Nick Price - Water Resources Planning Manager

Transcription

1 1 Nick Price - Water Resources Planning Manager

2 Overview 1. Introduction Southern Water supply area 2. Supply and demand forecasts pressures and uncertainties Sustainability reductions Resilience to drought Climate change Raw water quality Demand forecast 4. Developing the strategy Baseline supply-demand balance Solutions 5. Reflections and forward look Lessons from WRMP19 Looking ahead to WRMP24 3. Approach to decision making Problem characterisation Integrated risk model Scenario generator model Real Options Analysis 2

3 Southern Water supply areas 14 Water Resource Zones supplying > 2.4 million people. Typically our water comes from groundwater (7%), rivers (23%) and reservoirs (7%).

4 Flow (Million litres per day) Sustainability reductions example of impact on River Test surface water source 2 Stochastic drought: Rafael Year 1 Year 2 4

5 Flow (Million litres per day) Sustainability reductions example of impact on River Test surface water source 2 Stochastic drought: Rafael Year 1 Year 2 5

6 Flow (Million litres per day) Sustainability reductions example of impact on River Test surface water source 2 Stochastic drought: Rafael MDO = 15Ml/d Year 1 Year 2 6

7 Flow (Million litres per day) Sustainability reductions example of impact on River Test surface water source 2 Stochastic drought: Rafael Year 1 Year 2 7

8 Flow (Million litres per day) Sustainability reductions example of impact on River Test surface water source 2 Stochastic drought: Rafael MDO = Ml/d SR = -15Ml/d (-14% total ADO/MDO) Year 1 Year 2 8

9 Company total ADO/MDO (Ml/d) Impact of certain and potential sustainability reductions on available supplies by Dry Year Annual Average / Minimum Deployable Output planning scenario (company level) Ml/d -26% Existing DO Uncertain SRs Certain SRs 9

10 Company total ADO/MDO (Ml/d) Impact of certain and potential sustainability reductions on available supplies by Dry Year Annual Average / Minimum Deployable Output planning scenario (company level) Ml/d -26% -2Ml/d -28% Existing DO Uncertain SRs Certain SRs 1

11 Company total ADO/MDO (Ml/d) Impact of certain and potential sustainability reductions on available supplies by Dry Year Annual Average / Minimum Deployable Output planning scenario (company level) 7-188Ml/d -26% -2Ml/d -28% -331Ml/d -46% Existing DO Uncertain SRs Certain SRs 11

12 Company total DO (Ml/d) Deployable Output against different drought severities in 2 year 1 in 2 year 1 in 1 year 1 in 2 year 1 in year 1 in 1 year Company total ADO / MDO Company total PDO 12

13 Company total DO (Ml/d) Deployable Output against different drought severities Reduction in ADO/MDO moving from 1 in 1 year drought severity to 1 in 2 year drought severity Ml/d -8% in 2 year 1 in 2 year 1 in 1 year 1 in 2 year 1 in year 1 in 1 year Company total ADO / MDO Company total PDO 13

14 Company total DO (Ml/d) Deployable Output against different drought severities Ml/d -8% -66Ml/d -12% Reduction in ADO/MDO moving from 1 in 2 year drought severity to 1 in year drought severity in 2 year 1 in 2 year 1 in 1 year 1 in 2 year 1 in year 1 in 1 year Company total ADO / MDO Company total PDO 14

15 Company total ADO/MDO (Ml/d) Impact of climate change and raw water quality upon baseline supply availability Dry Year Annual Average / Minimum Deployable output planning scenario (company level) 8 +14Ml/d +2% Existing DO Climate change WQ write downs 15

16 Company total ADO/MDO (Ml/d) Impact of climate change and raw water quality upon baseline supply availability Dry Year Annual Average / Minimum Deployable output planning scenario (company level) 8 +57Ml/d +8% +14Ml/d +2% Ml/d -7% Existing DO Climate change WQ write downs 16

17 Company total ADO/MDO (Ml/d) Impact of climate change and raw water quality upon baseline supply availability Dry Year Annual Average / Minimum Deployable output planning scenario (company level) 8 +57Ml/d +8% +14Ml/d +2% 124Ml/d -17% Ml/d -7% Existing DO Climate change WQ write downs 17

18 Revised draft WRMP demand forecast 18

19 Problem characterisation to inform decision making approach UKWIR, 216, WRMP 219 Methods Decision Making Process: Guidance, UK Water Industry Research Limited Used to inform the degree of modelling complexity and method Outcome supports adoption of more complex extended decision making tools Strategic Needs Score ( How big is the problem? ) -1 (None) 2-3 (Small) 4-5 (Medium) 6 (Large) Complexity Factors Score ( How difficult is it to solve? ) Low (<7) Medium (7-11) High (11+) Central Area Eastern Area Western Area Company 19

20 Overview of the Integrated Risk Model (IRM) and Scenario Generator Model (SGM) 2

21 Planning for a range of futures 21

22 Probabilistic SDB (Ml/d) Baseline supply-demand balance (Western area) MDO Western area (Scenario A) - 1 in 2yr -2 8% to 9% -4 7% to 8% % to 7% 5% to 6% 4% to 5% 3% to 4% -16 2% to 3% % to 2% 22

23 What s in our plan better use of existing water Leakage has reduced by 63% since privatisation. We are aiming for a further 15% reduction by 225 followed by a further 25% reduction by 25 reducing water use to 1 litres per person per day by 24 Installing more water meters to 1% in some areas Sharing meter readings every month Catchment First engaging with farmers and landowners to improve water quality New pipe networks to move water around. 23

24 What s in our plan...finding new water Aquifer storage and recovery Recycling cleaned water from our wastewater treatment works Desalination Reservoirs Improving groundwater sources Trading water with neighbouring water companies: Portsmouth Water, Bournemouth Water, South East Water 24

25 Conclusions Reflections from WRMP19 Significant downward pressure on current deployable output - particularly from sustainability reductions Considerable uncertainties around our forecasts Problem characterisation and advanced modelling methods have helped us develop solutions Real Options Analysis has enabled us to develop a flexible strategy to cope with uncertainties. Concept well received but challenges around communicating the preferred strategy Looking towards WRMP24 Future uncertainty in supply availability remains a challenge Outcome of large Water Industry National Environment Programme is key in the short term Higher resilience to drought? Stronger regional planning influence Greater emphasis on integration of supply networks (and not just between companies) Environmental accounting to the fore to better account for wider benefits and impacts of potential solutions. UKCP18 climate change forecasts 25

26 26 Nick Price - Water Resources Planning Manager Nicholas.price@southernwater.co.uk