were assessed using an economic model to determine the least costly combinations of options or programmes of options that fit certain scenarios (e.g. least cost, metering, resilience and best environmental). By looking at a variety of factors such as cost (construction, operational and environmental), yield uncertainty and resilience, the programmes were compared to identify the best balance of options to be selected as the Company s preferred plan to manage supply and demand over the next 25 years. LCS/ NTS Page 4 of 7 June 2014

5 Sutton and East Surrey Water Our Preferred Plan Our preferred plan provides best value to customers and the environment. The options included in the preferred plan are shown in the figure below. Short-term 2015/16 to 2019/20 Customer-side water efficiency and metering options Water efficiency audits at non-household properties and at metered households with higher than usual water use Installation of water saving devices in the hospitality sector and in households Provision of water butts at a reduced cost Metering of properties when there is a change of occupier Medium-term 2020/21 to 2029/30 Resource management options Increase water treatment works capacity Customer-side water efficiency options Installation of water saving devices in schools and households Long-term 2030/31 to 2039/40 Resource management options New borehole source Advanced water treatment for a disused source Customer-side water efficiency options Installation of water saving devices in schools and elderly care homes Distribution-side options Leak detection and repair above the Company s leakage target The timescales for implementing the preferred plan over the 25 year planning period have been considered in terms of the short-term, medium-term and long-term. Water efficiency options feature highly in the short-term and take into account feedback received by the Company during different customer consultation activities. In the short-term, the Company also proposes to install 32,000 new meters on previously unmeasured properties through a combination of change of occupier and voluntary basis. This is a continuation of the Company s existing metering programme and has been supported in the feedback we have received from our customer consultations. Water efficiency programmes continue throughout the medium and long-term. These include the installation of water saving devices such as dual flush toilets, low flow showerheads and push taps in schools, elderly care homes and household properties. In the medium-term, increasing the amount of water that can be treated from the Company s only river source and improving the network to enable water to be moved around the supply area, is expected to improve the reliability of supplies to customers. Additional resource management options in the long-term include developing a new borehole source and providing advanced water treatment for one of our existing licensed borehole sources which is currently out of supply due to water quality issues. Although the Company s current level of leakage is below its leakage target and one of the lowest in the UK water LCS/ NTS Page 5 of 7 June 2014

6 Ml/d Sutton and East Surrey Water industry, even more challenging targets to reduce leakage via a leak detection and repair programme are identified in our preferred plan. Final Plan supply-demand forecast The graphs below show the Company s final planning forecast of water supply and demand for an average dry year and for peak water demand. The forecast demand takes into account the planned water demand saving options and planned reduction in leakage from the pipe network. The amount of water available for use changes over time as a result of many factors. The graphs below have been labelled in blue to show the timing of resource management options that will provide additional water and labelled in pink to show the timing of bulk transfers which will supply water to other water companies. The graphs show that demand is rising slowly but with the options included in our preferred plan, there is sufficient water available for use Bulk supply to South East Water from 2019/20 (5 Ml/d) Final Plan Supply-Demand Balance Average Dry Year Bulk supply to South East Water (additional 1.18 Ml/d from 2022/23) New borehole (additional 3.4 Ml/d from 2034/35) Improvement at existing borehole (additional 2.07 Ml/d from 2038/39) Demand Demand plus Target Headroom (uncertainty) Water Available For Use Resource management options (providing additional water for use) Bulk transfer options (water provided to other water companies) LCS/ NTS Page 6 of 7 June 2014

7 Ml/d Sutton and East Surrey Water Bulk supply to South East Water from 2019/20 (5 Ml/d) Final Plan Supply-Demand Balance Peak Period Reservoir A upgrade to 70 Ml/d (additional 20 Ml/d from 2022/23) Bulk supply to South East Water (additional 5 Ml/d from 2022/23) New borehole (additional 3.4 Ml/d from 2034/35) Improvement at existing borehole (additional 4.54 Ml/d from 2038/39) Demand Demand plus Target Headroom (uncertainty) Water Available For Use Resource management options (providing additional water for use) Bulk transfer options (water provided to other water companies) Conclusion The preferred plan meets the many different objectives the Company set out to achieve: to reflect Government policy priorities, the preferences of our customers, to protect the environment, and to demonstrate a robust strategy for long-term resilience against future uncertainties, particularly climate change. We have tested our plan to see how it performs to changes in supply or demand for water. This has confirmed that the options identified in our preferred plan will also meet potential challenges due to uncertainties in forecasting supply and demand over the longer term. The options in our preferred plan are resilient to potential changes in supply and demand, and the additional options we have identified can be brought forward to meet additional growth in demand, or changes in our supplies, as necessary. In addition, because our plan for the next 5 years is focussed on a combination of further metering, water efficiency and resilience measures, it also allows us to respond flexibly should the forecast future demand for water not materialise. Our preferred plan, together with the additional options identified, allows us to bring forward or delay options depending on the trends in the balance of water supply and demand. LCS/ NTS Page 7 of 7 June 2014