Revised Draft Drought Plan 2018-2023 Main report Revised Draft Drought Plan December 2017
This revised draft drought plan 2017 has been published following public consultation on the draft drought plan 2017.
This document has been reviewed to assess the sensitivity of information from a national security perspective and it was not thought necessary to exclude any information. No commercially sensitive information has been excluded from this plan.
We consulted on our draft drought plan in autumn 2017 for eight weeks from the 4 September 2017 until the 29 October 2017. A copy of this plan was made available on our website (at www.southeastwater.co.uk) and hard copies were available at our head office in Snodland, Kent. We also sent copies directly to our consultees:
The Secretary of State for the Environment, Food and Rural Affairs Environment Agency Defra Ofwat Consumer Council for Water (CC Water) Natural England Affinity Water Portsmouth Water Southern Water Sutton and East Surrey Water Thames Water
To assist consultees, we presented a list of questions that they may have wished to consider when reviewing our draft drought plan:
1. Overall structure and presentation of the plan. We have written the plan with the aim of it being accessible to the informed stakeholder and to be handy to refer to in a drought. Do you have any suggestions on how to improve the accessibility?
2. Do you think that our approach to monitoring drought and setting the triggers for action is appropriate and sets the right balance between flexibility and certainty over the drought triggers?
3. Do you have views based on your experience during recent droughts as to what in our approach went well or less well?
4. Does this draft plan provide you with an adequate understanding the temporary use ban restrictions process, which replaces the old hosepipe bans, or do you feel further explanation is required?
5. Do you think our proposed phasing of restrictions is reasonable?
6. Do you have any concerns about the implementation of restrictions, or are there any restrictions identified in this draft drought plan that you feel might be unfair to implement?
7. Do you feel our approach to implementing restrictions for certain customers (e.g. small businesses) is reasonable?
8. We feel that the introduction of emergency demand measures such as standpipes and rota cuts is only considered in the event of an unprecedented drought event (i.e. a drought that is significantly worse than anything recorded in the past). Do you think it is ever acceptable to introduce them?
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9. The analysis for this draft plan shows that our plan would not be resilient to an extreme drought (1:500 years on average) and that planning to meet such a rare even would have implications for investment of a scale that is disproportionate to the likelihood of such a drought occurring and therefore inappropriate for our customers. Do you agree?
10. Does our draft drought plan strike an appropriate balance between customer measures (temporary use bans on water use etc.) and actions that might affect the environment (e.g. reducing environmental flows in rivers)? How might the order of implementation these be changed?
11. Do feel we have addressed all potential measures?
Following the public consultation, we prepared a statement of response to representations received on our draft drought plan, which accompanies this document. Based on our responses to these representations, we have made amendments or provided further information in this revised draft drought plan.
The following steps will now be taken to complete our final drought plan: Publication of our statement of response and revised draft drought plan Secretary of State to review statement of response and revised draft drought plan Direction from Secretary of State that our statement of response and revised draft drought plan have been accepted Preparation of final drought plan Environment Agency review of final drought plan for compliance with Secretary of State directions Publication of final drought plan
Statement from Security Manager:
I certify that I have reviewed the drought plan, and can confirm it does not contain any information that would compromise national security interests.
I also confirm the plan does not contain any information that may be considered commercially confidential.
Barry Hayes Emergency Planning and Security Manager
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CONTENTS EXECUTIVE SUMMARY ...... XII 1 INTRODUCTION ...... 17 1.1 OVERVIEW OF DROUGHT PLANNING PROCESS ...... 17 1.1.1 Regulatory background ...... 17 1.2 SOUTH EAST WATER BACKGROUND INFORMATION ...... 19 1.2.1 Water resources planning ...... 19 1.2.2 The water supply area ...... 24 1.3 BASELINE WATER RESOURCES SITUATION AND LEVELS OF SERVICE ...... 24 1.4 CONSULTATION ON THE DROUGHT PLAN ...... 25 1.4.1 Pre-draft drought plan preparation consultation ...... 25 1.4.2 Consultation on the draft drought plan and the statement of response ...... 26 1.5 STRUCTURE OF THE DROUGHT PLAN DOCUMENT ...... 26 2 DROUGHT MONITORING AND TRIGGERS ...... 28 2.1 TRIGGER ASSESSMENT AND DROUGHT ACTION LEVELS ...... 28 2.2 STAGE 1: GROUNDWATER TRIGGERS ...... 29 2.3 STAGE 1: SURFACE WATER TRIGGERS ...... 32 2.4 STAGE 1: RECHARGE TRIGGERS ...... 33 2.5 STAGE 1: DEMAND TRIGGERS...... 37 2.6 STAGE 2: OVERRIDE TRIGGERS FOR BULK SUPPLY AND SHARED USE ...... 38 2.7 STAGE 2: DROUGHT TRIGGER MATRIX ...... 39 2.8 DATA SOURCES AND ARRANGEMENTS ...... 44 2.9 ADDITIONAL HYDROMETRIC DROUGHT MONITORING ...... 45 2.10 FORECASTING ...... 45 2.11 STAGE 3: LINK TO ACTIONS ...... 46 3 DROUGHT MANAGEMENT ACTIONS ...... 47 3.1 DEMAND-SIDE ACTIONS ...... 47 3.1.1 Water conservation campaigns and calls for voluntary restraint (DAPD1) ...... 47 3.1.2 Operational works to reduce demand (DAPD2) ...... 48 3.1.3 Background to the legislation and guidance for restricting customers’ water use ...... 49 3.1.4 Temporary use bans (DAPD3) ...... 51 3.1.5 Restrictions on uses of water through a Drought Order (DAPD4) 59 3.2 SUPPLY-SIDE ACTIONS ...... 62 3.2.1 Operational works (DAPS1) ...... 62 3.2.2 Infrastructural connectivity and source improvements (DAPS2) and disused sources (DAPS3) ...... 63 3.2.3 Shared resources and bulk transfer agreements (DAPS4 agree extensions, and DAPS5 new agreements) ...... 64 3.2.4 Potential drought permit (DAPS6) and drought order sites (DAPS7) ...... 72
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3.2.5 Emergency drought planning procedures (DAPS8) ...... 79 3.2.6 Emergency drought orders (DAPS9) ...... 79 3.3 DROUGHT ACTIONS SUMMARY ...... 81 4 ENVIRONMENTAL IMPACTS ...... 89 4.1 INTRODUCTION ...... 89 4.2 ASSESSING THE RISKS TO THE ENVIRONMENT ...... 90 4.3 ENVIRONMENTAL ASSESSMENT OF DROUGHT PERMITS/ORDERS ...... 92 4.3.1 The River Ouse drought permits/orders (DAPS6) ...... 112 4.3.2 The River Cuckmere drought permit/order (DAPS6) ...... 125 4.3.3 The Chasewood drought permit/order (DAPS6) ...... 132 4.3.4 The Balcombe drought permit/order (DAPS6) ...... 133 4.3.5 The Hackenden drought permit/order (DAPS6) ...... 135 4.3.6 The Southlands and Oakland’s licence drought permit/order (DAPS6) ...... 136 4.3.7 The Halling No.8 drought permit/order (DAPS6) ...... 138 4.4 ENVIRONMENTAL MONITORING AND DATA PROVISION ...... 142 4.4.1 Baseline monitoring requirements for all River Ouse Drought Permit sites ...... 142 4.4.2 Baseline monitoring requirements for the River Cuckmere drought permit/order ...... 146 4.4.3 Summary baseline monitoring requirements for all drought permit/order sites ...... 146 4.4.4 Monitoring requirements during drought permit/order operation. 150 4.5 MITIGATION MEASURES ...... 154 4.5.1 General measures ...... 154 4.5.2 Ouse ...... 154 4.5.3 Cuckmere, and Sedlescombe ...... 158 4.5.4 Remaining groundwater abstraction sites ...... 158 4.5.5 Working in partnership with key stakeholders ...... 158 4.5.6 Post drought ...... 159 4.5.7 Longer term monitoring recommendations during drought permit/order operation...... 159 5 IMPACTS ON THE COMMUNITY ...... 160 5.1 INTRODUCTION ...... 160 5.2 ASSESSING THE IMPACTS TO THE COMMUNITY ...... 160 6 MANAGEMENT AND COMMUNICATIONS STRATEGY ...... 167 6.1 MANAGEMENT STRUCTURE ...... 167 6.1.1 Introduction ...... 167 6.1.2 Drought management team roles and responsibilities ...... 167 6.2 COMMUNICATIONS PLAN ...... 169 6.2.1 Introduction ...... 169 6.2.2 Drought communications management ...... 171 6.2.3 Objectives ...... 171 6.2.4 Target audiences ...... 171
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6.2.5 Working in partnership during drought ...... 176 6.2.6 Communication channels ...... 178 6.2.7 Drought Communication Action Plan ...... 178 6.2.8 Evaluation ...... 200 7 POST DROUGHT ACTIONS ...... 201 7.1 LIFTING INTERVENTION OPTIONS AND DECLARING END OF THE DROUGHT ...... 201 7.2 CONSULTATION DURING DROUGHT RECESSION ...... 201 7.3 POST DROUGHT REVIEW ...... 202 8 TESTING THE PLAN ...... 204 8.1 TESTING AGAINST DROUGHT SCENARIOS ...... 206 8.1.1 Short-term drought (2003) ...... 206 8.1.2 Medium duration, multi season drought (1995-1997) ...... 210 8.1.3 Long term drought (2003-2006) ...... 216 8.1.4 Two dry winter drought (2010-2012) ...... 221 8.1.5 Overall findings from the historic scenarios ...... 226 8.1.6 Historic scenario testing conclusion ...... 227 8.2 TESTING AGAINST A RANGE OF ALTERNATIVE DROUGHT SCENARIOS ...... 227 8.2.1 Summary of worst historic, severe and extreme drought scenarios 239 8.3 TESTING AGAINST A THIRD DRY WINTER DROUGHT SCENARIO ...... 242 8.4 CONCLUSIONS AND LINKAGES WITH OUR WATER RESOURCES MANAGEMENT PLAN ...... 245 9 APPENDICES ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX A REFERENCES ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX B GLOSSARY ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX C FIGURES ...... ERROR! BOOKMARK NOT DEFINED. C.1 OVERVIEW FIGURES ...... ERROR! BOOKMARK NOT DEFINED. C.2 STATUTORY ENVIRONMENTAL DESIGNATIONS NEAR TO DROUGHT PERMIT/ORDER LOCATIONS ...... ERROR! BOOKMARK NOT DEFINED. C.3 HERITAGE DESIGNATIONS NEAR TO DROUGHT PERMIT/ORDER LOCATIONS ...... ERROR! BOOKMARK NOT DEFINED. C.4 DROUGHT PERMITS/ORDERS AND WFD WATER BODY STATUSES .... ERROR! BOOKMARK NOT DEFINED. APPENDIX D DROUGHT OPTION FORMSERROR! BOOKMARK NOT DEFINED. D.1 DEMAND-SIDE DROUGHT MANAGEMENT ACTIONSERROR! BOOKMARK NOT DEFINED. D.2 SUPPLY-SIDE DROUGHT MANAGEMENT ACTIONSERROR! BOOKMARK NOT DEFINED. APPENDIX E DROUGHT TRIGGER CURVESERROR! BOOKMARK NOT DEFINED.
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E.1 EXAMPLES OF EACH TYPE OF TRIGGER CURVE FOR EASTERN (6-8) ERROR! BOOKMARK NOT DEFINED. E.2 EXAMPLES OF EACH TYPE OF TRIGGER CURVE FOR WESTERN (4-5) ERROR! BOOKMARK NOT DEFINED. E.3 EXAMPLES OF EACH TYPE OF TRIGGER CURVE FOR EASTERN (1-3) ERROR! BOOKMARK NOT DEFINED. APPENDIX F DEMAND TEMPORARY BANS ON WATER USE AND DROUGHT ORDER ESTIMATED WATER SAVINGS ...... ERROR! BOOKMARK NOT DEFINED. F.1 COMPANY DATA ...... ERROR! BOOKMARK NOT DEFINED. F.2 ESTIMATES AND ASSUMPTIONS ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX G RIVER OUSE (WINTER PERIOD / SUMMER PERIOD) DROUGHT PERMITS/ORDERSERROR! BOOKMARK NOT DEFINED. G.1 ENVIRONMENTAL BASELINE AND ASSESSMENTERROR! BOOKMARK NOT DEFINED. G.2 TEMPLATES FOR DROUGHT PERMIT/ORDER APPLICATION SUB-OPTIONS ...... ERROR! BOOKMARK NOT DEFINED. G.2.1 River Ouse Summer period drought permit/order template Error! Bookmark not defined. G.2.2 River Ouse Winter period drought permit/order template.... Error! Bookmark not defined. APPENDIX H RIVER CUCKMERE DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX I BALCOMBE DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX J HACKENDEN DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX K CHASEWOOD DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX L HALLING NO. 8 DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX M SOUTHLANDS & OAKLANDS DROUGHT PERMIT/ORDER (DAPS6/7) ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX N ENVIRONMENTAL MONITORINGERROR! BOOKMARK NOT DEFINED. APPENDIX O IDENTIFICATION OF PRIORITY LOCATIONS AND POTENTIALLY SUITABLE DESIGNS FOR EEL PASSES IN THE RIVER OUSE, SUSSEXERROR! BOOKMARK NOT DEFINED. APPENDIX P HABITATS REGULATION ASSESSMENT SCREENING ...... ERROR! BOOKMARK NOT DEFINED.
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P.1 INTRODUCTION ...... ERROR! BOOKMARK NOT DEFINED. P.2 THE STAGE 1 SCREENING ASSESSMENTSERROR! BOOKMARK NOT DEFINED. P.3 IN COMBINATION ASSESSMENT ...... ERROR! BOOKMARK NOT DEFINED. P.4 CONCLUSIONS OF THE HRA SCREENING AND NEXT STEPS ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX Q WATER FRAMEWORK DIRECTIVE ASSESSMENTS ...... ERROR! BOOKMARK NOT DEFINED. Q.1 INTRODUCTION ...... ERROR! BOOKMARK NOT DEFINED. Q.2 APPROACH ...... ERROR! BOOKMARK NOT DEFINED. Q.3 CONCLUSIONS ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX R TEMPORARY USE BAN AND COMMUNICATIONS PLAN ADDITIONAL INFORMATIONERROR! BOOKMARK NOT DEFINED. R.1 DROUGHT COMMUNICATION AUDIENCES ERROR! BOOKMARK NOT DEFINED. R.2 TEMPORARY USE BAN – SOUTH EAST WATER GUIDANCE NOTES .... ERROR! BOOKMARK NOT DEFINED. R.2.1 What can South East Water restrict?Error! Bookmark not defined. R.2.2 How does South East Water effect the water restrictions? . Error! Bookmark not defined. R.2.3 How does South East Water enforce the water restrictions? Error! Bookmark not defined. R.2.4 Impact on charges – compensation?Error! Bookmark not defined. R.2.5 Can customers claim compensation during temporary use bans or non-essential use bans? ...... Error! Bookmark not defined. R.3 CUSTOMER SERVICE LETTER TEMPLATES AND CUSTOMER CONTACT PROCESS/ESCALATION PROCEDURES.... ERROR! BOOKMARK NOT DEFINED. R.4 EXAMPLE OF PUBLIC NOTICE FOR TEMPORARY USE BAN ...... ERROR! BOOKMARK NOT DEFINED. R.5 TEMPORARY USE BAN ENFORCEMENT POLICYERROR! BOOKMARK NOT DEFINED. R.6 COMMUNICATION CHANNELS ...... ERROR! BOOKMARK NOT DEFINED. APPENDIX S CONSULTATION DURING PREPARATION OF THE DROUGHT PLAN ..... ERROR! BOOKMARK NOT DEFINED. S.1 PRELIMINARY DISCUSSION CONSULTATION LETTERERROR! BOOKMARK NOT DEFINED. S.1.1 South East Water’s Pre-consultation letterError! Bookmark not defined. S.1.2 CC Water’s pre-consultation responseError! Bookmark not defined. S.1.3 Statement of how the drought plan has taken account of CC Water’s pre-consultation commentsError! Bookmark not defined.
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S.1.4 Environment Agency’s pre-consultation response ...... Error! Bookmark not defined. S.1.5 Statement of how the drought plan has taken account of the Environment Agency’s pre-consultation comments ...... Error! Bookmark not defined. S.1.6 Natural England’s pre-consultation responseError! Bookmark not defined. S.1.7 Statement of how the drought plan has taken account of Natural England’s pre-consultation commentsError! Bookmark not defined. S.1.8 Southern Water’s pre-consultation responseError! Bookmark not defined. S.1.9 Statement of how the drought plan has taken account of Southern Water’s pre-consultation commentsError! Bookmark not defined. S.2 ENVIRONMENT AGENCY PRELIMINARY DISCUSSIONERROR! BOOKMARK NOT DEFINED. S.2.1 Meeting 1, 1st November 2016, Ergon House London ...... Error! Bookmark not defined. APPENDIX T DROUGHT SCENARIOS TESTEDERROR! BOOKMARK NOT DEFINED. T.1 STOCHASTIC DROUGHT SCENARIOS ...... ERROR! BOOKMARK NOT DEFINED. T.1.1 Drought region overview ...... Error! Bookmark not defined. T.1.2 Recharge ...... Error! Bookmark not defined. T.1.3 Groundwater levels ...... Error! Bookmark not defined. T.1.4 Reservoir levels ...... Error! Bookmark not defined. T.2 THIRD DRY WINTER SCENARIO ...... ERROR! BOOKMARK NOT DEFINED. T.2.1 Drought region overview ...... Error! Bookmark not defined. T.2.2 Recharge ...... Error! Bookmark not defined. T.2.3 Groundwater levels ...... Error! Bookmark not defined. T.2.4 Reservoir levels ...... Error! Bookmark not defined.
FIGURES Figure 1.1 – Water company drought planning process ...... 18 Figure 1.2 – Map of South East Water’s supply area ...... 21 Figure 1.3 – Map of South East Water’s drought management areas ...... 23 Figure 2.1 – Groundwater Units and groundwater trigger observations boreholes (OBH) ...... 30 Figure 2.2 – Groundwater level data ...... 31 Figure 2.3 – Ardingly Reservoir smoothed drought trigger curves ...... 33 Figure 2.4 – Arlington Reservoir smoothed drought trigger curves...... 33 Figure 2.5 – Example cumulative recharge curve: Chalk North Downs 2006 ...... 35 Figure 2.6 – Groundwater units and rainfall stations ...... 36 Figure 2.7 – Example demand trigger graph: Eastern (1-3) region, 1995 ...... 38 Figure 2.8 – Trigger schematic tool – showing an example month ...... 43 Figure 3.1 – Phasing of demand restrictions...... 51 Figure 3.2 – South East Water and bulk supplies and inter-zonal transfers ...... 66 Figure 6.1 – Drought management strategy structure ...... 168
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Figure 8.1 – Trigger schematic tool – Eastern (W) 2003 ...... 208 Figure 8.2 – Trigger schematic tool – all drought regions August 1996...... 212 Figure 8.3 – Trigger schematic tool – all drought regions December 2004 ...... 217 Figure 8.4 – Trigger schematic tool showing 11 June 2012 to 30 June 2012 ...... 222 Figure 8.5 – Storage at Ardingly Reservoir during the 2010-2012 drought event ... 223 Figure 8.6 – Storage at Arlington Reservoir during the 2010-2012 drought event .. 223 Figure 8.7 – Storage levels at Ardingly and Arlington Reservoirs during the worst historic drought scenario ...... 232 Figure 8.8 – Storage levels at Ardingly and Arlington Reservoirs during the severe drought scenario ...... 235 Figure 8.9 – Storage levels at Ardingly and Arlington Reservoirs during the extreme drought scenario ...... 238 Figure 8.10 – Storage levels at Ardingly and Arlington Reservoirs during the third dry winter drought scenario ...... 244
Figure C.1 – Overview drought trigger site locations .. Error! Bookmark not defined. Figure C.2 – Drought permit/order locations ...... Error! Bookmark not defined. Figure C.3 – Lower River Ouse drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.4 – Upper River Ouse drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.5 – River Cuckmere drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.6 – Balcombe drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.7 – Hackenden drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.8 – Chasewood drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.9 – Halling No.8 drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.10 – Southlands drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.11 – Oaklands drought permit/order and statutory environmentally designated sites ...... Error! Bookmark not defined. Figure C.12 –River Ouse (winter/summer periods) drought permit/order and heritage designated sites – lower catchment ...... Error! Bookmark not defined. Figure C.13 – River Ouse (winter/summer periods) drought permit/order and heritage designated sites – upper catchment ...... Error! Bookmark not defined. Figure C.14 – River Cuckmere drought permit/order and heritage designated sites ...... Error! Bookmark not defined. Figure C.15 – Balcombe drought permit/order and heritage designated sites ..... Error! Bookmark not defined. Figure C.16 –Hackenden drought permit/order and heritage designated sites .... Error! Bookmark not defined. Figure C.17 – Chasewood drought permit/order and heritage designated sites .. Error! Bookmark not defined. Figure C.18 – Halling No.8 drought permit/order and heritage designated sites . Error! Bookmark not defined. Figure C.19 – Southlands drought permit/order and heritage designated sites ... Error! Bookmark not defined.
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Figure C.20 – Oaklands drought permit/order and heritage designated sites ..... Error! Bookmark not defined. Figure C.21 –River Ouse (winter/summer periods) drought permit/order and WFD Water body statuses – lower catchment ...... Error! Bookmark not defined. Figure C.22 –River Ouse (winter/summer periods) drought permit/order and WFD Water body statuses – upper catchment ...... Error! Bookmark not defined. Figure C.23 – River Cuckmere drought permit/order and WFD Water body statuses ...... Error! Bookmark not defined. Figure C.24 – Balcombe drought permit/order and WFD Water body statuses ... Error! Bookmark not defined. Figure C.25 –Hackenden drought permit/order and WFD Water body statuses .. Error! Bookmark not defined. Figure C.26 – Chasewood drought permit/order and WFD Water body statuses Error! Bookmark not defined. Figure C.27 – Halling No.8 drought permit/order and WFD Water body statuses ...... Error! Bookmark not defined. Figure C.28 – Southlands drought permit/order and WFD Water body statuses . Error! Bookmark not defined. Figure C.29 – Oaklands drought permit/order and WFD Water body statuses .... Error! Bookmark not defined. Figure E.1 – Cornish groundwater trigger curve ...... Error! Bookmark not defined. Figure E.2 – Ardingly Reservoir smoothed surface water trigger curve...... Error! Bookmark not defined. Figure E.3 – Arlington Reservoir smoothed surface water trigger curve ...... Error! Bookmark not defined. Figure E.4 – Cumulative Recharge – Chalk South Downs Unit (Poverty Bottom) ...... Error! Bookmark not defined. Figure E.5 – Eastern (6–8) region: demand trigger 2003Error! Bookmark not defined. Figure E.6 – Winslade Farm OBH groundwater trigger curveError! Bookmark not defined. Figure E.7 – Cumulative recharge: East Hants Downs Unit (Basingstoke) ...... Error! Bookmark not defined. Figure E.8 – Western region demand trigger ...... Error! Bookmark not defined. Figure E.9 – Dane Court Farm OBH groundwater trigger curveError! Bookmark not defined. Figure E.10 – Cumulative recharge: Chalk Stour Unit (Boughton)Error! Bookmark not defined. Figure E.11 – Eastern (1-3) region: demand trigger.... Error! Bookmark not defined. Figure N.1 – River Ouse monitoring during drought permit/order use ...... Error! Bookmark not defined. Figure R.1 – Customer contact process during droughtError! Bookmark not defined. Figure R.2 – Escalation process during drought ...... Error! Bookmark not defined. Figure T.1 – Trigger site overview for 1 in 100 worst historic drought scenario ... Error! Bookmark not defined. Figure T.2 –Drought region overview for 1 in 100 worst historic drought scenario ...... Error! Bookmark not defined. Figure T.3 – Trigger site overview for 1 in 200 severe drought scenario ...... Error! Bookmark not defined. Figure T.4 – Drought region overview for 1 in 200 severe drought scenario ...... Error! Bookmark not defined.
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Figure T.5 – Trigger site overview for 1 in 500 extreme drought scenario ...... Error! Bookmark not defined. Figure T.6 – Drought region overview for 1 in 500 extreme drought scenario ..... Error! Bookmark not defined. Figure T.7 – Recharge trigger sites for 1 in 100 worst historic, 1 in 200 severe and 1 in 500 extreme drought scenarios ...... Error! Bookmark not defined. Figure T.8 – Groundwater trigger sites for 1 in 100 worst historic, 1 in 200 severe and 1 in 500 extreme drought scenarios ...... Error! Bookmark not defined. Figure T.9–Reservoir trigger sites for 1 in 100 worst historic, 1 in 200 severe and 1 in 500 extreme droughts scenarios for restricted and unrestricted demand ...... Error! Bookmark not defined. Figure T.10 – Trigger site overview for third dry winter drought scenario ...... Error! Bookmark not defined. Figure T.11 – Drought region overview for third dry winter drought scenario ...... Error! Bookmark not defined. Figure T.12 –Recharge trigger sites for Third Dry Winter droughtError! Bookmark not defined. Figure T.13 –Groundwater trigger sites Third Dry Winter drought scenario ...... Error! Bookmark not defined. Figure T.14 –Reservoir trigger sites for third dry winter drought scenario for restricted and unrestricted demand ...... Error! Bookmark not defined.
TABLES Table 2.1 – The site composition of the four triggers per drought region with indicative trigger scores for an example month ...... 41 Table 2.2 – Initial trigger matrix for regional drought risk assessment –showing scoring for an example month ...... 42 Table 2.3 – Overall trigger matrix for regional drought risk assessment – showing an example month ...... 43 Table 2.4 – Trigger site data sources ...... 44 Table 2.5 – Additional hydrometric monitoring sites...... 45 Table 3.1 – Part 1: temporary use ban - summary of intervention options for water use ...... 54 Table 3.2 – Part 2: Summary of intervention options for water use ...... 61 Table 3.3 – Company bulk transfers/ shared supply arrangements ...... 67 Table 3.4 – Potential drought permits or drought orders ...... 74 Table 3.5 – Potential drought permit or drought order options for reservoir sites ..... 74 Table 3.6 – Potential drought permit or drought order options for additional supply sites ...... 77 Table 3.7 – Drought management actions: summary table ...... 82 Table 4.1 – Supply side drought management options summary table ...... 91 Table 4.2 – Groundwater drought permit/order Site of Special Scientific Interest source pathway receptor analysis ...... 95 Table 4.3 – River Ouse Site of Special Scientific Interest source pathway receptor101 Table 4.4 – River Cuckmere Site of Special Scientific Interest source pathway receptor ...... 106 Table 4.5 – Summary of archaeological features within Kent County Council’s HER ...... 111 Table 4.6 – Summary of the River Ouse summer period residual effects ...... 114 Table 4.7 – Summary of the River Ouse winter period residual effects ...... 120
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Table 4.8 – Summary of the Cuckmere residual effects ...... 127 Table 4.9 – Potential environmental changes and effects associated with the Halling No.8 drought abstraction ...... 140 Table 4.10 – Drought permit/order monitoring sites ...... 142 Table 4.11 – Summary of monitoring points which relate to the environmental baseline and continuous annual monitoring requirements for the surface water drought permit/order sites ...... 147 Table 4.12 – Summary environmental baseline and continuous annual monitoring requirements for the five groundwater sources of supply drought permit/order sites ...... 149 Table 4.13 – Summary of monitoring required for the duration of drought permit/order operation ...... 153 Table 4.14 – Reactive drought permit/order mitigation ...... 155 Table 5.1 – Key for significant effect scoring for impacts on the community assessment ...... 160 Table 5.2 – Assessment of impacts to the human environment ...... 161 Table 5.3 – Mitigation to lessen impacts to the human environment ...... 163 Table 8.1 – Initial trigger matrix for September 2003 scenario ...... 206 Table 8.2 – Overall trigger matrix for September 2003 scenario ...... 208 Table 8.3 – 2003 Drought scenario regional drought scores and summary of actions likely to be implemented ...... 210 Table 8.4 – Initial trigger matrix for August 1996 scenario ...... 211 Table 8.5 – Overall trigger matrix for August 1996 scenario ...... 211 Table 8.6 – 1995–97 Drought scenario regional drought scores and summary of actions likely to be implemented ...... 213 Table 8.7 – Initial trigger matrix for December 2004 scenario ...... 216 Table 8.8 – Overall trigger matrix for December 2004 scenario ...... 217 Table 8.9 – 2003–2006 Drought scenario regional drought scores and summary of actions likely to be implemented ...... 219 Table 8.10 – Initial trigger matrix for June 2012 ...... 221 Table 8.11 – Overall trigger matrix for June 2012 ...... 222 Table 8.12 – 2010-2012 Drought scenario regional drought scores and summary of actions implemented ...... 224 Table 8.13 – Worst historic drought scenario regional drought scores ...... 230 Table 8.14 – Worst historic drought scenario timeline of actions ...... 231 Table 8.15 – Severe drought scenario regional drought scores ...... 233 Table 8.16 – Severe drought scenario timeline of actions...... 234 Table 8.17 – Extreme drought scenario regional drought scores ...... 236 Table 8.18 – Extreme drought scenario timeline of actions ...... 237 Table 8.19 - Summary Findings from the scenario testing ...... 240 Table 8.20 – Third dry winter drought scenario regional drought scores ...... 243 Table 8.21 –Drought plan performance against alternative plausible droughts ...... 245
Table N.1 – Environmental monitoring weekly checklistError! Bookmark not defined. Table P.1 – Screening of all sites scoped into the assessment for the Southlands and Oaklands abstraction ...... Error! Bookmark not defined. Table P.2 – Screening of all sites scoped into the assessment for the Halling No.8 abstraction ...... Error! Bookmark not defined. Table Q.1 – WFD assessment for the River Ouse Drought Permit options...... Error! Bookmark not defined.
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Table Q.2 – WFD assessment for the Cuckmere Drought Permit options...... Error! Bookmark not defined. Table Q.3 – WFD assessment for the five groundwater Drought Permit options.Error! Bookmark not defined. Table Q.4 – WFD assessment for the three unconfined groundwater Drought Permit options...... Error! Bookmark not defined. Table R.1 – Template letters ...... Error! Bookmark not defined.
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EXECUTIVE SUMMARY
Overview and key changes From a public water supply perspective, drought events are defined as periods of unusually low rainfall, compared to the weather conditions upon which our longer-term water resources management plans (WRMPs) and forecasts are based.
These types of drought events can last anywhere from a few months to several years in duration, and our experience has been that no two droughts are ever the same - each impacting on our area of supply in different ways, to different degrees, and presenting a different set of challenges to contend with.
This revised draft drought plan therefore sets out a framework that we will follow and actions that we will implement before, during and after every drought event to maintain a secure supply of water. It updates our final drought plan published in 2013, and sets out our tactical approach to managing droughts that may occur during the period 2018 to 2023. It also takes into account representations made during the public consultation on our draft drought plan 2017.
The plan includes detail of the monitoring, drought management actions, environmental impacts and mitigation and communication activities to be taken during a drought, and what steps we will take after a drought to review and improve our approach to respond to future droughts.
In line with the guideline requirements provided by our regulators the plan has been tested against a range of historic droughts, and against a range of alternative ‘plausible droughts’ – these droughts have been derived from best practice stochastic analysis, and are more extreme and rare than those we have seen in the historical record. Nonetheless they are important to our understanding of the current levels of resilience we provide to the environment and customers.
The findings from the testing of historical and alternative plausible droughts has fed directly through to the updating of our long-term water resources management plan 2019 (dWRMP19), a draft version of which has been submitted to Defra in December 2017 ahead of a wider consultation in 2018.
Taking this approach ensures there is a strong linkage between decisions we take in our longer term water resources management plan to meet future population growth and adapt to the impacts of climate change, and our ability in the shorter term to retain resilience of supplies during drought events caused by periods of unusually low rainfall.
Consultation process During the preparation of the draft drought plan we completed a pre-consultation exercise with our regulators, neighbouring water companies and the Consumer Council for Water.
Some of the key responses received focussed on:
The importance of aligning the data we used to test historic and ‘plausible droughts’ with data sets being used by national level studies
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being clear in our plan how we will interact during drought with non-household retailers following the non-household water retail market opening in April 2017
ensuring environmental data and assessments for our drought plan and drought options within the plan are up to date
re-affirming the volumes of supply we can expect under different drought conditions from existing bulk supply import agreements we hold with neighbouring water companies.
Our draft drought plan was then made available for public consultation for an eight- week period through September and October 2017. Representations received during this public consultation have been compiled, and our response to each of them can be viewed in our statement of response, which accompanies this revised draft drought plan. We have reviewed our plan and made amendments or provided additional information in response to the representations received.
This revised draft drought plan and statement of response to representations received on our draft drought plan will be submitted to Defra on 15 December 2017 and published on our website. We will then await confirmation from Defra as to whether we can publish it as our final drought plan during 2018.
Drought monitoring and triggers To understand how a drought is developing, we monitor four types of indicators: groundwater level, reservoir level, effective rainfall (recharge) and demand. We define the severity of a drought by comparing the indicator levels against pre-defined trigger levels. We also consider the status of bulk supplies that need careful management in time of drought.
The triggers then implement a series of management actions that we have identified to conserve resources.
Communication actions We have a communications plan which is implemented during a drought so that our employees, customers and other stakeholders understand the implications of a drought as it develops. Effective communication helps to reduce water use during a drought, increase water available for supply and also reduce any potential impact on the environment. It is also an opportunity to explain and clarify the role and responsibilities of ourselves, our regulators, consumer interest groups and other partners in managing the drought. We have therefore included an operational communication plan within this drought plan.
The communication plan includes a detailed and flexible action plan that links with the drought triggers. It sets out key messages for target audiences and actions at each drought status. The communication plan incorporates lessons learnt from previous droughts, in particular that experienced in 2010-2012.
The recent development of non-household retail markets and creation of non- household retailers has not in itself altered how we will seek to liaise and interact with non-household customers, rather it introduces a new step where we will liaise directly with all non-household retailers in our area on a consistent level playing fields basis to
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agree with them how and by whom those communication messages are best delivered at the time.
Demand restriction actions In line with legislation (Flood and Water Management Act 2010), we also have powers to restrict water use in times of drought, termed a temporary use ban. The drought plan details our proposals of how these powers will be implemented, and the phased approach that we will apply to restricting water use. Following the implementation of a temporary use ban by us, and other water companies, in April 2012, a review has been undertaken of our proposals and internal procedures. However, it should be noted that every drought is different in terms of regional impact, duration and severity and that we believe that it is important to be able to have a flexible proposal for the implementation of the temporary use ban. We will aim to allow a two week period for representations to be made on our proposals for these restrictions.
Consideration has also been given to how management actions will be lifted once we are in a recession phase of a drought.
Environmental actions As a drought escalates, options to increase supply are available as well as demand reduction. One option is to take extra water from specific water sources beyond licensed conditions or to commission unlicensed sources that are currently disused. To exceed licence conditions, we need to apply for a drought permit/order which identifies the potential impacts of taking extra water. This drought plan identifies potential locations where we might propose to apply for a drought permit/order to alter existing abstractions and assesses the potential impact of the action. In addition, surveillance/monitoring and mitigation measures to assess the baseline environmental condition and to ameliorate any impacts associated with the proposed drought management actions are discussed. Further environmental monitoring is currently on- going on some of the groundwater drought permits/orders to develop sufficient baseline information in case of future use.
We have considered the need for a Strategic Environmental Assessment (SEA), but we have taken the view that since the drought plan is a temporary operational plan, it does not set a framework for future development consent of projects within Annexes I and II to the EIA Directive. We have carried out a Habitat Regulations Assessment (HRA) ‘screening exercise’ for the draft drought plan to demonstrate that there will be no significant effects on European sites for any of the eight drought permits/orders either on their own or in combination. It should be noted that where any investment is recommended as a result of this plan, it has been carried through to the dWRMP19 (as Table 10), where it has then been subject to SEA.
Testing the drought plan All drought events are subtly different and minor differences, particularly in pre-drought conditions, can change potential impacts significantly. We have investigated the performance of the resource and supply system during both historic and a range of alternative ‘plausible’ droughts to assess resource availability under a range of scenarios.
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Our testing confirms that, supported by the actions set out in our drought plan, we have very good levels of resilience to historical droughts events, and also to some of the more severe plausible drought events tested.
We found that we would be able to maintain a secure supply of water during a drought of equal severity and duration to the worst historic drought monitored in our area (this has a probability of occurring once in 100 years on average, or a one per cent probability of occurring in any given year).
In addition, we have tested the plan against hypothetical more severe and longer duration droughts. It is reassuring to find that we could maintain supply during a more severe drought that could occur once in 200 years on average (i.e. a drought that has a 0.5 per cent probability of occurring in any given year). This is half as likely to occur as the worst historic drought.
Following the 2010-2012 drought, we wanted to know how we would have managed if that drought had continued into a third dry year. Again, we found that our plan would enable us to meet our levels of service.
We went on to test how we would respond to an extreme drought with a probability of occurring once in 500 years on average (i.e. a 0.2 per cent probability of occurrence in any given year). This is a very extreme scenario, under which we would not be able to meet supply without introducing more drought options and / or increasing the likelihood of needing to introduce emergency drought order measures i.e. standpipes and rota cuts.
The extreme drought showed that our plan will need to be developed further if we are to remove entirely the likelihood of needing to rely on emergency drought order measures, but this was expected given the low likelihood and extreme nature of the scenario.
The testing has shown that we are more resilient to longer droughts (typically longer than a single season) that allow us more time to implement our drought actions, particularly those that allow us to increase abstraction during winter months.
Linkages with our draft water resources management plan 2019 (dWRMP19) The historical and plausible drought testing assumes that all our drought actions including drought permits/orders (allowing us to temporarily take more water from the environment for short periods during drought) can be applied in all scenarios.
Having assessed how these are needed, especially in the severe drought scenario, we identified that without improving levels of resilience there is a high reliance on drought permits and drought orders; more so than we and some others who have made representation on our plan feel is acceptable.
Our initial testing of the drought plan (ahead of dWRMP19) made the assumption that our current network infrastructure is capable of being operated flexibly under the more challenging range drought conditions we tested.
Since we published our draft drought plan, we have revisited all of the assumptions concerning drought permits/orders, and the capability of our network infrastructure
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under more severe drought scenarios as part of the preparation of our dWRMP19, to be published for wider public consultation in early 2018.
Through further scenario modelling, decision making and consideration of customers’ preferences undertaken as part of our dWRMP19 we have proposed moving from current levels of resilience meeting worst historic droughts on record i.e. one in 100 year (one per cent probability of occurrence each year), to a more robust one in 200 year level of resilience (0.5 per cent probability of occurrence each year).
We explain our reasons for moving our levels of resilience to one in 200 year (0.5 per cent probability of occurrence each year) in the dRWMP19, and why this is both cost effective and possible to achieve during the period 2020 to 2025. In doing so we are also striving for consistency with the Water UK Long term National Water Resources Planning Framework recommendations.
The improvement in levels of resilience will reduce our reliance on drought permits and orders to more acceptable levels, and supports some modest further investment in a combination of network improvements and new sources, improving levels of resilience more generally overall.
At this stage we cannot prejudge the outcome of the consultation on our dWRMP19 or the subsequent acceptance of our dWRMP19 by the Secretary of State for Defra in 2018.
However, once our WRMP19 has been approved in its final form, we will review this drought plan and take steps that are necessary to ensure both plans remain aligned.
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1 INTRODUCTION
1.1 Overview of drought planning process
1.1.1 Regulatory background Water companies have a duty under Section 39B and 39C of the Water Industry Act 1991, as amended by the Water Act 2003 and the Water Act 2014 to prepare and maintain drought plans. The Water Act 2014 also amended the Water Industry Act 1991 to allow for holders of water supply and/or sewerage licences (‘licensees’) to buy wholesale services from undertakers and sell these on with retail services to customers. These licensees and the wholesalers are governed by the Market Arrangements Code (MAC) via their Instruments of Appointment. The following legislation provides the legal framework for producing the statutory drought plans:
Drought Plan Regulations 2005 Flood and Water Management Act 2010 Water Use (Temporary Bans) Order, 2010 Drought Permits and Drought Orders, 2011 Drought Direction 2011 The Drought Plan (England) Direction 2016 Process E6 of the Operational Terms of the Market Codes
The Department for Environment, Food & Rural Affairs (Defra) and the Environment Agency have also issued updated guidelines on preparing plans in its Water Company Drought Plan Guideline (Defra and Environment Agency, July 2015). This note sets out guidance to help companies prepare, write and publish their drought plans to demonstrate how they will manage a drought.
Timescales and overall process The water company drought plan process involves each of the water companies (in England):
Preparing a draft drought plan and submitting it to the Secretary of State within four years and three months after the date on which the last drought plan was published (for us this was April 2017) publishing the draft drought plan and consulting on it (for us this was an eight-week consultation period in September/October 2017) assessing the representations received and preparing a statement of response with a revised draft drought plan taking account of the representations received (for us this will need to be published within 15 weeks of publishing the draft plan for consultation so the date is 15 December 2017) after confirmation from the Secretary of State, publishing the revised draft plan as the final drought plan (for us this is likely to be in spring/summer 2018)
A detailed summary of the steps water companies must follow is shown in Figure 1.1. This revised draft drought plan publication represents Stage 11 of the process as set out in Figure 1.1.
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Figure 1.1 – Water company drought planning process
After Environment Agency, “Water company drought plan guidance”, June 2011.
Planning for more severe droughts Defra and the Environment Agency’s Drought Plan Guidelines (July, 2015) set out a requirement for water companies to plan for and provide supply during droughts of at least equal severity to historic droughts. In addition, the guidance encourages water companies to plan for droughts of lower rainfall and longer duration than the worst historic drought.
To satisfy this requirement, we have tested our plan against a range of observed historic and stochastically generated droughts that vary in terms of severity, duration and hence impacts. The approach was to test our triggers and drought status
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classification system against these droughts and demonstrate how our drought management actions would be implemented in each case.
Section 8 details this testing process and finds that the plan is robust to drought events up to and including droughts of severity that are likely to occur once in 200 years on average. This is half as likely as the worst historic drought on record in our area. There is more resilience against longer droughts (greater than a single season) as there is more warning time to implement drought actions, particularly winter drought permits/orders.
A longer “third dry winter” event was simulated by repeating the second drought year of a two year drought (April 2010 – April 2012), and the plan was found to be robust. Although longer events might seem to represent a more extreme level of risk, the random nature of our weather and the probabilities involved suggest that shorter events will tend to be more intense, which means they represent a larger risk.
Links with the Water Resource Management Plan The testing assumes that the drought permits/orders can be applied in all scenarios. Seeing how these are needed, especially in the severe drought scenario, we have identified that, currently, there is a high reliance on drought permits/orders, more so than we feel might be acceptable. There is an uncertainty associated with obtaining these permits especially under more severe drought scenarios therefore reducing the reliance on them will result in a more robust plan. Our testing also assumes that our current network infrastructure is capable of being operated flexibly under the more challenging drought conditions we tested. This might not be the case under certain drought conditions and additional drought resilience options to increase connectivity might need to be considered.
We assessed all of the above assumptions further as part of our dWRMP19 to identify whether potential investment is needed to enhance resilience. Our dWRMP19 assessed our customers’ support for investment in resilience options that will reduce reliance on drought permits/orders, and to invest in improvements to our existing network infrastructure. 1.2 South East Water background information
1.2.1 Water resources planning South East Water is one of 12 regulated ‘water only’ supply companies in England and Wales. Our water supply area covers an area of some 5,657 sq km across areas of Kent, Sussex, Surrey, Berkshire and Hampshire. Within this area we provide clean water to a population of around 2 million customers in nearly 900,000 domestic households and 76,000 commercial properties. This makes us one of the largest water supply only companies in the country. We have a statutory duty to provide water for our customers. In doing so we must make sure we have a robust system to ensure water resources are managed efficiently and effectively to meet the demands of our customers. Our overall approach to managing water resources is set out in our dWRMP19, submitted to Defra 1 December 2017. The dWRMP19 sets out our plans to provide a secure supply for customers from 2020 to 2080.
South East Water was created by the merger of the former South East Water and Mid Kent Water, in October 2006. The previous 2013 drought plan combined the 2007 drought plans from the two water companies. The plan also took account of applicable
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new statutory requirements and guidance, in particular the Flood and Water Management Act (FWMA) 2010 and updated guidance from the Environment Agency ‘How to write and publish a drought plan’ (July 2015).
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Figure 1.2 – Map of South East Water’s supply area
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Our supply area is divided into two regions – the western region, and the eastern region (as shown in Figure 1.2). For the purposes of water resource management planning it is further divided into eight resource zones. Resource zones 4–5 are in the western region and resource zones 1–3 and 6–8 are in the eastern region.
Drought management takes place at these three sub-regional levels: Eastern (1-3), Eastern (6-8) and Western (4-5) (Figure 1.3). Some management actions, particularly those of an operational nature can be site, local or resource zone specific.
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Figure 1.3 – Map of South East Water’s drought management areas
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1.2.2 The water supply area Over 70 per cent of the water we deliver is groundwater that comes from more than 250 boreholes and wells. The remainder comes from surface water, which includes surface water sources that come from six river intakes, and five surface water reservoirs. Some of these surface water sources are shared, with eight per cent of our supplies coming from sources owned and operated by other water companies under joint rights or bulk supply agreements. The largest of these is the River Medway scheme (including Bewl Reservoir), of which we have a 25 per cent share of the yield with Southern Water Services having the remaining 75 per cent share.
The water from all of the sources is treated and then distributed to our customers’ properties through more than 14,500 km of mains.
1.3 Baseline water resources situation and levels of service
We prepare Water Resource Management Plans (WRMP) that set out how we will provide security of supply to our customers over a minimum 25 years, and the levels of service our customers expect to receive.
Our current levels of service (LoS) are shown in our dWRMP19 and are:
Temporary use bans no more than once in 10 years on average (10 per cent annual probability of occurrence)
Non-essential water use restrictions (drought orders) no more than once in 40 years on average (2.5 per cent annual probability of occurrence)
Application for permission (via drought permits/orders) to vary abstraction licence conditions and quantities no more than once in 50 years on average (2.0 per cent annual probability of occurrence)
Emergency drought order (Abstraction restrictions further relaxed, rota cuts, standpipes and tankering) no defined LoS although would be implemented during the emergency planning phase; we will do everything in our power to avoid their use.
Emergency drought orders are considered further in section 8 of this revised draft drought plan. Based on our analysis we consider the potential risk of needing recourse to emergency drought orders is incredibly remote and would most likely only be considered under very extreme droughts (such as a one in 500 year drought event with a probability of occurrence of 0.2 per cent in any given year).
We have reviewed our levels of service in relation to those set by other water companies to see how they compare. They align well; for example, most other water companies in the south east of England also plan to implement temporary use bans no more than once in 10 years on average.
In our dWRMP19, we have demonstrated the linkages between our WRMP and our drought plan by the completion of Table 10 within the supply demand tables. This
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helps us demonstrate how our supply system will respond to a range of droughts, from historic to include more severe and extreme modelled droughts. This drought plan examines how we would respond to the same range of droughts in Section 8. Through this process we have been able to determine appropriate levels of service in relation to an improved knowledge of drought resilience in our supply system. Section 8.4 provides further details on the linkages between this drought plan and our dWRMP19.
Close alignment of levels of service between water companies is very important, and is being delivered through the Code of Practice (UKWIR, 2013) and the Water Resources in the South East (WRSE) group taking a regional view and ensuring close alignment of conditions contained within bulk supplies agreements for the purposes of operating during drought events.
1.4 Consultation on the drought plan
1.4.1 Pre-draft drought plan preparation consultation As part of the formal statutory process, we undertook preliminary discussions before updating the drought plan. To initiate the discussions, we sent out a consultation letter in September 2016 (copy included in Error! Reference source not found.) setting out proposed updates to the drought plan. The letter was issued to the following statutory consultees:
Secretary of State for the Department of Environment Food and Rural Affairs (Defra) – Defra is the Government department responsible for defining policy within the water and environmental sectors, and for directing companies on the content of their final statutory WRMP; Environment Agency – the Environment Agency has a duty to safeguard the interests of the environment and to conserve, manage and secure the proper distribution of water resources in England & Wales, as the Government’s appointed environmental regulator. For WRMP the Environment Agency has also act as expert technical adviser to Defra; The Water Service Regulatory Authority (Ofwat) – Ofwat sets the price limits for water and sewerage companies in England and Wales through a five-yearly determination process called the Periodic Review which takes account of the companies’ business plans. Ofwat has a duty to ensure that companies can finance their functions, a duty to encourage water companies to promote water efficiency by their customers, and a duty to make a contribution to sustainable development, while protecting customers’ interests by making sure they receive a reliable service which remains value for money; Neighbouring wholesale water suppliers – Neighbouring wholesale water company plans impact one another, particularly with regard to the potential for sharing supplies between companies. We consulted with Portsmouth Water; Southern Water Services; Sutton and East Surrey Water; Thames Water; and Affinity Water in this capacity. Natural England (NE) – Natural England is the Government’s advisor on the natural environment. They provide practical advice on how best to safeguard England’s natural wealth for the benefit of everyone, and work with farmers and land managers; business and industry; planners and developers; national and local government; interest groups and local communities to help them improve local environments.
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We also chose to consult with non-statutory consultee who were likely to be affected by actions in the plan. These included:
Consumer Council for Water (CCWater) – CCWater is the independent customer representative body responsible for ensuring customer interests are protected;
Four responses were received from the CCWater, the Environment Agency, Natural England and Southern Water. Each response focused on a variety of topics. Full details of the information received from individual respondents during the pre- consultation are included in Error! Reference source not found..
We also held a series of pre-consultation meetings with the Environment Agency throughout the time that we were updating the draft drought plan. Details relating to these discussions can be seen in Error! Reference source not found..
1.4.2 Consultation on the draft drought plan and the statement of response We consulted on our draft drought plan in autumn 2017 for eight weeks from the 4 September 2017 until the 29 October 2017. A copy of this plan was made available on our website (at www.southeastwater.co.uk) and hard copies were available at our head office in Snodland, Kent. We also sent copies directly to our consultees and wrote to over 2,000 stakeholders.
Following the public consultation, we prepared a statement of response to representations received on our draft drought plan, which accompanies this document. Based on our responses to these representations, we have made amendments or provided further information in this revised draft drought plan.
The following steps will now be taken to complete our final drought plan:
Publication of our statement of response and revised draft drought plan. Secretary of State to review statement of response and revised draft drought plan. Direction from Secretary of State that our statement of response and revised draft drought plan have been accepted. Preparation of final drought plan. Environment Agency review of final drought plan for compliance with Secretary of State directions. Publication of final drought plan. 1.5 Structure of the drought plan document
Our revised draft drought plan sets out the process that the Drought Management Team follows to make decisions and take action when in a drought.
Section 2 describes the hydrometric and demand triggers that we analyse to determine the drought status of each of our three drought regions. These have been tested using different historic scenarios to ensure they are appropriate.
The implementation of drought actions (Section 3) is largely dependent on the region’s drought status, although we also use some specific reservoir and demand triggers to define when some specific actions should commence. Section 3 introduces the demand and supply side actions that could be implemented in a drought.
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Section 4 assesses the environmental impacts and Section 5 assesses impacts to the community which result from implementing drought actions. Section 5 has been added as a result of representations received during consultation on the draft drought plan 2017.
Section 6 sets out the management strategy and communications plan. Further detail has been added to the communications plan for this draft drought plan to make it a useful tool during a drought.
Post drought actions are described in Section 7 and Section 8 tests out the drought triggers and actions against historic and modelled (stochastic1) drought scenarios.
The appendices contain supporting information such as summaries of the drought options, drought trigger curves, supporting map outputs, further communications plan documents and the environmental baseline and assessments for supply side actions (such as the eight drought permits that are discussed in Section 3).
1 Stochastic analysis provides a statistical representation of drought sequences with the same statistical characteristics of observed droughts allowing us to explore the likelihood and impact of more extreme events.
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2 DROUGHT MONITORING AND TRIGGERS
We monitor a number of indicators which are used to decide if we are in or approaching drought conditions. The drought plan presents details of how we will monitor the severity of the drought as it develops and then passes. The indicators are used to trigger actions to respond to the drought as it develops. Section 2 describes how we:
Decide what individual trigger sites are used to provide data to base drought management decisions on; Examine four types of drought triggers and decide what drought status each of our three drought regions are at; Instigate drought management actions depending on the status of each drought region; Select how actions are implemented as a trigger is activated.
In summary, we monitor drought triggers that assess the status of groundwater units, recharge of the groundwater units, reservoirs, and demand. The data from all four types of trigger are fed into a matrix that enables analysis and assessment of drought severity to be determined for each drought region of our area. A Drought Management Team (see section 6.1 for further details) uses the outputs from the matrix analysis to assess the extent and severity of drought for each drought region as a whole. The matrix can also look in more detail at individual resource levels i.e. groundwater units and South East Water owned reservoirs. Drought management actions will be applied at the drought region level; however, resources and their supply areas considered most at-risk can be identified, and targeted to assist the situation if necessary and appropriate. 2.1 Trigger assessment and drought action levels
We have adopted a three-stage system for the evaluation of the appropriate level of response to a progressing drought event. There is regular review and reassessment of each stage throughout a drought event:
Stage 1: Monitoring of key representative groundwater, rainfall, and reservoir individual trigger sites, and of demands per drought region. The rainfall data feed into a recharge calculation so recharge is monitored for each groundwater unit;
Stage 2: Matrix assessment of four types of triggers (groundwater, reservoir, recharge and demand) to determine drought severity status;
Stage 3: Decision making and selection of drought actions for responding to and managing change in drought status.
As part of normal routine operational practice, every month we review data for each drought trigger site and for regional demand. This information is used to determine the start and extent of a drought event. Data for groundwater levels, rainfall and reservoir levels are collected at drought trigger sites, recharge is calculated and monitored, and demand is monitored at a regional level. Trigger sites have been identified that are most indicative of the overall drought status.
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We use a matrix type assessment involving use of four types of drought trigger to determine an overall drought status. These are:
Groundwater levels of each groundwater unit; Three year cumulative recharge of each groundwater unit (note - the rainfall data is used to calculate recharge); Reservoir levels for reservoirs owned by South East Water; Demand per drought region.
All of our significant surface water sources are either bulk supplies or are shared resources with Southern Water Services, so their inclusion within the triggers assessment process is dealt with separately, by use of an override trigger (see Section 2.6 for further details). For this reason, river gauging station data does not feed into the process of determining drought status.
In line with Environment Agency terminology, we have chosen to define the development of a drought in four stages:
Normal status Developing drought status Moderate drought status Severe drought status.
A fifth term ‘post drought’ describes the period after the drought has ended. The actions we take to manage a drought will change with changing drought status.
(Please note that civil emergencies are not included in the above scale, and are covered by our Emergency Plans). 2.2 Stage 1: Groundwater triggers
Groundwater sources account for over 70 per cent of our yield of available water (deployable output) and, consequently, the resource is considered critical to the management of a progressing drought event. For operational purposes we already routinely monitor the water levels and performance of the majority of our production boreholes. We also routinely monitor the water levels at a number of additional (approximately 18) observation boreholes across our area. In order to develop a robust groundwater drought trigger, the sources and their catchments have been subdivided into nine primary groundwater units, as shown in Figure 2.1. The groundwater units comprise either one aquifer, or several aquifers located adjacent to one another and with similar characteristics. A tenth groundwater unit ‘The Medway Gravels’ was identified. It contributes approximately five per cent of deployable output to the Eastern (6-8) drought region, therefore consideration has been given to whether it would be possible to develop a drought trigger to represent it. During preparation of this revised draft drought plan, and in response to a representation from the Environment Agency, we have committed to working with the local Environment Agency team to locate and install a new observation borehole (OBH) during the 12 months following the publication of our final drought plan. We propose to fund and manage construction of this new OBH, and will also monitor and manage it going forward.
Please refer to Figure 2.1 for details of all the groundwater units.
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Figure 2.1 – Groundwater Units and groundwater trigger observations boreholes (OBH)
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The status of each of these groundwater units are monitored through the routine recording of water levels at carefully selected observation borehole sites which are considered to be representative of the general water levels across the whole of the unit. The boreholes have been selected as being essentially unaffected by local impacts of pumping and abstraction sources, and having a good historical record of water conditions. These trigger borehole sites are shown in Figure 2.1.
Decisions on drought status are made by comparing actual groundwater levels to the historical minima and proportions of the long-term average (LTA) level.
An example (Figure 2.2) for the Chalk North Downs groundwater unit is shown below, where Duckpit Farm is the monitoring borehole.
Figure 2.2 – Groundwater level data
Using historical minima levels and the long-term average (LTA) water levels as the two primary reference points, the following trigger thresholds have been developed for drought monitoring and planning purposes:
Normal to developing drought status trigger threshold: The upper edge of the green curve represents the LTA for the groundwater levels. The length of record varies from over 100 years of data to 40 years of available data. Developing to moderate drought status trigger threshold: The upper edge of the orange curve has been developed as the arithmetic midpoint between the LTA and the historic minima. Moderate to severe drought status trigger threshold: The upper edge of the red area is the historic minima for the water level at this source.
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The example plot (in Figure 2.2) shows that, water levels at this source had declined dramatically from normal status in November 2004 to severe drought status in January 2006.
2.3 Stage 1: Surface water triggers
Although we have surface water abstractions from some rivers within our area, the controls on the operations and the deployable outputs are in part constrained by other factors which are inbuilt into the assessment of output during a drought. Consequently, we do not consider it necessary to use river flows as drought triggers, although they continue to be monitored and managed in accordance with licence and operational parameters.
Of the five surface reservoirs which are used by us, three of these (Bewl, Darwell and Weir Wood) are managed for drought purposes by Southern Water Services and are incorporated as override drought triggers within our drought plan (as described in Section 2.6). Further details of the drought monitoring and management arrangements relating to Southern Water Services bulk supplies is provided in Section 3.2.3.
Drought curves have been developed for the two reservoirs that are wholly owned and operated by South East Water, at Arlington and Ardingly. As part of the deployable output review of Ardingly and Arlington Reservoirs undertaken for the dWRMP19, submitted to Defra in December 2017, these drought curves have been updated. Use of these updated curves in our drought plan has ensured that our drought plan is consistent with our dWRMP19.
In both reservoirs, drawdown (when the reservoir storage begins to be used because demand is higher than the supply available within the rivers) occurs between May and October / November. Refill of the reservoirs normally begins in late October.
In the example trigger curves for Ardingly and Arlington Reservoirs (see Figure 2.3 and Figure 2.4) the charts indicate that the reservoir storage rapidly fell during the 2003 drought. In terms of triggers Ardingly Reservoir indicated developing or normal drought status in June 2003 and reached severe drought status by October 2003. In comparison Arlington Reservoir indicated normal to developing drought status in April 2003 but levels rapidly declined throughout the spring to severe drought status and remained well below the severe drought status in October 2003.
The drawdown approach is considered to be more precautionary compared to producing curves based on remaining deployable output. Following an independent review by AMEC in spring 2012 (AMEC, March 2012) we have ensured there are robust procedures in place to monitor reservoir storage. In addition, the surface water trigger curves have been checked to ensure compatibility with relevant historic drawdown curves and emergency storage provisions. To demonstrate this, the drought year data presented in Figure 2.3 and Figure 2.4 are the same drought years as used in three of the four historic scenario tests (see Section 8 for further details). The graphs indicate that relevant drought triggers for the reservoirs are appropriately activated as the drought severity increases.
It is important to keep in mind that surface water triggers are only one of four types of triggers used by us to determine our drought status and any subsequent actions that are initiated.
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Figure 2.3 – Ardingly Reservoir smoothed drought trigger curves
Figure 2.4 – Arlington Reservoir smoothed drought trigger curves.
2.4 Stage 1: Recharge triggers
Rainfall is a vital factor for estimating the recharge to the groundwater sources, and therefore is a key input to the drought plan. However, as a measure of the effectiveness of rainfall for groundwater, it is not the amount of rainfall per se that is important, but the amount that actually recharges the aquifers. We, therefore, make an assessment
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of cumulative recharge using a calculation of Soil Moisture Deficit (SMD). This allows us to calculate actual recharge which is the effective rainfall to the aquifer. Analysis is undertaken monthly using data from multiple rain gauge stations across the supply area during both normal status and drought conditions.
The analysis allows for a calculation of recharge over a three year period, and it is this cumulative recharge which is used to define the recharge drought trigger for each of the nine catchment units. We consider this year on year analysis over a three year period an especially important tool in determining the overall drought status.
The recharge trigger is used to give an indication of the availability of groundwater resources in the future, and is particularly important in understanding the critical winter recharge period.
The locations of the nine rain gauge stations used to represent each of the units are shown in Figure 2.6, and details for the rain gauges can be found in Table 2.4 in section 2.8.
An example plot for the Chalk North Downs Unit (using data from the Boughton Rainfall Gauging station) is shown in Figure 2.5 for the 2003 to 2006 water year recharge seasons.
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Figure 2.5 – Example cumulative recharge curve: Chalk North Downs 2006
Note: Called Chalk East Medway (Chalk North Downs) in Drought Montioring Matrix.
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Figure 2.6 – Groundwater units and rainfall stations
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The three drought trigger thresholds for the cumulative recharge plot have been developed as follows:
Normal to developing drought status trigger threshold: Calculated from the LTA cumulative recharge for the catchment unit; Developing to moderate drought status trigger threshold: Calculated as 80 per cent of the LTA cumulative recharge; Moderate to severe drought status trigger threshold: Calculated as 60 per cent of the LTA cumulative recharge.
On the example above the catchment moved from developing to moderate drought status in March 2004 and from moderate to severe drought status in October 2005. 2.5 Stage 1: Demand triggers
The critical curves which are used to develop the demand trigger profile have been developed for each drought region i.e.
Eastern (1-3) - RZ1-3 Western (4-5) - RZ4-5 Eastern (6-8) - RZ6-8
The profile comprises three curves across the year against which the monthly demand, and the rolling monthly demands are assessed.
The three control curve levels are derived as follows:
Normal to developing drought status trigger threshold: The lower edge of the green area marks the trigger threshold from normal (white area) to developing drought (green area) as presented in our WRMP. The monthly profile has been developed based upon the typical year profile of monthly demands for each drought region and therefore differs between drought regions; Developing to moderate drought status trigger threshold: The lower edge of the middle orange area is based upon our WRMP Planned Dry Year Demands for the region. The average demand for the year is derived from our WRMP and the monthly profile is as described above, using the typical year profile of monthly demands; Moderate to severe drought status trigger threshold: The lower edge of the red area reflects the worst case monthly demands that the drought region could currently sustain. The demands during the winter period to March are the highest historical demands recorded during the winter months, and the upper constraint in summer represents the highest demands that can currently be supported within our production plan. This takes into account constraints within the system, the peak deployable outputs of the sources, and operational headroom.
An example plot for the Eastern (6-8) region over the 1995 period is shown in Figure 2.7.
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Figure 2.7 – Example demand trigger graph: Eastern (1-3) region, 1995
Figure 2.7 shows the demands from February exceeding the developing/moderate triggers and in July and August exceeding the severe trigger. 2.6 Stage 2: Override triggers for bulk supply and shared use
Eight per cent of our supplies come from water transferred from sources owned and operated by other water companies under joint rights or bulk supply agreements. This makes us the highest net importer of water of any water company in the South East region. Of the five contracted bulk supply agreements, four are imports and one is an export. The imports affect all three drought regions and the export affects the Eastern (6-8) drought region. Further specific details on the bulk supplies or shared use agreements in relation to the drought plan can be found in Section 3.2.3.
We need to take account of the deployable output that we import and export in the drought plan. A neighbouring company upon whom we depend for a bulk supply may be in a worse drought situation than us due to factors such as localised rainfall phenomena or potentially different demands placed on their water resource systems by their customers. The agreements which govern use of the joint rights or bulk supplies could potentially lead to a reduction in Water Available For Use (WAFU). It is a requirement of our drought plan that we maintain on-going discussion between ourselves and neighbouring water companies about our bulk supply arrangements as a drought progresses (see Section 3.2.3 for details on the level and frequency of communications with respect to bulk supply and shared use arrangements). This allows greater transparency in the arrangements and reduces the risk of an import of water suddenly being lost from supply, without sufficient prior warning. However, in the unlikely event that one of our imports of water is suddenly no longer available or was reduced, we have decided that an override trigger will be used to take account of the loss of WAFU in the regional drought risk assessment.
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An override trigger enables us to ‘override’ the results of the hydrometric / demand triggers and accelerate the actions associated with the next drought status, should we need to reduce demand or increase available supplies to accommodate the loss in WAFU. A degree of flexibility will be required with such an approach, with actions and associated WAFU loss volumes not set in stone, in order for us to respond most effectively to the situation depending on the exact extent and timing of the loss of WAFU, plus of course the status of our own sources. A new drought status would be determined dependent on the magnitude of the import lost, the donor company’s proposed response in terms of drought permits/orders that may support reinstatement of some/all of the bulk supply, and the proximity of our hydrometric/demand metrics to our drought status triggers in each of the drought regions. In the drought trigger matrix tables (see section 2.7) the bulk supplies and shared resources have been listed alongside the Stage 1 triggers to provide a complete overview.
We have considered the sensitivity of bulk supply override triggers being activated on our drought triggers and actions in the scenario testing section of our plan, section 8. However, it should be noted that the override trigger is really only effective when we reach developing drought level 1 status and before reaching level 2 moderate drought status. This is because, on reaching level 2 drought status, we already trigger an action to liaise closely with other water companies about existing bulk supplies (as set out in Table 3.7 later in this report), in which case the override trigger becomes redundant as a means of triggering the action. Where it is most effective is when we are in developing drought and a donor company reaches its drought triggers earlier and alerts us that the bulk supply may be at risk. In this scenario, even though our own drought status has not necessarily changed, it triggers the override action and we escalate our dialogue and actions earlier than we would have otherwise done given our drought status and action plan. This provides a greater level of resilience to our drought management approach. 2.7 Stage 2: Drought trigger matrix
The Stage 1 triggers are collated together and a drought status is recorded for each groundwater unit, reservoir or demand per drought region.
Table 2.1 indicates how the information for groundwater units, reservoirs, recharge units and demand per drought region is grouped together, using artificial data for one month as an example. In total, there are 22 individual trigger sites / areas which provide information to aid the decision-making process for triggers 1 to 4. A map showing all drought trigger sites together is presented in Error! Reference source not found.. The final column lists the override triggers for bulk supplies or shared resources. For the supply side triggers (groundwater, reservoirs and bulk supplies / shared resources) there is an indication of the proportion of the total deployable output for each drought region and for South East Water as a whole.
Some of the groundwater and rainfall trigger sites are replicated in the Table 2.1 because their status is used to inform assessment of more than one drought region. The percentage values in the table represent the proportion of deployable output that the groundwater and recharge units provide for each drought region. The Eastern (1- 3) drought region groundwater unit percentages do not total 100 per cent because the Medway Gravels (DO proportion less than five per cent) was considered not significant enough to need to be represented by a trigger.
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A drought status (normal to severe) is recorded against all of the trigger sites / areas for triggers 1 - 4. The override trigger would usually be scored at normal status i.e. ‘0’, because there are agreements in place which ensure water supply will continue into drought conditions. In these circumstances, we plan to have on-going discussion with neighbouring water companies about bulk supplies and shared sources, however there may be situations when imports of water are suddenly no longer available or need to be reduced. In this case we would determine that there is a high risk of a reduction or suspension of a bulk supply or transfer from a shared resource, and the score would be increased to a ‘3’.
Scores have been added to Table 2.1 (in red) to demonstrate a worked-through example. The next stage is to determine an overall score for triggers 1-3 for each of the three drought regions. To calculate this, results from the groundwater and recharge trigger units are amalgamated together using a decision-making process that takes account of the proportion of deployable output from each unit supporting that drought region.
For example, an overall score of 2 (moderate drought) was determined for trigger 1 (groundwater) for Eastern (1-3) because although the largest proportion of deployable output (44 per cent) is from the East Sussex Chalk unit (which was at developing drought status), the Ashdown Beds (32 per cent) and Greensand West of the Medway (20 per cent) units had respectively exceeded the severe and moderate drought status thresholds. The reservoirs’ drought statuses are combined using a similar approach dependent on how close the reservoir levels are to the threshold levels and reservoir capacity. The scores for the three triggers are entered into Table 2.2, alongside trigger 4 and any override triggers.
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Table 2.1 – The site composition of the four triggers per drought region with indicative trigger scores for an example month Drought Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Region Trigger Resources Status Recharge Demand/ Bulk supplies Groundwater (GW) Reservoirs Forecast (BS) / Shared GW trigger site Rainfall trigger site demand sources (SS) (GW Unit) (Recharge Unit) Per cent (%) Deployable Per cent (%) Deployable output from GW unit for output from recharge unit drought region for drought region Eastern A) Cornish Farm Widgens D) Ardingly F) Poverty Bottom I) Eastern (1-3) (Chalk South Downs) (0-1) (Chalk South Downs) 1-3 44% (2) 44% (0) (2) E) Arlington B) Elphicks Farm Trial (0-1) G) Goudhurst (Ashdown Beds) (Ashdown Beds) 32% (1-2) 32% (0)
C) Ryarsh No 2 H) Cramptons (Greensand West of the (Greensand West of Medway) Medway) 20% (2) 20% (1)
Proportion of the total DO for Eastern (1-3) Region each supply side trigger represents: 59% 34% - - 7% Western A) Winslade Farm No trigger D) Basingstoke G) N) Egham (0) (4-5) (East Hants Downs) sites (East Hants Downs) Western 38% (1) 38% (0) (4-5) (2) B) Hambledon Old School E) Borden (Wey Loddon Greensand (Wey Loddon Greensand & HB) & HB) 37% (1) 37% (2)
C) Stonor Park F) Cleve (Chalk Maidenhead) (Chalk Maidenhead) 25% (1) 25% (1) Proportion of the total DO for Western (4-5) Region each supply side trigger represents: 71% 16% - - 13% Eastern A) Dane Court Farm No trigger F) Boughton K) 0) Belmont (6-8) (Chalk Stour) sites (Chalk Stour) Eastern 6- Scheme (0) 43% (1) 43% (0) 8 (2) P) Kingston B) Charing No 7 G) Charing (0) (Greensand East of the (Greensand East of the Medway) Medway) Q) River 23% (1) 23% (1) Medway (Bewl) (0) C) Duckpit Farm H) Boughton (Chalk North Downs) (Chalk North Downs) R) R. Medway 22% (0) 22% (0) (Burham) (0)
D) Ryarsh No 2 I) Cramptons (Greensand West of the (Greensand West of the Medway) Medway) 7% (2) 7% (1)
E) Elphicks Farm Trial J) Goudhurst (Ashdown Beds) (Ashdown Beds) 5% (1-2) 5% (0) Proportion of the total DO for Eastern (6-8) drought region each supply side trigger represents: 82% 8% - - 10% Compan Proportion of the total DO for South East Water each supply side trigger represents: y wide 71% 18% - - 11% Total 3 11 (9 different GW trigger 11 (8 different Rainfall 5 BS / trigger 2 drought sites) trigger sites) 2 SS site nos. regions Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
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Table 2.2 – Initial trigger matrix for regional drought risk assessment –showing scoring for an example month Drought Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Region Trigger drought Resources Status Recharge Demand/ Bulk supplies / region GW Reservoirs Forecast Shared score demand sources Eastern 2 0-1 0 2 0 (1-3) Western 1 NA 1 2 0 (4-5) Eastern 1 NA 0-1 2 0 (6-8) Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Once the initial trigger matrix is complete, we are able to make an assessment of the extent of the drought and the potential impact on the supply demand balance. To assist in the decision, we have developed a schematic tool to aid the comparison between the scores of the different trigger types. The approach considers the relative balance of the current resources position coupled with a resources future outlook i.e. recharge is plotted against the risk of continuing high demands in the coming months.
The balance between resources and demand for each drought region is plotted onto the schematic tool as shown in Figure 2.8 for the example month. The gradation of colours helps to illustrate what status of drought is experienced depending on the relationship between resources/recharge and demand. For example, high resources / recharge together with high demands could lead to an overall drought status of developing progressing to moderate. Alternatively, very low resources / recharge would likely indicate a moderate drought, but as demand increases this would progress towards a severe drought. If the override trigger for a drought region was scored at a severe drought status, this would push that drought region into a low resource situation. If the demands were low it is likely that the drought region would at minimum be at developing drought status and if demands were higher, a moderate to severe drought status would be attained. Further examples which demonstrate the use of this schematic tool can be found in Section 8.
We consider this a flexible approach which could be used to consider different types of droughts. It can also be used to plot the progression of drought status of a region through a drought (see Figure 8.1 in the Drought Scenarios) and is a powerful communications mechanism.
Using this approach an overall drought region score is determined for each of the drought areas (see Table 2.3). An explanation and/or a justification is also presented in a comments box.
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Figure 2.8 – Trigger schematic tool – showing an example month
H 3 2 to 1
W (4-5)
E (6-8)
E (1-3) Demand
2 1 to 0 L L H Resources / Recharge
0 1 2 3 Normal Developing Moderate Severe Status Drought Drought Drought
Table 2.3 – Overall trigger matrix for regional drought risk assessment – showing an example month Drought Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Region Trigger drought Resources Status Recharge Demand/ Bulk region GW Reservoirs Forecast supplies score demand / Shared sources Developing Drought - 1 (Likely to move towards moderate Eastern 2 0-1 0 2 0 drought in near 1 (1-3) future if reservoirs continue to fall and there is reduced recharge.) Developing Drought - 1 (This drought region experienced the Western 1 NA 1 2 0 highest demands 1 (4-5) this month. Overall the triggers indicate a developing drought.) Developing Drought - 1 (The triggers indicate a developing drought. If recharge reduces Eastern 1 NA 0-1 2 0 further and 1 (6-8) groundwater levels continue to fall this drought region could move to moderate drought in the near future.) Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
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2.8 Data sources and arrangements
Having established the set of drought triggers, arrangements to ensure data availability have been put in place. The timely and efficient provision of data for each of the sites is fundamentally important to making a robust decision when managing a drought. The sources of the data, mechanism of retrieving the data and the period for which it is obtained are shown in Table 2.4.
Table 2.4 – Trigger site data sources Data type Trigger site Owner Type of Data Data data collected Interval by Groundwater Cornish Farm Widgens EA L EA Monthly levels Elphicks Farm Trial SEW M SEW Monthly Ryarsh No 2 SEW M SEW Monthly Winslade Farm Private M EA Monthly Hambledon Old School Private M EA Monthly Stonor Park Private L EA Logger Dane Court Farm Private M SEW Monthly Charing No 7 SEW M SEW Monthly Duckpit Farm Private M SEW Monthly Rainfall Poverty Bottom SEW L EA Daily levels Goudhurst SEW L EA Daily Cramptons Road SEW L EA Daily Boughton Private T Private Daily Bordon Private L EA Daily Basingstoke Private L EA Daily Cleve Private L EA Daily Charing SEW L EA Daily Reservoir Arlington Reservoir SEW T SEW Daily total storage Ardingly Reservoir SEW T SEW Daily Demand Resource Zones 1-8 SEW - SEW - Key: M: Manual, T: Telemetry, L: Logger, SEW: South East Water, EA: Environment Agency
The owner of the data is also the provider of the data, unless otherwise stated. The South East Water data is provided by the Operations Centre. Data is received by our Resources Planning team electronically every month. If data is not available then an explanation is provided and in rare cases an alternative site (where applicable) may be used as a surrogate.
A variety of reading and data handling processes are used. There is currently a mixture of manual readings, logged data and sites on telemetry, although this is being reviewed. The use of logging and telemetry is considered the most effective long-term method for timely provision of data and the opportunity for ‘real-time’ analysis.
We are working with the Environment Agency to examine the feasibility of installing permanent telemetry at rainfall trigger sites that the Environment Agency collect data at, and are investigating online data sharing techniques.
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2.9 Additional hydrometric drought monitoring
In addition to collecting monitoring data for the drought trigger sites, we also continually collect monitoring data at a wealth of sites across our area. The data collection at these sites will continue during a drought and although it will not feed into the drought matrix assessment and lead necessarily to drought status decisions, it will be useful to look in detail at specific areas and may be used to help inform where operational activities should be targeted. The types of monitoring data that are obtained are shown in Table 2.5.
Table 2.5 – Additional hydrometric monitoring sites Data type Monitoring sites How data is obtained? Groundwater SEW Production boreholes SEW Operations team levels Other SEW Observation boreholes e.g. SEW Operations team Stansted No. 1 Other EA Observation boreholes (at approximately 19 additional sites) e.g. Cross in EA Hand Knaves Rainfall Rainfall stations located across the SEW area in SEW Operations team levels point and areal format and EA Soil Moisture For each of the 9 recharge trigger units, and Uses rainfall data and Deficit also for other smaller units e.g. Medway a SEW model to Gravels. calculate SMD Reservoir Directly from Southern Bewl Reservoir twice weekly levels total storage Water Services Darwell Reservoir daily levels Directly from Southern Water Services Directly from Southern Weir wood Reservoir twice weekly levels Water Services Pembury Reservoir - per centage fall in daily SEW Operations team levels River Levels Environment Agency Daily Flow Data for Directly from EA various sites linked to operational controls EA South East Region Water Situation Monthly EA website reports Key: SMD: Soil Moisture Deficit, SEW: South East Water, EA: Environment Agency
2.10 Forecasting
It is difficult to predict the future resource availability during the development of a drought for two reasons: firstly, it is difficult to accurately predict future rainfall; and secondly, it is difficult to predict the impact of different rainfall events on yields of groundwater and surface water sources. Variations in demand magnitude are also equally difficult to forecast. In an effort to reduce the uncertainty associated with forecasting we have developed and enhanced our recharge and demand calculations tools, which are now used as part of the trigger assessment.
Our three year cumulative recharge assessment (as used in the trigger assessment) takes into account actual recent rainfall levels at representative rain gauges for each groundwater unit. The recharge values calculated are in effect an indication of
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groundwater resources in the future. How far in the future depends on the characteristics of each groundwater unit. We can also input Meteorological Office rainfall forecasts to this model to provide an indication of the groundwater position further into the future. The modelling using forecasted rainfall data provides a prediction with a greater level of uncertainty, so we have not used this type of forecast within the trigger assessment. It is however useful as a standalone tool to provide additional information to take into account in the decision-making process.
Our demand tool can also be used to provide a demand forecast. During the trigger assessment, this tool is used to compare actual demands to demand thresholds and determine a level of operational and supply risk, which is directly translated into a drought status. A sensitivity analysis can also be used to examine what drought status would be triggered if a historic worst-case demand forecast were to occur over the next few months, and what impact this would have on the overall drought status for each drought region. The year chosen for each drought region’s worst-case demand forecast is different.
2.11 Stage 3: Link to actions
As part of any drought permit/order application there is a need to prove there has been an ‘exceptional shortage of rain’ as part of the case of need. The recommended method for this is through an analysis of the ‘Standard Precipitation Index’ (SPI). SPI represents the statistical deviation of rainfall totals over a defined period (e.g. 12 months). We will incorporate this into any application as a matter of course. A significant negative SPI (negative represents a rainfall deficit) will, by definition, lead to some of our drought monitoring triggers being breached and we will determine which SPI periods are most representative of the current resource situation when we make the application. We do not therefore prescribe the duration of the SPI metric that we will use in advance as this may limit our ability to apply for the relevant drought permit/order.
Our trigger assessment will determine the overall drought status for each drought region. Depending on the drought status, a series of actions will be triggered to manage both resources and demand. The actions are discussed in Section 3. The demand side and supply side actions have been grouped into categories for each status of drought (see Section 3). Once a drought status for a drought region has been determined the Drought Management Team will commence actions applicable to that drought status. They will make informed decisions about the timings of the actions within each drought status. In Table 3.7 the actions have been put in an assumed order of implementation. We do not consider it appropriate to set a predetermined schedule for the implementation of every demand and supply side action, because the timing, severity, nature and extent of drought can be dramatically different. There is a need for flexibility so that we can have a practical and timely response in a developing drought situation. The Drought Management Team will also target the most at-risk resources and their supply areas within each drought region when implementing the actions.
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3 DROUGHT MANAGEMENT ACTIONS
Once the drought triggers have led to the Drought Management Team deciding to change drought status, we will implement a range of actions to maximise resources and minimise demand. Section 3 of the drought plan presents details of the range of management and operational actions we will consider as the severity of the drought increases and then recedes.
Lessons learnt from previous droughts have been incorporated into this plan to help us improve our management of future droughts. 3.1 Demand-side actions
South East Water has an on-going water efficiency campaign which we actively pursue during drought and non-drought conditions. During a drought, alongside an enhanced demand reduction campaign, it is important that we also take steps to reduce our own demand on water supply, for example by scaling down some routine operational activities.
Demand management is an important part of balancing supply and demand in all years, irrespective of whether there is a drought. The latest demand management measures being proposed are documented in our dWRMP19. Our strategy is summarised below:
Compulsory metering to cover 90 per cent of customers by 2020; Additional leakage reduction; and Water efficiency programme including:
- education and water efficiency information provided to all customers being metered; - individual water audits carried out pre-installation; - provision of basic water efficiency products such as cistern displacement devices; and - innovative behavioural economics – providing customers with more information about their water use on a regular basis and using nudge theory and social norming to allow customers to compare their use with others.
At times of drought water companies can, at their own discretion, apply certain temporary use restrictions. Section 36 of the Flood and Water Management Act (FWMA) 2010 amends the Water Industry Act 1991 by substituting a new section 76 to update the legislation on temporary use restrictions. Details on these changes and are set out in Section 3.1.3.
A summary of the demand actions that we will use to manage a drought is set out in Table 3.7 later in this section. Full details are described in Section 3.1.1 to 3.1.5. Each action has been given a specific Drought Action Plan or “DAP” identification code.
3.1.1 Water conservation campaigns and calls for voluntary restraint (DAPD1) Programmes of demand management and customer education will continue to be actively promoted to highlight the need to be water efficient. The drought plan will accelerate and supplement these measures to reinforce messages to customers with
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respect to water conservation. It is envisaged that calls for voluntary restraint (i.e. highlighting concern of impending drought conditions) will add impetus and renewed context to the water efficiency message.
It is equally important for us to explain in communications with our customers how we are reducing demand, especially during the early stages of the drought. We need to lead by example while encouraging demand restrictions in other sectors.
CCWater’s research in June 2012 (carried out during the temporary use ban which began in April 2012) confirms this expectation of customers. The research found that when there is a drought or temporary use ban are in place, around nine out of 10 believe it is acceptable for water companies to ask them to reduce water consumption. However, it was also clear that customers expect to see water companies pulling their weight too.
The research confirmed that customers are more likely to say that water companies are not doing enough to fix leaks, capture and manage resources effectively, help people use less water and reduce the chance of temporary use bans being introduced (CCWater, June 2012).
Please refer to Section 3.1.2 for details on the actions we will take to address these issues and lead by example.
We carried out our own customer research following the 2010-2012 drought to understand the impact of our water conservation campaign. This research showed the importance of our campaign to highlight drought and the need for water efficiency. One of the research’s conclusions was that the communication campaign was an effective way of increasing awareness among customers of the nature and severity of the drought (increased from 81 to 88 per cent) and the temporary use ban (increased from 94 per cent to 97 per cent). Positively, it was found that the South East Water campaign specifically had a greater impact on this than communications from any other source (South East Water, November 2012).
3.1.2 Operational works to reduce demand (DAPD2) During a developing drought, we will make changes to our operations which will act to reduce demand. The types of activities include:
Continue active leakage control with work progressing through to implementing a programme for enhanced leakage detection Initiate pressure management to reduce demand Review of water conservation schemes.
These activities are described in the following sub-sections.
Leakage management We are committed to reducing leakage further in line with our dWRMP19.
However, it is recognised that actions taken to further or enhance leakage reduction can play an important role in managing drought events. As such, during a drought event we shall undertake a review of the existing leakage strategy, and operational leakage practices and activities, making specific reference to the drought regions or other defined areas, which have been identified as being at highest risk i.e. where the
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water resources are most severely stretched. Consideration will be given to enhancing response times and additional targeted leakage location and repair activities in line with the risk assessment and current leakage levels in each water resource zone.
The review may result in scaling down routine operational activities such as flushing and mains rehabilitation and diverting resources to reducing leakage through programmes of enhanced active leakage control and pressure reduction (see next section) where appropriate.
Pressure management Pressure management is already widely implemented across our three supply regions. Our dWRMP19 has included further leakage reduction, and as part of this we propose to implement a programme of pressure reduction. In the event of a drought we will undertake a review of further pressure reduction opportunities and implement them accordingly in the appropriate regions. Given the level of pressure management already achieved, it is considered that the benefits of further drought-related pressure management are likely to be minimal, other than reducing pressure in areas with known leaks to minimise loss until leaks are fixed because of the potential impacts on customers.
Review of water conservation schemes In April 2017, the market for non-household customers changed, and we no longer have a direct relationship with commercial businesses. Water efficiency programmes such as audits and metering monitoring, are undertaken by retail companies.
During a drought as the wholesaler, we will work closely with the retailers to encourage them to use their relationships with commercial customers to encourage water conservation and ensure discussions and updates happen as the drought severity intensifies (see section 6.2 for communications plan).
Ahead of/at the time of a temporary use ban being implemented, in addition to liaising with our domestic customers we will also contact all water retail businesses to inform them of the water resources shortage and encourage them to consider how their customers could use water more efficiently. Template letters have been developed ready for use.
Demand could still be reduced further by ensuring early engagement and focusing on specific groups of non-domestic users, such as local authorities, cricket clubs, golf clubs and public gardens to ensure they understood any immediate impact of temporary use bans on their own operations.
A dedicated section of website for retailers, businesses and organisations would be created and updated with the latest situation reports and material to download such as water efficiency posters for staff washrooms and kitchens.
3.1.3 Background to the legislation and guidance for restricting customers’ water use After the 2004-2006 drought Defra carried out a review of the policy governing water use restrictions during drought, and the legislation was amended and passed into law in 2010. Section 36 of the Flood and Water Management Act (FWMA) 2010 thus amends the Water Industry Act 1991 by substituting a new section 76 to update the
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legislation on temporary use restrictions. This means that a water company can apply certain temporary restrictions at their own discretion.
Water use restrictions, which in the past were commonly known as sprinkler or hosepipe bans, are now referred to as temporary use bans and are covered by a revised set of legislation. The Drought Direction 2011 has also been updated to cover a revised list of ‘non-essential’ uses of water, still requiring application by water companies for a drought order before implementation.
Following the change in legislation, UKWIR published a Code of Practice and Guidance on Water Use Restrictions (UKWIR, May 2011), intended to support and inform water company drought plans. It was updated in 2013 following the 2010-2012 drought and recommendations have been incorporated into this drought plan.
The Code of Practice and Guidance on Water Use Restrictions-2013 (UKWIR, May 2014) provides advice on the categories of water use under the new legislation and sets out four guiding principles for implementing restrictions: taking a consistent and transparent approach; ensuring restrictions are proportionate; communicating clearly with customers; and considering representations fairly. We have taken both this code of practice and the Environment Agency’s Guideline (Environment Agency, June 2011) into account when developing this drought plan, and included proposals for likely implementation during times of drought, for consultation.
Water companies can now implement temporary water restrictions without needing to apply for a drought order. Further restrictions on non-essential use do still need to be authorised using a drought order.
The approach used to implement the new powers is explained in Section 3.1.4. The temporary use ban will be implemented in Phases 1 (with concessions) and 2 (with concessions removed) and the drought orders will be implemented by Phases 3 (with concessions) and 4 (with concessions removed). Figure 3.1 demonstrates this approach.
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Figure 3.1 – Phasing of demand restrictions Phase 1 Phase 2 Phase 3 Phase 4
temporary use bans to restrict water use drought orders to primarily to restrict water primarily to restrict domestic hosepipe use. use for business users. Concessions include: All concessions Concessions include: All concessions blue badge holders, removed. blue badge holders, removed. drip or trickle irrigation pools serving industrial systems fitted with a centre training where pressure reduction justified and small valve and timer and businesses whose sole business specialising operations are in hand car washing cleaning of non- that use hosepipes as domestic buildings. part of their process. (For full list see Table (For full list see Table 3.2) 3.1)
May be implemented together in a rapidly worsening drought situation
3.1.4 Temporary use bans (DAPD3) Supporting information, definitions and statutory exemptions for each water use activity covered by the FWMA are detailed by The Water Use (Temporary Bans) Order 2010. The scope of temporary use bans is now much wider than it used to be as a sprinkler / hosepipe ban, and there are now 11 categories of use as follows:
Watering a garden using a hosepipe; Cleaning a private motor-vehicle using a hosepipe; Watering plants on domestic or other non-commercial premises using a hosepipe; Cleaning a private leisure boat using a hosepipe; Filling or maintaining a domestic swimming or paddling pool; Drawing water, using a hosepipe, for domestic recreational use; Filling or maintaining a domestic pond using a hosepipe; Filling or maintaining an ornamental fountain; Cleaning walls, or windows, of domestic premises using a hosepipe; Cleaning paths or patios using a hosepipe; Cleaning other artificial outdoor surfaces using a hosepipe.
The definition of each of these terms is explained in the (Water Industry Act (“WIA”) section 76(1)) and the Water Use (Temporary Bans) Order 2010 (“the Order”). A guide to these can be found in Appendix Error! Reference source not found..
Under the FWMA 2010, companies are permitted to determine which category of temporary use ban to impose, which concessions and exemptions to offer and the timing / phasing of those restrictions. The intention of this flexibility is to enable water companies to balance water savings with any adverse impacts on customers and their businesses, and implement restrictions in an effective and equitable manner.
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Our temporary use ban representation process Wherever possible we would implement the temporary use bans in two phases, with the intention of keeping the message simple to customers while realising the benefits of gradual implementation. Phase 1 would be to restrict all eleven of the purposes set out above, with a number of concessions. Phase 2 would then remove all of the concessions. Table 3.1 sets out a full summary showing the temporary restrictions definitions, and concessions, with estimated savings for the restrictions.
Before implementing temporary use bans, we will provide a period of notice to allow customers and non-household retailers to make representations, and for us to respond where appropriate. This process is summarised below:
There will be a lead in time of a month to allow time for the preparation of adverts and detailed statements.
In our capacity as a wholesaler we will inform and consult with non-household retailers to comply fully with the requirements of Process E6 of the Operational Terms of the Market Codes.
For the initial noticing of the restrictions, two weeks will be allowed for customer and non-household retailer representations during both Phase 1 and Phase 2 restrictions. We will publish adverts explaining the restrictions and concessions proposed at each phase in two local newspapers (where available) and in the affected area, and on our website. Other methods such as radio will also be used to communicate more extensively across the drought regions affected. Press interviews on TV and Radio will also be utilised as they were clearly proven during the 2010-2012 drought to be successful medium of delivering messages more widely and are a trusted source for customers. CCWater’s research in June 2012 found that the vast majority surveyed (80 per cent) heard about the recent hosepipe bans from TV news and of those that did 74 per cent felt it was clear and 73 per cent a source of trusted advice (CCWater, June 2012). This conclusion was similar our own research which found that the most effective way for us to communicate about drought is to use national media channels, such as television, newspaper and radio. Local newspapers are also important, and a common way in which customers accessed drought information during the 2010-2012 drought (South East Water, November 2012). Social media and digital channels available now will also be an important way of issuing messages widely and to specific geographic regions.
One week will be allowed for us to respond to representations where appropriate and to make changes to the restrictions plan. Restrictions will then be implemented using further advertising as per the communications plan.
When removing the restrictions for each of the two phases, we will publicise this via local newspapers and other media outlets, and on our website and inform non- household retailers to comply with Process E6 of the Operational Terms of the Market Codes.
When removing the restrictions, we will write to all those stakeholders we communicated with during the restrictions. We will also write to all those customers and non-household retailers who had contacted us about the restrictions to advise them of the removal and thank them for their support.
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There is no need for a period of representation and the restrictions will cease immediately.
A minimum of one week for representations is considered an appropriate period for both Phase 1 and 2 temporary use bans. The temporary use bans have already undergone a consultation process as part of the consultation on our draft drought plan.
To ensure that we manage any further representations in a fair and even-handed approach, which is balanced against the need for demand savings, we have developed internal procedures to ensure that any individual requests to be exempt from particular restrictions are considered.
A dedicated drought telephone line would be promoted for our household customers and template letters are already prepared to respond to expected contacts (see Appendix Error! Reference source not found. for list of the topics these letters cover).
Appendix Error! Reference source not found. shows a flow diagram which details how Customer Service Advisors would deal with any customer contacts relating to the drought. These include requests for exemptions, reports of misuse and general enquiries. This process ensures all contacts are logged and that we have a record of who has contacted us over the course of a drought. We would write to these logged contacts if the drought escalates or once the restrictions are lifted or the drought is over to confirm the latest position.
To comply with Process E6 of the Operational Terms of the Market Codes, separate arrangements will be put in place that allow us, as a wholesaler, to provide the same services as appropriate during drought to non-household retail customers.
We have a comprehensive list of expected uses of water and which uses would be restricted during a drought. However, there are some uses of water which may be queried that are currently not detailed, or where customers wish to double check the position. Appendix Error! Reference source not found. shows the escalation procedure which has been prepared for Customer Service employees to follow. This ultimately leads to a weekly surgery group made up of Customer Service and Communications colleagues, with input as necessary from Legal and Water Resources. In extreme cases, this may be raised up to the Drought Management Team to make a final decision on.
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Table 3.1 – Part 1: temporary use ban - summary of intervention options for water use
Estimated Estimated
ns Ref in Max Max Proposed concessions
Current No Activity Definition includes Definition excludes riction Savings Savings for Phase 1 rictio Legislation Average Peak
Phase 1 Phase 2
Rest (Ml/d) (Ml/d)
Rest
Garden includes: park, gardens open to public, • Elderly and/or disabled lawn, grass verge, area Garden does not • Food crops at of grass for sport, include: agricultural household premises or allotment garden, any land, land for private allotments growing for • Watering of newly laid WIA1991 area of allotment used commercial use, turf for first 28 day s76 Watering a for non-commercial used by National period amended 1 garden with purposes, any other 12.55 18.82 Plant Collection, • Newly bought plants FWMA 2010 a hosepipe green space temporary garden or • Watering with certain s36 flower display, plants water efficient apparatus Hosepipe: drawing water in outdoor pot or drip / micro-irrigation, through hosepipe from a under cover. Health etc container, filling or partly and safety. • National / international filling a container by sport events means of a hosepipe
• Non-household Cleaning a Private motor-vehicle: business specialising in WIA1991 private mechanically propelled hand car washing that s76 motor- for use on road or trailers use hosepipes as part of amended 2 0.77 1.16 vehicle their process FWMA 2010 using a Hosepipe: see definition • Specific low water-use s36 hosepipe No.1 apparatus, such as pressure washers Watering Does not include plants on Watering of plants in an watering plants WIA1991 • Elderly and/or disabled domestic or outdoor pot or in the grown or kept for s76 • Newly bought plants non- ground, under cover. sale or commercial amended 3 • Watering with certain 2.53 3.79 commercial use, or are part of a FWMA 2010 water efficient apparatus premises Hosepipe: see definition National Collection or s36 drip / micro-irrigation using a No.1 temporary garden hosepipe display • Non-household micro business whose business depends on Vessel, other than a work involving this seaplane, designed, Does not include WIA1991 Cleaning a • Vessels which are constructed or adapted clearing of any area s76 private primary residence to move in, on, or over of a leisure boat amended 4 leisure boat • Cases where fouling is 0.02 0.04 water enclosed by roof or FWMA 2010 using a causing increased fuel walls. Health and s36 hosepipe consumption Hosepipe: see definition safety • Removal of graffiti No.1 • Engines designed to be cleaned with a hosepipe Excludes: filling or maintaining (a) in • Pools with covers as course of evaporative losses low construction (b) • Pools with approved Filling or using hand-held WIA1991 water conservation / maintaining Pools in or on land of a container from tap (c) s76 recycling system a domestic building used as a designed for medical amended 5 • Paddling pools at early 1.81 2.71 swimming or dwelling, other than a treatment (d) for FWMA 2010 stages of moderate paddling pool used for business decontaminating s36 drought pool animals (e) for • Pools subject to veterinary treatment significant repair and (f) fish are being renovation reared or kept in captivity (a) recreational use with Drawing WIA1991 pool (b) recreational use water, using s76 on land as part of a hosepipe, amended 6 dwelling 3.04 4.56 for domestic FWMA 2010 recreational s36 Hosepipe: see definition use No.1 Excludes fountains in WIA1991 Filling or • Fountains / cascades A cascade or any other or near a fish pond s76 maintaining for aerating a stagnant display of moving water. and whose purpose amended 7 an pond even without fish 0.003 0.004 Includes filling by is to supply sufficient FWMA 2010 ornamental • Water features with permanent plumbing oxygen to keep the s36 fountain religious significance fish healthy Cleaning of External walls or • Non-household micro WIA1991 walls or windows. Includes business whose s76 8 Health and safety 0.02 0.03 windows of dwellings, garages, business depends on amended domestic sheds, outbuildings, work involving this
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Estimated Estimated
ns Ref in Max Max Proposed concessions
Current No Activity Definition includes Definition excludes riction Savings Savings for Phase 1 rictio Legislation Average Peak
Phase 1 Phase 2
Rest (Ml/d) (Ml/d)
Rest
FWMA 2010 premises walls within the curtilage • Very low water use s36 using a of a dwelling technologies hosepipe • Cleaning apparatus not Hosepipe: see definition connected to mains No.1 supply • Removal of graffiti • Non-household micro business, whose sole Paths and patios of any operations are cleaning WIA1991 material and on both of hard standings Cleaning of s76 domestic and • Non-household paths or amended 9 commercial premises. Health and safety business, where dust 0.20 0.30 patios using FWMA 2010 suppression is a a hosepipe s36 Hosepipe: see definition requirement No.1 • Removal of graffiti • Low water use technologies • Non-household micro (a) paved or laid with business, whose sole hard or artificial material Cleaning of operations are cleaning (b) timber decking (c) a WIA1991 other of such surfaces quay (d) trailer for s76 artificial • Non-household launching boats (e) the amended 10 outdoor Health and safety business, where dust 0.01 0.01 roof of any domestic FWMA 2010 surfaces suppression is a premises s36 using a requirement
hosepipe • Removal of graffiti Hosepipe: see definition • Low water use No.1 technologies Pond (manmade or natural), including a swimming pond, not WIA1991 Filling or Excludes ponds in being used for s76 maintaining which fish or other commercial purposes. amended 11a a domestic aquatic animals are 0.01 0.01 Includes both filling and FWMA 2010 pond using a being reared or kept topping up. s36 hosepipe in captivity
Hosepipe: see definition No.1 Totals: 20.96 31.45
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Managing communications about temporary use bans between our drought regions and across other water company areas When only one or two drought regions are to implement restrictions, it will be difficult to communicate who is restricted and who is not. It will become even more difficult if the drought regions have different phases of restriction at the same time. To help mitigate customer confusion, if one of Eastern (6-8) or Eastern (1-3) regions is to implement a restriction, we will consider whether it is justified to put the restriction on in both drought regions. Western (4-5) Region is geographically separate so it is unlikely to influence Drought Management Team decisions in this way.
We have consulted with neighbouring water companies on the phasing and concessions to be implemented by restrictions; and proposals are in general alignment, with most companies opting for two phases.
The 2010-12 drought saw seven water companies introduce restrictions at the same time. This practical experience of introducing a temporary use ban found that while there was general alignment there were some differences which led to some confusion in the early stages of restrictions. The water companies worked together to bring their restrictions into closer alignment and worked well together to communicate this with customers.
A consideration of the timing of neighbouring water company’s restrictions will be taken into account when our Drought Management Team makes decisions. It is important to appreciate that there can be differences between neighbouring water companies due to the different water resources available to each. Below in Box 1 is an agreed statement between the water companies in the south east region.
Box 1 - The basis for the variability of responses to water use restrictions from water companies in South East England In the South East region, we and other water companies source our supplies of raw water prior to treatment in the following ways:
1) River abstraction; 2) Reservoirs filled by river abstraction or impoundment of river water; 3) Groundwater abstraction from boreholes and springs.
The percentage balance of these varies from company to company, and even within company areas and this causes variability in drought resilience and response.
Unlike unseasonably dry soil that constitutes an agricultural drought and which can arise from only a few weeks of dry and sunny weather over the growing season, it takes at least several months of below average rainfall to initiate a water resources drought. Particularly important is winter rainfall as it is this that replenishes most water resources. The low groundwater levels and river flows that result from this type of dry period reduce water availability from rivers and boreholes, and reservoir levels fall. This poses a risk to our ability to supply its customers.
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Box 1 (Continued)
To manage this risk, water use restrictions are an important measure we can use to reduce demand during drought. They not only enable us to maintain essential supplies but also help to conserve water resources for later in a drought and reduce the environmental impacts of abstraction during this critical period. We will only impose water use restrictions upon our customers if they are absolutely necessary, and in accordance with their Levels of Service for water supply. We appreciate the confusion that can be caused among some customers when one company introduces restrictions but its neighbouring company does not. Clearly from a customer point of view, if restrictions need to be imposed then a simple and consistent approach should be adopted for introducing water use restrictions across the South East. When we need to appeal for restraint or impose restrictions, we will always give as much information to you as possible. The reasons why companies may have to react differently in terms of restrictions and their timing are explained below: Differing levels of drought severity across the region: While droughts across the South East will generally be caused by a regional trend of several months of below average rainfall, sub-regional differences in rainfall may cause differing levels of drought severity across the region. In other words, the need to impose restrictions for one company may not equally apply to another company in the South East.
Differing vulnerabilities at Water Resource Zone level: Due to the way the water supply system has developed over time, many water company supply areas are sub-divided into Water Resources Zones (WRZs). These are defined as the largest possible zone in which all resources, including external transfers, can be shared and hence the zone in which customers experience the same risk of supply failure from a resource shortfall. WRZs can be divided into those dependent upon:
River abstraction only Groundwater abstraction only Reservoirs filled by abstracting local river water or by impounding river water Various combinations of the above
This mix of WRZ types means that even if there were not a significant difference in drought severity across the region, WRZs will tend to react differently to the same drought, with certain zones experiencing higher levels of risk to supplies than others. That means in similar drought conditions, rivers, groundwater sources and reservoirs across the region can respond differently in terms of risk to supply. For example, a WRZ dependent on combined river abstraction and reservoir storage for supply may have a different level of risk to one based on groundwater abstraction. This difference in WRZ vulnerability has an impact both at the company level and regional level.
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Box 1 (Continued)
We may find it necessary to introduce water use restrictions preferentially in more vulnerable WRZs during drought but not to extend restrictions to all of our WRZs. At a south east regional level one water company may need to impose water use restrictions earlier in a drought than its neighbours, while another water company is able to withhold the imposition of restrictions until much later or not at all.
The introduction in 2010 of new powers in the form of the temporary bans provided the opportunity for us, the water companies in the South East, to review our Drought Plans in 2013 to provide clearer, more consistent and more unified approaches to introducing water use restrictions across the region.
Consequently, the water companies in the South East developed their plans in 2013 to ensure temporary use bans are interpreted in as consistent a way as possible cross the region. This approach has been retained in this plan too.
As mentioned previously the CCWater’s research in June 2012 found that the vast majority surveyed (80 per cent) heard about the recent temporary use bans from TV news and of those that did 74 per cent felt it was clear and 73 per cent a source of trusted advice (CCW, June 2012). We intend to use TV and radio as the main mediums through which to deliver our communications during the drought. These will be supported by our website and social media which will provide specific detail on who and what activities are restricted.
Radio advertising (and to an extent TV advertising) will most likely use County or UK regional boundaries instead of water company boundaries to let customers know what temporary use bans are in place. This method is likely to work best when neighbouring water companies also have restrictions in place (albeit these restrictions may be slightly different). Customers may be slightly confused about the specific restrictions in their area, but the overall message that water savings are required is considered the main aim. Efforts will be made to ensure our customers are aware of the specific restrictions by other advertising particularly on the website, social media, through the local press and by sending out letters to key stakeholders.
Triggers for implementing the temporary use bans There are no specific triggers for these temporary use bans on water use actions; however, the following will be taken into account:
The Phase 1 restrictions will be advertised and then implemented after DAPD1&2 actions have commenced; It is likely that the latest the Phase 1 restriction will be advertised and then implemented when the drought region is at moderate overall drought status and the severe drought demand threshold has been exceeded for one month or predicted to be exceeded; It is likely that the Phase 2 restrictions will be advertised after the Phase 1 restrictions have been implemented. The implementation of Phase 1 would be the prompt to consider Phase 2 restrictions. However, if the drought situation looks to be worsening rapidly the two phases potentially could be applied for concurrently;
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It is likely that the latest stage at which Phase 2 restrictions will be advertised and then implemented is when the severe drought demand threshold has been exceeded for two consecutive months when the drought region is at overall moderate drought status (or worse) or predicted to be at this status. This would also be the trigger for a Drought Order application (see Section 3.1.5).
The scenario testing demonstrated that it is most likely that Phase 1 will be advertised and implemented separately for the individual drought regions. Phase 2 is more likely to be a company-wide ban because a drought which is severe (or progressing rapidly towards severe) is likely to be affecting a larger geographic area.
Timings for lifting the temporary use bans The temporary use bans are likely to remain in place until the end of the drought i.e. a developing drought status or normal status has been attained or is forecast to be attained. A lifting of restrictions would imply that the drought has ended, and so to deliver a very clear message, we do not intend to do this until the end of a drought. Every drought is different and therefore there may be exceptional circumstances when it is appropriate to remove the restrictions early.
3.1.5 Restrictions on uses of water through a Drought Order (DAPD4) Restrictions introduced as a result of a water company applying for an ordinary drought order to the Secretary of State used to be covered by the Drought Direction 1991 and were commonly known as ‘non-essential use bans’. The scope of these restrictions has been recently revised alongside the temporary water use restrictions, and the Drought Direction 1991 has been revoked. It has replaced by the Drought Direction 2011 which sets out the updated range of water use activities that may be prohibited with the successful application of a drought order. The activities are defined such that they specifically do not overlap with the activities covered by a temporary use ban, and are generally worded to apply to non-domestic purposes. There are 10 categories of use under the revised Drought Direction 2011:
Watering outdoor plants on commercial premises; Filling or maintaining a non-domestic swimming or paddling pool; Filling or maintaining a pond; Operating a mechanical vehicle-washer; Cleaning any vehicle, boat, aircraft or railway rolling stock; Cleaning non-domestic premises; Cleaning a window of a non-domestic building; Cleaning industrial plant; Suppressing dust; Operating cisterns.
The Environment Agency Drought Plan Guideline (Environment Agency, June 2007) states that companies should ‘be able to demonstrate that appropriate demand measures have been implemented before applications for drought permits/orders are made’ and that they are ‘unlikely to...support drought permit/order applications unless a company has already implemented all appropriate demand-side actions prior to making an application’. In line with this, we have stated that we would only apply for a drought order to restrict ‘non-essential’ uses of water after implementation of the full suite of temporary water use restrictions, including removing all concessions.
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For drought orders to be granted in England, the Secretary of State needs to be satisfied both that:
either a serious deficiency of supplies of water in any area or such a deficiency in the flow or level of water in any inland waterway as to pose a serious threat to any flora or fauna which are dependent on those waters exists or is threatened, and that the reason for the deficiency is an exceptional shortage of rain
Once granted, the drought order can last up to six months, although they can be amended to last up to a total of one year.
We have decided we would be likely to apply for drought orders in two phases. The first drought order application would be to restrict all ten of the purposes set out above, with a number of concessions. This has been termed ‘Phase 3’ of demand restrictions. The second drought order application would then remove all of the concessions. This has been termed ‘Phase 4’ of demand restrictions. Table 3.2 sets out a full summary showing the non-essential use restrictions definitions, and exemptions, with estimated savings for the restrictions. If the drought status is severe (or progressing towards severe), we believe we should be enforcing maximum demand restrictions i.e. without any concessions in order to conserve remaining resources.
The Phase 3 drought order is likely to be applied for either at the same time as DAPD3 Phase 2 restrictions are implemented, or soon afterwards. There is not a specific trigger for Phase 3 drought order to be applied for; however, the following will be taken account of:
the Phase 2 restrictions being implemented; and/or it is likely that the latest the Phase 3 restrictions would be applied for is when the severe drought demand threshold has been exceeded for two consecutive months and when the drought region is at overall moderate drought status (or worse); and/or The Phase 4 restrictions will be applied for and implemented after (or at the same time as) the Phase 3 restrictions. This is the final demand type action that can be implemented before the emergency plan is invoked.
In practice Phases 3 and 4 may need to be applied for together if the drought situation looks to be worsening rapidly, because of the 8 to 12-week duration for drought order applications. However, we believe that it is important to be able to have a flexible approach because droughts each have different durations and severities. The reason we have decided not to have one phase of drought order application is because if faced with a long duration drought of gradually worsening severity there could be sufficient time to phase in the drought order restrictions and provide some concession to a small number of specified users for as long a time as possible.
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Table 3.2 – Part 2: Summary of intervention options for water use
Savings Savings Definition Proposed concessions No Activity Definition includes Average Peak excludes for Phase 3 rder rder
rought rought o o (Ml/d) (Ml/d)
Phase 3 Phase 4
D D
Ref in Current Legislation Pond (manmade or natural), including a Excludes ponds swimming pond, being in which fish or Drought Filling or used for domestic or other aquatic Direction 11b maintaining a commercial purposes. 0.02 0.02 animals are 2011 pond Includes both filling being reared or and topping up, kept in captivity including by fixed pipes. Operating a Mechanical car and Drought • Washers that recycle mechanical truck washers, Direction 12 less than 23 l/wash 0.12 0.18 vehicle whether automatic or 2011 • Biosecurity grounds washer not • Low water use technologies • Small businesses whose Cleaning with a sole operations are Cleaning of hosepipe. Includes all cleaning of vehicles etc Drought any vehicle, vessels and road Health and • Those using vessels as Direction 13 boat, aircraft 0.13 0.20 vehicles including safety primary residence 2011 or railway those used for • Cases where fouling of rolling stock commercial purposes. hulls causes increased fuel consumption • Elderly or disabled • Removal of graffiti Using a hosepipe to Drought Cleaning clean equipment Health and Direction 14 industrial • Removal of graffiti 0.04 0.06 necessary for an safety 2011 plant industrial operation. Drought Covers domestic and Suppressing Health and Direction 15 non-domestic areas, • Nuisance control 0.02 0.03 dust safety 2011 using a hosepipe Automatically operated flushing cistern Drought • Offer concessions to Operating servicing a WC or Direction 16 charities, churches and 0.77 1.16 cisterns urinal in a building that 2011 non-profit organisations is unoccupied or closed. Does not include watering plants grown or Watering Watering of plants in kept for sale or • Newly bought plants Drought outdoor an outdoor pot or in commercial use, • Watering with certain Direction 17 plants on 2.53 3.79 the ground, under or are part of a water efficient apparatus 2011 commercial cover National drip / micro-irrigation premises Collection or temporary garden display Excludes: (a) open to all public (b) during construction (c) • Pools serving industrial A pool other than as using hand-held centre training where defined as a domestic containers justified pool above. Filling or (d)used for • Pools with covers as
Drought maintaining a decontamination evaporative losses low Note: pools that are Direction 18 non-domestic of animals • Pools with approved 0.07 0.11 restricted to members 2011 swimming or (e)designed for water conservation / only e.g. hotel pool, paddling pool medical recycling system private leisure club etc. treatment (f) fish • Pools subject to fall under this are being reared significant repair and restriction or kept (g) use renovation by school for swimming lessons • Some businesses may Cleaning Any exterior part of be reliant on building Drought non-domestic non-domestic building Health and washing Direction 19 premises or a non-domestic 0.02 0.02 safety • Removal of graffiti 2011 using a wall, excluding • Low water use hosepipe windows technologies • Businesses reliant on Cleaning a Any building not used Drought building washing window of a principally as a Health and Direction 20 • Cleaning apparatus not 0.01 0.01 non-domestic dwelling, any other safety 2011 connected to mains building structure supply Totals: 3.73 5.59
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The application could be made for each drought region individually (as per the outcomes of the drought matrix), however in practice it is thought likely that in a moderate to severe drought a similar situation would be experienced across more than one drought region.
The estimated savings for each activity are shown in the final right-hand two columns of Table 3.1 and Table 3.2. The first column provides an estimate of maximum average savings and the second column an estimate of maximum peak savings. Total savings have been presented for Phase 1 and 2 together (21.0Ml/d Average, 31.5Ml/d Peak) and Phases 3 and 4 together (3.8Ml/d Average and 5.6Ml/d Peak). The estimates are not considered accurate enough to be able to produce the splits between with and without concessions, but it has been assumed that the concessions will represent the smaller fraction of the overall saving so the majority of water will be saved in Phases 1 and 3.
In order to calculate the average and peak savings, a bottom up approach was used to work out per option what proportion of the customer base this would impact and how much water the activity cessation would save. The data, estimates and assumptions are presented in Error! Reference source not found..
3.2 Supply-side actions
As well as actions to reduce demand, we have a number of supply-side options that can be used during a drought. In general, supply-side options can be broadly split into the following categories:
Operational works Infrastructural connectivity and source improvements (including bringing disused sources online and developing new sources) Changes to bulk supplies and use of shared resources Drought Permits and Drought Orders Emergency Drought Order e.g. tankering and standpipes.
Details of each of the supply actions we will use to manage a drought are set out in Table 3.7 and are described in Sections 3.2.1-3.2.6.
3.2.1 Operational works (DAPS1) Optimisation of existing sources (DAPS1a) All water companies optimise their operations across their supply area as part of their normal operational functions. During a developing drought the first step would be to review the potential effects of increased pressure on resources on the local supply regime. The optimal way of achieving this support will be assessed and a new operating regime will be defined at a drought region level. The new operating regime will continue whilst the threat remains constant, until the drought recedes or develops further.
We use a strategic operational and decision support tool, MISER, to help to identify the optimal operating regime. Within MISER, scenarios can be run to manage the resources available and investigate alternative management strategies within the constraints of system infrastructure and source output constraints. The tool can be used to investigate system capability to meet resource allocation targets and how to
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maximise yield during critical periods, or to identify constraints and bottlenecks within the distribution system.
Distribution / connectivity efficiency (DAPS1a) The outputs of some sources are constrained by the distribution system. In conjunction with optimising of existing sources the MISER modelling will help to evaluate network efficiency and may lead to changes in the way water is moved around the network.
Operational use and delivery programme (DAPS1b) During a moderate drought there will be a review of the operation use and delivery programme, and any non-essential maintenance programmes are likely to be deferred. This will lead to demand savings because water will not be lost through flushing processes and will improve performance of source output through increased availability of supplies with less interruption.
3.2.2 Infrastructural connectivity and source improvements (DAPS2) and disused sources (DAPS3) Our WRMP includes water resource schemes, and schemes to upgrade the distribution network and water treatment works to allow greater connectivity and operational flexibility. During preparation of the 2013 final drought plan we assessed a number of schemes which have been considered for development over the next 25 years, to see if it would be practical to include them as a potential ‘acceleration’ options for increasing supply during a drought. Additional options outside of the WRMP were also considered such as: sources where pumps could be lowered for short term increased outputs, and sources which could be ‘borrowed’ from commercial users within the supply area. A workshop involving staff from different departments within South East Water was used to generate and develop potential drought options.
During the 2016-2017 update of the draft drought plan we have reviewed the options that could be brought forward to ensure they are still relevant, and to check if there are any new options.
The following sources that were listed in the 2013 drought plan remain options that could potentially be brought forward:
two sources where existing schemes could be developed, and abstraction increased (Southlands and Oaklands, and Halling No.8); and, three disused sources (Hackenden, Chasewood, and Balcombe) which potentially could be re-commissioned. The reasons for their disuse typically were poor yield or inadequate treatment facilities to treat poor water quality.
No new options have been identified during the 2016/2017 updating of the draft drought plan. Sedlescombe and Cowbeech have been removed from the 2017 draft drought plan. Sedlescombe is no longer viable because it has been infilled and capped and the abstraction licence has been given up. Cowbeech has been reconsidered for delivery as part of our long term water resources plan and is therefore no longer an additional drought option.
During a developing drought, we would undertake a new review process to see if any other options linked to acceleration of planned schemes would also be feasible (DAPS2). We would also seek to identify any sources that have recently become
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disused or reduced in output. If an abstraction licence is held, they could be quickly brought back into supply (DAPS3). It is unlikely that we would propose to abstract above any licence limits in such cases.
During a moderate drought, all feasible options under DAPS2 and DAPS3 would be fully developed into schemes. This would require detailed design work and relevant planning and environmental assessments, detailed discussion with the Environment Agency and then application for abstraction licences.
The Southlands and Oaklands scheme, Halling No.8 and three disused sources that have been identified during the preparation of the draft drought plan all require drought permit/order applications to revise or provide for new abstraction licences. Further information on these schemes, including details on timings and prioritisation can be found in Section 3.2.4. We have assumed that it is very unlikely that these schemes will be operational before the severe stage of drought because there are considerable constraints on quality and volumes of water that can be put in to supply and the consequent amount of engineering required for commissioning.
Any new options identified under DAPS2 may require a change in / or a new abstraction licence. A drought order would need to be applied for because they would have not been identified upfront in our draft drought plan. See Section 3.2.4 for further details.
During the post drought phase, we will also re-assess potential options to consider whether any schemes under DAPS2 could be accelerated over the next 6-12 months period to assist in case a drought situation develops in the future.
3.2.3 Shared resources and bulk transfer agreements (DAPS4 agree extensions, and DAPS5 new agreements) We have a number of bulk supply and shared resource agreements already in place with neighbouring companies Southern Water Services and Affinity Water (See Table 3.3 for specific details). All bulk supplies are treated water transfers with the exception of the supply from Southern Water Services into our Water Resource Zone 3.
Figure 3.2 provides an overview of the bulk supplies and also inter-zonal transfer links during normal conditions.
Inter-company transfers play an important role in maintaining a balance between supply and demand across the South East, with bulk supplies making up eight per cent of our current supply alone.
The movement of water from areas of relative surplus to relative deficit is an efficient use of water resources. We address security of supply issues relating to our existing bulk supplies in our dWRMP19, to ensure our existing bulk supply arrangements remain resilient to future challenges. This will ensure that all our bulk supplies include improved clarity in terms of the levels of resilience they provide, and importantly how they will be operated under drought conditions.
Table 3.3 summarises the outputs from our bulk supplies we can expect under a range of different drought severities i.e. worst historic drought (one in 100 year event, with a one per cent probability of occurring in any given year), severe drought (one in 200 year event, with a 0.5 per cent probability of occurring in any given year) and extreme
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drought (one in 500 year event, with a 0.2 per cent probability of occurring in any given year). This approach is an advance on the basic ‘pain share’ principle employed in our latest published drought plan 2013.
Table 3.3 also summarises the current contractual arrangements for each of our bulk supply and shared resource agreements, with specific reference to how the agreement will be managed under drought conditions.
During a drought, communication with Affinity Water and Southern Water Services regarding South East Water’s imports is extremely important. As mentioned in Section 2.6 we have included an override trigger as part of the drought triggers because eight per cent of our water comes from bulk supplies or shared use schemes. Throughout a drought it is essential we are aware of and alert to the water situation of Affinity Water and Southern Water Services, so that if there is a reduction in an import, we can make a timely decision in accordance with our drought plan.
We maintain regular communication with both Affinity Water and Southern Water Services about the bulk supplies and shared use systems during normal conditions. However, once we reach developing drought status (within a particular drought region) we plan for more formal monthly meetings to take place between the respective water resource experts to discuss the relevant transfers for that drought region. If the drought intensifies and we reach moderate drought status we plan to meet more frequently, increasing to fortnightly meetings at the water company Director level. If there is perceived to be any risk to the planned imported volumes (as set out in Figure 3.2) we would seek an immediate meeting with the appropriate water company to resolve any uncertainty.
These communications will help us to decide whether it is necessary to implement the override trigger. It is hoped that we will never have to use the override trigger, and use of it does seem unlikely assuming sufficient communication between the water companies. However, we have concluded that the override trigger should remain in this revised draft drought plan because eight per cent of water resources are external to us. Further reference to drought action triggers for bulk supplies and communications with respective bulk supply water companies is provided in Table 3.7.
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Figure 3.2 – South East Water and bulk supplies and inter-zonal transfers
7.8 Ml/d 36 Ml/d
12 Ml/d 2 Ml/d 12 Ml/d 5 Ml/d 5.4 Ml/d 4 Ml/d 5 Ml/d 8 Ml/d 6 Ml/d
26 Ml/d
Key: Inter-Zone Transfer Inter-Company Bulk Import Inter-Company Bulk Export
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Table 3.3 – Company bulk transfers/ shared supply arrangements Location Resource Company Volume (or capacity) (Ml/d) under different Time Description Zone design drought severities (see Chapter 8) constraints 1 in 100 year 1 in 200 year 1 in 500 year
Bulk transfer agreements
Weir Wood RZ2 Southern PDO: 5.4 PDO: 5.4 PDO: 4.27 From The agreed contractual volume is 5.4 Ml/d for the average Water ADO: 5.4 ADO: 5.4 ADO: 4.27 2011/12 to day and peak day condition. There is no pain sharing Services 2020/21 clause in this contract although we are working with Import Southern Water Services on updating the contract document in readiness for renewal, aiming to make it fit for the future term. However, during a drought which would typically be triggered by one dry winter, both companies would meet and discuss the requirements from the reservoir during the course of the year.
Darwell RZ3 Southern PDO: 8.0 PDO: 8.0 PDO: 4.0* From Under the terms of the contract SEW is permitted to Reservoir Water ADO: 8.0 ADO: 8.0 ADO: 4.0* 2011/12 to abstract up to 8 Ml/d over any rolling 28 day period and up Services 2026/27 to 12 Ml/d during any period as long as it does not exceed Import the condition above. The abstraction takes place from the Darwell reservoir.
There is a pain sharing clause in this contract which shares the volume of additional water available for transfer from Bewl Water to Darwell reservoir on a 8/17 SEW to 9/17 SWS basis. This provision was determined through a section 40 agreement.
Under developing drought conditions, the supply would be progressively limited to 8/17 of flow in the pipeline subject to a minimum of 1Ml / day. During a drought, which would typically be triggered by one dry year, both companies would meet and discuss the requirements from the reservoir during the course of the year.
The bulk supply has been subject to review during 2016/17 that is ongoing.
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For the time being, and until any such time new arrangements are formalised, the existing bulk supply is retained unchanged as per existing contractual arrangements through to 2026. Egham RZ4 Affinity PDO: 36.0 PDO: 36.0 PDO: 36.0 In No formal specified drought conditions included within Water ADO: 36.0 (32.4**) (30.6**) perpetuity existing agreement. For drought management purposes Import agreement Affinity Water has agreed to report changes to their ADO: 36.0 ADO: 36.0 drought status routinely (monthly) to SEW as part of normal operational activity. (32.4**) (30.6**)
In the event of a drought trigger being threatened or breached the respective drought management plans refer to formal dialogue being held and documented to forecast future output in a timely manner and negotiate pain share agreements. There are no pain share agreements for the bulk supply. In previous droughts the bulk supply has proven to be very reliable. Belmont RZ6 Southern PDO: 7.39 PDO: 7.39 PDO: 5.54 From As part of the Belmont scheme, South East Water can Scheme Water ADO: 6.85 ADO: 6.85 ADO: 5.14 2011/12 to take its entitlement at Matts Hill. There is also the Services 2023/24 provision for South East Water to pump water into the Import Eastling main at Stockbury Valley and take water out at Bottom Pond. However, the net maximum daily and annual average volumes that South East Water is entitled to remain the original volumes given in the Belmont scheme agreement. There are no pain share agreements for the bulk supply, and in previous droughts the bulk supply has proven to be very reliable.
The current arrangements / volumes to remain in place for the 25 year planning period 2015 to 2040.
Shared resource agreements
R. Medway RZ7 SEW and PDO: 11.92 at PDO: 11.92 at PDO: 8.17 From Under the terms of the River Medway Scheme (RMS) (Bewl) SWS WRMP14 WRMP14 ADO: 4.25 2015/16 agreement, South East Water can take their entitlement at River retained retained through the Bewl Water and Burham WSW. Medway moving to moving to planning period The maximum volume of water that South East Water can scheme 10.42 once 10.42 once new RMS new RMS take at Bewl Water is governed by the abstraction licence (RMS) agreement agreement which was issued to Southern Water.
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and enabling and enabling work is work is The overall amount available to SEW from the supplies at delivered in delivered in Bewl and Burham is defined as 25 per cent of the yield of 2023 2023 the RMS.
ADO: 7.92 at ADO: 7.92 at As a drought situation develops the companies hold WRMP14 WRMP14 regular discussions to agree any restrictions or retained retained concessions for bulk supplies as triggers are met. moving to moving to 5.62 once 5.62 once The nature of the bulk supply will depend on how both new RMS new RMS companies are affected by any given drought. agreement agreement and enabling and enabling work is work is delivered in delivered in 2023 2023
R. Medway RZ6 SEW and PDO: 9.00 at PDO: 9.00 at PDO: 3.53 From See above for R.Medway (Bewl) (Burham) SWS WRMP14 WRMP14 ADO: 3.78 2015/16 River retained retained through the Medway moving to 4.50 moving to 4.50 planning period scheme once new once new RMS RMS agreement agreement and enabling and enabling work is work is delivered in delivered in 2023 2023
ADO: 8.18 at ADO: 8.18 at WRMP14 WRMP14 retained retained moving to 5.00 moving to 5.00 once new once new RMS RMS agreement agreement and enabling and enabling work is work is
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delivered in delivered in 2023 2023 Key: SEW – South East Water, SWS – Southern Water Services, RZ – Resource Zone, PDO – Peak Deployable Output, ADO – Average Deployable Output
* We discussed with Southern Water (for the purpose of testing our drought plan to a 1 in 500 year event, with a 0.2 per cent probability of occurring in any given year) a reduction in the yield of the Darwell bulk supply from 8 M/d to 4 Ml/d. We consider this best reflects the dialogue between the two companies of what the yield is likely be under such an extreme drought event.
** Affinity Water request that we retain 36 Ml/d as the outputs of the bulk supply under different drought condition at the present time, until it has completed testing the reliability of the transfer under different drought conditions – It expects to complete that testing shortly. For the testing of 1 in 200 year (0.5 per cent probability of occurring in any given year) and 1 in 500 year (0.2 per cent probability of occurring in any given year) drought events in our plan, we applied the lower figures included in brackets - these figures are based on factors applied to Affinity Water’s source outputs for the purpose of the Water Resources in the South East regional modelling work, 2017.
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Weir Wood It has been recognised by both Southern Water Services and South East Water that the Weir Wood contract is not specific enough to be effective under drought conditions, especially with regard to the pain share approach. How volumes available for this bulk supply will vary during any specific drought is indicated in Table 3.3, but will depend on a number of factors. These factors will include the relative status of available supplies, at the time and predicted in the future, and the demand restrictions in place for each company. It has been agreed between the companies that there will be a number of stages at which decisions with regard to the provision of supplies will be undertaken:
Under normal conditions, the volumes will remain at the full rates under the agreement; As trigger levels are approached, and possibly breached, there will be discussion as to whether the full agreement volumes can be provided. It would generally be expected that the deployable outputs in the water resources plan would still be available up to drought trigger level; As trigger levels are breached and the situation deteriorates, further discussion would take place in order to determine if some rateable reduction in volume can be managed.
It has been agreed that the trigger levels used for the management of Weir Wood are those used by Southern Water Services, which ensures that there is an equitable approach to the management of Southern Water Services’ available supplies. Principally, ongoing discussions for Weir Wood have involved the agreement of a single set of reservoir control curves and thus the potential drought trigger levels. We will continue to work with Southern Water Services to gain a better understanding of this bulk supply contract and its management under drought conditions.
Darwell Reservoir In accordance with the relevant Ofwat determination, the yield arising from the enhanced Bewl Darwell scheme is shared between South East Water and Southern Water Services in the respective proportions of 8/17 and 9/17 in case of drought (or restriction caused by other events).
Under non-drought conditions, South East Water is entitled to a standard supply of 8Ml/d at Darwell coming from a transfer from the Bewl reservoir. The current arrangement is that the Darwell reservoir is managed at a standard control curve level. Transfers will normally take place when Darwell reservoir is below its own control curve and Bewl is above its control curve. A second lower trigger control curve for the Bewl reservoir is used to determine when a pain share mechanism must be implemented.
When the Darwell reservoir is below its control curve and Bewl is below its trigger control curve, the available yield arising from the scheme as determined at the time is shared in the proportions of 8/17 for South East Water and 9/17 for Southern Water Services, subject to a minimum of 1Ml/d.
The bulk supply has been subject to review during 2016/17, with Southern Water Services and ourselves exploring a mutually beneficial option for water resources management plan 2019 that might involve our entitlement coming directly from Bewl Water in the future, rather than from Darwell reservoir.
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For this revised draft drought plan, and until such time any new arrangements are formalised, the existing bulk supply is retained as per existing contractual arrangements, with the scheme unchanged through to a formal review date in 2026.
Egham In non-drought conditions South East Water receives a standard supply of 36 Ml/d from Affinity Water. Under emergency operating conditions a proportional sharing arrangement is included in the contract which entitles South East Water to receive 36/103 of the quantity of water available at the treatment works.
There is not a formal drought pain share agreement for the bulk supply, but in previous droughts the bulk supply has proven to be very reliable.
Belmont Scheme We have a formal agreement from 1963 with Southern Water Services known as the Belmont Agreement. This relates to a defined proportion of output from the Belmont group of sources in the North Downs Chalk aquifer. Currently the agreed deployable output has been set at 6.8 Ml/d with a peak capacity of 7.4 Ml/d. The sources pump into the Eastling Treatment Works which outputs into a primary transfer main in north Kent. The water can be taken from various locations agreed with Southern Water Services along the trunk main, although it is typically taken from Matt’s Hill and Bottom Pond. The current agreement remains in force until 2023 and will then require renegotiation.
There is not a formal drought pain share agreement for the bulk supply, but in previous droughts the bulk supply has proven to be very reliable.
River Medway Scheme The River Medway Scheme (RMS) is a pumped storage scheme which abstracts River Medway water and stores it in Bewl reservoir. From the reservoir it can be obtained either directly as a raw output, or it is released and re-abstracted downstream at Springfield in Maidstone for treatment at Burham Water Treatment Works. We have a 25 per cent share in the overall scheme yield, and we obtain its yield either as a raw output from Bewl reservoir or as treated water output from Burham Water Treatment Works.
The overall scheme is managed and operated by Southern Water Services, with costs shared in accordance with the share of the yield. The level and operation of Bewl reservoir is against an agreed control curve which regulates the filling, abstraction and release of water at the reservoir. Agreements on pain-share during drought events are in place between the companies.
Further details relating to agreed deployable outputs are provided in Table 3.3.
3.2.4 Potential drought permit (DAPS6) and drought order sites (DAPS7) Drought permits can only authorise a water undertaker to take water from specified sources or modify or suspend restrictions or obligations to which that undertaker is subject; relating to the (existing) taking of water from any source i.e. they act to increase available supplies.
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Drought orders may go further than drought permits. They can deal with discharges of water, abstractions and discharges by people other than the undertaker affected, supply, filtration and treatment obligations. As mentioned in Section 3.1.5 they can also allow water undertakers to prohibit or limit particular uses of water.
Drought permits are judged by the Environment Agency and drought orders by the Secretary of State.
The water company’s drought permit application must demonstrate:
a serious deficiency of supplies of water in any area exists or is threatened; and that: the reason for the deficiency is an exceptional shortage of rain.
And, a drought order application must demonstrate that:
a serious deficiency of supplies of water in any area, exists or is threatened; or such a deficiency in the flow or level of water in any inland waterway to pose a serious threat to any flora or fauna which are dependent on those waters, exists or is threatened; and that the reason for the deficiency is an exceptional shortage of rain.
Both drought permits and drought orders can last up to six months, although this period can be extended to last up to a total of a year.
We would not undertake a drought permit/order application lightly. Triggers for drought permit/order applications are linked to drought status and are dependent on the type of drought permit/order being applied for. Further details on triggers are provided later in this Section 3.2.4. Pre-application discussions would be held with the Environment Agency and other key stakeholders to ensure preparations are made with regard to potential environmental effects and their monitoring and mitigation.
We have identified eight locations where drought permits/orders could be sought. Three of these relate to surface water activities and the other five to groundwater activities. The types and locations of the eight sites are set out in Table 3.4.
A map showing the drought permit/order locations can be found in the Appendix, please see Error! Reference source not found..
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Table 3.4 – Potential drought permits or drought orders
Drought Site* Environment South East Type permit Agency Water drought /order type region region (RZ) River Ouse South East Eastern (2) Surface water (Winter period: for use autumn - spring) (Ardingly Reservoir) Surface River Ouse South East Eastern (2) Surface water water (Summer period: for use only in summer) (Barcombe Mills) River Cuckmere South East Eastern (3) Surface water (Arlington Reservoir) Chasewood South East Eastern (1) Groundwater Balcombe South East Eastern (2) Groundwater Ground- Hackenden South East Eastern (2) Groundwater water Southlands & Oaklands South East Western (5) Groundwater Licence Change Halling No. 8 South East Eastern (6) Groundwater * Note – The sites have been categorised by type and ordered by Resource Zone number. They are not listed within a preferred or likely order of application. The order of application will be specific to the drought experienced.
Surface water sites Sub-options for each of the three surface water drought permits or drought orders to assist with reservoir water conservation or refill have been set out in Table 3.5. These drought permits/orders will be used during a moderate or severe drought in the Eastern (1-3) drought region, and also at the appropriate time of year (see column labelled ‘period’).
The trigger for these applications will be when the overall drought region status is moderate (or worse) and the individual reservoir control curves indicate a severe drought. Depending on the time of application preceding demand management actions DAP3 and DAP4 may or may not have been implemented.
For example, if the River Ouse (summer) Drought Permit is required during the May to end of October period, the DAPD3 (temporary use bans on water use) and DAPD4 (drought orders to restrict demand) will have been implemented before the application is made. The drought permit/order application is most likely to be when the drought region drought status is severe. However, if the same drought permit/order is required during the autumn or winter period, the DAPD3 and DAPD4 measures are unlikely to be in place because the demand savings are considered to be negligible over this winter period.
Table 3.5 – Potential drought permit or drought order options for reservoir sites Site Period Options* River Ouse Autumn - Maintain the MRF of 20 Ml/d but allow spring abstraction of everything above this up to the licensable limit
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Site Period Options* (Winter period: for Reduce the MRF to 15 Ml/d and abstraction of use autumn - only 45 per cent of the amount between 40 Ml/d spring) and 90 Ml/d up to the licensable limit Reduce the MRF to 10 Ml/d and abstract only 45 per cent of the amount between 40 Ml/d and 90 Ml/d up to the licensable limit Reduce the MRF to 10 Ml/d and abstraction of everything above this up to the licensable limit Reduce augmentation to 2 from 4 Ml/d Reduce augmentation to 1 Ml/d Extend the abstraction period by 2 months either side of the licensed period River Ouse Summer Maintain the MRF of 20 Ml/d but allow only abstraction of everything above this up to the (Summer period: licensable limit for use only in Reduce the MRF to 15 Ml/d and abstraction of summer) only 45 per cent of the amount between 40 Ml/d and 90 Ml/d up to the licensable limit Reduce the MRF to 10 Ml/d and abstract only 45 per cent of the amount between 40 Ml/d and 90 Ml/d up to the licensable limit Reduce the MRF to 10 Ml/d and abstraction of everything above this up to the licensable limit River Cuckmere Winter Reduce the MRF to 4.54 Ml/d from 9.09 Ml/d (Arlington) only (and no augmentation from Arlington) * Notes: The River Ouse drought permit sub-options have been grouped into two categories: winter period and summer period, to help clarify the potential options available at different times of year. This grouping replaces the original Upper and Lower Ouse drought permit sub-option groupings. There have been no changes to potential sub-options set out within our final drought plan 2013.
Groundwater sites It is likely that drought permit/order applications would only be made at the five groundwater sites in a worse than one in 200 year (0.5 per cent probability of occurring in any given year) drought event (termed a ‘severe’ drought in our scenarios presented in section 8.2). As a result, the applications are more likely to be for drought orders, as the resource situation is likely to be reaching critical levels by that point. In each case infrastructure complexity constraints have been identified which would require durations of several weeks to be factored in to the implementation process. Three of these sites (Chasewood, Hackenden, and Balcombe) are currently disused groundwater sources which have been used as supply sources in the past. The reasons for their disuse are typically due to poor yield and/or inadequate facilities to treat poor water quality. We no longer hold abstraction licences for any of these sources and so if they were to be brought back online, a drought permit/order would need to be granted. None of the applications would be to exceed previous licensed conditions and there are no restoring sustainable abstraction issues in any of the catchments. The potential for any permit to cause environmental impact is considered below. Information on WFD classifications for the applicable groundwater bodies can be found in Error! Reference source not found..
Southlands and Oaklands drought permit/order involves an increase of existing abstraction licences from the Hythe Beds formation. Two new boreholes were licensed
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within the last three years, but not to the full output quantities originally applied for as it was deemed unnecessary by the Environment Agency to support the average and peak supply in RZ5. A drought permit/order application would be made to allow us to be able to pump the original full quantity. The potential yield calculations on both of the boreholes indicate that they could abstract up to 4 Ml/d above the existing licence. Pumping tests of the confined boreholes have proved that there is no impact on surface water features.
In 2005, we drilled and tested the Halling No.8 borehole and proved a connection between adjacent quarry water and the chalk borehole water. The drought permit/order would be required to increase the existing Chalk licence to be able to take advantage of the connection and abstract the quarry water.
The trigger for the application of these five additional supply drought permits/orders will most likely be during the severe drought status, and definitely follow the implementation of demand management actions DAPD3 (temporary use bans on water use) and DAPD4 (drought orders to restrict demand).
Drought permits or drought orders and their likely use Table 3.6 ranks the sites in order of their likely use, taking into account deployable output, lead time, engineering cost / complexity, and environmental sensitivity and benefits. The three surface water sites are considered most likely to be used at a moderate or severe drought status whereas the groundwater sites are unlikely to be used until a severe drought status is reached.
Consideration of and subsequent application for drought permits/orders will be dependent not only on the level of resource status in relation to trigger curves, but also on the seasonality of when these levels approach or breach the trigger curves. As set out in Table 3.5 and Table 3.6, most of our proposed drought permit/order options are very season-specific.
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Table 3.6 – Potential drought permit or drought order options for additional supply sites
Benefit Lead time Engineering cost / Environmental Rank Option WRZ Type (Ml/d) (Months) complexity Sensitivity Benefit River Ouse Variable Yes (likely to remove (depending 1-2 for permit L-M (depending upon E(1-3)1 (Winter period: for 2 L need for permit upon permit application permit application) use autumn - following summer) application) spring)
ater 1-2 for permit E(1-3)2 River Cuckmere 3 4.6 L L n/a application
Surface w River Ouse Variable
(depending 1-2 for permit M-H (depending upon E(1-3)3 (Summer period: 2 L n/a upon permit application permit application) for use only in application) summer) E(1-3)1 Hackenden 2 1.0 6 - 12 L- M M n/a
E(1-3)2 Chasewood 1 1.5 6 - 12 M M n/a
ater Yes E(1-3)3 Balcombe 2 0.7 12 - 18 M M (augment flows) E(6-8)1 Halling No.8 6 2.0 6 - 12 M M n/a
Groundw Southlands & W(4-5)1 Oaklands Licence 5 4.0 3 - 6 L L n/a Change Key: Rank: 1 (highest priority) to 6 (lowest priority), W(4-5): Western Region (4-5), E(1-3): Eastern (1-3) Region, E(6-8): Eastern (6-8) Region, L: Low, M: Medium, H: High
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The environmental sensitivity scores have been derived as part of the environmental assessments for each drought permit/order (see Section 4 for further details). The low, medium and high sensitivities are defined as follows:
Low sensitivity - Where there is a good up-to-date ecological baseline and firm understanding of the local hydrology and as a result have a firm grasp of likely impacts, their nature and longevity. Drought permits/orders ascribed this category will have limited, short term ecological impact. For groundwater, this has been ascribed to systems which are highly confined in nature, and no surface water pathways in evidence (and hence no sensitive ecological pathways present).
Medium sensitivity - where the drought permit/order could result in localised impacts of a short term or temporary nature and the baseline/hydrological understanding is incomplete. Drought permits/orders within this category are unlikely to induce any long-term impacts (greater than one year).
High sensitivity - has been assigned to drought permits/orders in known ecologically sensitive areas which are dependent on surface water as part of their ecological importance and where the current ecological and/or hydrological understanding cannot rule out potential long term ecological impacts (i.e. greater than one year).
Other options and drought orders If other options (such as accelerating planned works) are identified under our review process during a developing drought status (see DAPS2), a drought order would need to be applied for. It is emphasised that we have made every effort to include all foreseeable options within this plan, however should alternatives become available we would advise the Environment Agency as soon as possible and would apply for a drought order.
Although application for a drought order to accelerate planned works is considered very unlikely, it would be applied for early, potentially during a moderate drought status. The timing of the application will depend on the implementation timescale of the scheme. It should also be noted that an application would only be made if the option has no or a low risk to the environment.
Environmental assessments Environmental statements have been completed for all eight of the drought permit/order sites and options. For further details; refer to:
Section 4.0 – for a summary of the environmental assessment. Appendices: Error! Reference source not found. to Error! Reference source not found. for the actual reports and conclusions. These have not been published with the revised draft drought plan as they are restricted due to reasons of security and concerns around disclosure of operational site information. They can be viewed at our offices on request.
The environmental screening only considers aspects relating to the change in abstraction. Additional environmental assessments would be required and would follow our planning and environmental strategy.
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Other information As described within the Drought Permits and Drought Orders Defra guide 2011, we would be liable to pay compensation to ‘people who suffer loss or damage as a result of a drought permit’ as set out within the rules of Schedule 9 to the WRA 1991. We do not consider that they would be liable for compensation payments for the use of any of our proposed drought permits/orders, however should we receive a claim in relation to this type of drought action the claims process would be followed through.
3.2.5 Emergency drought planning procedures (DAPS8) We have an emergency plan which would be activated in exceptional circumstances, for example, if the severity of the drought was such that we could no longer maintain a secure supply to all our customers. At this point we will have implemented all the feasible actions in our drought plan.
We would work with relevant emergency planning bodies to manage the situation and would ensure that our emergency plan is compatible with other relevant emergency plans from neighbouring water companies and Local Authorities.
During a moderate drought, the plan would be reviewed and in a severe drought, plans would be put in place to prepare for activation, should the need arise. Demand side emergency drought order preparation would form part of the planning process. For further information on the actions we would take to communicate with our stakeholders during emergency planning phase see Section 6.2.7.
3.2.6 Emergency drought orders (DAPS9) Where emergency drought orders are concerned, the Secretary of State must be satisfied both that:
by reason of an exceptional shortage of rain, a serious deficiency of supplies of water in any area exists or is threatened; and that: the deficiency is such as to be likely to impair the economic or social well-being of persons in the area.
Emergency drought orders are more extensive than environmental drought orders. Abstraction restrictions can be further relaxed and importantly the water undertaker would have complete discretion on the uses of water that may be prohibited or limited, and it can authorise supply by stand-pipes, rota cuts or the use of water tanks. Preparation for the use of an emergency drought order would take place when initially reviewing emergency drought planning procedures at a Moderate drought status. An application would not be made until in a severe drought status. These are extreme actions and by this stage it would be anticipated that the drought situation would have to be recognised nationally by Government for these actions to be introduced and implemented. An emergency drought order is granted for three months and can be extended for an additional two months.
Given their severity, it is of paramount importance that water companies do everything within their powers to avoid the use of emergency drought orders. It is understood through consultation with the Environment Agency that ‘potentially damaging environmental drought orders’ should be considered as a further action prior to the application for an emergency drought order. We explore the frequency of implementation of emergency drought orders further in section 8, but from the analysis
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undertaken for this revised draft drought plan, we consider the potential risk of needing recourse to emergency drought orders is incredibly remote and would most likely only be considered under very extreme droughts (such as the one in 500 year drought event with a probability of occurrence of 0.2 per cent in any given year).
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3.3 Drought actions summary
Table 3.7 summarises the groups of actions that will be taken during the different drought statuses. To provide a comprehensive overview (in addition to the drought management supply and demand side actions) the table also sets out the associated actions related to environmental monitoring and communications.
We do not consider it appropriate to set a predetermined schedule for the implementation of every action (within the drought status groups of actions), because the timing, severity, nature and extent of drought can be dramatically different. There is a need for flexibility so that we can have a practical and timely response in a developing drought situation. Our Drought Management Team will also target the most at-risk resources and their supply areas within each drought region when implementing the drought region actions.
In terms of the order of implementation of our drought actions, the Environment Agency (2017) states that "The water company will also need to demonstrate that it has implemented additional water conservation measures before making an application [for a drought permit/order]." Table 3.7 sets out in detail all the water conservation measures we intend to implement at the different stages of a drought, such as enhanced leakage reduction, additional promotion of water efficiency, and restrictions on water use. We acknowledge the importance of managing demand before placing additional demands on the environment during a drought event, but feel it is important to recognise that certain demand management actions will have limited effect at particular times of year, e.g. temporary use bans that primarily target discretionary uses of water such as garden watering are less likely to result in demand savings if they are implemented as a result of trigger breaches during winter months. However, our approach ensures we are able to impose in a timely way appropriate demand management measures that reflect seasonal effectiveness.
It is important for us to be able to manage a drought as it recedes as well as when it advances. The triggers outlined in Section 2 can be used in a similar fashion to monitor and determine the de-escalation of a drought event. The recession of the drought and the lifting of restrictions or stopping of actions is discussed further in Section 7. A summary of post drought actions is shown in Table 3.7, but further details of the review process can also be found in Section 7.
Details for all of the demand and supply drought management actions are presented in proformas (See Error! Reference source not found.), as set out in the Water Company Drought Plan Guideline (Environment Agency, July 2015). The proformas include an approximation of the demand savings or deployable outputs, triggers for implementation, implementation times, and risks for each action. For the supply side actions, there is also a summarised version of the environmental assessment.
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Table 3.7 – Drought management actions: summary table Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) Routine Operational performance Promote water Regular South East Water Via WRSE Comms Regular No action WRSE WRSE Prepare and Routine and and output monitoring efficiency updates website updated Group and meetings communicati communication release press Baseline activities given on the Proactive WaterUK check with ons s statements environmental Routine standard groundwater, water communication situation/messages Wholesale monitoring surface water and rainfall Core brief to resources during Customer of other water Service Updates in Updates in Proactive monitoring include water situation Metering companies Desk “The Source” “The Source” press resource Programme (CMP) (newsletter) (newsletter) releases
Monthly Water Resources & update If necessary Updates to non- Environmental Department update on “Great water butt household retailers Updates to Promote Report. Ensure briefed South East giveaway” and water Local website via on the water Water’s efficiency Resilience social media Monthly production planning situation situation via promotions via Forums meeting. messages letter/email billing information
Updates in Summer roadshow Normal Operation Normal “The Source” and school (newsletter) education/ community talk programme
Save Water South East promotions Social media DEMAND SIDE ACTIONS: Core Brief Inform Updating the South Via WRSE Comms Regular No action WRSE WRSE Prepare Update ecological DAPD1: Water conservation message Environment East Water website Group and meetings stakeholder stakeholder press records from County campaigns and calls for voluntary Agency of homepage and WaterUK check with newsletter newsletter statements Record Centre, restraint. Intranet update drought water resources situation/messages Wholesale Environment Agency to link through status pages of other water Service Update via Proactive and Natural England DAPD2a: Continue active leakage to website companies Desk “The Source”. press control and plan for enhanced information Instigate Pledge campaign releases to Assess current leakage detection programme. regular posters Begin drought Update Local stimulate environmental Initiate pressure management to MD Briefings to meetings related Resilience increased TV condition against reduce demand. Review of water include water with WRSE website communication Forums and radio baseline conservation schemes. resources and Environment with neighbouring coverage raise Agency and Proactively Water Companies Commence Awareness raising DAPD3a: Prepare for understanding Water approach events for (see Section 3.2.3 discussions Start a water with Natural England
Developing Drought Developing implementing temporary bans on in the business Companies summer roadshow for further details with local efficiency and local water use. in the South and on bulk supply / authorities blog and environmental Implement East schools/community shared use with regard to promote groups DAPD4a: Consider and review Customer groups for talks communications) watering messages Drought Order (to restrict Service Update regimes for via Twitter demand) application. competition to Natural
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) SUPPLY SIDE ACTIONS: encourage England at Update the Updates to non- parks and Use DAPS1a: Optimise operations to promotion of monthly school/community household retailers gardens “Wanted” conserve supplies where water efficiency meetings talk slides and brief poster deployable output is threatened. devices speakers campaign in Improve the efficiency of the Inform DWI local network to distribute water Briefing to field of drought newspapers between connections and staff via Team status (4 week resource zones. Briefs campaign) Keep and local DAPS2a: Consider infrastructural Prepare training updated on radio adverts connectivity or source material for staff situation via improvements, and / or accelerate regarding email. planned works, including: lowering Temporary Use of borehole pumps, source Ban enhancements e.g. rehabilitation or installing new production boreholes, water treatment works enhancements or development and network improvements.
DAPS3a: Review disused sources and consider if there are any which could be reinstated (that South East Water has an abstraction licence for). Plan for bringing online.
DAPS4: Seek extension to existing bulk supplies above existing agreements, within all resource zones.
DAPS5: Consider options for new bulk supplies, and progress if feasible, within all resource zones
DAPS6a: Consider and review Drought Permit application(s).
DAPS7a: If appropriate - Consider Drought Order (to vary licences linked to accelerating planned works) application.
DEMAND SIDE ACTIONS: Core Brief Continue Updating the South Via WRSE Comms Regular Ask Retail Letter/Email Letter/Email Prepare Undertake protected DAPD2b: Implement enhanced message regular East Water website Group and meetings companies press species surveys on leakage detection programme to meetings homepage and WaterUK check with to begin site Update Local statements. potential Drought reduce leakage, undertake site Intranet update with water resources situation/messages Wholesale visits to Resilience Permits and/or
Drought Moderate Moderate visits to high demand commercial to link through Environment pages high Forum Drought Orders
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) users and complete more water to website Agency and of other water Service demand Proactive efficiency audits. information Natural Set up dedicated companies Desk commercial press Review and update England to telephone line users to releases environmental DAPD3b: Consider implementing Q&A’s for update on Updates to non- help reduce Joint press statements within temporary bans on water use employees drought Add message to household retailers demands conference if permit applications Phase 1 options. development phones required – Members of the (also provide Work with non- Friston Update monitoring DAPD4b: Consider and prepare Drought Environment Direct mail about household retailers borehole and mitigation plan Drought Order (to restrict Management Agency with situation - site visits to high media day. demand) application. Team to attend data demand Awareness raising SUPPLY SIDE ACTIONS: Team Briefs exchange) Summer roadshow commercial users Advertising with Natural England DAPS1b: Review of operational across the and school to help reduce campaign and local use and the delivery programme, company Keep education/communit demands “Let’s Save environmental to include: updated on y talk programme it” groups Deferring any non-essential Posters up situation via maintenance programmes and around offices email Update WRSE Continue Temporary further optimisation of operations website communication Use Ban – to conserve supplies. Roll out staff Give with neighbouring notices and training on CCWater full Update website Water Companies press release DAPS2b: Full development of Temporary Use briefing (see Section 3.2.3 feasible infrastructural Ban ahead of any for further details Radio connectivity or source restrictions on bulk supply / adverts to improvements, and / or accelerate Login alert and shared use begin planned works. email to all staff Inform DWI communications) following the of drought two week DAPS3b: Reinstate disused status and consultation sources (that South East Water convey and media has an abstraction licence for). relevant days information DAPS7b: If appropriate - Create a Consider and prepare Drought Twitter Order (to vary licences linked to Hashtag accelerating planned works) campaign to application. get increase strength of DAPS6b: Consider and prepare messaging Drought Permit application(s). DAPS8a: Review and consider emergency planning procedures for a drought. DEMAND SIDE ACTIONS: Core Brief Consult with Updating the South Via WRSE Comms Regular Update on WRSE WRSE Prepare Undertake protected DAPD3c: Consider implementing message Defra if a East Water website Group and meetings South East stakeholder stakeholder press species surveys on temporary bans on water use drought order homepage and WaterUK check with Water and newsletter newsletter statements potential Drought
Drought Drought Phase 2 options (when demand Intranet update application is water resources situation/messages Wholesale WRSE Permit/ Order sites if trigger exceeded and/or when to link through necessary. pages of other water Service website Updates to 1-2-1 meetings not already updated. application submitted for Drought to website companies Desk targeting Local Proactive Order (to restrict demand)). information Increase the Pledge campaign businesses Resilience press Update
Moderate Moderate or Severe Drought or Severe frequency of posters and stickers Forums releases environmental
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) DAPD4c: Apply for and Staff meetings Continue Water audit statements within implement Drought Order (to “roadshow” with Envelope branding communication promotion Drought Publication of permit applications restrict demand) (timing depends Environment with neighbouring Forums official on how rapidly the drought is Agency and Updates on South Water Companies Through notices as Update monitoring progressing). Natural East Water and also (see Section 3.2.3 Retailers - required for and mitigation plan SUPPLY SIDE ACTIONS: England to the WRSE website for further details Write to all any drought DAPS2c: Commissioning of update on on bulk supply / non- order Awareness raising feasible infrastructural drought Arrange for South shared use household with Natural England connectivity or source development. East Water vehicles communications) customers Further radio, and local improvements, and / or accelerate This is likely to be branded with newspaper environment groups planned works – it is likely to take to involve water message Update on South Hotel cards and possible several months to complete site discussions East Water and and shower TV Implementation of works. Depending on when works about Water Watch stickers agreed monitoring start the status may be Moderate potential website targeting promotion. and mitigation or Severe. Non- businesses Sally protocol on granting Essential Shower of permit DAPS7c: If appropriate – Apply Use Bans, Work with non- timers to for and implement a Drought and Drought household retailers hairdresser Order (to vary licences linked to Permit to promote water s accelerating planned works) applications. audit programmes application (timings depend on the (Also provide duration required to develop Environment works options). Agency with data DAPS6c: Apply for and exchange) implement Drought Permit(s) .Drought permits for winter refill Keep may need to be applied for during updated on Moderate Drought. Drought situation via permits for summer conserving email supplies or additional supplies will not be applied for until Severe Inform DWI Drought, temporary bans and of drought Drought Order (to restrict demand status and have been implemented). convey relevant information SUPPLY SIDE ACTIONS: Core Brief Consult with Updating the South Via WRSE Comms Regular Updates on WRSE WRSE Prepare Undertake protected DAPS6d/7c: Continue to message and Defra if a East Water website Group and meetings South East stakeholder stakeholder press species surveys on consider, prepare, apply for and update Q&A’s drought order homepage and WaterUK check with Water and newsletter newsletter statements potential Drought implement further Drought Permit for staff or water resources situation/messages Wholesale also the Permit/ Order sites if / Order application(s). emergency pages of other water Service WRSE Update Local Proactive not already updated. Members of the drought order companies Desk website Resilience press DAPS9a: Apply for Emergency Drought application is Begin Enact “Water Forum releases Update Drought Orders Management necessary. Drama” Continue Retailers environmental
Severe Drought Severe Team to attend communication will increase Publication of statements within DAPS8b: Plan for emergency Team Briefs Continue Loud hailers with neighbouring water official permit applications situation frequent Customer mailshot Water Companies notices as
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) across the meetings (see Section 3.2.3 efficiency required for Continue to update company with Updates on South for further details activities any drought monitoring and Environment East Water and also on bulk supply / order mitigation plan Posters up Agency and the WRSE website shared use around offices Natural communications) Further radio, Awareness raising and login alert England to newspaper with Natural England and email to all update on Updates to non- and possible and local staff and drought household retailers TV environment groups roll out staff development. –ongoing training on non- This is likely promotion of water Implementation of essential use to involve audit programmes agreed monitoring ban discussions and mitigation about further Updates on South protocol on granting Intranet update Drought East Water and of permit to link through Permit also the WRSE to website applications website information that South East Water is preparing. (Also provide Environment Agency with data exchange)
Keep updated on situation via email
Inform DWI of drought status and convey relevant information
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) SUPPLY SIDE ACTIONS: Daily briefings Consult with Details and example Via WRSE Comms Regular Details and Notice of Notice of Extensive Continue Emergency drought actions as per to all Defra over of how customers Group and meetings example of implementati implementatio radio and TV environmental the South East Water Emergency employees emergency can continue to save WaterUK check (probably how on of n of notification of monitoring and Plan. drought order water situation/messages daily at this customers emergency emergency areas to be mitigation where DAPS9b Implement Emergency applications. of other water stage) with can drought drought orders affected by feasible. Drought Orders Progress on how companies. Wholesale continue to orders supply cuts Notice of company is Service save water Explaining the implementati implementing new Updates to non- Desk Explaining areas covered Local media on of supplies and household Progress on the areas by restrictions advertising emergency maximising retailers. how covered by and how to with maps, drought efficiency company is restrictions find if within summary of orders Details and implementin and how to affected areas restrictions, Explain intention to example of how g new find if within penalties Explaining enforce bans and non-household supplies affected Explanation of the areas the penalties for customers can and areas areas to be covered by non-compliance continue to save maximising affected by restrictions water efficiency Explanation emergency and how to Web based maps of of areas to drought orders find if within the areas likely to be Continue Explain be affected and rota cuts affected affected by rota cuts communication intention to by areas to supply and web with neighbouring enforce emergency based gazetteer so Water Companies bans and drought Explanation customers can (see Section 3.2.3 the orders and of areas to locate their property for further details penalties for rota cuts
Emergency Planning Emergency be affected on bulk supply / non- by shared use compliance. emergency communications) drought Web based orders and maps of the rota cuts areas likely to be Inform DWI, affected by Environment rota cuts to Agency and supply and Natural web based England of gazateer so drought customers status and can locate convey their relevant property information
DEMAND SIDE ACTIONS: Full briefing to Briefings to Update website to Update website to Briefings to Update WRSE WRSE Return to Continue to update DAPD3/4: Lift temporary ban confirm South confirm back confirm return to confirm return to confirm website to stakeholder stakeholder normal monitoring and restrictions and Drought Orders. East Water is to normal normal operations normal operations back to confirm newsletter/Th newsletter/The conditions mitigation plan SUPPLY SIDE ACTIONS: back to normal operation. normal return to e Source e- Source e-
Drought Drought DAPS6/7: Remove Drought operation Include messages Updates to non- operation normal newsletter newsletter Complete any
Recession / Recession
Post Drought Post Permits and Drought Orders. about the drought household retailers operations environmental post
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Drought Operational and management Communications Actions zone actions Water Customers Environmental Internal Household Non-household Key Regulators companies (non- Community Media actions employees customers customers stakeholders (retail) household) Stop other demand side and Core brief, Review of and lessons learnt in Review of Update Local drought monitoring supply side actions. Apply for Team brief and lessons next customer billing Continue normal lessons Retailers to Resilience required. abstraction licences or variations Spout! article learned communications routine learned write to all Forum to existing licences for any communications commercial Continue to update accelerating planned works Focus groups Meetings to Carry out final with Affinity Water Meetings to customers monitoring and brought online during the drought. and staff discuss evaluation efforts and Southern discuss to advice mitigation plan surveys to get approaches Focus groups and Water Services approaches back to DAPS2a: Consider infrastructural opinions surveys regarding bulk normal connectivity or source supplies and improvements, and / or accelerate shared use Carry out planned works, including: lowering arrangements final of borehole pumps, source output evaluation enhancements e.g. rehabilitation efforts or installing new production boreholes, water treatment works enhancements or development and network improvements. Internal review of drought activities to include: Interventions, Triggers, Decisions taken, Lessons learnt, Updating of the drought plan
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4 ENVIRONMENTAL IMPACTS
4.1 Introduction
In accordance with the Environment Agency Drought Plan Guideline, (Environment Agency, December 2015) we have made an assessment of the environmental impacts of the drought plan actions, and have proposed monitoring plans to measure the impacts.
There have been some changes to the drought plan actions since the issue of the previous drought plan in 2013. Our former final drought plan (2013) included drought permit/order options for the Cowbeech and Sedlescombe sources. We decided not to take these options forward as part of this revised draft drought plan. We have consulted with Natural England about both of these option changes and they have confirmed that they are in support of the approach taken.
In accordance with ODPM ‘A Practical Guide to the Strategic Environmental Assessment Directive (2005)’, we consider that a Strategic Environmental Assessment SEA) is not required for this update of the drought plan. We consider the drought plan to be a temporary operational plan which does not set a framework for the future development consent of projects within Annexes I and II to the EIA Directive. We have carried out a Habitat Regulations Assessment (HRA) ‘screening exercise’ for this for this revised draft drought plan to demonstrate that there will be no significant effects on European sites for any of the eight drought permits/orders either on their own or in combination. This assessment can be found in Error! Reference source not found.. Natural England and the Environment Agency were informed of the level of detail within this assessment during its preparation. Following our screening appraisal, we consider that no further HRA assessment beyond this screening is required.
We considered environmental impacts for all options within the drought plan, and completed environmental assessment where appropriate. We have a duty under Regulation 9(5) of the Conservation of Habitats and Species Regulations 2010 to have regard to the requirements of the Habitats Directive. The environmental baseline data collected as part of this assessment is being updated alongside the plan.
Based on our assessment, we have concluded that there are no likely significant effects on European designated sites. In addition to this we also have a duty under the Wildlife and Countryside Act 1981 (as amended by the Countryside and Rights of Way Act 2000) to consider conservation and enhancement of Site of Special Scientific Interest (SSSI) features. SSSIs have been considered throughout the environmental assessment process for all drought permit sites. We have concluded that there are no likely significant adverse effects on SSSIs. Under section 40 of the Natural Environment and Rural Communities Act 2006 water companies are to act to conserve biodiversity through restoring or enhancing population or habitat. Protected species have been taken into account during the environmental assessments and risks to the environment have been (and also will continue to be) taken into account of when prioritising drought plan options for implementation.
As part of preparing the draft drought plan South East Water was asked to consider eel and fish passage impacts with respect to the drought permit/order options. This is
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only considered relevant to the River Ouse Drought permits/orders and is considered in detail in the environmental assessment in Error! Reference source not found. and also in an Eel passage summary document in Error! Reference source not found..
4.2 Assessing the risks to the environment
Each supply side drought management action was first assessed as to whether there was a requirement for an environmental assessment of the likely impacts from implementing the action. The findings are set out in Table 4.1.
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Table 4.1 – Supply side drought management options summary table
Supply side drought management Risk to Environment Need for environmental assessment Y/N option DAPS1 Operational works None No perceived risk to environment DAPS2 Infrastructural connectivity and Unknown – depends on specific scheme identified Yes - Environmental assessments will be undertaken as and when the source improvements scheme is identified as part of the full development of planned works. Insufficient scheme information is available at present. DAPS3 Reinstate disused sources (for Unknown – risks are unlikely because source would have been in which South East Water holds an recently use. abstraction licence) DAPS4 Seek extension to existing bulk Assumed to be low – if within existing abstraction licence condition (or by Environmental assessments will be agreed and undertaken as part of supplies above existing agreements using a Drought Permit). If a Drought Order is required the risk could be the agreement with the donor company during a drought event if a higher. feasible option is identified DAPS5 Consider options for new bulk Assumed to be low – if within existing abstraction licence condition (or by Treated or raw water will be abstracted within existing abstraction supplies and progress if feasible using a Drought Permit). If a Drought Order is required the risk could be licence (or extended by use of Drought Permits and Orders). higher. Environmental assessments will be undertaken as part of the agreement as the scheme becomes further defined. DAPS6 drought permit/order applications Unknown - potential risk Yes. Environmental assessment included below, see Section 4.3. DAPS8 Emergency planning procedures None No - no perceived risk to the environment for a drought DAPS9 Potentially damaging South East Water has not identified specific sites where abstractions Yes – an Environmental assessment and potentially an HRA would be environmental drought orders (supply- could be increased above licensed quantity (for this emergency stage of required in the event of this type of emergency drought order. However, side), and emergency drought orders a drought) because it is likely that the only available sites will be those South East Water has not identified any specific sites where emergency (demand-side) which may cause environmental damage. drought orders would be considered, therefore there is currently no perceived risk to the environment. For demand type actions under an emergency drought order (i.e. No - A reduction in demand would be beneficial as less water would standpipes and rota cuts), the risk is none. need to be abstracted.
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Only the drought permit /order applications have been currently assessed in terms of their environmental impacts. The other schemes are either considered to have no environmental risk or cannot be assessed until schemes are identified during the drought review process and details become more clearly defined. 4.3 Environmental assessment of drought permits/orders
Three surface water drought permit/order options (DAPS6) were previously included with the South East Water drought plan (2013), and Johns Associates completed ecological assessments for these sites (Upper Ouse at Ardingly, the Lower Ouse at Barcombe and the Cuckmere at Arlington) in 2012. Following the 2010-2012 drought the River Ouse environmental baseline has been fully updated by Johns Associates (see Appendix Error! Reference source not found.). The ecological baseline for all drought permit sites was further updated by Johns Associates in the autumn of 2016, and this baseline was updated in spring 2017 to provide information that has been used to update the revised draft drought plan. There has not been a significant change observed in the baseline data collected in autumn 2016 as part of this update when compared to previous survey information. As a result, the findings of the 2013 environmental assessment are considered to be unchanged and the monitoring and mitigation suggested will remain the same as in the previous drought plan.
The River Ouse drought permit/order environmental assessments are now presented as two templates; one for a winter period application and a second for a summer period application (see Appendix Error! Reference source not found.). As in the 2013 drought plan the River Ouse drought permits/orders are separated into two forms of drought permits/orders in terms of their period of use; instead of continuing to use the original ‘Upper’ and ‘Lower’ names (which were considered potentially confusing). The template environmental assessments provide two examples of the types of drought permit/order that could applied for on the River Ouse. The other sub-options which we could apply for are listed in Table 3.5. These are considered to have lesser environmental impacts than the two options used in the templates.
The Cuckmere drought permit/order baseline was updated during the process of preparing the September 2011 draft drought plan (South East Water, 2011). The drought permit/order is considered to have a low environmental sensitivity and is therefore considered a relatively low risk option. The baseline for the Cuckmere Drought permit/order was considered adequate by the regulators and therefore did not require updating as part of the final drought plan. This approach has also been followed for the 2017 draft drought plan. Johns Associates prepared a template environmental assessment for this drought permit in 2012 (see Appendix H) which includes details of the updated baseline from the draft drought plan which has been further updated for this version of the Plan. The triggers for using these surface water drought permits/orders are linked to the specific reservoir control curves for the Eastern (1-3) drought region. They would not be applied for until that region is between developing and severe drought. It is very unlikely that a summer drought permit/order application would be made until a severe drought trigger had been crossed.
The five groundwater drought permit/order options (DAPS6) are considered to be very unlikely to be required before the severe stage of drought. Each option is constrained by infrastructure, quality, and volumes that can be abstracted. Further details on their constraints and their prioritisation for implementation can be found in Table 3.6. We have collected ecological baseline data for these sites in autumn 2016 and
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environmental assessments have been prepared by Johns Associates. The environment baseline was further updated in spring 2017. The environmental reports for these drought permits/orders are included in Error! Reference source not found. to Error! Reference source not found..
In Sections 4.3.1 to 4.3.2, summary details (including environmental baselines and impacts) for the eight drought permit/order environmental assessments have been presented in turn. These sections should be read in conjunction with the details on potential operation of drought permit/order sites included in Section 3.2.4
The monitoring and mitigation plans for all eight drought permits/orders are presented later in Section 4.4.
An assessment of potential impacts to Sites of Special Scientific Interest (SSSIs) as a result of drought permit/order operation has also been undertaken as part of the drought plan. SSSIs within 5km of drought permit/order sites were considered in terms of their hydrological connectivity and the presence of water dependent features. The majority of sites were screened out due to a lack of hydrological connectivity to permit/order operations.
Further investigation was undertaken of West Dean Brooks, which form part of the Seaford to Beachy Head SSSI, Milton Gate Marsh SSSI and Arlington Reservoir SSSI which are in hydrological connectivity to the River Cuckmere and Offham Marshes SSSI and Lewes Brooks SSSI which are in hydrological connectivity to the River Ouse (Ref: River Cuckmere Drought Permit Application: Ecological Assessment, Entec 2006) and (Ref: River Ouse and River Cuckmere Drought Permits: Review of Hydrological Functioning of SSSIs and Potential Impacts, Entec 2004). It was agreed with Natural England that operation under a drought permit/order would not cause impacts to these sites.
On the Ouse, both the Offham Marshes and Lewes Brooks SSSIs are hydrologically independent of the river, and as such any upstream reduction in MRFs will have negligible impacts on the sites. Neither site receives direct inflows from the Ouse although there may be small amounts of seepage under the tidal flood banks. The SSSIs are also adjacent to the tidal reach of the Ouse and so although there may be a reduction in fresh water flows, the levels will be largely controlled by the tide and unlikely to be significantly affected by the drought permit/order.
In the case of Milton Gate Marsh SSSI it was found that the reduced MRF would not affect flood flows and therefore the influence of the drought permit/order on the hydrological functioning of the SSSI was not thought to be significant. For the West Dean Brooks, it was considered that these were impacted through groundwater flows and the operation of Milton Lock and as a result would not be impacted by the operation of a drought permit/order. It was agreed with Natural England that operation under a drought permit/order would not cause impacts to these sites.
Table 4.2 summarises the screening assessments for all groundwater SSSIs within a 5km radius of the drought permit/order sites. Table 4.3 summarises the screening assessments for the surface water permit/order sites on the Ouse and Table 4.4 summarises the screening assessments for the surface water permit/order sites on the Cuckmere.
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Designated sites within 5km of drought permit/order locations are presented in Appendix C.2.
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Table 4.2 – Groundwater drought permit/order Site of Special Scientific Interest source pathway receptor analysis Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest Halling Halling to Chalk grassland and beech NO 0.5 km NW Depending on NO No. 8 Trottiscliffe woodland on chalk. distance and Escarpment Outstanding assemblages of elevation, there may SSSI plants and invertebrates. be a hydrological relationship. However, the habitats are typically found on freely draining soils and as such groundwater will not be a critical factor in their ongoing resilience and success. Halling Holborough to Floodplain habitat of the tidal YES 1.7 km SE This is possible NO No. 8 Burham Medway including reedbeds, because of the Marshes SSSI open water, fen, grassland, presence of more scrub and woodland. Supports permeable strata. a wide variety of breeding birds However, the small and is also important for quantity being wintering wildfowl and waders. abstracted is highly unlikely to have a drawdown cone affecting surface habitats beyond 1km. This SSSI is located
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Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest beyond this distance, with intervening tidal creeks and a hydrological/hydrologi cal relationship will not be evident. Halling Houlder and Sediments found provide NO 1.1 km SW This is possible NO No. 8 Monarch Hill lithostratigraphic/ because of the Pits SSSI biostratigraphic evidence for presence of more environmental changes during permeable strata. the Late Devensian. However, the small quantity being abstracted is highly unlikely to have a drawdown cone affecting exposed geological features to the point where accelerated weathering occurs. Balcomb Worth Forest Ancient Wealden ghyll YES 1.5 km N This is possible NO e SSSI woodland which is an example because of the of a base-poor springline alder presence of more wood, supporting a range of permeable strata. water dependant plants. However, the small quantity being abstracted is highly unlikely to have a
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Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest drawdown cone affecting surface habitats beyond 1km. This SSSI is located beyond this distance and a hydrological/hydrologi cal relationship will not be evident. Cow Wood & Ancient woodland with several YES 1.9 km SW This is possible NO Harry’s Wood moist ghylls that have a moist because of the SSSI warm microclimate favouring presence of more ‘Atlantic’ bryophytes and ferns. permeable strata. Ponds are also present which However, the small are important for dragonflies. quantity being The SSSI supports a rich abstracted is highly community of breeding birds. unlikely to have a drawdown cone affecting surface habitats beyond 1km. This SSSI is located beyond this distance and a hydrological/hydrologi cal relationship will not be evident.
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Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest Tangier/ Eridge Park Parkland and ancient YES 1km SW NO. ABSTRACTION NO Chasew SSSI woodland particularly rich IS CONSIDERED TO ood range of epiphytic lichens. BE FROM A Varied habitats CONFINED SOURCE also support diverse insect and bird communities, and it is recognised as being nationally important for dragonflies. .
Southlan Shortheath Mires and bog habitats, YES 1.5 km N NO. ABSTRACTION NO ds and Common SSSI together with dry heath and IS CONSIDERED TO Oakland (part of bog woodland. Significant BE FROM A s Shortheath populations of invertebrates CONFINED SOURCE Common SAC) including important assemblages of dragonflies and butterflies. Wick Wood Woodland with slopes, rich in NO 0.9 km NW NO. ABSTRACTION NO and Worldham vascular plants, bryophytes IS CONSIDERED TO Hangers SSSI and old pollards. BE FROM A (part of East CONFINED SOURCE Hampshire Hangers SAC)
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Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest Coombe Wood Woodland with slopes, rich in NO 0.9 km NW NO. ABSTRACTION NO and The Lythe vascular plants, bryophytes IS CONSIDERED TO SSSI (part of and old pollards. BE FROM A East CONFINED SOURCE Hampshire Hangers SAC)
Woolmer Wet and dry heathland, YES 1.7km SE NO. ABSTRACTION NO Forest SSSI valley bogs, broad IS CONSIDERED TO (part of leaved and BE FROM A Woolmer coniferous woodland, CONFINED SOURCE Forest permanent grassland and SAC/SPA) open water. The only site in Britain known to support all twelve native species of reptiles and amphibians and supports a nationally important heathland flora, with associated birds and invertebrate fauna.
Binswood Habitats include acidic poorly NO 0 NO. ABSTRACTION NO SSSI drained unimproved pasture IS CONSIDERED TO with scattered old oaks and BE FROM A beeches, areas of denser CONFINED SOURCE woodland with a sparse
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Drought SSSI name Reason for notification Presence of Distance from Hydrological / Potential for permit/ water sensitive abstraction hydrogeological significant order features of (km) pathway impact site interest shrub layer and ground flora, and former encoppicements now open to grazing. Very rich invertebrate assemblage.
Wick Wood Woodland with slopes, rich in NO 0.9 km NW NO. ABSTRACTION and Worldham vascular plants, bryophytes IS CONSIDERED TO Hangers SSSI and old pollards. BE FROM A (part of East CONFINED SOURCE Hampshire Hangers SAC)
Shortheath Mires and bog habitats, YES 0.4 km SE NO. ABSTRACTION NO Common SSSI together with dry heath and IS CONSIDERED TO (part of bog woodland. Significant BE FROM A Shortheath populations of invertebrates CONFINED SOURCE Common SAC) including important assemblages of dragonflies and butterflies.
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Table 4.3 – River Ouse Site of Special Scientific Interest source pathway receptor SSSI name Reason for Distance from Presence of Hydrological / Potential for notification abstraction (km) water hydrogeological significant sensitive pathway impact features of interest Asham Quarry Geological. Key site 8km from point of NO NO – no hydrographical NO for quaternary abstraction connection indicated studies, key (downstream) using EA flood zone and reference site for surface water extent biostratigraphical mapping. and lithostratrigraphical evidence. Primarily geological. 15km from point NO NO – no hydrographical NO Brighton to Newhaven Cliffs It is a nationally of abstraction connection indicated important reference (downstream) using EA flood zone and section for the upper surface water extent Cretaceous. Locally mapping. important colony of breeding seabirds, a diverse community of beetles, and pockets of unimproved chalk grassland. Buxted Park Biological. Diverse 8km point of NO NO – no hydrographical NO variety of abstraction connection indicated unimproved (upstream) using EA flood zone and grassland surface water extent communities, the mapping.
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SSSI name Reason for Distance from Presence of Hydrological / Potential for notification abstraction (km) water hydrogeological significant sensitive pathway impact features of interest site is of exceptional importance for the conservation of invertebrates. Clayton to Offham Escarpment Biological. Good 4km from point of NO NO – no hydrographical NO quality chalk abstraction connection indicated grassland habitat is (downstream) using EA flood zone and prevalent and the surface water extent site supports a rich mapping. community of breeding birds. Firle Escarpment Biological. 8km from point of NO NO – no hydrographical NO Extensive stretch of abstraction connection indicated chalk grassland (downstream) using EA flood zone and supporting several surface water extent unusual and rare mapping. plant species. Lewes Brooks Biological. Supports 6km from point of YES NO – although majority of NO - Offham a wide diversity of abstraction the sites is within flood Marshes SSSI invertebrates within (downstream) zone 2 and 3, flood is situated the flood plan of the defences limit within the River Ouse. Salinity hydrological connectivity. floodplain of the of key ditches varies Ouse over 3km across the site. downstream of Barcombe Mills. Previous
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SSSI name Reason for Distance from Presence of Hydrological / Potential for notification abstraction (km) water hydrogeological significant sensitive pathway impact features of interest studies (e.g. Entec UK Ltd, 2004) have demonstrated that this site is not hydrologically linked to the Ouse. Lewes Downs Biological. Contains 4km from point of NO No – no hydrographical NO extremely rich chalk abstraction connection indicated grassland which (downstream) using EA flood zone and supports a surface water extent nationally important mapping. orchid, invertebrates, as well as locally important breeding community of downland birds. Offham Marshes Biological. Alluvial 4km from point of YES NO – although majority of NO - Lewes grazing marsh abstraction the sites is within flood Brooks SSSI is supporting large (downstream) zone 2 and 3, flood downstream of amphibian defences limit Offham populations atypical hydrological connectivity. Marshes and is of this habitat in adjacent to the Sussex. Freshwater much more
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SSSI name Reason for Distance from Presence of Hydrological / Potential for notification abstraction (km) water hydrogeological significant sensitive pathway impact features of interest field ditches are key tidally- breeding sites. influenced reaches of the Ouse and does not receive direct in-flow from the river. Plashett Park Wood Biological. Area of 1.5km point of NO NO – no hydrographical NO ancient woodland abstraction connection indicated that contains a rich (upstream) using EA flood zone and community of surface water extent breeding birds and mapping. also supports nationally restricted plant and invertebrate populations. Rock Wood Biological. Small 10km point of No – no hydrographical NO area of ancient abstraction connection indicated woodland that (upstream) using EA flood zone and supports a number surface water extent of different mapping. broadleaved woodland types.
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SSSI name Reason for Distance from Presence of Hydrological / Potential for notification abstraction (km) water hydrogeological significant sensitive pathway impact features of interest Southerham Grey Pit Geological. Site is 6km from point of NO Yes – a majority of the NO the only inland abstraction site is within flood zone 3. exposed section of (downstream) Chalk Marl and Grey Chalk in southern England / Northern France. Single most important section of these two beds in western Europe. Southerham Machine Bottom Pit Geological. 6km from point of NO No – no hydrographical NO Provides an abstraction connection indicated exceptional diversity (downstream) using EA flood zone and of fossil fish. surface water extent mapping. Southerham Works Pit Geological. Site 6km from point of NO No – no hydrographical NO provides the best abstraction connection indicated remaining (downstream) using EA flood zone and exposures through surface water extent the Ranscombe, mapping. Lewes, and Seaford Members.
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Table 4.4 – River Cuckmere Site of Special Scientific Interest source pathway receptor SSSI name Reason for Distance from Presence of Hydrological / Potential for significant notification abstraction (km) water hydrogeological impact sensitive pathway features of interest Arlington Reservoir Biological. Important Adjacent to point of YES YES – apart from NO – because the water is ornithological site, abstraction. the water intake impounded at the intake, over 170 species of from the river to the raising levels locally and the birds on passage have reservoir, the only channel is deep and slow been recorded, with ‘natural’ flowing, and contained within wintering bird counts relationship is a concrete lined channel. regularly exceeding between the river Even if there are minor 10,000. and the adjacent hydrological connections to right hand banks the riparian area of the SSSI that are included in the channel water level is the SSSI boundary. unlikely to significantly change and the riparian corridor habitats are not dependant on the channel. Firle Escarpment Biological. Extensive 4km from point of NO NO – no NO stretch of chalk abstraction hydrographical grassland supporting (downstream) connection several unusual and indicated using EA rare plant species. flood zone and surface water extent mapping. Lower Dicker Geological. Provides 4.6km from point of NO NO – no NO the most southerly abstraction hydrographical exposure of Weald (upstream) connection indicated using EA
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SSSI name Reason for Distance from Presence of Hydrological / Potential for significant notification abstraction (km) water hydrogeological impact sensitive pathway features of interest Clay sand members in flood zone and Britain. surface water extent mapping. Lullington Heath Biological. Site 3km from point of NO NO – no NO contains nationally abstraction hydrographical uncommon chalk (downstream) connection heath, and chalk indicated using EA grassland habitats. flood zone and surface water extent mapping. Milton Gate Marsh Biological. Site 0.6km from point of YES Yes – NO - Entec (2005) contains a rich mosaic abstraction approximately half undertook a review of the of marshy grassland (downstream) of the site is within likely hydrological habitats that supports flood zones 2 and functioning of SSSIs a rich assemblage of 3. associated with the River invertebrates and Cuckmere. locally important bird The wet grassland habitat, species. that forms part of the Milton Gate Marsh SSSI, depends on natural inundation from the Cuckmere during the winter-time. As the proposed Drought Permit relates to a reduction in MRF and therefore potential effects being more likely with low flows (not floods), there will
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SSSI name Reason for Distance from Presence of Hydrological / Potential for significant notification abstraction (km) water hydrogeological impact sensitive pathway features of interest be minimal impact on the frequency and duration of over-bank events and therefore on the hydrological functioning of the SSSI. Water from the Cuckmere enters the West Dean Brooks though a series of ditches which are fed though a sluice above Milton Lock. Figure 4.1 shows that the level at Milton Lock fell below the feeder sluice invert level on 4 occasions in 2005. This also happened on occasions in 2001, 2002, 2003 and 2004. Section 5.3 of this report considers the potential effects of the proposed Drought Permit on this SSSI. The Arlington Reservoir SSSI site boundary includes a component of the River Cuckmere and its floodplain. The reservoir also has a ‘hydrological’ relationship
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SSSI name Reason for Distance from Presence of Hydrological / Potential for significant notification abstraction (km) water hydrogeological impact sensitive pathway features of interest with the river through the abstraction of river water.
Seaford to Beachy Biological and 5.6km from point of YES – the majority NO - Entec (2005) Head – West Dean geological. Diverse abstraction of the northwestern undertook a review of the Brooks range of nationally (downstream) portion of the site is likely hydrological important habitats that within flood zones functioning of SSSIs support nationally 2 and 3. associated with the River rare, scarce, and Cuckmere significant plants, Water from the Cuckmere invertebrates, and enters the West Dean birds. The cliffs are of Brooks though a series of outstanding for their ditches which are fed though geological and a sluice above Milton Lock. geomorphological Evidence shows that the interest. level at Milton Lock fell below the feeder sluice invert level on 4 occasions in 2005. This also happened on occasions in 2001, 2002, 2003 and 2004. St. Dunstan's Farm Biological. 13km from point of NO NO – no NO Meadows Unimproved abstraction hydrographical grasslands (upstream) connection representing a good indicated using EA example of species- flood zone and rich grassland: being
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SSSI name Reason for Distance from Presence of Hydrological / Potential for significant notification abstraction (km) water hydrogeological impact sensitive pathway features of interest managed through surface water traditional techniques. extent mapping. Wilmington Downs Biological. Nationally 3km from point of NO NO – no NO uncommon chalk abstraction hydrographical grassland which (downstream) connection supports diverse flora indicated using EA and fauna including flood zone and two nationally rare and surface water several notable extent mapping. invertebrates.
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Following comments from Historic England on our draft drought plan in 2011, we undertook a heritage environmental assessment as part of producing the 2013 version of the drought plan. It has been assumed that the archaeological baseline has not changed in the interim and no further searches have been undertaken as part of this updated plan.
Sites of heritage value (using Historic England Geographical Information Systems layers) within 5km from the drought permit/order locations are presented in Appendix Error! Reference source not found.. For the surface water drought permits/orders no adverse impacts are expected to heritage features during use of those drought permits/orders.
We consider that the only pathway by which there could be a potential impact on the historic environment is from increased borehole abstraction, lowering the water table and leading to an adverse local impact on archaeological deposits. This situation could potentially arise at either Halling No.8 or Oaklands and Southlands drought permit/order locations. Following Historic England’s advice we have searched the Kent and Hampshire County Council’s heritage databases i.e. the Heritage Environment Records (HER) on their websites to see if there are any archaeological features within close proximity to the drought permit/order locations. The presence of these features would not prevent us from attaining a drought permit/order, but an early screening helps to identify if mitigation would be required, and would likely ensure that the application process for a drought permit/order would be more efficient.
By using the Kent County Council’s Historic Environment Record tool (http://www.kent.gov.uk/ExploringKentsPast/ ) 47 historic sites were identified within a 1km radius of the Halling Drought Permit. Of these only seven appear to be an archaeological feature which could be at-risk. These are presented in Table 4.5.
Table 4.5 – Summary of archaeological features within Kent County Council’s HER HER reference Archaeological feature which has the potential to be at-risk within 1km of Halling DP. TQ 66 SE 7 Romano-British burials and associated grave goods TQ 66 SE 16 Romano-British Burials TQ 66 NE 15 Romano-British Cremation burial urns, Upper Halling TQ 66 SE 29 Inhumation burials and ring ditches, possible barrow, Pring's Quarry, Upper Halling TQ 66 SE 52 Buried late glacial soils found by borehole survey in 2003 TQ 76 SW 60 Mesolithic site at Halling Parish TQ 76 SW 108 Whittings Farm, Medway Valley Palaeolithic Project source/event record
Hampshire County Council has an archeology and historic building record search on its website (http://historicenvironment.hants.gov.uk/AHBSearch.aspx) but searches can only be carried out for a parish or district area as a whole. The Southland drought permit/order location is within Kingsley Parish which returned 182 records for monuments, historic buildings and spot locations. The Oaklands drought permit/order
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location is within Worldham Parish which returned 165 records for monuments, historic buildings, parks and gardens and spot locations. A large proportion of the records indicate a type of archeolgical site; but a detailed screening of sites within a close proxmity of the drought permit/order has not been carried out.
4.3.1 The River Ouse drought permits/orders (DAPS6) The River Ouse has two types of drought permit/order options on it (see Section 3.2.4) one relating to a summer period drought permit/order and one associated with a winter period drought permit/order.
Environmental baseline The River Ouse is the second largest river in Sussex, draining a catchment of approximately 430 km2 to the point where it breaches the chalk escarpment of the South Downs at Lewes. The river rises in the hills of the High Weald in the north and flows across undulating slopes in the Vale of Sussex. The headwaters are characterised by deeply cut stream channels, whilst the lowland stretches are wide and relatively slow flowing with a predominantly clay substrate in places. The catchment is rural and heavily wooded. The main river is approximately 62 kilometres long with an estimated tidal length of 21 km. Barcombe Mills marks the approximate tidal limit of the Ouse. The Ouse is extensively modified at Barcombe Mills, particularly downstream of South East Water’s abstraction intake at Barcombe Reservoir.
Downstream of the abstraction point the main river splits into a network of five smaller channels: the Main Channel, House Stream, Siphon Channel, Fish Ladder Stream and Andrew’s Stream (including a remnant of the Iron River). Flow is regulated and modified by a complex series of weirs, sluices and fish ladders.
The river supports a diverse assemblage of fish, macroinvertebrates, mammals, birds and plants associated with the river corridor and adjacent floodplain. The catchment includes a number of designated sites (e.g. Sites of Special Scientific Interest), although these are not directly or hydrologically connected to the main channel of the river.
The river is used as a source of drinking water by us, and we manage the surface water abstractions, (including from the Ouse in the upper catchment at Ardingly), a reservoir at Ardingly and the release of water from the reservoir into the river for abstraction downstream at Barcombe Mills. There are two water treatment works: one at Barcombe Mills and one at Ardingly. Treated wastewater effluent is discharged into the river by Southern Water. The largest wastewater treatment works on the main river is at Scaynes Hill, which typically accounts for 30 per cent of all treated sewage discharges to the river downstream of this location. Other wastewater treatment works discharge into tributaries of the Ouse. Other discharges to the river occur, including those from land, roads and urban centres, which may include a wider range of potential contaminants including hydrocarbons, pesticides, metals and other deleterious substances.
The river was extensively modified in the past, enabling its efficient use for navigation and trade for a considerable length of the main channel between Newhaven and beyond Ardingly Reservoir, near Balcombe (a distance of some 22 miles). Historic features associated with this navigable use are still present and some are the focus of restoration works by the Sussex Ouse Restoration Trust.
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Recreational activities associated with the river include angling (both coarse fishing and angling for the notable sea trout population), walking and boating (in the lower reaches).
A wide range of organisations are associated with the river including the Environment Agency, Ouse and Adur Rivers Trust, South East Water, Southern Water, the National Trust, the Sussex Wildlife Trust, the Sussex Ouse Restoration Trust as well as numerous landowners and other residents.
Water Framework Directive classification Since the arrival of the Water Framework Directive (WFD) in 2000, the Environment Agency has developed a more sophisticated way of assessing the entire water environment. It reports on over 30 parameters, grouped into ‘ecological status’ (including biology and elements such as phosphorus and pH) and ‘chemical status’ (priority substances).
The River Ouse is located within the Adur and Ouse catchment. There are 51 water bodies in this catchment. 40 are rivers and 11 are heavily modified water bodies.
The South East River Basin Management Plan (2016) identifies the following water body classifications for the River Ouse. The Ecological Status of the Upper Ouse, characterised as a heavily modified water body, is classified as being of Poor Ecological Potential. The Middle and Lower Ouse are both classified as having a poor- moderate ecological status. The ecological status of the River Ouse does not appear to have changed significantly since the previous baseline report completed in 2012.
The Ouse currently achieves good chemical water quality throughout all orders of the tributary network. This is a significant improvement observed since the previous drought plan environmental baseline was completed in 2012.
The current ecological and chemical quality of these water bodies is illustrated in a figure in Appendix Error! Reference source not found..
A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the Drought Permit on water bodies is provided in the following section.
Summary of the drought permit/order effects - The summer drought scenario Table 4.3 sets out an analysis of predicted residual effects after the proposed monitoring, mitigation and restoration works have been implemented. Those worst- case scenario effects, which are predicted, to be significant and negative are identified in the third column. The influence of summer rainfall and an associated reduction in abstraction at Barcombe on the significance of the effect is shown together with a conclusion as to whether the effects are predicted to be permanent or not.
Overall, the unavoidable and essential implementation of the drought permit/order will result in a number of short term negative significant environment effects. However, as a result of the proposed monitoring, mitigation and restoration measures, these are predicted to be reversible and are expected to not persist in the medium term (i.e. >6 months to 2 years). It should also be remembered that the impact assessment is also
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based on a worse case and precautionary perspective and as a result the magnitude of the effects or their duration is likely to be less extensive. It should also be remembered that the ‘Do Nothing’ scenario is considered to result in a greater range of negative significant effects.
Table 4.6 – Summary of the River Ouse summer period residual effects
Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Reduced water velocity, depth & volume
Likely reduction in Smothering of vegetation and Yes Yes No erosion and spawning gravel with fine increase in sediments resulting in: sediment deposition vegetation dieback, reduction in diversity of available invertebrate habitats, loss of cover for fish, and reduction in spawning opportunities for some fish species (e.g. trout, rudd and lamprey). Conversely, an increase in nursery habitat for lampreys.
Reduction in Reduction in fish pass Yes Yes No depth and flow efficacy/fish ability to negotiate type over fish other obstacles and reduction passes and other structures in fish migration to key (e.g. (including high spawning) habitats points in channel Fish entrapment in isolated bed) reaches/features (e.g. pools below weirs/fish passes) Short term increase but long term decrease in prey abundance for species such as otter Increased likelihood of short term angler catch success and potential for injury/mortality Increased likelihood of fish poaching and mortality Medium to long term decrease in population levels of a number of fish species
Sub-aerial Exposure of fish spawning Yes Yes No exposure of habitats resulting in aquatic habitats desiccation/mortality of eggs, including marginal vegetation and damage to habitat viability through formation of sediment ‘concretions’
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Loss/ reduction in the diversity and/or quality of invertebrate habitats Potential for damage to or dieback of marginal vegetation through reduction in support from water column and drying out of bank face soil/sediment Loss of cover for prey species (e.g. tree roots, aquatic macrophyte stands) Reduced accessibility/quality of marginal bird nesting habitats
Reduced Reduction in availability of Yes Yes No abundance of spawning habitat for some fish riffles and runs, and shallow water, well aerated increase in glides and pools habitats for some invertebrate species Loss / local extinction of conservation-notable invertebrate / macrophyte species that are sensitive to reduced water velocity and/or depth
Reduction in Increased habitat opportunities No Yes No aquatic physical for burrowing species such as habitat diversity water vole, solitary bees/ and increase in ‘terrestrial’ bank wasps, and cavity dwellers face habitats such as sand martins and kingfisher Reduction in ecological niches and associated biodiversity
Increased growth Potential impediment to fish Yes of aquatic passage macrophytes and ‘channel choking’ Increased coarse fish recruitment Likely dominance of limited number of macrophyte species Reduction in chemical water quality, particularly diurnal dissolved oxygen levels
Reduced water quality
Reduction in river Potential for mortality of fish, Yes Yes No water quality due invertebrates and variation in to decreased macrophyte assemblages effluent dilution capacity, reduced Increased growth of algae and aeration, sewage fungus, smothering increased algal vegetation and sediment,
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? growth and effects resulting in localised associated with fluctuations in dissolved higher summer oxygen levels and reduced water temperatures spawning success of some fish species Poor water quality may cause physio-chemical barriers to fish passage Reduction in fish ‘fitness’ and increased susceptibility to parasites and disease Reduction in prey species for otter
Increased algal Increased growth of algae and No growth with sewage fungus, smothering associated vegetation and sediment which changes to dissolved oxygen, could lead to a reduction in the BOD and pH quality and diversity of available habitats
Reduction in pH may result in mortality of e.g. molluscs and crustaceans Growth and dieback of algal population may cause localised fluctuations in dissolved oxygen concentrations and subsequent fish/invertebrate mortalities Reduction in habitat quality leading to a reduction in spawning success & successful development of fish juveniles
Increased risk of Fish/invertebrate mortalities Yes Yes No oxygen depletion from dieback of Reduction in prey species for large biomass of fish and otter vegetation
Reduced river Potential for mortality of fish, Yes Yes No flow in tidal invertebrates and variation in reaches, resulting macrophyte assemblages in increased penetration Reduction in habitat quality upstream of saline water
Effect on the Reduction in water quality from No Yes No Water Framework drought conditions resulting in Directive Status a failure of the water chemistry status of the River Ouse.
Impacts on other habitats
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Reduction in Fish concentrated in reduced Yes Yes No volume of water area/ depth of water and and water depth potential strandings in within Ardingly Reservoir (albeit a inaccessible submerged reduced level of structures e.g. historic flight impact compared ponds to the ‘do-nothing’ Increased rate of fish predation scenario) e.g. from cormorants
Reduction in Potential for fish mortality Yes No No water quality due to reduction in Loss/ changes to macrophyte dissolved oxygen, and macroinvertebrate increased populations/ communities and temperature, subsequent impacts to SNCI increased turbidity, eutrophication & increased mobilisation of metals associated with the bed of Ardingly Reservoir (albeit a reduced level of impact compared to the ‘do-nothing’ scenario)
Significant Loss/ changes to bryophyte, No Yes No exposure of littoral macrophyte and areas at Ardingly macroinvertebrate populations/ Reservoir that are typically communities and subsequent submerged (albeit impacts to SNCI a reduced level of impact compared to the ‘do-nothing’ scenario)
Reduction in Dieback in key vegetation No Yes No water dependant communities and succession floodplain habitat by non-valued species presence and viability Loss of amphibian spawning habitats Mortality/reduction in breeding success of birds (including lapwing) through a reduction in prey availability and loss of suitable habitats Reduction in prey species for some animals (e.g. grass snake)
Impacts on Other Ecosystem Services
Reduction in Potential for upper reaches of No Yes No recreational value the river (and associated of the river and
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Ardingly tributaries) and/ or Ardingly Reservoir LNR Reservoir LNR to be dry for some periods, thereby reducing its aesthetic and recreational value to the local community and local tourists. Potential fish kills arising from changes in water quality and/or stranding of fish downstream of fish passes and other structures will also reduce the amenity and recreational value of the river/ reservoir. Reduction in use of riverside footpaths/ bridleways and picnic areas as water levels drop and/or chemical water quality decreases Reduction or temporary cessation of angling along parts of the river.
Reduction in Exposure of previously No Yes No landscape value submerged marginal features of the river (lower banks, sediment bars) and potentially dry channels. Dieback of vegetation in channel and potentially on banks.
Economic impacts Less day tickets available for No Yes No arising from a sale to anglers as impacts on reduction in fish species occur opportunities for angling, boating Less interest from the local etc community to use the river as a recreational resource (e.g. boating/ use of riverside pubs) as water levels fall and/or chemical water quality decreases/risk of algal blooms increases.
Increased human, Potential for health effects from No Yes No livestock and poor water quality, decreased domestic animal sewage/other discharge health risk from reduced water dilution, algal blooms to quality. humans (e.g. when boating/paddling), cattle (watering) and dogs (swimming/drinking).
Drying out and Reduced water levels at No Yes No damage to historic structures will cause them to be structures along sub-aerially exposed and the river. subject to drying out,
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? desiccation etc until water levels rise. Supporting banks will be subject to drying out with local weathering. Typical flows through and operation of remaining mill structures will be reduced as a result of lower river flows.
A WFD assessment has been carried out (see Error! Reference source not found.) and concluded that the River Ouse (summer period) drought permit/order has a medium risk of deterioration of WFD objectives. This is because a reduction in freshwater flows, as a direct result of the proposed drought permit/order, could increase the upstream presence of the saline wedge during high spring tides. The likelihood of having no rain to flush the system will increase risk during the summer months. Mitigation measures have been suggested and will be put in place during drought permit/order use.
Taking into account the ability of the riverine ecosystem to recover from climatic events such as drought and the post-drought monitoring and restoration, it is predicted that negative significant effects will not be present after six to 24 months and the ecosystem will recover. We have made a provision to extend our post drought monitoring beyond this period if necessary and by working in partnership with a wide range of stakeholders and through implemented specific measures (e.g. reconfiguration of Barcombe Mills for low flow fish passage, catchment scale land management, and potentially contributing to the funding of river restoration project delivery), we will be in a position to facilitate more longer term enhancements to the River Ouse to secure its sustainable management.
Summary of drought permit/order effects - The winter drought scenario Table 4.4 sets out an analysis of predicted residual effects associated with the winter drought permit/order scenario (limited to the river downstream of our abstraction at Barcombe, but assessed between Anchor Gates sluice and Hamsey Weir to incorporate a control reach) after the proposed monitoring, mitigation and restoration works have been implemented.
Those worst-case scenario effects, which are predicted to be significant and negative are identified in the third column. The influence of summer rainfall and an associated reduction in abstraction at Barcombe on the significance of the effect is shown together with a conclusion as to whether the effects are predicted to be permanent or not.
Overall, the unavoidable and essential implementation of the drought permit/order will result in a number of short term negative significant environment effects. However, as
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a result of the proposed monitoring, mitigation and restoration measures, these are predicted to be reversible and are expected to not persist in the medium term (i.e. >6 to 24 months). It should also be remembered that the impact assessment is also based on a worse case and precautionary perspective and as a result the magnitude of the effects or their duration is likely to be less extensive. It should also be remembered that the ‘Do Nothing’ scenario is considered to result in a greater range of negative significant effects.
Table 4.7 – Summary of the River Ouse winter period residual effects
Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? Reduced water velocity, depth & volume
Likely reduction in Smothering of vegetation Yes Yes No erosion and and spawning gravel with increase in fine sediments resulting sediment deposition in: vegetation dieback, reduction in diversity of available invertebrate habitats, loss of cover for fish, and reduction in spawning opportunities for some fish species (e.g. trout, rudd and lamprey). Conversely, an increase in nursery habitat for lampreys.
Reduction in Reduction in fish pass Yes Yes No depth and flow efficacy/fish ability to type over fish negotiate other obstacles passes and other structures and reduction in fish (including high migration to key (e.g. points in channel spawning) habitats bed) Fish entrapment in isolated reaches/features (e.g. pools below weirs/fish passes) Short term increase but long term decrease in prey abundance for species such as otter Increased likelihood of short term angler catch success and potential for injury/mortality Increased likelihood of fish poaching and mortality Medium to long term decrease in population
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Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? levels of a number of fish species
Sub-aerial Exposure of fish Yes Yes No exposure of spawning habitats aquatic habitats resulting in including marginal vegetation desiccation/mortality of eggs, and damage to habitat viability through formation of sediment ‘concretions’ Loss/ reduction in the diversity and/or quality of invertebrate habitats Potential for damage to or dieback of marginal vegetation through reduction in support from water column and drying out of bank face soil/sediment Loss of cover for prey species (e.g. tree roots, aquatic macrophyte stands) Reduced accessibility/quality of marginal bird nesting habitats
Reduced Reduction in availability of Yes Yes No abundance of spawning habitat for riffles and runs, some fish and shallow increase in glides and pools water, well aerated habitats for some invertebrate species Loss / local extinction of conservation-notable invertebrate / macrophyte species that are sensitive to reduced water velocity and/or depth
Reduction in Increased habitat No Yes No aquatic physical opportunities for habitat diversity burrowing species such and increase in ‘terrestrial’ bank as water vole, solitary face habitats bees/ wasps, and cavity dwellers such as sand martins and kingfisher
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Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? Reduction in ecological niches and associated biodiversity
Increased growth Potential impediment to Yes of aquatic fish passage macrophytes and ‘channel choking’ Increased coarse fish recruitment Likely dominance of limited number of macrophyte species Reduction in chemical water quality, particularly diurnal dissolved oxygen levels
Reduced water quality
Reduction in river Potential for mortality of Yes Yes No water quality due fish, invertebrates and to decreased variation in macrophyte effluent dilution capacity, reduced assemblages aeration, Increased growth of algae increased algal and sewage fungus, growth and effects smothering vegetation associated with higher water and sediment, resulting in temperatures e.g. localised fluctuations in due to a dissolved oxygen levels prolonged mild and reduced spawning autumn success of some fish species Poor water quality may cause physio-chemical barriers to fish passage Reduction in fish ‘fitness’ and increased susceptibility to parasites and disease Reduction in prey species for otter
Increased algal Increased growth of algae No growth with and sewage fungus, associated smothering vegetation changes to dissolved oxygen, and sediment which could BOD and pH lead to a reduction in the associated with a quality and diversity of prolonged and available habitats mild autumn Reduction in pH may result in mortality of e.g. molluscs and crustaceans Growth and dieback of algal population may cause localised
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Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? fluctuations in dissolved oxygen concentrations and subsequent fish/invertebrate mortalities Reduction in habitat quality leading to a reduction in spawning success & successful development of fish juveniles
Increased risk of Fish/invertebrate Yes Yes No oxygen depletion mortalities from dieback of large biomass of Reduction in prey species vegetation during for fish and otter the autumn
Reduced river Potential for mortality of Yes Yes No flow in tidal fish, invertebrates and reaches, resulting variation in macrophyte in increased penetration assemblages upstream of saline Reduction in habitat water quality
Effect on the Reduction in water quality No Yes No Water Framework from drought conditions Directive Status resulting in a failure of the water chemistry status of the River Ouse.
Impacts on other habitats
Reduction in Dieback in key vegetation No Yes No water dependant communities and floodplain habitat succession by non-valued presence and viability species Loss of amphibian spawning habitats Mortality/reduction in breeding success of birds (including lapwing) through a reduction in prey availability and loss of suitable habitats Reduction in prey species for some animals (e.g. grass snake)
Impacts on Other Ecosystem Services
Reduction in Potential for lower No Yes No recreational value reaches of the river of the river associated with
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Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? Barcombe Mills to be dry for some periods, thereby reducing its aesthetic and recreational value to the local community and local tourists. Potential fish kills arising from changes in water quality and/or stranding of fish downstream of fish passes and other structures will also reduce the amenity and recreational value of the river. Reduction in use of riverside footpaths/ bridleways and picnic areas as water levels drop and/or chemical water quality decreases Reduction or temporary cessation of angling along parts of the river.
Reduction in Exposure of previously No Yes No landscape value submerged marginal of the river features (lower banks, sediment bars) and potentially dry channels. Dieback of vegetation in channel and potentially on banks.
Economic impacts Less day tickets available No Yes No arising from a for sale to anglers as reduction in impacts on fish species opportunities for angling, boating occur etc Less interest from the local community to use the river as a recreational resource (e.g. boating/ use of riverside pubs) as water levels fall and/or chemical water quality decreases/risk of algal blooms increases (autumn only).
Increased human, Potential for health effects No Yes No livestock and from poor water quality, domestic animal decreased sewage/other health risk from reduced water discharge dilution, algal quality. blooms (autumn only) to
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Environmental Potential generic effect Is worst case Is effect made less Will effect be change scenario effect significant by permanent negative & rainfall & significant? opportunity to reduce abstraction? humans (e.g. when boating/paddling), cattle (watering) and dogs (swimming/drinking).
Drying out and Reduced water levels at No Yes No damage to historic structures at Barcombe structures along Mills will cause them to be the river. sub-aerially exposed and subject to drying out, desiccation etc. until water levels rise. Supporting banks will be subject to drying out with local weathering. Typical flows through and operation of remaining mill structures will be reduced as a result of lower river flows.
A WFD assessment has been carried out (see Error! Reference source not found.) and concluded that the River Ouse (winter period) drought permit/order has a low risk of deterioration of WFD objectives.
Taking into account the ability of the riverine ecosystem to recover from climatic events such as drought and the post-drought monitoring and restoration, it is predicted that negative significant effects will not be present after six to 24 months and the ecosystem will recover.
4.3.2 The River Cuckmere drought permit/order (DAPS6) Environmental baseline The Cuckmere has a catchment of 134.7 km2, described by the National River Flow Archive website (http://www.nwl.ac.uk) as “a rural catchment developed on mixed geology (Hastings Beds predominate)”. The catchment land use is principally arable or grassland, with significant areas of woodland. Geologically, the catchment is predominantly moderate-low permeability, which results in a flashy flow regime within the Cuckmere.
The lower section of the Cuckmere meanders over a narrow floodplain between the South Downs before joining the sea at the Cuckmere Haven. Sections of the river (particularly downstream of Shermans Bridge) have been straightened and embanked. The tidal limit of the river is artificially formed by Milton Lock.
The head of water retained behind Milton Lock is essential for maintaining;
flow over the fish pass; and
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flow through a feeder siphon which feeds a series of ditches leading to the West Dean Brooks (which forms the start of the Seaford to Beachy Head SSSI).
The river supports a diverse assemblage of fish, macroinvertebrates, mammals, birds and plants associated with the river corridor and adjacent floodplain. The catchment includes a number of designated sites, although these are not directly or hydrologically connected to the main channel of the river.
Abstraction from the Cuckmere at Arlington Water Treatment Works is the largest abstraction on the river. There are several minor agricultural abstractions in the upper part of the Cuckmere, the most significant being an agricultural abstraction between Michelham Priory and Arlington (TQ 55610 09220) which is licensed at a maximum abstraction of 1.19 Ml/d. Abstraction at Arlington is licensed at a maximum of 68.2 Ml/d, and as a result has the potential to have a large impact on the flow of the Cuckmere downstream of the abstraction point.
Upstream of Arlington Weir, the channel has been extensively modified. The channel has been re-sectioned and partially reinforced with concrete banks and set back embankments. The land either side is unimproved grassland, which is grazed under a stewardship scheme by both sheep and cattle.
Abstracted water is transferred to Arlington Reservoir, a SSSI notified in particular for its bird assemblages.
A weir structure across the River Cuckmere forms a significant impoundment that acts to hold water behind it. The weir incorporates a fish pass, which allows water to flow through it on all river flow scenarios. Sea trout are known to utilise the fish pass. The fish pass was modified in September 2011 when an eel pass was constructed to aid elver passage.
The channel immediately downstream of the abstraction weir has been artificially widened, and the section closest to the weir has been reinforced. Downstream of the pool at the foot of the weir there are significant vegetated sediment deposits, and between these deposits the channel is narrow and fast flowing. During flash events, the sediment deposits and lower banks are covered with water.
Downstream of the road bridge at TQ 537 068 the river assumes a more natural channel.
Water Framework Directive classification The River Cuckmere is located within the Cuckmere and Pevensey Levels catchment. There are 25 water bodies in this catchment. Nine are rivers and 16 are heavily modified/artificial water bodies. Only three of the nine non-heavily modified river water bodies are currently considered to be in good condition.
The South East River Basin Management Plan (December 2009) identifies the Cuckmere from Alfriston to Arlington, the water body which includes the abstraction that refills the reservoir, to be ‘Heavily Modified’ and classified as ‘Moderate’ overall potential. The current ecological and chemical quality of these water bodies is illustrated in a figure in Appendix Error! Reference source not found..
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A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
Summary of the drought permit/order effects Table 4.5 sets out an analysis of predicted residual effects after the proposed monitoring, mitigation and restoration works have been implemented. Those worst- case scenario effects, which are predicted, to be significant and negative are identified in the third column. The influence of rainfall and an associated reduction in abstraction at Arlington on the significance of the effect is shown together with a conclusion as to whether the effects are predicted to be permanent or not.
Overall, the unavoidable and essential implementation of the drought permit/order will result in a number of short term negative significant environment effects. However, as a result of the proposed monitoring, mitigation and restoration measures, these are predicted to be reversible and are expected to not persist in the medium term (i.e. >6 to 24 months). It should also be remembered that the impact assessment is also based on a worse case and precautionary perspective and as a result the magnitude of the effects or their duration is likely to be less extensive. It should also be remembered that the ‘Do Nothing’ scenario is considered to result in a greater range of negative significant effects.
Table 4.8 – Summary of the Cuckmere residual effects
Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Reduced water velocity, depth & volume
Likely reduction in Smothering of vegetation and No Yes No erosion and spawning gravel with fine increase in sediments resulting in: sediment deposition vegetation dieback, reduction in diversity of available invertebrate habitats, loss of cover for fish, and reduction in spawning opportunities for some fish species (e.g. trout, rudd and lamprey). Conversely, an increase in nursery habitat for lampreys.
Reduction in Reduction in fish pass Yes Yes No depth and flow efficacy/fish ability to negotiate type over fish other obstacles and reduction passes and other structures in fish migration to key (e.g. (including high spawning) habitats points in channel Fish entrapment in isolated bed) reaches/features (e.g. pools below weirs/fish passes) Short term increase but long term decrease in prey
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? abundance for species such as otter Increased likelihood of short term angler catch success and potential for injury/mortality Increased likelihood of fish poaching and mortality Medium to long term decrease in population levels of a number of fish species
Sub-aerial Exposure of fish spawning No Yes No exposure of habitats resulting in aquatic habitats desiccation/mortality of eggs, including marginal vegetation and damage to habitat viability through formation of sediment ‘concretions’ Loss/ reduction in the diversity and/or quality of invertebrate habitats Potential for damage to or dieback of marginal vegetation through reduction in support from water column and drying out of bank face soil/sediment Loss of cover for prey species (e.g. tree roots, aquatic macrophyte stands) Reduced accessibility/quality of marginal bird nesting habitats
Reduced Reduction in availability of No Yes No abundance of spawning habitat for some fish riffles and runs, and shallow water, well aerated increase in glides and pools habitats for some invertebrate species Loss / local extinction of conservation-notable invertebrate / macrophyte species that are sensitive to reduced water velocity and/or depth
Reduction in Increased habitat opportunities No Yes No aquatic physical for burrowing species such as habitat diversity water vole, solitary bees/ and increase in ‘terrestrial’ bank wasps, and cavity dwellers face habitats such as sand martins and kingfisher Reduction in ecological niches and associated biodiversity
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Increased growth Potential impediment to fish No No No of aquatic passage macrophytes and ‘channel choking’ Increased coarse fish recruitment Likely dominance of limited number of macrophyte species Reduction in chemical water quality, particularly diurnal dissolved oxygen levels
Reduced water quality
Reduction in river Potential for mortality of fish, Yes Yes No water quality due invertebrates and variation in to decreased macrophyte assemblages effluent dilution capacity, reduced Increased growth of algae and aeration, sewage fungus, smothering increased algal vegetation and sediment, growth and effects resulting in localised associated with higher summer fluctuations in dissolved water oxygen levels and reduced temperatures spawning success of some fish species Poor water quality may cause physio-chemical barriers to fish passage Reduction in fish ‘fitness’ and increased susceptibility to parasites and disease Reduction in prey species for otter
Increased algal Increased growth of algae and No Yes No growth with sewage fungus, smothering associated vegetation and sediment which changes to dissolved oxygen, could lead to a reduction in the BOD and pH quality and diversity of available habitats
Reduction in pH may result in mortality of e.g. molluscs and crustaceans Growth and dieback of algal population may cause localised fluctuations in dissolved oxygen concentrations and subsequent fish/invertebrate mortalities Reduction in habitat quality leading to a reduction in spawning success & successful development of fish juveniles
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Increased risk of Fish/invertebrate mortalities No Yes No oxygen depletion from dieback of Reduction in prey species for large biomass of fish and otter vegetation
Reduced river Potential for mortality of fish, Yes Yes No flow in tidal invertebrates and variation in reaches, resulting macrophyte assemblages in increased penetration Reduction in habitat quality upstream of saline water
Effect on the Reduction in water quality from No Yes No Water Framework drought conditions resulting in Directive Status a failure of the water chemistry status of the River Ouse.
Impacts on other habitats
Reduction in Fish concentrated in reduced No Yes No volume of water area/ depth of water and and water depth potential strandings in within Ardingly Reservoir (albeit a inaccessible submerged reduced level of structures e.g. historic flight impact compared ponds to the ‘do-nothing’ Increased rate of fish predation scenario) e.g. from cormorants
Reduction in Potential for fish mortality No No No water quality due to reduction in Loss/ changes to macrophyte dissolved oxygen, and macroinvertebrate increased populations/ communities and temperature, subsequent impacts to SNCI increased turbidity, eutrophication & increased mobilisation of metals associated with the bed of Ardingly Reservoir (albeit a reduced level of impact compared to the ‘do-nothing’ scenario)
Significant Loss/ changes to bryophyte, No Yes No exposure of littoral macrophyte and areas at Ardingly macroinvertebrate populations/ Reservoir that are typically communities and subsequent submerged (albeit impacts to SNCI a reduced level of impact compared to the ‘do-nothing’ scenario)
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? Reduction in Dieback in key vegetation No Yes No water dependant communities and succession floodplain habitat by non-valued species presence and viability Loss of amphibian spawning habitats Mortality/reduction in breeding success of birds (including lapwing) through a reduction in prey availability and loss of suitable habitats Reduction in prey species for some animals (e.g. grass snake)
Impacts on Other Ecosystem Services
Reduction in Potential for upper reaches of No Yes No recreational value the river (and associated of the river and tributaries) and/ or Ardingly Ardingly Reservoir LNR Reservoir LNR to be dry for some periods, thereby reducing its aesthetic and recreational value to the local community and local tourists. Potential fish kills arising from changes in water quality and/or stranding of fish downstream of fish passes and other structures will also reduce the amenity and recreational value of the river/ reservoir. Reduction in use of riverside footpaths/ bridleways and picnic areas as water levels drop and/or chemical water quality decreases Reduction or temporary cessation of angling along parts of the river.
Reduction in Exposure of previously No Yes No landscape value submerged marginal features of the river (lower banks, sediment bars) and potentially dry channels. Dieback of vegetation in channel and potentially on banks.
Economic impacts Less day tickets available for No Yes No arising from a sale to anglers as impacts on reduction in fish species occur opportunities for
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Environmental Potential generic effect Is worst Is effect made Will effect be change case less significant permanent scenario by rainfall & effect opportunity to negative & reduce significant? abstraction? angling, boating Less interest from the local etc community to use the river as a recreational resource (e.g. boating/ use of riverside pubs) as water levels fall and/or chemical water quality decreases/risk of algal blooms increases.
Increased human, Potential for health effects from No Yes No livestock and poor water quality, decreased domestic animal sewage/other discharge health risk from reduced water dilution, algal blooms to quality. humans (e.g. when boating/paddling), cattle (watering) and dogs (swimming/drinking).
Drying out and Reduced water levels at No Yes No damage to historic structures will cause them to be structures along sub-aerially exposed and the river. subject to drying out, desiccation etc. until water levels rise. Supporting banks will be subject to drying out with local weathering. Typical flows through and operation of remaining mill structures will be reduced as a result of lower river flows.
A WFD assessment has been carried out (see Error! Reference source not found.) and concluded that the Cuckmere drought permit/order has a low risk of deterioration of WFD objectives.
Taking into account the ability of the riverine ecosystem to recover from climatic events such as drought and the post-drought monitoring and restoration, it is predicted that negative significant effects will not be present after six to 24 months and the ecosystem will recover.
4.3.3 The Chasewood drought permit/order (DAPS6)
Environmental baseline The Chasewood source consists of the No 1 borehole constructed in 1968 and first operated in 1976. The borehole has been recently inspected and found to be in reasonable condition with major inflows between 20m and 54m below the surface from the Ashdown Beds sandstone aquifer. The aquifer is confined at this location so there
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are no impacts on surface features. The source has a limited yield potential. During the summer months, the borehole was operated at 0.8 Ml/d, but was reduced to 0.4 Ml/d during the remainder of the year. Raw water quality is known to be good at this site with low levels of both iron and manganese being present within the raw water.
Local land use is characterised by open areas of farmland with a series of extensive and interconnected woodland blocks and copses. A number of larger open water bodies are present to the east, beyond a railway cutting. The High Weald Landscape Trail and Tunbridge Wells Circular Walk are located to the west. A number of dwellings and farms are present in the local area.
The local area includes a number of sites designated for their nature conservation interest including Eridge Park SSSI, Frant Meadows SNCI, Hawkenbury Farm Meadows SNCI and Clays Wood SNCI. There is no hydrological connectivity between the abstraction and these sites.
The source is in proximity to a number of small tributary watercourse and associated woodland. A number of springs are present in the local area. Further to the east are a number of larger water bodies associated with the Frant Lakes.
Water Framework Directive classification Water bodies (including their current ecological and chemical status) within 2km of the drought permit/order are illustrated in a figure in Appendix Error! Reference source not found.. A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
Summary of the drought permit/order effects In support of the assessment of potential effects associated with the drought permit/order it has been assumed that:
All appropriate infrastructure is in place at the source; Pump testing will have been undertaken and used to confirm the extent of any surface water drawdown and inform the need to re-scope this assessment with respect to potential groundwater effects; Abstracted water meets all quality criteria associated with both Environment Agency consenting requirements and requirements for potable supply; All abstracted water is transferred to supply via existing pipe works.
Taking into account the assumptions made above particularly with regards draw down effects, no significant negative environmental effects are predicted.
Due to the unconfined nature of the aquifer further survey work would be required to establish the nature of any potential drawdown effects prior to the implementation of a drought permit/order. Once complete if it is established that there is a risk of deterioration to WFD objectives, potential impacts and mitigation measures will be detailed in the Environmental Sections of the drought permit/order.
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4.3.4 The Balcombe drought permit/order (DAPS6) Environmental baseline The Balcombe source comprises a well and borehole, constructed in 1890 and 1901 respectively, abstracting from the Tunbridge Wells Sandstone from a depth of 95m. The source was abandoned in 1981 due to poor yields associated with sand ingress which constrained the output for 0.3 Ml/d. Water levels fluctuated between 86.5m and 89.8m AOD, with the surface at 144m AOD, the water levels some 55m below surface. The Balcombe source licence allowed for 0.68 Ml/d on average to be abstracted with a peak daily limit of 1.36 Ml/d.
It is proposed that South East Water will reinstate the Balcombe source to provide additional water resources, particularly in times of drought. Water abstracted from Balcombe would be put into supply. This will alleviate pressure on Ardingly Reservoir, where water is abstracted and treated at the adjacent Shell Brook Water Treatment Works or used to augment the flows in the River Ouse downstream of the reservoir, with further abstraction possible at Barcombe Mills. Water abstracted from Balcombe therefore also supplements the refill of Ardingly Reservoir.
No international sites of nature conservation importance are present within 5km of the point of abstraction at Balcombe. However, the site is surrounded by semi-natural broad-leaved woodland (Broadhurst Woods), with areas of wet woodland habitat lying to the east and south. Worth Forest Site of Special Scientific Interest is located less than 2km to the north and Cow Wood & Harry’s Wood SSSI is located less than 2km to the south. Four non-statutory Local Wildlife Sites are also present within 2km of the source. None of these sites are believed to be in hydrological continuity with the abstraction source.
The site lies within the High Weald Area of Outstanding National Beauty (AONB). Local land use is characterised by woodland with some open areas of farmland. A small number of dwellings are scattered through the local area, together with farms. The railway is located in a cutting (and tunnel) to the east and the South East Water site is adjacent to a small rural road, Handcross Lane.
The site is located at a local high point of approximately 148mAOD. Ordnance Survey mapping illustrates that a number of small water courses (locally known as ‘Ghyll Woodlands’ are present in the area, some of which flow to the east and form the headwaters of the Shell Brook, itself a tributary of the River Ouse (Sussex). Shell Brook drains this rural landscape before entering Ardingly Reservoir.
A number of surface water features are also present in the local area, typically characterised by ponds, although a number of other natural features such as springs and artificial features such as weirs, reservoir, and water tower are also present.
Water Framework Directive classification Water bodies (including their current ecological and chemical status) within 2km of the drought permit/order are illustrated in a figure in Appendix Error! Reference source not found.. A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
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Summary of the drought permit/order effects For the purposes of assessing the potential impacts of this drought permit it has been assumed that:
All appropriate infrastructure is in place at the source Pump testing will have been undertaken and used to confirm the extent of any surface water drawdown and inform the need to re-scope this assessment with respect to potential groundwater effects Abstracted water meets all quality criteria associated with both Environment Agency consenting requirements and requirements for potable supply All abstracted water is transferred to supply via existing pipe works or temporary pipes
Taking into account the assumptions made, no significant negative effects are predicted. Non-significant positive effects are predicted as the groundwater abstraction and transfer of this water into the resource zone will result in a minor reduction in pressure on the Ardingly Reservoir resource.
A WFD assessment has been carried out (see Error! Reference source not found.), however further work is still being carried out on assessing all environmental impacts of the groundwater abstraction on the Shall Brook, which is due to be completed in summer 2017. Once complete if there is a risk of deterioration to WFD objectives mitigation measures will be detailed in the environmental sections of the drought permit/order for this site.
4.3.5 The Hackenden drought permit/order (DAPS6) Environmental baseline The Hackenden Source (TQ396 396) comprises one operational well (No 1) following the infilling of the other well (No 2) in recent years due to contamination of that source. The No 1 well was constructed before 1910 and is located within the existing site building. The source is sited on the Ardingly Sandstone.
Historically the source had a licence allowing an average yield of 1.1 Ml/d and peak of 1.8 Ml/d, although it was typically only operated as a peak source during summer months to supplement local demands.
Raw water quality is known to be high in iron, manganese and suspended solids. Historically there were bacteriological problems with this source originating from the outside No. 2 well. Remediation work was carried out in 2008 to seal out the source of the bacteriological contamination.
Local land use is characterised by the urban environment of the north of East Grinstead and open areas of farmland with a series of extensive and interconnected woodland blocks and copses. No European or nationally statutorily designated Local Wildlife Sites are located with 5km or 2km of the source (respectively). Two non-statutory sites (Ashplatts Wood SNCI and Worth Way SNCI) are present within 2km but are not in hydrological continuity with the source.
A number of surface water features are also present in the local area. These are typically characterised by a dense clustering of ponds, lakes and some ghyll woodland.
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The site lies on the edge of the High Weald Area of Outstanding Natural Beauty.
Water Framework Directive classification Water bodies (including their current ecological and chemical status) within 2km of the drought permit/order are illustrated in a figure in Appendix Error! Reference source not found.. A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
Summary of the drought permit/order effects For the purposes of this assessment it has been assumed that:
All appropriate infrastructure is in place at the source Pump testing will have been undertaken and used to confirm the extent of any surface water drawdown and inform the need to re-scope this assessment with respect to potential groundwater effects Abstracted water meets all quality criteria associated with both Environment Agency consenting requirements and requirements for potable supply All abstracted water is transferred to supply via existing pipe works
Taking into account the confined nature of this source and the assumptions made, no significant negative effects are predicted.
Taking into account the fact that this source is highly confined and the assumptions (i.e. transfer directly into the supply network, no drawdown effects on surface water features, appropriate water quality to meet Environment Agency consent and potable water quality requirements), no potential effects arising from the implementation of the drought permit/order on environmental receptors have been identified. This is because of an absence of a physical pathway between the source (of the water) and environmental receptors.
4.3.6 The Southlands and Oakland’s licence drought permit/order (DAPS6) Environmental baseline The source is associated with new boreholes constructed and licensed in the past three years at two separate locations (Southlands and Oaklands). These abstract from the highly confined Hythe Beds formation, around 137 – 139m below ground level. The construction of Southlands and Oaklands boreholes ensures that no water is abstracted from the upper formations. The boreholes are cased out preventing vertical water movement. This was proven during the pumping tests and consequently there is no impact on any surface water features2,3. Abstraction licences have been granted for these sources but not to the full output quantities applied for as it was deemed unnecessary by the Environment Agency to support the average and peak supply in Resource Zone 5.
2 RZ5 New source development at Oaklands Borehole pump test interpretative report South East Water Dec. 2009 3 Groundwater enhancement scheme, new source development Southlands. Southlands Boreholes A and B pumping test factual report April 2011
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The potential yield calculations on both the boreholes, however, indicated that they could abstract in excess of the 2.4 Ml/d licence application.
The Hythe Beds Formation is between 100m and 200m below ground level at Southlands, and is confined by 50m of Sandgate clays and the Folkestone Formation. For this reason, the new boreholes are unable to impact any surface water features.
Both the Southlands and Oaklands sites are rural in character with small dwellings, farms and villages in the local area. The topography is undulating and comprises areas of woodland and more open farmland.
A number of European and nationally statutorily designated Local Wildlife Sites are present within 5km and 2km (respectively) of the sources.
For Southlands, these are:
Shortheath Common Special Area of Conservation (SAC) and Site of Special Scientific Interest (SSSI), which is approximately 1.55km to the north of the site East Hampshire Hangers SAC, which is approximately 875m to the northwest of the site. This section of the SAC is also designated as two SSSI: Wick Wood and Worldham Hangers, and Coombe Wood and the Lythe Wolmer Forest SAC and SSSI, which is approximately 1.7km to the southeast of the site. This site also forms part of the Wealden Heaths Special Protection Area (SPA)
For Oaklands these are:
Shortheath Common Special Area of Conservation (SAC) and Site of Special Scientific Interest (SSSI), which is approximately 1.15km to the southeast of the site East Hampshire Hangers SAC Wolmer Forest SAC and SSSI, which is approximately 1.7km to the southeast of the site. This site also forms part of the Wealden Heaths Special Protection Area (SPA) The site is also located on the northern edge of Binswood SSSI, which represents a fragment of the old Royal Forest of Woolmer
Water Framework Directive classification Water bodies (including their current ecological and chemical status) within 2km of the drought permit/order are illustrated in a figure in Appendix Error! Reference source not found.. A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
Summary of the drought permit/order effects For the purposes of this assessment it has been assumed that:
All appropriate infrastructure is in place at the source
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Abstracted water meets all quality criteria associated with both Environment Agency consenting requirements and requirements for potable supply All abstracted water is transferred to supply via existing pipe works
Taking into account the fact that this source is highly confined and the assumptions (i.e. transfer directly into the supply network, no drawdown effects on surface water features, appropriate water quality to meet Environment Agency consent and potable water quality requirements), no potential effects arising from the implementation of the drought permit/order on environmental receptors have been identified. This is because of an absence of a physical pathway between the source (of the water) and environmental receptors.
4.3.7 The Halling No.8 drought permit/order (DAPS6) Environmental baseline The Halling source currently comprises two operational boreholes (No 4 and No 7) and adits abstracting from the Upper Chalk horizons, and one borehole from the lower Greensand Formation (No 6). The source has current licences, which allow 2.2 Ml/d average from the Chalk and 3.0 Ml/d from the Greensand, with 4.0 Ml/d peak for both the aquifers.
Immediately adjacent the site to the north is a very large flooded quarry (the Grey Pit) which is now no longer worked. In 2005, South East Water drilled and tested the No 8 borehole on the edge of the site and proved that there was a connection between the lake water and the chalk water at this location (i.e. the abstraction from borehole No 8 effectively is from the quarry lake). Currently the Grey Pit overflows during most of the year as the historic abstraction by the pit operator (Cemex) is no longer used. It now overflows from the eastern corner into the part of the adjacent Medway marshes, but this overflow stops during the summer months.
Local land use is characterised by undulating areas of wooded, the small settlement of Halling, together with features associated with industrial activity. These include the flooded quarry, an area shown as works to the north east of the lake, former chalk pits and a waste water works. A number of smaller dwellings and farms are present in the local area. To the east is part of the Medway marshes together with tidal channels.
The source is adjacent to the lower part of the Medway catchment and is in hydrological continuity with the adjacent flooded quarry pit. The Medway at this location is tidal and a range of estuarine features are evidence (e.g. salt marsh, mudflats, creeks and tidal channels). Part of the marshland at this location is freshwater marsh, including the area into which the Grey Pit overflows during the winter months. Macroinvertebrate survey of the freshwater marsh will be carried out in summer and autumn of 2017 in order to expand on the baseline survey data and in order to assess potential environmental impacts of the groundwater abstraction. Once 2017 surveys are complete, any risk of deterioration mitigation measures will be included in this assessment if required.
A number of European and nationally designated Local Wildlife Sites are present within 5km and 2km (respectively). These are:
Peters Pit Special Area of Conservation (SAC) and Site of Special Scientific Interest (SSSI), which is approximately 2.5km to the southeast of the site.
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Peter’s Pit is an old chalk quarry with large ponds situated amongst grassland, scrub and woodland. The ponds have widely fluctuating water levels and large great crested newt Triturus cristatus populations have been recorded breeding here. The site is considered to be one of the best areas in the UK for this protected species.
North Downs Woodlands SAC, which is approximately 2.9km to the southwest of the site.
This site consists of a number of different habitat types, Asperulo-Fagetum beech forests, Taxus baccata woodland, and semi-natural dry grasslands and scrubland facies; for which the area is considered to either support a significant presence, or be one of the best areas in the United Kingdom.
Halling to Trottiscliffe Escarpment SSSI, which runs approximately 11km southwest to northeast, being approximately 500m northwest of the site at its closest point Holborough to Burham Marshes SSSI, which is approximately 1.7km to the southeast of the site Houlder and Monarch Hill Pits SSSI, which is approximately 1.1km to the south west of the site Four non-statutory Local Wildlife Sites are also present and are the:
Local Wildlife Site TM03 River Medway and Marshes, Wouldham Local Wildlife Site TM35 Arable Field, Lad’s Farm, Upper Halling Local Wildlife Site TM30 Leybourne Lakes etc., Snodland Local Wildlife Site ME10 South Hill and Houlder Quarries
It is considered that these sites are not in direct hydrological continuity with the source4.
Water Framework Directive classification Water bodies (including their current ecological and chemical status) within 2km of the drought permit/order are illustrated in a figure in Appendix Error! Reference source not found.. A WFD assessment has been carried out (see Error! Reference source not found.) and further detail of the potential impact of the drought permit/order on water bodies is provided in the following section.
Summary of the drought permit/order effects For the purposes of this assessment it has been assumed that: All appropriate infrastructure is in place at the Halling source Pump testing will have been undertaken and used to confirm the extent of any drawdown of the adjacent quarry water and inform the need to re-scope this assessment with respect to potential effects Abstracted water meets all quality criteria associated with both Environment Agency consenting requirements and requirements for potable supply All abstracted water is transferred to supply via existing infrastructure
4 Aquaterra, Halling feasibility study for Mid Kent Water, U124/B1/020 February 2007
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Potential effects arising from the implementation of the drought permit/order on the associated flooded former quarry lake and its biodiversity are considered to be associated with:
Effects associated with reduced water depth, drawdown and exposure of the littoral zone of the associated flooded quarry pit
The effects arising from the potential environmental changes are explored further in Table 4.8, which sets out the potential environmental changes associated with the implementation of the drought permit/order. These changes (the impacts) and resulting effects have been considered in detail, with respect to Valued Ecological Receptors, legally protected and/or notable species and other environmental receptors and have resulted in the identification of appropriate precautionary drought impact mitigation, monitoring and post drought restoration.
Table 4.9 – Potential environmental changes and effects associated with the Halling No.8 drought abstraction
Environmental change Potential generic Is worst case Is effect made Will effect be effect scenario effect less permanent negative & significant by significant? rainfall & opportunity to reduce abstraction? Sub-aerial exposure of Exposure of fish aquatic habitats including spawning habitats Yes Yes No marginal vegetation resulting in desiccation/mortality of eggs, and damage to habitat viability through formation of sediment ‘concretions’ Loss/ reduction in the diversity and/or quality of invertebrate habitats Potential for damage to or dieback of marginal vegetation through reduction in support from water column and drying out of bank face soil/sediment Loss of cover for prey species (e.g. tree roots, aquatic macrophyte stands) Reduced accessibility/quality of marginal bird nesting habitats Sub-aerial exposure of potential crayfish habitat.
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Environmental change Potential generic Is worst case Is effect made Will effect be effect scenario effect less permanent negative & significant by significant? rainfall & opportunity to reduce abstraction? Sub-aerial exposure of potential water vole habitat.
Reduction in lake water Potential for mortality quality due to decreased of fish, invertebrates Yes Yes No water volume and dilution and variation in capacity, increased concentration of algal macrophyte biomass and effects assemblages associated with higher Increased growth of summer water temperatures algae smothering vegetation and sediment, resulting in localised fluctuations in dissolved oxygen levels and reduced spawning success of some fish species Reduction in fish ‘fitness’ and increased susceptibility to parasites and disease
Increased algal growth with Increased growth of associated changes to algae, smothering Yes Yes No dissolved oxygen, BOD and vegetation and pH sediment which could lead to a reduction in the quality and diversity of available habitats Reduction in pH may result in mortality of e.g. molluscs and crustaceans Growth and dieback of algal population may cause localised fluctuations in dissolved oxygen concentrations and subsequent fish/invertebrate mortalities Reduction in habitat quality leading to a reduction in spawning success and successful development of fish juveniles
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Environmental change Potential generic Is worst case Is effect made Will effect be effect scenario effect less permanent negative & significant by significant? rainfall & opportunity to reduce abstraction? Increased risk of oxygen Fish/invertebrate depletion from dieback of mortalities Yes Yes No large biomass of vegetation Reduction in prey species for fish and otter
A WFD assessment has been carried out (see Error! Reference source not found.), however further work is still being carried out on assessing all environmental impacts of the groundwater abstraction. Once complete if there is a risk of deterioration to WFD objectives mitigation measures will be included in this assessment.
Taking into account the ability of established ecosystems to recover from climatic events such as drought and the post-drought monitoring, it is predicted that negative significant effects will not be present after six to 24 months and the local ecosystem will recover.
4.4 Environmental monitoring and data provision
For the three surface water Drought Permit sites the Environment Agency already collects a large amount of physio chemical, ecological and hydrological data. Standard Environment Agency methods are used throughout. See Error! Reference source not found. for a summary for the Environment Agency monitoring locations for reservoir Drought Permit monitoring location details. For the reservoir sites it is considered that the routine data gathered by the Environment Agency allows good coverage and enables long term trend analysis of any changes within the Drought Permit catchment, as is shown in the updated environmental baseline.
We acknowledge the Environment Agency’s representation on our draft drought plan concerning overreliance on Environment Agency monitoring data. For the Ouse abstractions, South East Water have undertaken significant baseline monitoring during 2017 at the survey locations set out in section 4.4.1. This has enabled us to update the previous baseline and set out the monitoring and mitigation for the Ouse should a Permit be implemented. In the case of the Cuckmere Permits, Environment Agency engagement during the early stages of drought plan development agreed that the current baseline information gathered would be sufficient for Permit application. Table 4.11 details current Environment Agency monitoring sites for fish, water quality, macroinvertebrates and flow. If these were to be discontinued, we would hope to discuss sites at which South East Water could continue to collect data to ensure that potential environmental impacts of Permit implementation could be monitored.
4.4.1 Baseline monitoring requirements for all River Ouse Drought Permit sites Further monitoring of the Ouse drought permit/order abstraction sites is considered necessary to assess any environmental impacts as they may occur, particularly if abstraction should be required during the summer period of a severe drought. Relevant
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available data will be used and updated regularly. The latest surveys undertaken to update the environmental baseline are as follows: Macroinvertebrate surveys in autumn 2016 and late spring 2017; Water quality in 2016; and River Habitat Survey in 2016.
We will include as part of our next business plan submission to Ofwat, funding to continue to gather baseline data at a wider range of sites throughout the Ouse catchment as listed in Table 4.10.
Table 4.10 – Drought permit/order monitoring sites Site Location Reason for site selection number 1 Ardingly Reservoir Potable water source supporting large fish biomass, is an SNCI and contributes flow and influence water quality in the Shell Brook and River Ouse. Potential for drought impacts resulting from reduced levels in reservoir. 2 Shell Brook immediately Is heavily influenced by Ardingly Reservoir and downstream of Ardingly influences water quality in the River Ouse. Reservoir 3 Abstraction point for Upper reach on the Ouse – is not affected by Ardingly on the R Ouse the Drought Permit. 4 Confluence of the Shell Upper reach on the Ouse - is affected by the Brook and the Ouse Drought Permit. 5 Downstream of Lower Large pool downstream of obstacle to fish Ryelands Bridge migration in low flows. 6 Upstream and Downstream Downstream is a large pool used for angling of East Mascalls Bridge and below obstruction to fish passage in low flow. Upstream includes riffle and glide habitat. 7 u/s Freshfield Bridge Main river site at EA gauging station upstream of farm and downstream of Scaynes Hill STW. 8 Location where channels Glide upstream of weir and upstream of channel split u/s of Freshfield Bridge divergence into historic canal. Downstream of (downstream of STW) Scaynes Hill STW. 9 Confluence of Cockhaise Long reach of channel upstream of Scaynes Hill Brook and Ouse upstream STW outfall through woodland with varied to d/s of main Ouse channel channel features and channel divergence. split 10 Cockhaise Brook This site has been removed from the assessment 11 Sheffield Park Station, d/s of Main channel downstream of road bridge with bridge riffle and glide habitats. 12 Fletching Mill, d/s left hand One of two channels associated with the Mill channel bridge with riffle habitat and downstream of road bridge. 13 Gold Bridge Main channel upstream of structure and downstream of bridge. 14 Sharpsbridge, immediately Channel dominated by glide upstream of bridge u/s of bridge and channel divergence. 15 Isfield, u/s of White Bridge to Long reach dominated by glides, including River Sutton Hall weir Uck confluence and terminating at Sutton Hall Weir and fish pass.
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Site Location Reason for site selection number 16 Anchor Inn Weir, River dominated by glides with flow control downstream and upstream structure and fish pass. 17 Confluence of the Bevern Downstream of confluence of watercourse with Stream with the Main Ouse perceived water quality issues, upstream of South East Water Barcombe intake. 18 Upstream of the South East Glide dominated reach at the location where Water abstraction point at South East Water abstract from the Ouse. Barcombe Reservoir 19 Barcombe Mills (u/s of the Glide dominated reach of the main Ouse Andrews Stream upstream of channel divergence. confluence) 20 Andrews Stream (including Downstream of South East Water abstraction. either side of the upper Andrews Cut (glide) and Andrews Stream/Pikes weir/fish pass and the Bridge Stream (riffle/run, pool/glide and fish downstream reach passes). Key fish passage channel and flow will be prioritised into this by the Drought Permit (DP). Considered to support spawning sea trout and lamprey. 21 Fishladder Stream Downstream of South East Water abstraction. Glide and pools with fish passes and Environment Agency gauging weir and flow will be stopped from flowing into this from the main channel by the DP. 22 Main Stream Downstream of South East Water abstraction. Main channel impounded by flood gates and flowing down a series of weirs pools. Flow will be prevented from entering this channel by the DP. 23 House Stream Downstream of South East Water abstraction. Glides and pools with fish pass. Flow from main channel restricted into this channel by DP. 24 Barcombe Mill Pool Downstream of South East Water abstraction. Large tidally affected pool below flood sluices and cascades. Believed that fish cannot pass beyond this point. 25 Main channel, d/s of Downstream of South East Water abstraction. confluence of all Barcombe Large glide dominated and tidally influenced Mill distributor channels & channel, supporting large coarse fish biomass. Pikes Bridge 26 Cowlease confluence Downstream of South East Water abstraction. Large glide dominated and tidally influenced channel, supporting large coarse fish biomass. Water quality issues sometimes associated with this tributary. 27 u/s of Hamsey Weir Downstream of South East Water abstraction. Large glide dominated and tidally influenced channel upstream of weir. Key: d/s - downstream, u/s – upstream
Baseline data gathered by South East Water in 2012 and where stated updated in 2016 is set out below. Subject to funding, this is also to be gathered in subsequent years.
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Survey metrics at all 26 sites (excluding Site 1 at Ardingly Reservoir) River Corridor Survey incorporating Target Notes for otter, water vole5 and other features of conservation note (1x 500m reach) Establishment of channel cross sectional profile (as part of RCS/RHS) to include channel width and depth profile (one depth measurement per m of width) from bed to bank full level; Wetted width and height from water surface to bank full level along adopted cross section Flow profile along representative cross section Depth of water above upper most obstruction and height below lower most obstruction and water surface (if present) Modular River Physical (MoRPh) survey (1x 500m reach) GeoRHS – channel element (1x 500m reach) Fixed point photograph Water quality from a turbidity monitor and a hand held multiparameter water quality probe (dissolved oxygen, electrical conductivity, pH, temperature, total dissolved solids, salinity). In addition, a visual and odour inspection of the water will be carried out. Ammonia sampling will be undertaken during winter low flow conditions Whether fish passes are clear of debris Survey metrics at former Environment Agency GQA and existing Environment Agency / South East Water drought monitoring sites (At Sites 2, 3, 6, 7, 11, 12, 13, 14, 15, 22, 26, 27 subject to funding)
Macro-invertebrate sampling to standard Environment Agency methodology, i.e. a 3 minute kick sample of representative habitats with additional 1 minute sweep of aquatic and marginal vegetation, in late May. The samples were be sorted and identified to species level by trained and experienced macroinvertebrate taxonomists in a lab with relevant quality control standards. Biological Monitoring Working Party (BMWP) and Average Score Per Taxon (ASPT) index scores were calculated and compared against historic Environment Agency and Ouse and Adur Rivers Trust (OART) data. LIFE scores were also calculated for each sample taken South East Water has requested that the OART macro-invertebrate surveyors undertake a standard sample from some of the tributaries of the Ouse (notably the Bevern, Uck, Iron River, Longford Stream, Shortbridge Stream, Pellingford Brook) At known/potential sea trout redd locations identified by OART and surveyed previously by John’s Associates Sea trout redd condition. Detailed inspections of known/ potential locations of sea trout redds (from data held by the OART) will be undertaken with OART specialists in January 2017. The purpose of this assessment is to confirm the condition of the redds in relation to fine sediment deposition and sediment concretions from current conditions (and other potential influences). This may identify the requirement to discuss redd habitat restoration opportunities with OART and its conservation volunteers
5 Completed bi-annually (e.g. March/April and September/October)
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Survey metrics at Ardingly Reservoir (Site 1) Water quality measurements taken at ten locations at 1.0m intervals in the water column (including turbidity, dissolved oxygen, electrical conductivity, pH, temperature, total dissolved solids, salinity). This has been updated in 2016 Macrophyte survey using grapnel to establish value of the submerged marginal community that is most vulnerable to littoral changes in water depth. This has been updated in 2016 Use of a portable downscan sonar to attempt to locate underwater structures that might trap fish in the reservoir under low level conditions, to identify feasibility of early deployment of aeration (e.g. a bubble curtain) Use of portable downscan sonar / fishfinder to identify key areas of fish congregations and potential fish habitat in relation to the depth profile of the reservoir. This will be used to inform the location of a possible ‘safe haven’ that can be oxygenated via a bubble curtain in order to provide refuge for fish should drought effects be manifested. This has been updated in 2016
In addition, Southern Water and the Environment Agency were approached to obtain records of waste water effluent quality and volumes for the purpose of understanding the relationship between receding channel flows, rainfall and the increasing dominance (and potential impact) of treated waste water in the riverine flow. South East Water provided rainfall data and abstraction data. Flow data was obtained from the Environment Agency. The data was added to the drought database and GIS.
4.4.2 Baseline monitoring requirements for the River Cuckmere drought permit/order We will use the data gathered by the Environment Agency to maintain our awareness of the environmental baseline to inform future drought permits.
4.4.3 Summary baseline monitoring requirements for all drought permit/order sites The list of monitoring sites within Table 4.10 will be reviewed and updated annually to ensure it remains accurate. The Environment Agency will be contacted as part of this review process to ensure monitoring locations or frequencies have not changed. We have however confirmed with the Environment Agency that monitoring at these sites is to be continued for the foreseeable future.
Table 4.11 outlines a proposed baseline monitoring plan for the additional source of supply drought permit sites. There will be consultation with the Environment Agency about the environmental baseline for these sites and monitoring procedures will be adjusted as appropriate.
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Table 4.11 – Summary of monitoring points which relate to the environmental baseline and continuous annual monitoring requirements for the surface water drought permit/order sites
See Figure N.1 in Error! Reference source not found. for the locations of the monitoring stations. In order to prepare the drought plan, we have consulted with the Environment Agency and agreed the locations of these monitoring sites for future data collection. Most of these sites are historic Environment Agency monitoring sites.
Drought Permit Site location Data type From To Frequency River Ouse Ardingly Sharpsbridge Q Fish 08/08/2002 Present Annual River Ouse Ardingly Upper Ryelands Fish 15/08/2001 Present Annual River Ouse Ardingly Avins Bridge Fish 09/08/2001 Present Annual River Ouse Ardingly East Mascalls Bridge Q Fish 09/08/2002 Present Annual River Ouse Ardingly Sloop Q Fish 13/08/2002 Present Annual River Ouse Ardingly Sheffield Bridge Q Fish 20/08/2002 Present Annual River Ouse Ardingly Newick Q Fish 09/10/2003 Present Annual River Ouse, Barcombe Highbridge Lane Fish 06/08/2002 Present Annual River Ouse, Barcombe Clappers Weir Fish 07/08/2002 Present Annual River Ouse, Barcombe Barcombe Mills Fish 24/09/2007 Present One off River Ouse, Barcombe Isfield Church Fish 02/10/2003 Present Annual Cuckmere, Arlington Sherman Bridge Q Fish 15/09/2003 Present Annual Cuckmere, Arlington Arlington Intake Q Fish 20/07/2000 Present Annual Cuckmere, Arlington Michelham Priory Q Fish 20/09/2002 Present Annual Cuckmere, Arlington Sessingham Farm Q Fish 20/09/2007 Present Annual U/s SE Water's Abstraction Macroinverts/ River Ouse Ardingly 20/05/2005 Present Spring and Autumn Point Ardingly /Macrophytes Macroinverts/ River Ouse Ardingly U/s Shell Brook Confluence 21/08/2006 Present Spring and Autumn /Macrophytes Macroinverts/ River Ouse Ardingly Ardingly Treatment Works 27/04/2006 Present Spring and Autumn /Macrophytes D/s Abstraction, D/s Shell Macroinverts/ River Ouse Ardingly 18/04/2007 Present Spring and Autumn Brook Confluence /Macrophytes Macroinverts/ River Ouse Ardingly Upper Ryelands Bridge 21/08/2006 Present Spring and Autumn /Macrophytes Macroinverts/ River Ouse Ardingly East Mascells 27/04/2006 Present Spring and Autumn /Macrophytes Macroinverts/ River Ouse Ardingly Freshfield Bridge 20/05/2005 Present Spring and Autumn /Macrophytes Macroinverts/ River Ouse Ardingly Sharpsbridge 28/04/2006 Present Spring and Autumn /Macrophytes Macroinverts/ River Ouse, Barcombe Isfield 13/04/2005 Present Spring and Autumn Macrophytes Macroinverts/ River Ouse, Barcombe 100m U/s Anchor weir 02/08/2007 Present Spring and Autumn Macrophytes Macroinverts/ River Ouse, Barcombe Barcombe Mills 13/04/2005 Present Spring and Autumn Macrophytes Macroinverts/ Cuckmere, Arlington Michelham Priory 11/04/2005 Present Spring and Autumn Macrophytes Macroinverts/ Cuckmere, Arlington Arlington Intake 08/05/2006 Present Spring and Autumn Macrophytes Macroinverts/ Cuckmere, Arlington Sherman Bridge 13/05/2005 Present Spring and Autumn Macrophytes Cuckmere, Arlington Michelham priory RHS RHS 2009 Present -
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Drought Permit Site location Data type From To Frequency River Ouse, Barcombe Barcombe RHS RHS 2009 Present - River Ouse Ardingly Ardingly RHS RHS 2009 Present - Abstraction Point Ouseby- River Ouse Ardingly Water Quality 1984 Present Monthly Ardingly River Ouse Tributary Shell River Ouse Ardingly Brook at Shellbrook Pumping Water Quality 1976 Present Monthly Station River Ouse Ardingly East Mascells Bridge Water Quality 1984 Present Monthly River Ouse Ardingly Sharpsbridge Water Quality 1987 Present Monthly River Ouse Ardingly Goldbridge Water Quality 1984 Present Monthly River Ouse Ardingly Fletching Mill Water Quality 1976 Present Monthly River Ouse Ardingly Sheffield Park Station Water Quality 1984 Present Monthly River Ouse Ardingly Freshfield Bridge Water Quality 1984 Present Monthly River Ouse, Barcombe Barcombe Mills Water Quality 1984 Present Monthly River Ouse, Barcombe Anchor Weir Water Quality 1984 Present Monthly Cuckmere, Arlington Sherman Bridge Water Quality 1984 Present Monthly Cuckmere, Arlington Arlington Intake Water Quality 1984 Present Monthly Cuckmere, Arlington Michelham Priory Water Quality 1984 Present Monthly River Ouse Ardingly Ardingly Shellbrook weir River Flow 01/01/1970 Present River Flow - Continuous River Ouse Ardingly Ardingly Weir River Flow 01/08/1979 Present River Flow - Continuous River Ouse, Barcombe Barcombe (fish ladder) River Flow 01/05/1981 Present River Flow - Continuous River Ouse, Barcombe Barcombe Ultrasonic River Flow 17/11/1999 Present River Flow - Continuous Cuckmere, Arlington Sherman Bridge River Flow 01/02/1959 Present River Flow - Continuous Cuckmere, Arlington Milton Lock River Level 14/07/1999 Present -
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Table 4.12 – Summary environmental baseline and continuous annual monitoring requirements for the five groundwater sources of supply drought permit/order sites
Environmental baseline monitoring Balcombe Hackenden Chasewood Halling Chalk no. 8 Southlands & Oaklands South East Water to determine the quantity and Yes Yes Yes Yes Yes quality of raw water from the boreholes, (particularly in relation to iron, manganese, ammonia, suspended solids and bacteria)
Once raw water quality is established South East Yes – discharge into Yes – to establish NA Yes – to establish NA – no surface water Water should undertake a review of the baseline Supply via temporary parameters of parameters of features will be with the Environment Agency to establish the pipeworks. abstraction licence for abstraction licence for impacted arrangements for discharge and/or abstraction at site site site. Assuming that raw water quality will meet Yes – for Shell Brook NA NA Yes for Grey Pit NA – no surface water acceptable levels. A baseline will be developed for features will be chemical water quality of both the raw water and impacted for the augmentation site. Data will be collected on a monthly basis (to provide an up-to-date baseline). Data will be collected before any discharge occurs to establish baseline conditions of the tributary prior to the release of any augmented flow. Baseline invertebrate data should be collected Yes NA NA Yes – to establish NA – no surface water prior to any abstraction taking place. The location impacts on features will be of sampling points should be discussed with the neighbouring Grey Pit, impacted Environment Agency but it is envisaged that they to include would be located upstream and downstream of the macroinvertebrates, abstraction site, with a further site being located at fisheries and protected the abstraction site itself. Spring and autumn species. invertebrate samples should be collected to monitor baseline conditions at this site. To establish a baseline for flow, spot flow gauging Yes at Balcombe NA NA NA NA – no surface water should be undertaken, this will be repeated three features will be times a year. Exact locations to be discussed with impacted the Environment Agency Once a baseline has been established, determine Yes Yes NA Yes NA – no surface water the location of weekly visual check sites to monitor features will be any impact of the operation of this scheme during impacted drought conditions.
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4.4.4 Monitoring requirements during drought permit/order operation. Section 4.4.3 above outlines baseline monitoring to be undertaken on a continuous basis and it is assumed that a complete baseline will be available for each site prior to implementation of any drought permit/order.
In addition to regular baseline monitoring, the following parameters will be measured to establish any impact of the utilisation of the drought permit/order.
The River Ouse The following parameters will be recorded at all 26 sites (excluding Ardingly Reservoir [Site 1]) during the period when the drought permit/order is implemented (i.e. MRF of 10 Ml/day at Barcombe):
Bankfull width and bankfull depth (to water surface) at the five established GeoRHS cross sections to allow calculation of change in water depth Flow measurement along representative cross section Depth of water above uppermost obstruction and above lowermost obstruction and distance between lowermost obstruction and water surface (if present) to demonstrate any changes in the functionality of the structure and the potential for continued fish passage Visual evidence of a reduction / increased vulnerability of key habitat features (e.g. sub-aerial exposure of key fish spawning habitat) Fixed point photograph Water quality from a hand-held probe (dissolved oxygen, electrical conductivity, pH, temperature, total dissolved solids, salinity [will be taken at 0.5m depth intervals below Barcombe Mills to detect the denser saline wedge], turbidity), as well as observation (odour and visual condition [e.g. colour, foam etc]). In addition, ammonia will be tested for. This is because with reduced flows the dilution from sewage effluent will be less and levels of ammonia will rise. Ammonia is toxic to aquatic life at relatively low levels and is probably the best field method for assessing how much sewage effluent is in the water Southern Water has provided sewage effluent data and this dataset will be maintained live. This, together with ammonia monitoring, will allow the monitoring of the potential effect of sewage effluent in the low flow conditions experienced in drought. The suite of 26 sites will encapsulate the various STW outfalls down through the catchment and a cumulative assessment of changes in ammonia, DO etc will be undertaken Algae – chlorophyll measurement, plus visual records (e.g. percentage cover, blooms, scum) Qualitative visual assessment from observation of fish mortality, poaching and predation; efficiency of fish ladders, evidence of stranded fish, algal and macrophyte growth together with any general observations of areas requiring further scrutiny
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Ardingly Reservoir The following parameters will be recorded at Ardingly Reservoir:
Water quality measurements taken at a minimum of 10 locations at 1m intervals in the water column (including turbidity, dissolved oxygen, electrical conductivity, pH, temperature, total dissolved solids, salinity)
Visible evidence of an algal bloom e.g. scums
Visible evidence of fish in distress
Use of downscan sonar/ fishfinder to confirm whether fish are using prospective ‘safe haven’ areas as drought conditions develop
Monitoring below Barcombe Mills
Continuous monitoring of conductivity/salinity below Barcombe Mills to help detect the upstream migration of the saline wedge that may result in fish and macroinvertebrate mortalities and trigger appropriate mitigation
Frequency of monitoring The weekly drought permit/order monitoring programme will be initiated once the Drought Permit has been issued and implemented. Weekly monitoring will commence on the following basis:
Weekly monitoring of 26 sites at a Mean Residual Flow (MRF) of 10 Megalitres a day at Barcombe Mills
Twice weekly monitoring of all 26 sites at a MRF of 10 Megalitres a day at Barcombe Mills and the exceedence of any of the prescribed drought thresholds associated with fish, dissolved oxygen, blue-green algae, pollution or the upstream migration of the tidal saline wedge below Barcombe Reservoir.
Daily monitoring immediately above and below Barcombe Mills and at Ardingly Reservoir to observe early signs of fish in distress and the need to trigger fish rescues
Daily monitoring of appropriate parameters (agreed with the Environment Agency) at those sites where mitigation measures are being implemented (see Table 5.2) until environmental conditions return to a state that does not trigger mitigation
The River Cuckmere In order to determine whether sufficient inflow to the West Dean Brooks System continues to occur, and to identify when limited inflow occurs, it is recommended that the feed of water from the Cuckmere through the siphon into the West Dean Brooks ditch system is monitored. The level of water in West Dean Brooks can be assessed using the level marker in the West Dean Brooks system (Natural England are currently monitoring this). In addition to this, a small gauging station could be installed downstream of the siphon outfall at Long Bridge to monitor the flow of water into the
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West Dean Brooks ditch system. This could be coupled with a gauging mechanism at the siphon intake upstream of Milton Lock. These structures would allow an assessment of the flow into the SSSI, and assist the Environment Agency in the correct operation of Milton Lock to ensure that sufficient water passes into the ditch system.
Summary for all sites Table 4.13 provides a summary of the environmental monitoring required for all drought permit/order sites.
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Table 4.13 – Summary of monitoring required for the duration of drought permit/order operation Drought permit monitoring actions Balcombe Hackenden Chasewood Halling Southlands Ouse Ouse Cuckmere Chalk no. 8 & Oaklands (Summer) (Winter) Weekly monitoring of the quantity of water discharged or abstracted and the Monitoring NA Monitoring Monitoring Monitoring Monitoring of Monitoring Monitoring raw water quality. water quantity of quantity of quantity of water of water of water discharged at groundwater groundwater groundwater abstracted abstracted abstracted
Shell brook abstracted abstracted abstracted and raw only only only water Weekly monitoring of water quality parameters (to include dissolved oxygen, Yes at Shell Yes at wet NA Yes at Grey NA Yes Yes Yes temperature, suspended solids, iron, manganese, total ammonia, UIA and brook both woodland Pit quarry pH). up and features. downstream (parameters of discharge to be based on dependent features) Increase macroinvertebrate sampling to cover a summer sample. Yes NA NA Yes NA Yes Yes Yes
Weekly water level monitoring of both the groundwater level and tributary (at Yes NA Yes Yes NA NA NA NA point of discharge). groundwater only Weekly visual checks to monitor any impact of the operation of this scheme Yes Yes - to be NA NA NA Yes Yes Yes during drought conditions e.g. Potential fish entrapment/ fish distress, based on reduction in water level etc. (in line with weekly monitoring checklist River Ouse & established for the Drought Permits for the rivers Ouse and Cuckmere). Cuckmere but amended Regular inspections should be undertaken below the impounding structures to apply to to identify if fish populations are distressed. It is recommended that this is wet weekly initially and increased to daily if distressed fish are located. Basic woodland water quality measurements could be recorded at this time (e.g. DO, features temperature, pH and conductivity). Weather conditions should also be recorded i.e. cloud cover and air temperature. If distressed fish are located during monitoring, then efforts should be made NA NA NA NA NA Yes Yes Yes to capture and manually lift fish over the structures to a point upstream of Augmentation any major impediments to migration. scheme Regular inspection and maintenance of the functioning of fish passes should NA NA NA NA NA Yes Yes Yes be undertaken. On-going, annual collection and review of photographic data (repeating that NA NA NA NA NA Yes Yes Yes carried out by South East Water in 2003) to monitor the effects of the proposed Drought Permit. Autopsies of dead/dying sea trout should be undertaken to confirm key NA NA NA NA NA Yes Yes Yes causes of mortality. Monitoring of conductivity/salinity below Barcombe Mill to confirm the NA NA NA NA NA Yes Yes NA presence and location of the saline wedge during the operation of the Drought Permit.
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4.5 Mitigation measures
4.5.1 General measures Water depth and flow velocity can be enhanced during low flow scenarios through the placement of temporary-channel structures along the toe of the bank (where land access and owner permission can be secured). These could comprise brash-filled coir rolls, gabion baskets filled with cobbles or other relatively inert non-polluting materials. In general terms, the following practical measures can be proposed for the mitigation of the potential risks associated with the concentration of the fish population below structures or potential obstacles:
Regular observations to be made of obstructions and the ability of fish to pass over them (see weekly site checklist in Error! Reference source not found.) Increased bailiff presence to restrict poaching at key locations, including above and below all obstructions and pools Protection of spawning redds with increased bailiff presence at these locations Fish ladders should be regularly checked and cleared of obstructions Draw up a contingency plan for the implementation of a fish rescue in the event of a pollution event, or other event resulting in poor water quality, to manually transport fish upstream of any incident
In terms of natural predation, no mitigation measures are proposed. Where surveillance of aquatic macrophyte growth is recommended, weed cutting and removal may need to be implemented if channels are becoming choked / impassable to fish. This should be carried out in a way that provides opportunity for the vegetation to provide a temporarily restricted channel with maintained water depth and velocity. Please refer to individual statements in Error! Reference source not found. and Error! Reference source not found. for specific case by case mitigation and monitoring recommendations where applicable.
A general water quality deterioration is considered to be unlikely but a water quality monitoring programme to identify changes and potential effects is proposed below.
For the Halling and the Southlands and Oaklands drought permit/order the environmental assessment determined a wealth of archaeological features within close proximity to the drought permit locations. These features could potentially be impacted by the effects of dewatering caused by increased abstraction. As part of the drought permit/order application process a more detailed screening of these features would be carried out and relevant mitigation to include regular monitoring at specific sites of concern will be agreed with Historic England and / or County archaeological officers
4.5.2 Ouse Mitigation measures identified for the Summer Ouse drought permit/order are listed below. Mitigation for the winter permit features a more restricted list as it takes into account winter flows above the abstraction at Barcombe and a more restricted extent of potential impacts. Please refer to the winter drought permit/order report for further information.
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Table 4.14 – Reactive drought permit/order mitigation Mitigation measures in italics relate to those where South East Water is reliant on a partner organisation to secure landowner permissions.
Mitigation Mitigation measure & ownership Potential locations reference M1 Environment Agency: Clear debris from fish E.g. Sutton Hall Weir/Pass, passes retained for use or alert EA of the Anchor Weir/Pass, House need to do if risk assessment identifies this Stream/Pass, Andrews is a specialist task (e.g. requires access Stream and Passes. keys or from boat). Trigger: Presence of debris at inlet to fish pass potentially reducing its effectiveness. M2 South East Water (SEW): Deploy 1 of (up e.g. Upstream of Barcombe to) 3 portable oxygenation kits to specific Mills, Anchor Weir, Sutton reaches. This kit will be held by SEW with at Hall Weir, Gold Bridge. least two teams trained in its use and maintenance. Trigger: 1) DO is below 6 mg/l but above 5 mg/l: Notify SEW of potential need to mobilise oxygenation kits if further DO reductions observed or fish in distress are recorded. 2) DO is below 5 mg/l but above 4 mg/l: SEW deploy oxygenation kits at required locations.
M3 SEW: Implement a fish rescue (co- All 26 monitoring sites OR ordinated with Mid-Kent Fisheries, the EA in response to and OART), with the release of fish to a pre- communication from agreed on-line River Ouse reach not subject landowners to similar water quality impacts or pre- agreed off-line temporary oxygenated holding pond. Oxygenation kits will be utilised at both source and receptor sites as appropriate. Proposed fish rescue receptor sites and aeration/access etc will be part of ongoing works agreed with EA in advance of permit application. Trigger: Fish recorded in distress (e.g. ‘gasping’) and DO levels below 4 mg/l or evidence of dead/dying fish. M4 SEW: Implement enhancement of riverine These benefits and structures at other locations owned by EA or mitigation measures will be County/District/Parish Councils (to be structure-specific. . agreed with Councils/EA and OART). Examples are provided in Annex B2. Final options will be presented to landowners and the EA as part of on-going pre-permitting discussions. Trigger: Qualitative evidence that the structure is no longer delivering existing benefits (e.g. oxygenation of water, enabling fish passage). M5 SEW: If communications with private Any reach of the river landowners have been successful, between Ardingly and implement agreed temporary in-channel Barcombe. drought mitigation measures (e.g. channel narrowing, removal of significant obstructions, increase in turbulence to increase aeration).
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Mitigation Mitigation measure & ownership Potential locations reference Trigger: Qualitative evidence that in-channel mitigation measures are required in response to landowner communication highlighting particular issues (e.g. reduction in flow, water depth, restriction in fish passage etc). M6 SEW: Alert Southern Water of emergency At Southern Water Sewage conditions and request implementation of Treatment Works (e.g. relevant options to positively influence the Scaynes Hill) riverine flow from sewage discharge (e.g. reduce discharge volume through use of holding tanks until forecasted rainfall occurs or maintain flow support from effluent if no issues with quality). Trigger: Deployment of SEW oxygenation kit. M7 SEW: Alert EA to observed pollution event Any reach of the main river and liaise with respect to drought monitoring and tributaries between and mitigation requirements. Ardingly and Barcombe. Trigger: Qualitative evidence that polluting material has entered the river channel (e.g. visual evidence [foam, sheen on the water/ vegetation / substrate], presence of dead fish etc). M8 SEW: Emergency release of water from Any main river location Ardingly Reservoir (if available) in response below Ardingly Reservoir. to major pollution incident or upstream movement of the saline wedge upstream of Hamsey Weir (if authorised by the EA). The proposed flush of water is used as a last resort primarily for moving the saline wedge downstream and avoiding a big fish kill. There may be an associated effect of an attractant flow for salmonids, although other factors will be prime reason for movement – and assuming 10 Ml/d over Andrews is occurring, the passage of fish should be facilitated in any case. Trigger: Either: Detectable upstream movement of the saline wedge (using a water quality probe) more than 400m upstream of Hamsey Weir and evidence of fish movement upstream and congregating below structures at Barcombe Mills (using a portable fish finder). Or: Notification by the EA of, or change in monitored water quality from averaged baseline data (e.g. pH, DO, electrical conductivity, turbidity) or qualitative evidence that, polluting material has entered the river channel (e.g. visual evidence [foam, sheen on the water/ vegetation / substrate], presence of dead fish etc) and resulting in a verifiable (by the EA) major pollution incident. M9 SEW: Undertake cleaning (e.g. raking or OART identified sea trout pressure washing in Autumn) of known sea redds in main river channel trout redds that have deteriorated in quality and tributaries. since pre-drought condition assessment.
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Mitigation Mitigation measure & ownership Potential locations reference Trigger: Post drought re-survey drought permit/order implementation highlights a deterioration in the condition of known sea trout redds from the established condition at the time of the 2012 baseline survey. This may include: increase in depth of sediment within gravel deposits and presence of sediment ‘concretions’ or exposure of redds above current water level. M10 SEW: Make a written request to the EA and Any key angling location angling clubs to restrict angling activities. downstream of Ardingly Reservoir. Trigger: Deployment of oxygenation equipment. Evidence of fish congregating at in-channel structures.
M11 SEW: Liaise closely with EA, anglers, OART Throughout Ouse and Sussex Police with respect to poaching catchment. risk or direct evidence. Trigger: When MRF at Barcombe is reduced to 10 Ml/d M12 SEW: 1) Along publically accessible 1) Installation of laminated notices stretches of the identifying the presence of a blue- main River Ouse. green algal bloom or other water- 2) River Ouse borne health hazard at locations downstream of where public access to the water is Ardingly likely (e.g. boating/paddling). Reservoir. 2) Emergency release of water from Ardingly Reservoir (if available) to attempt to flush the bloom from the river. Trigger: 1) WQ monitoring (turbidity, temperature and OART nutrient analysis). Visual evidence that a blue-green algal bloom is occurring (from scums). 2) After reports of animal deaths, with agreement of EA and EHO.
M13 SEW: South East Water to monitor river and Ardingly Reservoir/River reservoir (Ardingly and Barcombe) water Ouse intake/Shell Brook quality to manage the effects of a reduction Treatment Works; and in abstracted water quality and/or reservoir Barcombe Mills Reservoir, quality on the effectiveness of current River Ouse intake and treatment system for potable water supply. Barcombe Mills Treatment SEW to implement measures to minimise Works; and effects through potential inter reservoir Arlington Reservoir. transfers (Barcombe and Arlington), direct abstraction to treatment plant or diversion into reservoir prior to treatment (Barcombe). Trigger: Deterioration in water quality in the main river or reservoirs below existing SEW operating thresholds. M14 SEW: Structural engineer to undertake E.g. Sutton Hall Weir condition assessment of historic structures/bridges. Provision of appropriate physical support of the structure if engineer assessment deems this to be necessary.
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Mitigation Mitigation measure & ownership Potential locations reference Trigger: Exposure of more than 50 per cent of previously submerged extent of historic structure/bridge and visual evidence of structural damage (e.g. cracks). M15 SEW: Deploy bubble curtain to create fish Ardingly Reservoir ‘safe haven’ at Ardingly Reservoir and monitor its effectiveness at maintaining oxygen concentrations.
Trigger: Reduction in DO concentration below 5 mg/l M16 SEW: Undertake fish rescue if safe and Ardingly Reservoir feasible, relocating fish to aerated ‘safe haven’ in Ardingly Reservoir. Trigger: Fish in distress or evidence of dead/ dying fish Key: EA: Environment Agency, OART: Ouse and Adur Rivers Trust, DO: Dissolved Oxygen, EHO: Environmental Health Officer.
4.5.3 Cuckmere, and Sedlescombe Critical reaches for fish passage and potential entrapment will be identified in association with the Environment Agency during the on-going baseline data gathering phase. These areas will be visited on a weekly basis or at a frequency agreed with the Environment Agency and will be assessed using the environmental checklist outlined in Error! Reference source not found. (in Error! Reference source not found.). The checklist will be used to assess on a regular basis whether the option is having an environmental impact. The data will also be used to identify situations where fish are in distress or at-risk from predation/poaching. With the aid of the Environment Agency, this will ensure that appropriate measures can be implemented to resolve specific environmental issues.
4.5.4 Remaining groundwater abstraction sites Subject to proposed pump testing, critical wetland habitats will be identified in association with the Environment Agency during the baseline data gathering phase. These areas will be visited on a weekly basis or at a frequency agreed with the Environment Agency and will be assessed using the environmental checklist outlined in Error! Reference source not found.. The checklist will be used to assess on a regular basis whether the option is having an environmental impact.
4.5.5 Working in partnership with key stakeholders We will work in partnership with a wide range of organisations to minimise the effects of the drought and this drought permit/order. At the time of preparing this document these included:
Environment Agency Ouse and Adur Rivers Trust (OART) Sussex Wildlife Trust
This partnership will include: The sharing of non-commercially sensitive data
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Transparency and regular communication about monitoring results and environmental effects Sharing of common objectives for the benefit of the river and its community We will provide a certain level of funding to Ouse and Adur Rivers Trust and the Environment Agency e.g. to:
- Enable the Environment Agency to modify and operate structures at Barcombe Mills for low flow conditions - Enable OART to deliver drought enhanced river restoration projects at locations where South East Water has no direct control
We will provide training (as necessary) and work with OART to maximise the opportunities for relevant data gathering and analysis ‘Co-badging’ key public information (e.g. posters) and co-hosting awareness events (e.g. at the Barcombe Water Festival)
We also have a good relationship with the other stakeholders associated with our watercourses and have completed a wide range of public engagement relating to drought and water efficiency with its customers and the general public. 4.5.6 Post drought For the River Ouse (summer period) drought permit/order, we will undertake post drought monitoring for two years.
For the Cuckmere and the groundwater source drought permit/order options, during single season drought events it is assumed that resilience in the aquatic environment should allow the riverine systems to recover without further intervention. However, where there are longer term effects observed as part of the drought monitoring, it may become apparent that pro-active restoration works may be required. This may be particularly associated with multi-season or particularly extreme events. Please refer to the specific drought permit/order assessments for detailed confirmation of the site- specific proposals. These can be found within Appendices Error! Reference source not found. to Error! Reference source not found..
4.5.7 Longer term monitoring recommendations during drought permit/order operation Longer term recommendations are made for the Ouse only. While not strictly relevant to satisfy the requirements of a drought permit/order application, they are relevant within the context of an ecological appraisal. These investigations, if carried out, would allow confirmation of current predictions.
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5 IMPACTS ON THE COMMUNITY
5.1 Introduction
As explained in Section 4.1 we do not consider that an SEA of the drought plan is necessary because of its temporary use, and because it does not set a framework for the future development consent of projects within Annexes I and II to the EIA Directive. Consultation on the 2012 draft drought plan did, however, lead us to include an additional environmental assessment of the impacts of any drought actions on the human environment i.e. the use of water for health and wellbeing of both customers and for other users (such as business users; including recreation and tourism). For each of the demand and supply side actions we have examined potential impacts and their significance. Where adverse impacts have been identified the likely mitigation measures to be implemented during use of that drought action have been set out.
5.2 Assessing the impacts to the community
The scoring system as shown in Table 5.1 has been used to assess potential impacts to the human environment. Specific consideration has been given to impacts to customer health and wellbeing, and impacts to other business, non-household water supply retailers or recreational related users.
Table 5.1 – Key for significant effect scoring for impacts on the community assessment
Key for Prediction of Significant Effects Minor Adverse
Major Adverse
Minor Beneficial
Major Beneficial
- Neutral Effect (i.e. no change)
Table 5.2 indicates the adverse impacts to the human environment that could occur in response to the demand side measures: temporary use ban and drought orders to impose further restrictions. The only major adverse impacts are expected during phase 3 or 4 of the water restrictions. This would be when non-essential use drought orders are in use and these are considered to be most likely to directly impact on some business users. There are not expected to be major impacts that will prevent community services such as hospitals, schools, residential centres, prisons etc. from operating as normal as a result of these demand side actions during a moderate or severe drought status.
For supply side measures, there could be minor impacts to the human environment as a result of changes to our sources of supply and connectivity of supply areas and as a result of surface water drought permits/orders. However, of most concern would be
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the use of emergency drought orders during an emergency drought situation. At this point our emergency plan would be activated and plans would be put in place with local authorities and other water companies to ensure a supply of water to essential users, and the wider community.
Mitigation measures are described within Table 5.3. During a severe drought status event, we would be planning for an emergency situation. It should be noted that the revised draft drought plan covers our operations until the severe drought status, and that emergency planning and emergency drought orders technically fall outside the scope of this drought plan. Their use would be governed by emergency planning procedures.
Table 5.2 – Assessment of impacts to the human environment Action Scoring Comment
Customer Customer health being well and users Other DAPD1 Water - Health and wellbeing conservation Raising awareness on the importance of water will result in reduced water campaigns usage. Reducing customer demand for water will reduce the abstraction at and calls for source which will in turn contribute to reducing the amount of energy needed voluntary for water abstraction, treatment and distribution. Campaigns could raise restraint other important issues and educate groups on the value of water for health and wellbeing.
Other users There would be no adverse impacts on recreational activities or tourism. DAPD2 - Health and wellbeing
Operational Leakage enhancement will contribute to reduced water loss, and pressure works to management and conservation schemes will lead to less water being used. reduce This is likely to influence and have a positive impact on customer water demand conservation campaigns.
Other users
Demand side There would be no adverse impacts on recreational activities or tourism. DAPD3 Health and well being Temporary Temporary water restrictions will contribute to water savings. However, there water use could be impacts to customers such as increased stress about conservation restrictions of water. Some customers are likely to be impacted through measures such as not (Phase 1 and being able to use a hosepipe to water a vegetable patch in a private garden 2 water use (Phase 1), wash a car (Phase 1) or clean a private leisure boat (Phase1). restrictions i.e. Customers who hold Blue Badges are a concession in Phase 1 and therefore a temporary will not be impacted until Phase 2. use ban) There are not expected to be major impacts that will prevent community services such as hospitals, schools, residential centres, prisons etc. from operating as they would under non-drought conditions. The Phase 1 and 2 water use restrictions i.e. a temporary use ban is not applicable to these community services.
Other users Impact on non-household retailers - some of the non-household businesses’ related activities may be impacted such as landscape gardeners not being able to water newly laid turf or plants with a hosepipe, carwash businesses
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that use hosepipes and golf courses and cricket grounds which are not used for national or international sports events. Although depending on the severity of drought concessions will be granted where possible to alleviate any impact (e.g. newly laid turf may be given concession for 28 days). DAPD4 Health and wellbeing Restrictions Significant impacts on the daily lives of public but only a slight increase in on uses of terms of risk to health from measure DAPD4 Temporary water use water through restrictions. a drought order Again there are not expected to be major impacts that will prevent community services such as hospitals, schools, residential centres, prisons etc. from (Phase 3 and operating as they would under non drought conditions. Drought orders to 4 water use restrict water use will not be applicable to these community services. restrictions) Other users Major adverse effects with respect to businesses that rely on water (e.g. window cleaners, and car washing businesses). Significant impacts on the daily lives of public and businesses. Non-household water supply retailers are also likely to be affected by this action. DAPS1 - - Health and wellbeing / other users Optimisation No impacts on customers or others. of existing sources DAPS2/3 - Health and wellbeing Infrastructural Due to changes to the network and bringing online of disused sources there connectivity may be a slight change in the taste of water that some customers are and source supplied with. Some customers could be concerned. improvements and use of Other users disused There would be no adverse impacts on recreational activities or tourism. sources DAPS4/5 - Health and wellbeing / other users Shared Due to changes to the network and bringing online alternative sources there resources and may be a slight change in the taste of water that some customers are bulk transfer supplied with. Some customers could be concerned. agreements (extensions / Other users new There would be no adverse impacts on recreational activities or tourism. agreements) DAPS6/7 There would be no impact on the amount of water customers could use. Drought However the following potential impacts to customers health and wellbeing permits / and other users have been identified and overall have been considered to orders present a minor adverse impact:
Supply sideSupply Health and wellbeing There could potentially be health risks to human, livestock and domestic animals from reduced river water quality arising from use of some of the surface water Drought Permit options e.g. use of the Summer Ouse drought permit/order. These have been assessed as having a minor adverse impact within this overall assessment; however localised issues identified within environmental assessments of specific drought permits/orders may attribute a higher severity of impact.
Some of the groundwater drought permits/orders involve bringing online disused sources. There may be a slight change in the taste of water that may be of concern to some customers.
Other users For surface water drought permits/orders there could be adverse impacts to recreational value of the rivers Ouse and Cuckmere and also adverse economic impacts arising from the reduction in opportunities for angling or boating.
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Upper reaches of the rivers may be dry or suffer from reduced flows reducing the aesthetic and recreational value to the local community and local tourists. Fish in distress, fish kills and algal blooms also reduce the amenity and recreational value of the river. Angling may have to reduce or stop along some river reaches. Some community members may be concerned about nature or historic environment conservation along the rivers through groups such as the Ouse and Adur River Trust and the Sussex Ouse Restoration Trust. Although perceptions are likely to be negative at the time of the drought permit/order use, this could have a longer term beneficial impact by encouraging more to people to become involved in conservation of their local river.
Angling businesses are likely to see a reduction in business because of pressure to reduce the number of tickets for sale. Boating and use of riverside pubs may also see a decline in interest as water levels fall or algal blooms occur.
No impacts on other users were identified for the groundwater drought permits/orders.
(For further details of specific drought permit/order impacts to the environment, or users of the environment, please refer to the environmental impacts assessment with Section 4.0) DAPS8 Plan - - Health and wellbeing / other users emergency No impacts on customers or others. This action involves preparing the plans drought but does not include implementation of any further actions. planning procedures DAPS9 Health and wellbeing / Other users Emergency Emergency drought orders are more extensive than environmental drought drought orders orders and allow abstraction restrictions to be further relaxed as well as the and authorisation of stand-pipes, rota cuts or use of water tanks. These emergency potentially could have a severe impact on some customer’s health and drought wellbeing. There may be a risk of discolouration during periods of reduced actions as per pressure or rota cuts, however in general the water quality is likely to be our unaffected. Water from stand pipes would need to be boiled before it is used Emergency for food preparation of drinking. If there are widespread restrictions over a Plan prolonged timeframe, there could be a significant impact on health and sanitation. There would be restrictions which would have a significant impact on recreation and businesses.
Table 5.3 – Mitigation to lessen impacts to the human environment
Action Scoring Mitigation (as per Table 5.2)
Customer Customer health being well and users Other DAPD1 Water - No mitigation required. conservation Demand side campaigns and calls for voluntary restraint DAPD2 - No mitigation required. Operational works to
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reduce demand DAPD3 Health and wellbeing / other users Temporary Every drought is different in terms of the rate at which it occurs and the type water use of resource that it impacts. This will effect when and how this measure is restrictions implemented. In this revised draft drought plan, we have set out what phasing and concessions /exemptions that we would expect to use. These (Phase 1 and could however be altered dependant on the exact situation, prior to giving 2 water use notice to customers. A two week period of notice will be provided to allow restrictions i.e. customers to make representations on the proposals. During Phase 1 a temporary restrictions we expect to be able to offer a number of concessions such as, use ban) use of a hosepipe to a Blue Badge holder, watering using drip or trickle irrigation systems fitted with a pressure reduction valve and timer and sports grounds linked to national or international sports events. (For full details see Table 3.1 and Table 3.2). During Phase 2 restrictions some of these concessions may be removed which would increase the adverse impact to the human environment. We consider that we have developed a fair approach to implementing a temporary use ban and that the representation procedure will help address significant adverse impacts to the community so that the residual effect will only be minor. DAPD4 Health and wellbeing / other users Restrictions To implement a drought order we must apply to the Secretary of State and on uses of demonstrate a serious deficiency of supplies of water and that the reason is water through an exceptional shortage of rainfall. This type of action will not be undertaken a drought lightly. drought orders are likely to impact to a greater extent on commercial order activities as well as domestic ones. Our drought orders implementation process will also have a two-phased approach as per the temporary use ban. (Phase 3 and Phase 3 Temporary Use Ban: 4 water use Phase 3 will offer a number of concessions such as to businesses reliant on restrictions) building washing or cleaning vehicles which will initially help to lessen the impacts to the human environment. Phase 4 will be indicative of a severe drought and all concessions will be removed. There will however be a representation process where customers will be able to make a case for certain activities to continue. This aims to allow concession to prevent unsafe practices. DAPS1 - - No mitigation required. Optimisation of existing sources DAPS2/3 - Health and wellbeing / other users Infrastructural As part of planning changes to the system we will identify supply areas where connectivity there could be changes in water treatment/type of water being supplied. To and source address concerns a media campaign would be used to target specific improvements customers and reassure them. We will continue to meet Drinking Water and use of Inspectorate standards. disused
sources DAPS4/5 - Health and wellbeing / other users Shared As part of planning changes to the system South East Water will identify resources and supply areas where there could be changes in water treatment/type of water bulk transfer being supplied. To address concerns a media campaign would be used to agreements target specific customers and reassure them. We will continue to meet Supply sideSupply (extensions / Drinking Water Inspectorate standards. new agreements) DAPS6/7 - The Environment Agency need to approve a drought permit application Drought before a drought permit can be used. Similarly, Defra needs to approve any permits / drought order before it can be used. As part of these processes we must orders submit environmental assessments which consider impacts to the natural and human environment and propose a series of mitigation measures to alleviate them. The Environment Agency would regulate the monitoring and mitigation activity undertaken by us during drought permit or drought order use.
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Mitigation measures are specific to the drought permit/order applied for. As an example, the following types of mitigation measure relevant to the human environment are proposed for the River Ouse drought permit/order to help address the minor adverse potential impacts identified in Table 5.2:
Health and well being Provision of public/landowner information e.g. laminated notices on the risk of a reduction in water quality during the drought and increased risk of human, livestock and domestic animal health impacts from water quality issues such as algal blooms. Provision of information to landowners relating to the vulnerability of the river to pollution incidents, and good practice measures that can be implemented to reduce the risk of diffuse pollution from occurring. We will identify supply areas where there could be changes in water treatment/type of water being supplied. To address concerns a media campaign would be used to target specific customers and reassure them. We will continue to meet Drinking Water Inspectorate standards.
Other users Recreational Provision of public information (through collaboration between ourselves, Environment Agency, Rivers Trusts and Wildlife Trusts) on the drought and measures being implemented to mitigation effects. Information boards (e.g. for the Ouse at Barcombe Mills) explaining the drought mitigation measures (e.g. diversion of residual flow down the Andrews Stream to enable fish passage and the associated lack of flow in other channels) to manage public reaction to a change in river condition. If water is available within a reservoir an emergency release of water could be made to flush algal blooms from the river. To help fish in distress portable oxygenation kits can be deployed to specific reaches. In addition, a fish rescue could be carried out to a pre-agreed location. Conservation Communicate with landowners about drought permit/order and issue checklist to enable landowner/tenant observation of key ecological impacts and to trigger alert authorities for investigation and potential mitigation. Suggest temporary in-channel drought mitigation options and request permission to implement should these become necessary (e.g. channel narrowing and introduction of sinuous vegetated low flow channel through use of coir rolls, provision of submerged cover for fish). Implement enhancement of river structures owned by Environment Agency or County/District/Parish Councils (where agreed). Provision of information to mill owners (other similar features) to identify a further reduction in river flow and that this may result in a change in how privately-owned structures (e.g. weirs, sluices, mill races) will function. Angling Liaise with the Environment Agency and angling clubs on the potential need to restrict angling in certain reaches under specific conditions (e.g. in pools when a fish rescue may be required) and on the need for additional vigilance with respect to increased poaching risk.
(For further details of specific drought permit/order mitigation for environment related impacts, please also refer to the environmental impacts assessment with Section 4.0 and within the individual environmental assessments which
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are included in Error! Reference source not found. to Error! Reference source not found.). DAPS8 Plan - - No mitigation required. emergency drought (We will consult with neighbouring water companies, Local Authorities planning (including Local Resilience Forums) and emergency services during this procedures planning stage). DAPS9 Health and wellbeing / other users Emergency To lessen the impact of emergency drought orders to the community we will drought orders work together with Local Resilience Forms to ensure health and safety and measures are in place for the community as a whole, as well as community emergency services such as schools, hospitals, residential units and water for firefighting drought etc. During any emergency drought situation, we would seek to continue actions as per supply to essential services such as hospitals and residential units and our supply for firefighting. We have a register of vulnerable customers and would Emergency individually notify and consult with them about any changes to their normal Plan supply, in order to be able to assess the impacts and put measures in place to address them.
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6 MANAGEMENT AND COMMUNICATIONS STRATEGY
6.1 Management structure
6.1.1 Introduction The drought plan is a tool to combine drought management actions, communications actions and environmental monitoring actions together and provides a structural framework throughout the differing stages of a developing drought. External parties including other water companies, the Environment Agency and the Government also have responsibilities during a drought and, where appropriate, we need to be able to react to their direction and maintain a joined-up management approach throughout a drought.
To manage these multiple different roles, we operate a Drought Management Team.
6.1.2 Drought management team roles and responsibilities Under normal operations the Head of Water Resources has responsibility for the continued hydrometric / hydrological monitoring and monthly reporting to the executive team. The executive team will decide when to convene the Drought Management Team; this occurs when one of the drought region’s moves to developing drought status. Under normal operations, the Head of Communications is responsible for a number of on-going pre-drought related tasks such as stakeholder engagement and defining customer services messages.
During a drought, the Head of Water Resources and the Head of Communications are joined by other senior managers from the following areas of the business:
Legal Assets and Regulations Water Quality Engineering Distribution Leakage Production Customer Services
Each of the Drought Management Team’s responsibilities are shown in Figure 6.1.
The drought management team is jointly managed by the Assets Director and Operations Directors, who report to the executive team.
If a severe drought is maintained and there is a risk of a water supply failure an emergency plan would be initiated. The Drought Management Team would continue their roles during emergency operation.
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Figure 6.1 – Drought management strategy structure
Executive Team
Drought Director
Programme Drought Head of Water Manager Manager Resources
Water Resources Communications Operational + Environment Asset Support Services + Customer Economic Water Quality Teams Management Engineering Services Regulation - hydrometric -legal compliance - optimise network including with non- - communication reporting and - delivery of drought - preserved water - manage water houseld retail plans modelling capital schemes - capital quality quality within market codes - demand - regulation matters - key messaging management - mitigate water - management of network management and - liaison with Ofwat, contractual matters - human resources - media contacts - programme quality impacts restrictions CC Water - maximise leakage - financial control managament - liaison with management and - customer service - Drought Permits / - liaison with non - network modelling Drinking Water reduction activities messages oders household retailers - asset information Inspectorate -manage source - stakeholder - liaison with and performance outputs and engagement, Environment reporting of including Customer Agency and Natral operational data Panel England
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6.2 Communications plan
6.2.1 Introduction South East Water has a policy of open information about our operations and investment programme, and we use a large amount of promotional publications and other literature to communicate key messages associated with our day-to-day activities.
A combination of proactive public relations and, where necessary, reactive communications has been identified to ensure that we can provide accurate and timely information to raise awareness of important issues within the wider community we serve when necessary, such as during a drought.
Communication is an essential element of drought management and can greatly assist in conveying the right messages to consumers, the wider general public, key stakeholders, and the media.
This specific drought communications plan has been developed as part of this drought plan. The drought communications plan actions are also represented within the second column of Table 3.7 in Section 3.
The South East of England was declared as being officially in drought in February 2012 and in April 2012 seven water companies had to implement temporary use bans for the first time. Many communications lessons were learnt during this experience, and these have been incorporated into this drought communications plan (A summary of the key recommendations for improvement for communicating during a drought from South East Water’s internal review of lessons learnt is detailed in Box 2).
A key lesson learnt from the 2010-2012 drought and previous experience is that every drought is different. Variances that can occur during a drought mean that flexibility is important for any communication action. These variations may include the severity of the drought, how external audiences perceive it, water company actions, and other public relations or communications/campaign activities.
However, while flexible enough to cope with these variations this drought communication plan clearly links between the drought triggers monitored as part of the revised draft drought plan and the communications actions that would initiate as a result of reaching each trigger level.
As detailed in Section 3.1.3, we have used UKWIR guidance documents to help prepare this revised draft drought plan, including this communication plan.
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Box 2 - A summary of key recommendations to improve our communications during drought following its lessons learnt from the drought in 2012.
Summary of communications lessons learnt from drought 2012 Target Audience Recommendations for improvement Action Media Appoint drought lead in communications Communications Appoint daily press officer for media calls Communications Daily drought catch/wash up in Communications Communications Team Use team of core spokespeople for company Communications specific interviews Develop media relationships outside of drought Communications Issue drought media statements to Customer Communications Service managers/staff Household Review fleet signage for generic messaging roll-out Support Services customers Ensure Customer Services (inc commercial) input Water Resources into statutory drought plan process Appoint drought lead in Customer Services Customer Services
Non-household Must comply with new non-household market Legal, customers codes – requirement to liaise in our capacity as a Wholesale, wholesaler with non-household retail customers Water concerning messaging and drought management Resources initiatives affecting non-household businesses
Key Stakeholders Review and refine master stakeholder database Communications and Regulators email data Build in business-as-usual updates to expanded Communications set of key stakeholders Key Stakeholders Ensure Emergency Planning & Security Manager Water Resources and Regulators engaged earlier in drought planning to improve Community linkages with Local Resilience Forums Improve targeted drought messages and campaign Commercial at SMEs and representative bodies. Services Supply press releases to Parish Councils Communications
Community Issue electronic campaign material to LPAs/3rd Communications Digital parties (rather than print)
Develop generic video resources messaging for Communications website Address deficiencies in use and effectiveness of Communications social media Internal Staff Develop direct electronic messaging mediums to Business staff, for example a desktop login message, or Information drought screensaver Systems
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6.2.2 Drought communications management The drought management team will include the Head of Communications so that the possibility of a drought can be communicated quickly and effectively. The Head of Communications will further assign a dedicated Drought Communications Manager to specifically manage communications during the drought. When a temporary use ban is brought in we will need to further resource the communications team so that between one and two full time equivalents can focus on drought communications.
Action Head of Communications assigns a Drought Communications Manager Action Drought Communications Manager reviews drought communications plan and assigns responsibility for actions
6.2.3 Objectives This drought communications plan sets out how we will communicate our actions during a drought. Effective communications can help to reduce customer demand during a drought, increasing the available water for supply and also reducing the potential impact on the environment. It is also an opportunity to explain and clarify the role and responsibilities of South East Water, our regulators, consumer interest groups and other partners in managing the drought.
During a drought, this communications plan will:
Increase customer awareness of the limited availability of water resources. Regularly inform consumers, relevant organisations and regulators about the development of the drought and the implementation of drought management actions Set out when and how we will communicate with wider interest groups and partners to help reduce demand in a drought Promote and enhance water efficiency advice and information, including initiatives already in operation under normal circumstances and those used during a drought Working through non-household retailers, encourage non-household businesses to become more water efficient and explain what they can do to help in a drought Announce and reinforce any water restrictions that may be introduced Promote the positive work we are undertaking, individually and in combination with others to manage the drought Monitor and evaluate the effectiveness of drought communication activities during a drought
6.2.4 Target audiences There are several different audiences which need to be addressed during a drought. While a consistent message is essential, each requires a different approach and specific information produced to meet their needs.
The main audience groups for this drought communications plan are as follows:
Internal employees Regulators
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Household customers Wholesale water companies Non-household retailers (and their customers) Community Key stakeholders Media
Appendix Error! Reference source not found. shows a detailed list of the people and organisations that are represented under each of these audience groups. We have updated this list following feedback from our Environmental Focus Group to ensure we have captured the full range of people we should communicate with. We maintain a database containing all these contacts. This list will change over time so it is important to regularly review it to ensure it is still up-to-date. Following the 2010-2012 drought this database has been further developed to ensure those interested parties receive early notice of future water shortage concerns.
The drought communication action plan (Section 0) details the specific actions that will apply to each of these groups at each trigger level, but a brief explanation of the audience group and some of the key organisations that will be communicated with under these groupings is given below.
Internal employees This includes all South East Water employees and partner organisations. It is important that no matter which department in the business that everyone is fully briefed and able to support their colleagues during the drought. During a drought messaging on the intranet pages will be updated with the drought situation as new information arises. Special training will be given where necessary. Contractors will also be included within this category who are often delivering customer facing projects on our behalf – e.g. mains laying schemes, metering programme.
Regulators We work closely with our regulators to ensure a no-surprises policy is followed. During times of drought this close working relationship is particularly important. Our drought plan is available on the corporate website, together with information about resource levels – which is expanded and updated more frequently as a drought progresses. We will make available specific drought related information requested by regulatory authorities as queries arise during the period of drought conditions. At the appropriate drought trigger levels, we will notify the statutory consultees and others listed in the action plan in regard of any developing drought situation. a) Environment Agency We will advise the Environment Agency when specific drought action trigger points are crossed. As a drought begins to escalate (from a developing drought status) we will attend and positively contribute to any water company / Environment Agency drought meetings which will be called by the Environment Agency. These meetings are essential to ensure information is exchanged regarding the drought and the position of other water companies and the Environment Agency.
Following the initiation of the drought meetings, we will provide information to the Environment Agency following reasonable requests for drought management information; this is likely to include:
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Current water resource situation (including reservoir levels, recharge, reservoir and groundwater drought status etc) Drought stage (according to the drought plan status) List of demand side actions being undertaken List of supply side actions being undertaken (including timescales of when we are likely to apply for drought permits/orders) Details of communication actions being undertaken Drought management actions under a range of different rainfall scenarios Where specified, regular abstraction return data for drought management purposes
In return, the Environment Agency will provide the following information, where available, to us:
Provide regional and national situation reports and/or updates Latest local and regional groundwater levels and forecasts Provide groundwater levels, rainfall and soil moisture deficit data for the company’s drought regions on agreed frequencies Provide an update on the declaration of a drought
As every drought is different the information requirements and frequency of data exchange may differ from the above provisionally agreed list. b) Defra We will advise Defra when specific drought action trigger points are crossed and agree information requirements together with frequency of data exchange. This will be proportionate with the situation as it develops. We will make available specific drought related information requested by Defra as queries arise during the period of drought conditions. c) Natural England We consult Natural England on all potential drought permits/orders during the statutory drought plan process. None of the potential drought permits/orders impact upon SSSI sites and mitigation which may be required has been incorporated into the drought plan.
We routinely meet with Natural England on a monthly basis, regardless whether we are in drought or not. However, during a drought the water situation and potential drought permits will be discussed within these meetings. d) Consumer Council for Water We will advise the Consumer Council for Water (CCWater) when specific drought action trigger points are crossed and agree information requirements together with frequency of data exchange. This will be proportionate with the situation as it develops. We will ensure CCWater receive copies of Customer Service frequently asked questions to be able to brief their own employees too, recognising that CCWater also plays an important role in helping to communicate to customers about the drought. e) Drinking Water Inspectorate We will advise the Drinking Water Inspectorate (DWI) when specific drought action trigger points are crossed and agree information requirements together with frequency
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of data exchange. As DWI day to day contact, the Head of Water Quality, or a nominated deputy, will be responsible for communication with the DWI. The key information to be conveyed to the DWI is likely to include:
Current water resource situation (including reservoir levels, recharge, reservoir and groundwater drought status) Potential impacts on water quality as a result of the water resource situation Impact on proactive and reactive flushing programmes Company communication plans
As every drought is different, the level and frequency of communication and information exchange with the DWI will be proportionate with the situation as it develops. f) Ofwat We will advise Ofwat when specific drought action trigger points are crossed and agree information requirements together with frequency of data exchange. This will be proportionate with the situation as it develops.
Customers (household) We will ensure we communicate effectively with our customers at every stage through a drought, particularly in the run up to and any introduction of water restrictions. The communication drought action plan gives details of all the methods we would use to ensure customers are aware of the situation. In particular a high-profile media campaign will ensure the message is delivered, along with other traditional and innovative ways to help get the messages across.
Water companies (wholesale) a) WRSE South East Water works closely with other water companies who are members of the Water Resources in the South East (WRSE) group. See Section 6.2.5 for more details on how the group works together to communicate messages. The WRSE members will be important to communicate closely with during the drought to ensure there are no surprises. In particular two companies, Southern Water and Affinity Water, need more careful communications as we take or provide bulk water supplies. i) Southern Water and ii) Affinity Water We include these water companies as a key audience in respect of drought management activity to ensure that they receive specific and targeted information due to the close working relationship with regard to bulk supply and shared use arrangements.
Eight per cent of the water supply to the South East Water area is provided by bulk transfers or shared use arrangements. The Bewl-Darwell transfer (operated under a long term contractual arrangement by Southern Water Services) and the Egham bulk supply (operated by Affinity Water) are the largest imports to South East Water.
Section 3.2.3 gives a detailed breakdown of how we will work together and communicate with neighbouring water companies regarding the bulk supply and shared use arrangements.
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It is likely that if we are experiencing a drought that Affinity Water and Southern Water will be similarly reaching their own drought triggers. During a potential drought that affects the South East of England all three water companies would be in regular contact with the south east region of the Environment Agency (following the communication protocol set out in the regional drought plan (Environment Agency, January 2012).
We will also work closely with Affinity Water and Southern Water Services on communication activity with other stakeholders and customers via the Water Resources in the South East Communications Group (Section 6.2.5), and any drought communications groups implemented by WaterUK. This also applies to working with other neighbouring water companies.
Non-household Water companies (retail companies) In our capacity as a wholesaler we will undertake drought management engagement with non-household retailers to comply with Process E6 of the Operational Terms of the non-household retail Market Codes.
This will ensure we provide appropriate levels of communication concerning drought messaging and the promotion/implementation of drought management initiatives with non-household retailers and the businesses they serve.
Customers (non-household) a) Small/Medium/Large enterprises We will work closely with non-household retailers to ensure consistent messaging and advice is provided through to their non-household customers during a drought.
We anticipate that direct communication of our drought messaging will be carried out through the non-household retailers rather than directly by ourselves. b) Trade associations During the 2010-2012 drought, the water industry had discussions with a number of trade associations such as the Horticultural Trades Association (HTA), Turf Growers Association (TGA) and British Swimming Pool Association (BSPA). Lessons have been learned and together with efforts by WaterUK the industry is finding ways to work in partnership to avoid or delay the use of a complete temporary use ban. We want to avoid the economic impact of a complete ban on hosepipe use and by communicating together it is hoped discretionary water use can be reduced, particularly in the early stages of a developing drought.
We have undertaken in future to contact trade associations as a drought develops and to forge links to local members.
Community This section includes all local elected stakeholders and councils and emergency services and health authorities. Water companies are “Category 2 Responders” under the Civil Contingencies Act 2004 and have a legal responsibility to share information with “Category 1 Responders” such as local authorities and the emergency services. To ensure we meet this responsibility we are a member of Local Resilience Forums (full list in Appendix Error! Reference source not found.) this is a valuable route for quickly communicating any increased severity in the drought conditions. All the Local Resilience Forums within our area operate a Severe Weather Advisory Group (SWAG)
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system and communication of the situation via this route will be important. We will ensure we begin to communicate with these groups early in the drought, but working closer together will become more important as severity increases and in particular if emergency planning stages are ever reached.
Key stakeholders These include a variety of organisations particularly environmental, wildlife and sporting/angling associations who will have an interest in the effects of drought and our response to drought. These organisations are vital partners in communicating updates on the drought.
South East Water will work in partnership with a wide range of stakeholders through the preparation and delivery of any drought permits/orders.
6.2.5 Working in partnership during drought It has been our experience that when we are affected by a drought neighbouring water companies are often similarly affected. The water companies have found that working together and alongside the Environment Agency and the Consumer Council for Water is a successful approach, giving the opportunity to share information and best practice, and implement joined-up communication activities. This joined-up working not only avoids ambiguous or contradictory statements during drought, it is also cost-effective. Sharing communication activities, such as advertising, design work, joint press conferences enables all those involved to benefit from shared costs.
During a drought, our Communications Team will regularly liaise with Water UK and the other water company communications managers to ensure consistency of approach, and a no-surprises culture. Much of this is achieved – at times of drought and indeed non-drought – through South East Water’s proactive membership (and current chairmanship) of the WRSE communications group.
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Box 3 - The WRSE Communications Group
The WRSE Communications Group includes water companies from the South East of England together with the Environment Agency, CCWater and Waterwise.
The purpose of the group is clear - to work together harmoniously to identify and achieve common aims and objectives within the remit of water resource/water efficiency communications. Principally, these can be listed as: communicating common information and messages to customers and stakeholders; seeking to work closely with and to inform and influence key stakeholders; ensuring all members are kept closely informed of each company’s specific activities.
Activities the group will implement in partnership during a drought include: Joint press releases/press conferences
Joint advertising campaigns (newspaper, radio, cinema)
Joint stakeholder newsletters and briefings.
Coupled with a willingness to implement decisions uniformly across the group the result is a powerful and, where necessary, reasonably funded instrument for informing, influencing and changing behaviour. Joint communication activities such as a five-week cinema advertising campaign, the “Water-Watch” website, gardening initiatives and stakeholder newsletters, plus sharing policies and strategies on temporary use bans and prosecution policy all proved immensely useful in previous droughts. The group continues to meet on a regular basis regardless of drought and coordinate its activities.
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6.2.6 Communication channels Experience from previous droughts has shown that making use of all available channels to communicate the message is important to help reach the diverse range of audience members.
Error! Reference source not found. gives a detailed list of the many communication channels we would choose from to help get the drought message across.
The drought in 2012 showed that use of national and local media coverage is a vital tool to engage with customers. Research during the drought in 2012 by Ipsos MORI6 showed that of the 93 per cent of customers that had recently seen or heard information about a drought in the southeast of England:
71 per cent had seen this on television 38 per cent had seen this in national newspapers 35 per cent had seen this in their local newspapers
As media is such an important channel we have included this as a separate audience group in the action plan that follows to ensure regular engagement with media and social media (which has grown in use since the 2012 drought).
6.2.7 Drought Communication Action Plan South East Water has developed an action plan that links with the drought triggers and our communication actions as part of the wider drought plan. It therefore follows that specific communication actions are required in the lead up to and subsequent hitting of drought triggers. The drought trigger levels are defined as:
Normal Developing drought Moderate drought Moderate drought or severe drought Severe drought Emergency planning Drought recession Post drought
The drought communications plan actions are also represented within the second column of Table 3.7 in Section 3. But this communication action plan now details how we will tailor specific communication actions for each of the audience groups identified in Section 6.2.4. The action plan details:
Which audience group specific actions apply to The key messages for these audiences When the actions will be taken in response to crossing drought triggers Any subsequent actions we will take.
6 Drought Communications Research conducted by Ipsos MORI for South East Water November 2012
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Drought trigger level - normal
We have an on-going water efficiency campaign which includes close communication with all the audience groups. This process begins during warm or dry periods with promotion of water efficiency messages, irrespective of water resource levels. If the Met Office and Environment Agency release notably or exceptionally low rainfall communications messages we expect increased customer and media queries.
Standard briefings and advertisements are already available for this level of communication.
Audience Actions Comments Internal employees Promote water efficiency We want employees to be activities via intranet, Spout! ambassadors for water (the staff magazine), Team efficiency. briefs and staff induction programme. Core brief to include water South East Water provides resource update. a monthly Core Brief to employees; this will include latest messages about water resources. Ensure briefed on the water Explain that the water situation messages. resource situation is normal, but that we always ask people to use water wisely. Regulators Include update on the water Explain that the water resources situation at regular resource situation is meetings. normal, but work together to promote water efficiency messages. If necessary update on South If other companies advise East Water’s situation via they are reaching drought letter/email. triggers then South East Water should proactively contact Regulators (Environment Agency, Natural England and CCWater in particular). Updates in “The Source”. South East Water e- newsletter for all stakeholders. Customers (household) Updating the South East Ensure links to water Water website. efficiency messages and reservoir level data and the online water calculator (interactive opportunity to learn about your own water use and how you could save more).
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Audience Actions Comments Proactive communication Delivery of water efficiency during Customer Metering advice and devices. Programme (CMP). Information at customer briefing sessions on water efficiency and also deliver water resource update. “Great water butt giveaway” Competition run on website and water efficiency and promoted in customer promotions via customer magazine to encourage billing information. people to complete an online water audit and be entered in prize to win a water butt. Summer roadshow and South East Water attends school education/community summer shows with water talk programme. efficiency trailer, manned by staff and giving advice to customers. Throughout the school year we visit schools and community groups to give a talk about water and water efficiency. Save Water South East South East Water promotions. contributes to SWSE which works year-round to encourage water saving. Social media We use Twitter and Facebook to regularly promote water efficiency messages Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. situation/messages of other Agree joint messages and water companies. prepare WRSE stakeholder newsletter. Water Companies Regular meetings with Meeting will confirm agreed (retail) Wholesale Service Desk for actions required from both them to onwardly wholesale and retail communicate with Retailers – (activity is unlikely at this clear messaging required as stage other than usual to what they communicate on water efficiency work). to NHH customers. Community WRSE communications. Activities via the WRSE group will update that resource levels normal. Updates in “The Source”. South East Water e- newsletter for all stakeholders. Local Resilience Forums Membership of LRF’s across the area ensures South East Water keep people updated on the water resources Key Stakeholders WRSE communications Activities via the WRSE group will update that resource levels are normal.
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Audience Actions Comments Updates in “The Source”. South East Water e- newsletter for all stakeholders Media Prepare and release press Explain that the water statements. resource situation is normal, but that we always asks people to use water wisely. Proactive press releases. Messages promoting water efficiency, particularly in the garden. E.g. water butt giveaways. South East Water will ensure consistency with other water companies. Promote website via social Use social media to keep media. directing people to water efficiency information.
Drought trigger level – developing drought
Once developing drought triggers are hit a pre-planned media campaign would be instigated. This campaign would aim to intensify the message, linking the demand for water directly to the impact on rivers, reservoirs and groundwater in order to:
Create sharp increase in customer awareness of the need to save water Make customers think about the impact of the way they use water Suppress demand for water Link demand for water to environmental impacts
The water efficiency campaigns run under “normal” conditions will continue, but they will be promoted more and South East Water will begin to look for further campaign opportunities.
The Drought Communications Manager would commence a weekly report on what we've actioned and achieved - reviewed at end of each week. This activity will continue throughout the drought period until confirmed return to normal.
Audience Actions Comments Internal employees Core Brief message. Explain that South East Water is now in developing drought, and that the drought plan has been implemented. Intranet update to link Reinforce importance of through to website messages for customers information. about using water wisely.
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Audience Actions Comments MD Briefings to include water South East Water’s MD resources and raise delivers regular briefings understanding in the via a six-monthly business. management meeting and a six-monthly tour of the business updating on key company issues. Implement Customer Service Customer Service staff are competition to encourage talking to customers on a promotion of water efficiency daily basis; they can help to devices. encourage water efficiency. Briefing to field staff via Provide water efficiency Team Briefs. leaflets and devices to hand out. Prepare training material for Ahead of reaching staff regarding Temporary moderate drought status a Use Ban. full training plan for Customer Service staff should be developed. Regulators South East Water will Use meetings as provide updates to the opportunity to advise on Environment Agency on the situation and to explain Water Resource position and actions South East Water is await Environment Agency to taking. instigate further drought meetings. Update Natural England on Use meetings as the Water Resource position opportunity to advise on at monthly meetings situation and to explain actions South East Water is taking Keep updated on situation Proactively contact via email. Regulators (Environment Agency, Natural England, and CCWater in particular). Customers (household) Updating the South East Update homepage to Water website homepage ensure water efficiency and water resources pages. message is visible and raise that South East Water is now in developing drought. Begin a monthly resource situation update. Pledge campaign posters. South East Water has a “make a pledge” webpage where customers can pledge different water efficiency promises. A range of posters is available to promote these messages and the webpage. Issue via a poster distribution company and/or stakeholders.
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Audience Actions Comments WRSE website. This is the joint water company website that should now be updated to explain South East Water (and any others) in developing drought. Proactively approach events Double the number of for summer roadshow and events attended during schools/community groups normal conditions. for talks. Update the South East Water has school/community talk slides dedicated school speakers and brief speakers. who will be briefed on latest situation. Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. situation/messages of other Agree joint messages and water companies. prepare WRSE stakeholder newsletter. Begin drought related Ensure “no-surprises” by communications with Affinity regular close contact. Water and Southern Water Services regarding bulk supplies and shared use arrangements as described in Section 3.2.3. Water companies Regular meetings with Meetings will confirm (retail) Wholesale Service Desk agreed actions required from both wholesale and retail. (Activity unlikely at this stage other than usual water efficiency work) Community WRSE stakeholder Prepare a newsletter to newsletter. update that South East Water is now in developing drought, drought actions and next steps. Update via “The Source”. Send further update via The Source e-newsletter. Local Resilience Forums Our membership of LRF’s across the area ensures South East Water keep people updated on drought status Commence discussions with Give heads up that South local authorities with regard East Water is concerned, to watering regimes for parks check details of who most and gardens. appropriate contacts for updates Key Stakeholders WRSE stakeholder Prepare a newsletter to newsletter. update that South East Water is now in developing drought, drought actions and next steps.
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Audience Actions Comments Media Prepare press statements. Explaining next steps/plans.
Proactive press releases to Explain details of the dry stimulate increased TV and period e.g. “We have had radio coverage. below average rainfall for X of last X months.” Call for voluntary restraint. Alert customers to where on South East Water’s website to find updates. Start a water efficiency blog The blog is a fun and and promote messages via friendly update on water Twitter. efficiency ideas, as the drought develops this can be used to continue to update customers. Use poster campaign in local Develop poster campaign. newspapers (4-week Be careful that the posters campaign) and local radio messages are appropriate adverts. given any changing weather patterns. Radio adverts will be short, sharp memorable messages and practical advice. Look to see if any joint working opportunities with other companies.
Drought trigger level – moderate drought
At this point, we would move from background publicity to a much higher intensity campaign and make direct appeals for the public to reduce their demand for water in order to reduce or delay the use of temporary use bans.
Company specific and joint communications work, if other companies are experiencing similar conditions, will progress at this stage. Preparations for the implementation of Phase 1 of the temporary use ban will begin and the ban will be implemented when necessary depending on the time of year for maximum impact.
Where temporary use bans are considered, we will advertise this fact widely in the local press, via local authorities and on the corporate website, together with a detailed explanation of the classes of use affected. We will state how customers may make representations and in what time period these representations will be considered. A two-week period in which customers may respond to the proposals is anticipated to be given (the consultation period is short because the plan requires restrictions to be implemented rapidly in order to curtail demand effectively). (See Section 3.1.4 for more information)
Communications actions in moderate drought will include:
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Audience Actions Comments Internal employees Core Brief message. Explain that South East Water is now in moderate drought, and the actions the company is taking. Intranet update to link Reinforce importance of through to website messages for customers information. about using water wisely. Q&A’s for employees. Ensure Customer Service Staff and Field teams are briefed. Members of the Drought This will enable fast alert to Management Team to attend staff on situation. Team Briefs across the company. Posters up around offices. When we know a temporary use ban is being introduced to remind staff of date. Roll out staff training on This will be both Customer Temporary Use Ban. Service staff and key customer facing staff (e.g. samplers, debt team, meter readers). Login alert and email to all The login alert is a pop-up staff. message that the IS team can set up to show on the computer screen when a member of staff logs into their computer. This will be put in place for the day South East Water announce temporary use ban so all staff are aware. Customer Service staff will also be sent briefing note and have press release printed off on desks for when they get in. Regulators Continue regular meetings Use meetings as opportunity with Environment Agency to to advise on situation and to update on drought explain actions South East development. Water is taking. This likely to involve discussions of upcoming drought permit applications (when appropriate). Update Natural England on Use meetings as opportunity the Water Resource position to advise on situation and to at monthly meetings. explain actions South East Water is taking. This likely to involve discussions of upcoming drought permit applications (when appropriate).
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Audience Actions Comments Keep updated on situation Proactively contact via email. Regulators (Environment Agency, Natural England, CCWater and Ofwat in particular). Give CCWater full briefing Ensure they have same ahead of any restrictions. Q&A’s as South East Water staff to help their call centres manage any contact. Customers (household) Updating the South East Begin to use images such Water website homepage as “before and after” photos and water resources pages. of reservoirs. Begin a weekly resource situation update. Refresh FAQ’s with ones about restrictions. Set up dedicated telephone This allows South East line. Water to monitor contacts specifically about drought. Add message to phones. Explain that South East Water is in drought and where on website to find latest information. Direct mail about situation. Where appropriate issue direct mailouts to customers affected, or include leaflets and updates with any customer letters sent (e.g. capital programme updates or customer service letters). Summer roadshow and South East Water attends school education/community summer shows with water talk programme. efficiency trailer, manned by staff and giving advice to customers. Throughout the school year South East Water staff visit schools and community groups to give a talk about water and water efficiency. Update WRSE website Begin to use stronger messaging and alert people to any upcoming restrictions.
Update website Website detailing the consultation process and showing maps of affected area
When temporary use ban actually announced have a “pop-up” message on website during the consultation period.
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Audience Actions Comments Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. Agree situation/messages of other joint messages and prepare water companies. WRSE stakeholder newsletter. Continue communications Ensure “no-surprises” by with Affinity Water and regular close contact. Southern Water Services regarding bulk supplies and shared use arrangements as described in Section 3.2.3. Site visits to high demand This will include completing commercial users to help more water efficiency audits. reduce demands.
Water companies (retail) Regular meetings with Meetings will confirm agreed Wholesale Service Desk actions required from both wholesale and retail. (See “Customer (non- household)”, below, for likely activities) Customers (non-household) Only following prior This will include completing agreement with non- more water efficiency audits. household retailers, and only if in accordance with non- household market codes - Site visits to high demand commercial users to help reduce demands. Community Letter/Email. Explain increasing concern and ask for support promoting voluntary restraint – e.g. printing articles in Parish Magazines and links on website. Local Resilience Forums Our membership of LRF’s across the area ensures we keep people updated on drought status Key Stakeholders Letter/Email. Explain increasing concern and ask for support promoting voluntary restraint – e.g. printing articles in members magazines and links on website. Media Prepare press statements. Explaining next steps/plans, work jointly with other water companies, WaterUK and Environment Agency. Proactive press releases. Explaining latest drought situation. What South East Water is doing and how customers can help. Alert customers to where on the website to find updates
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Audience Actions Comments Joint press conference Work with other companies, Environment Agency and CCWater for a joint press conference to announce moderate drought. Advertising campaign “Let’s Use advertorial style Save it”. promotions of explaining situation, what South East Water is doing and how customers can help. Temporary use ban – Official notice for Phase 1 to notices. be sent to be published in local papers (see Appendix Error! Reference source not found.). Temporary use ban – press To coincide with publication release. of the notice.
Radio adverts to begin Once the restrictions are following the two-week confirmed South East Water consultation. would begin radio campaign to ensure people have the correct message. Friston borehole media day. If groundwater is suffering South East Water will arrange a media day/days to go down inside Friston borehole. Create a Twitter Hashtag #SaveWaterSussex campaign to get increase #SaveWaterKent etc. strength of messaging.
Drought trigger level – Moderate to severe drought
At this stage we would have implemented the Phase 1 temporary use ban. Depending on the progress of the drought we will need to prepare the public for the need for Phase 2 temporary use ban (the removal of concessions). It may be that due to speed of the drought that at the same time the drought management team will be preparing for drought orders to restrict non-essential use of water and possible drought permits/orders. If drought permits/orders are applied for, we will set notice with the relevant authorities and advertise the intentions in the local media, on the corporate website and the London Gazette.
At this point, it is expected that there would be a considerable and self-sustaining media interest in the developing situation and little if any further media stimulation would be required. South East Water would continue with the use of media as in moderate drought and include.
Key messages across audiences will be:
The need for temporary use bans to reduce demand and avoid supply failure
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Details and examples of how customers can save water Details of how South East Water is saving water and implementing new supplies Explain intention to enforce bans and the penalties for non-compliance Explaining the areas covered by restrictions and how to find if within affected areas The severity and impact that further restrictions would have on homes and businesses Setting out the consultation for the next phase of household temporary use bans
Communications actions in moderate to severe drought will include:
Audience Actions Comments Internal employees Core Brief message. Explain that South East Water is now moving towards a severe drought status, and the actions the company is taking. Intranet update to link Reinforce importance of through to website messages for customers information. about using water wisely. Staff “roadshow”. Senior management to tour the company area offices briefing staff face-to-face and asking for suggestions of things to help secure supplies. Regulators Consult with Defra if a Use meetings as drought order application is opportunity to advise on likely. situation and to explain actions we are. Increase the frequency of Use meetings as drought update meetings with opportunity to advise on Environment Agency. situation and to explain actions South East Water is taking. This is likely to involve discussions about potential drought order non- essential use bans, and drought permit applications that South East Water is preparing. Update Natural England on Use meetings as the water resource position at opportunity to advise on frequent meetings. situation and to explain actions South East Water is taking. This is likely to involve discussions about drought permit applications that South East Water is preparing. Keep updated on situation via Proactively contact email. Regulators (Environment Agency, Natural England and CCWater in particular).
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Audience Actions Comments Customers (household) Updating the South East Continue a weekly resource Water website homepage situation update. and water resources pages. Pledge campaign posters Run competition to and stickers. encourage people to “Take the Pledge”. Envelope branding. Arrange for all South East Water envelopes to be branded with message – ensure works whatever the weather. Updates on South East Web based maps of the Water and also the WRSE area covered by the South website. East Water temporary use ban Web based gazetteer so customers can locate their property. Weekly updates of reservoir levels and monthly of groundwater levels. Arrange for South East Water Ensure this is a message vehicles to be branded with that will work in all weather. water message. E.g. “Whatever the weather – please save water”. Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. Agree situation/messages of other joint messages and prepare water companies. WRSE stakeholder newsletter. Continue communications Ensure “no-surprises” by with Affinity Water and regular close contact. Southern Water Services regarding bulk supplies and shared use arrangements as described in Section 3.2.3. Water companies (retail) Regular meetings with Meetings will confirm Wholesale Service Desk agreed actions required from both wholesale and retail (see “Customer (non- household)”, below, for likely activities) Customers (non-household) Only following prior Write to and promote via agreement with non- Chamber of Commerce etc household retailers, and only that South East Water is if in accordance with non- offering free water audits. household market codes - Water audit promotion. Through Retailers - Write to Ask for voluntary restraint all non-household customers and advise of ways they can help.
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Audience Actions Comments Updates on South East Begin to target businesses Water and also the WRSE with information about the website. impact they can make and calling for voluntary restraint and risk of non-essential use ban. Only following prior Arrange delivery to hotels agreement with non- and gyms of promotional household retailers, and only material to encourage water if in accordance with non- efficiency. household market codes - Hotel cards and shower stickers promotion. Sally Shower timers to hairdressers. Community WRSE stakeholder This regular newsletter will newsletter. update that situation is now moving to severe drought status, the actions being taken and next steps. Local Resilience Forums Our membership of LRF’s across the area ensures we keep people updated on drought status Drought Forums. Invite to Drought Forums in each county affected – work with any other water company that crosses boundaries. Key Stakeholders WRSE stakeholder This regular newsletter will newsletter. update that situation is now moving to severe drought status, the actions being taken and next steps. 1-2-1 meetings. Arrange meetings as required to begin to discuss possible drought permits/orders. Media Prepare press statements. Explaining next steps/plans and add FAQs to media page of the website.
Proactive press releases. Begin weekly media updates. Promote what South East Water is doing. Leakage efforts, capital schemes. Continued updates on impact of weather. Preparation and consultation on drought permits/orders.
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Audience Actions Comments Publication of official notices Notice in the London as required for any drought Gazette of application to permit/order. Defra for drought orders to restrict non-household consumption (Phase 3 non- essential use ban detailed in Section 3.1.5). Further radio, newspaper and Local media advertising possible TV. including regional radio and television advertising with maps, summary of restrictions, penalties for non-compliance.
Drought trigger level - Severe drought
Once the severe drought stage has been reached we would continue to progress with the company specific and joint communications work. It is likely by this stage that other water companies in the South East will be experiencing the same conditions and therefore working together and ensuring consistent approaches where applicable, or understanding of the reasons for differences will be important.
At this stage we are likely to reach the point where we need to implement the drought order (for non-essential use ban) and therefore widespread promotion of this will be required. Any concessions currently in place will be removed and we will ensure all those customers who had them are informed.
The message to customers at this point will focus on the rapidly deteriorating resources position and the need for substantial reductions in consumption. We will highlight the increasing probability of a water supply failure and begin to indicate the areas that will be affected by supply cuts should they become necessary as set out below:
Explaining the phase 2 household temporary use ban Details and examples of how customers can continue to save water Progress on how the company is implementing new supplies and maximising efficiency Explain intention to enforce bans and the penalties for non-compliance. Explaining the areas covered by restrictions and how to find if within affected areas Explanation of demand side emergency drought orders, which may include standpipes and rota cuts The severity and impact that rota cuts will have on businesses and households Providing indicative locations of areas that may be subject to rota cuts
Communications actions in severe drought will include:
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Audience Actions Comments Internal employees Core Brief message. Explain that South East Water is now at severe drought status, and the actions the company is taking. Update Q&A’s for staff. Ensure Customer Service staff and field staff are briefed.(provide these to CCWater) Members of the Drought This will enable fast alert to Management Team to attend staff on increasing severity Team Briefs across the of situation. company. Posters up around offices. When South East Water know non-essential use ban is being introduced to remind staff of date. Roll out staff training on non- This will be both Customer essential use ban. Service staff and key customer facing staff (e.g. samplers, debt team, meter readers). Login alert and email to all This will be put in place for staff. the day South East Water announce non-essential use ban so all staff are aware. Customer Service staff will also be sent briefing note and have press release printed off on desks for when they get in. Intranet update to link Reinforce importance of through to website messages for customers information. about severity of drought and why we are taking these steps. Regulators Consult with Defra if a drought order or an emergency drought order application is likely. Continue frequent meetings Use meetings as with Environment Agency to opportunity to advise on update on drought situation and to explain development. actions South East Water is taking. This is likely to involve discussions about further drought permit applications that South East Water is preparing.
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Audience Actions Comments Update Natural England on Use meetings as the Water Resource position opportunity to advise on at frequent meetings situation and to explain actions South East Water is taking. This is likely to involve discussions about further drought permit applications that South East Water is preparing. Keep updated on situation via Proactively contact email. Regulators (Environment Agency and Natural England in particular). Customers (household) Updating the South East Use striking imagery to Water website homepage really show the problem. and water resources pages. Begin Enact “Water Drama”. Tour 70 schools within the company area with interactive play. Loud hailers. South East Water vans will deliver messages around area. Customer mailshot. South East Water will write to all customers affected and use email updates where possible. Updates on South East Carry on with campaigns for Water and also the WRSE domestic customers. website. Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. Agree situation/messages of other joint messages and prepare water companies. WRSE stakeholder newsletter. Continue communications Ensure “no-surprises” by with Affinity Water and regular close contact. Southern Water Services regarding bulk supplies and shared use arrangements as described in Section 3.2.3. Water companies (retail) Regular meetings with Meetings will confirm Wholesale Service Desk agreed actions required from both wholesale and retail (see “Customer (non- household)” for likely activities). Customers (non-household) Updates on South East Ensure full details of any Water and also the Water- non-essential use ban. Watch website. Community WRSE stakeholder This regular newsletter will newsletter. update that situation currently at severe drought status, current actions and next steps.
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Audience Actions Comments Local Resilience Forums Our membership of LRF’s across the area ensures we keep people updated on drought status Key Stakeholders WRSE stakeholder This regular newsletter will newsletter. update that situation is currently at a severe drought status, current actions and next steps. Media Prepare press statements. Explaining next steps/plans.
Proactive press releases Joint press releases to explain that drought is now at a severe drought status. Possibly hold another press conference. Highlight what other organisations are doing to help. Publication of official notices Notice in the London as required for any drought Gazette of application to order Defra for drought orders to restrict non-essential use (Phase 4 – removal of concessions) Further radio, newspaper and Local media advertising possible TV including regional radio and television advertising with maps, summary of restrictions, penalties for non-compliance.
Emergency planning
If severe drought status is maintained South East Water has an emergency plan which would be activated in exceptional circumstances, for example, if the severity of the drought was such that we could no longer maintain a secure supply to all our customers and there is a possibility of a water supply failure. This plan details the additional communication actions that would be required. At this point we will have implemented all the feasible actions in this drought plan.
We will continue to progress specific and joint communications work already underway. Severe drought actions will continue.
The proposed actions could affect or prevent the operation of certain businesses. In addition, vulnerable customers and businesses will need to be reassured that we will continue to provide a secure supply to them, while other less sensitive parts of the network will be subject to supply interruptions.
South East Water will work closely with Local Resilience Forums (See Appendix Error! Reference source not found.) during this phase of a drought to ensure we meet our responsibility as a “Category 2 Responder” under the Civil Contingencies Act 2004 and
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will ensure we are working closely with “Category 1 Responders” such as the local authorities and the emergency services.
Audience Actions Comments Internal employees Daily briefings to all Via email and intranet. Daily employees morning update briefings particularly for Operations staff (dealing with rota cuts); Communications team; Customer Service and Water Quality Regulators Consult with Defra over emergency drought order applications. Notice of implementation of emergency drought orders
Explaining the areas covered by restrictions and how to find if within affected areas
Explanation of areas to be affected by emergency drought orders and rota cuts Customers (household) Details and examples of how customers can continue to save water
Progress on how company is implementing new supplies and maximising efficiency
Explain intention to enforce bans and the penalties for non-compliance.
Web based maps of the areas likely to be affected by rota cuts to supply. Web based gazetteer so customers can locate their property Water companies Via WRSE Comms Group Ensure “no-surprises” by (wholesale) and WaterUK check regular close contact. Agree situation/messages of other joint messages and prepare water companies. WRSE stakeholder newsletter. Continue communications Ensure “no-surprises” by with Affinity Water and regular close contact. Southern Water Services regarding bulk supplies and shared use arrangements as described in Section 3.2.3.
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Audience Actions Comments Water companies (retail) Regular meetings (probably Meetings will confirm agreed daily at this stage) with actions required from both Wholesale Service Desk wholesale and retail (see “Customer (non-household)” for likely activities. Customers (non-household) Details and example of how customers can continue to save water
Progress on how company is implementing new supplies and maximising efficiency
Explain intention to enforce bans and the penalties for non-compliance.
Web based maps of the areas likely to be affected by rota cuts to supply.
Web based gazateer so customers can locate their property Community Notice of implementation of - emergency drought orders Explaining the areas covered by restrictions and how to find if within affected areas
Explanation of areas to be affected by emergency drought orders and rota cuts Key Stakeholders Notice of implementation of - emergency drought orders
Explaining the areas covered by restrictions and how to find if within affected areas
Explanation of areas to be affected by emergency drought orders and rota cuts Media Extensive radio and TV - notification of areas to be affected by supply cuts
Local media advertising with maps, summary of restrictions, penalties
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Drought recession
As the drought recedes it is important to continue company specific and joint communications work until a normal status has been attained. The communications activities will be proportionate to the level of drought status we have stepped down to (see Section 2 for drought triggers).
Communications will be required to explain why restrictions or drought permits/orders are still in place and why and when they will be removed.
Communication actions during a drought recession will include:
Audience Actions Comments Internal employees For all audiences we will We will reinforce the Regulators continue the actions that fit importance of keeping any Customers (household) the appropriate trigger level restrictions in place until at Water companies stepped down to. normal drought status or it is (wholesale) known that the water Water companies (retail) resources situation is Customers (non-household) secure. Community Key Stakeholders Use behaviour change expertise to help develop messaging to thank everyone for their efforts and encourage continued support.
Post drought
It is important that after a drought we learn lessons for future droughts and carry out a full review of what worked well and what didn’t work as well.
Throughout the drought we will have engaged with customers to see how well we are doing at communicating and empowering action. Following the drought, we intend to carry out an in depth review to ensure we learn lessons (see evaluation below).
Communication actions post drought will include:
Audience Actions Comments Internal employees Full briefing to confirm South Include thank you messages East Water is back to normal for staff efforts and reward operation. and recognise staff who demonstrated employee Core brief, Team brief and values relating to the Spout! article. drought. Ask staff to feedback into Focus groups and staff “Lessons learnt” report. surveys to get opinions.
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Audience Actions Comments Regulators Briefings to confirm back to - normal operation.
Review of lessons learned.
Meetings to discuss approaches. Customers (household) Update website to confirm Thank you messages and return to normal operations request to keep up water efficiency “whatever the Include messages about the weather”. drought and lessons learnt in next customer billing Evaluation methods detailed communications. in Section 6.2.8.
Carry out final evaluation Post-drought case studies efforts. by region – highlight positives and review for next Focus groups and surveys time. Water companies Via WRSE Comms Group - (wholesale) and WaterUK check messages of other water companies to ensure consistency. Continue normal routine - communications with Affinity Water and Southern Water Services regarding bulk supplies and shared use arrangements. Water companies (retail) Briefings to confirm back to Include thank you messages normal operation. for retailers’ efforts and reward and recognise good Review of lessons learned. practice.
Meetings to discuss Ask retailers to feedback approaches. into “Lessons learnt” report. Customers (non-household) Update website to confirm Thank you messages and return to normal operations reminder that retailers can provide advice on water Retailers to write to all efficiency. commercial customers to advice back to normal.
Carry out final evaluation efforts. Community WRSE stakeholder Update on any lessons newsletter/The Source e- learnt, thank them for newsletter. support. Update any databases with new contacts made. Local Resilience Forums Update on any lessons learnt, thank them for their support
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Audience Actions Comments Key Stakeholders WRSE stakeholder Update on any lessons newsletter/The Source e- learnt, thank them for newsletter. support. Update any databases with new contacts made. Media Return to normal conditions. Ensure a press release sent out saying thank you for customers efforts and confirming return to normal.
6.2.8 Evaluation Messaging effectiveness will be measured during and after the drought by: Media monitoring to assess take up of South East Water’s messages and the audience numbers reached; Data capture on visitor numbers, page views, downloads etc. on South East Water website; Use of social media monitoring tools and evaluation methods. These will be used during the drought to monitor and manage conversations. The analytical tools also enable the effectiveness of messaging to be measured – e.g. understanding demographics of people engaged in the conversation. Request from customers for information/water saving devices/water efficiency information; Level of demand for advice from Local Authorities and the business community; Change in demand for water; Customer surveys and polls commissioned by South East Water or other organisations such as CCWater; South East Water employee surveys and feedback via Team Brief process; Reviews undertaken with South East Water’s online customer panel; Monitoring the monthly customer satisfaction scores (a South East Water survey of customers asking how satisfied they are with our service) – consider more in depth review/increase in numbers during the drought; Review 5/5 scores following customer contact (a text/phone message survey of all customers who contacted us to rate the service they received).
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7 POST DROUGHT ACTIONS
7.1 Lifting intervention options and declaring end of the drought
During the recession of a drought the triggers outlined in Section 2 will be used in a similar fashion to monitor and determine the de-escalation of a drought event. As the drought status is stepped down to a reduced level the Drought Management Team will discuss which actions are no longer necessary and these will be stopped. During this process, we will take account of the scale and the social and environmental impacts of each option, and will aim to cease those which have the largest or the greatest impacts first.
Some drought actions will continue to remain in place for a longer period of time than would be dictated by the de-escalation of drought severity triggers. For example, temporary use bans, drought orders (to restrict demand), and drought permits/orders are likely to remain in place until normal conditions have resumed in case the drought re-escalates. Temporary use bans may also be kept in place over a winter period if there is a risk of the drought re-occurring the next year.
We will continue to monitor our resources, looking particularly at the recharge of groundwater over the winter period. The recharge of groundwater following a drought will be especially important as an indicator of resource availability for the following year and as an indicator of potential for a multi-season drought.
The end of the drought will be determined when the following statements are true:
all of our drought regions are at normal overall drought status, and the recharge triggers indicate a normal or a developing drought status for each individual trigger site (eight sites in total), and the reservoir trigger curves indicate a normal status, and We have stopped using and has returned all drought permits/orders 7.2 Consultation during drought recession
As a drought recedes we will continue to liaise with a range of consultees and seek agreement where possible on a timescale for the de-escalation of interventions, including: -
Regulators including the Environment Agency and Natural England Non-household Retailers Neighbouring Water Wholesalers Household customers Media Other groups as appropriate
We will confirm with the Environment Agency that the water resource situation has returned to normal before declaring the end of the drought to its customers. Prior to this we will also inform the Environment Agency when each of the drought regions are
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at normal overall drought status. For further details on communications during a recession please refer to Section 6. 7.3 Post Drought Review
After we have declared the end of the drought, we will initiate an internal review of drought management activities and will aim to prepare a ‘Lessons learnt’ report within six months of the end of drought declaration. This report will include a summary of the decisions taken and their timescales, as well as actions to improve the drought planning methodology. Timescales will be set for the implementation of these actions. The post drought review will include the following (as adapted from the Environment Agency Drought Plan Guideline, June 2011 and the Environment Agency Drought Plan Guideline, July 2015):
Environmental: - Review the environmental effects of drought management actions by analysing the baseline, in-drought and post-drought data using appropriate analytical techniques. Determine if the appropriate environmental monitoring of baseline, during and after a drought was carried out to measure the impact of any drought permits/orders. Update the environmental assessment and environmental monitoring plan if needed. (Note – updates of environmental reports and monitoring plans will be actions coming out of the ‘lessons learnt’ report. It is expected that the environment could take a long time to recover after the drought has ended) - Review the effectiveness of any mitigation measures implemented Management actions: - Review the triggers and suggest improvements - Review the success, effectiveness and costs of all drought management actions, including a comparison of their actual and planned timings, and including effects of restrictions to water use - Assess how well individual sources delivered additional water and identify further work required - Complete a review of the drought action (DAPS2) i.e. consider whether there are any infrastructural or source improvements which could be brought online sooner than planned to reduce the supply failure risk in a future drought - Assess whether the estimates of demand reductions from the implementation of demand-side drought management actions matched actual reductions - Identify if we need to make any changes to its demand forecast or strategy Future planning - The results of the review may lead to an update of the WRMP being required. We will consider: - what actions are needed to maintain the sources used during the drought e.g. investing in them or reassessing yields - whether the drought triggers were effective at identifying when to implement actions - if the demand management strategy needs revision following the drought - whether any investments made as a result of the drought will affect other plans or programmes
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There will be consultation with the Environment Agency and Natural England during the environmental component of the review and we will reconcile any changes (resulting from drought actions) with the WRMP.
After the lessons learnt report has been prepared, this drought plan will be updated if relevant. In addition to completing the review, we will need to apply for abstraction licences for any schemes that were brought online during the drought and were licensed temporarily via a drought order. At this point in time we also expect to agree and pay compensation costs to the Environment Agency and Natural England in relation to any drought permit/order work undertaken.
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8 TESTING THE PLAN
The Defra and the Environment Agency updated guidelines require companies to test their plans against a range of plausible droughts to demonstrate their flexibility and robustness. The guidelines state that:
‘Your plan should include how you’ll deal with a range of droughts including both long duration and very low rainfall relative to expected conditions in your water resource zones (WRZs). You should at least plan to be able to provide supplies through a repeat of historic droughts in your company records. However, we strongly encourage you to plan for drought events that are of longer duration and lower rainfall than those in the historic record, or if not you should explain why. You should understand what drought events your supply system is vulnerable to and what the probability of such an event occurring is.’
To satisfy this requirement, we have tested our plan against a range of observed historic (including the worst historic drought, 2010-2012) and stochastically generated droughts that are different in terms of severity, duration and hence impacts. The approach was to test our triggers and drought status classification system against these droughts and demonstrate how our drought management actions would be implemented in each case. The trigger curves for our two reservoirs have been updated for this revised draft drought plan to ensure consistency with our dWRMP19.
Wherever possible, we have assigned a return period to the drought event for the scenarios we have presented. A return period is terminology used to analogise the likely frequency of occurrence of an event. Return periods can also, perhaps more helpfully in this instance, be viewed in terms of a probability of occurrence in any one year. For example, classifying a drought in terms of having a one in 100 year return period means there is a one per cent probability that a drought of that magnitude could be experienced in any one year. Similarly, a one in 200 year drought has a 0.5 per cent probability of occurring in any one year.
We have selected the following historic drought scenarios as the most appropriate droughts to use:
Short-term drought (2003) characterised by high demand triggered by hot dry summer, but with relatively high groundwater conditions; Medium duration, multi season drought (1995-1997) characterised by sequential years of hot dry weather with below average recharge; Long term drought (2003-2006) characterised by sequential years of below average recharge and high forecast demands; and Two dry winter drought (2010-2012) characterised as the name suggests by two consecutive dry winters resulting in very low groundwater levels.
Although the 1995–1997 and 2003–2006 scenarios have the same period of duration, the 1995–1997 presents alternating patterns of drought severity between the different drought regions, whereas 2003–2006 represents a more ‘uniform’ long term drought. The 2010-2012 drought has been illustrated using modelled operation of our two reservoirs (Ardingly and Arlington) in response to observed rainfall-runoff sequences during that drought event, as opposed to observed storage level data. This is because our two reservoirs were operated abnormally during this period and hence using
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observed storage levels would be misleading and inappropriate. Alternative drought examples for the short, medium and long-term drought scenarios were also considered; however, due to a lack of available data for some drought regions, 2003 has been used as the short-term example scenario as well as the starting year of the long-term drought example scenario.
In addition to the assessment of historic droughts, we have developed alternative drought sequences using a stochastic approach. A wide range of droughts were selected for testing, representing varying severity and duration:
Three stochastic worst historic droughts: characterised the probability of occurring once in 100 years on average (1 per cent chance of occurring in a given year), and by having a similar severity to the observed worst historic drought. The three droughts have varying durations of 12, 18 and 24 months Three stochastic severe droughts: characterised the probability of occurring once in 200 years on average (0.5 per cent chance of occurring in a year), and by having a higher severity to the observed worst historic drought. The three droughts have varying durations of 12, 18 and 24 months Three stochastic extreme droughts: characterised the probability of occurring once in 500 years on average (0.2 per cent chance of occurring in a year), and by having a much higher severity to the observed worst historic drought. The three droughts have varying durations of 12, 18 and 24 months
To test our plan further, and understand its performance under a prolonged drought, we have developed a third dry winter drought scenario. We have adopted a ‘what if’ approach and extended the 2010-2012 drought to continue onto a third dry winter.
At the end of each scenario, we have provided a brief explanation of the extent to which drought triggers and actions taken may be impacted by the triggering of the bulk supply override triggers described in section 2.6.
This involved applying all the bulk supply override triggers in each month of the drought scenarios we have tested to see what effect this might have on our drought action response. When assuming the override trigger has occurred it has been given a level three severe drought score, and the bulk supply yield is assumed to align with one in 500 year drought yields (see Table 3.3). We have then observed what effect the introduction of the override trigger has had on the overall drought status each month during the drought. This has been done in the context that we would not likely lose the whole output from the bulk supply, just a portion of it (as per the values stated in Table 3.3), and that bulk supplies only provide between seven per cent and 11 per cent of the total supply across our drought regions.
The overall purpose of this scenario testing section is to demonstrate our response and show the effectiveness of our plan to the range of selected droughts.
Since our plan will be tested against our drought triggers a distinction has to be made between the severe drought status defined by the breach of our monitoring triggers (described in Section 3) and the severe drought events we have generated to test the system. For the purpose of clarity, the following terms will be used in this section:
1. ‘Severe drought status’: This refers to the fourth stage of drought development (as defined by the Environment Agency) determined by
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monitoring the breach of a combination of drought triggers as described in Chapter 2. Severe drought status would enact a specific set of operational, management, communication and environmental actions.
2. ‘Severe drought impact’: This refers to the stochastically generated plausible drought event that has a modelled severe impact on our system and with a probability of occurring once every 200 years. This definition is in line with industry guidance. 8.1 Testing against drought scenarios
The guidance suggests that the selected historic drought scenarios should include current water resource infrastructure, demands and operations. The demand sequence selected for the modelling of all scenarios is January to December 2003 (because it presents a realistic worst-case scenario). Error! Reference source not found. shows graphs of the 2003 demands for each of the three drought regions.
The historically observed drought scenarios are presented and analysed in the following sub-sections. The four scenarios were tested on all three drought regions, to examine response across our whole area.
Overall the drought scenarios affect the three drought regions at different times and with differing magnitudes. We have ensured that the scenarios used lead to each drought region moving from one drought status to another, and thus triggering drought actions. A selection of the 2003–2006 groundwater, recharge, and reservoir storage curves for each of the drought regions are shown in Error! Reference source not found..
8.1.1 Short-term drought (2003) 2003 has been selected as an illustration of the situation when demands were exceptionally high in mid-summer, but the groundwater resources were generally sufficient. The 2003 scenario is considered to have a greater than one per cent probability of occurrence in any given year, i.e. a return period of greater than one in 100 years. The 2003 scenario also forms part of the 2003-2006 long term drought scenario, see Section 8.1.3.
For each month of 2003 the trigger scores were collated and entered into the drought assessment matrices. To demonstrate the workings of the initial and overall trigger matrices, September 2003 is presented in Table 8.1 and Table 8.2.
The month of September indicates that overall (see Table 8.2) Eastern (1-3) was at a moderate drought status and Eastern (6-8) and Western (4-5) were at developing drought status. The reservoirs in Eastern (1-3) (see Table 8.1) were extremely low, indicating a moderate / severe drought. Recharge and demand triggers across our area were indicating a developing to moderate drought.
Table 8.1 – Initial trigger matrix for September 2003 scenario
Surface Groundwater Recharge Demand Water Elphicks Farm Trial Goudhurst (Ashdown Beds)
1 Ardingly (Ashdown Beds) (32%) 2 (32%) 1
3)
- East (1-3) 2 Cornish (Chalk S Downs) Poverty Bottom (Chalk South
East (1 0 Arlington (44%) 3 Downs) (44%) 2
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Surface Groundwater Recharge Demand Water Ryarsh (Gs W of Cramptons (Greensand West of Medway) (20%) 1 Medway) (20%) 2
Hambledon Old Schl (Gs Cleve (Chalk Maidenhead) 0 1
6) Wy+Lod) (37%) (25%)
- Stonor Park (Maidenhead Basingstoke (East Hants Chalk) (25%) 1 n/a Downs) (38%) 1 West (4-6) 1 Winslade Farm (E Hants Borden (Wey Loddon West (4 Downs) (38%) 0 Greensand and HB) (37%) 1 Charing No 7 (Gs E of Goudhurst (Ashdown Beds) Medway) (23%) 1 (5%) 1 Dane Court (Chalk Stour) Cramptons (Greensand West of (43%) 0 Medway) (7%) 2 Duckpit Farm (Chalk N Boughton (Chalk North Downs) Downs) (22%) 0 n/a (22%) 2 East (7-8) 2
8) - Elphicks (Ashdown Beds) Charing (Greensand East of (5%) 0 Medway) (23%) 2 Ryarsh (Gs W of
East (7 Boughton (Chalk Stour) (43%) Medway) (7%) 1 2 Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Applying the override trigger during September 2003 (the time period reflected in Table 8.1), i.e. escalating our drought status to take account of a reduction in bulk supply volume from a neighbouring company, would not alter the overall scores much at a drought region level. Although it would likely move the status of our groundwater triggers from developing to moderate drought, our overall regional assessment is already likely to be at moderate drought due to the combined status of our surface water, recharge and demand triggers. Therefore, if another company hit its triggers then it would escalate our drought management actions such that we plan for the loss of some/all of a neighbouring water company’s bulk supply earlier. In this way, we see the true benefit of the override trigger and how it would have worked really well in practice.
To help determine the drought status for each drought region the trigger schematic tool was used to help compare the balance between the current and predicted resources and demand. Figure 8.1 plots selected drought months for a selected drought region throughout 2003 and shows the progression of the drought in terms of the increase in demands through to August and the falling resources throughout the year until October, when the resources situation begins to improve. The grey arrows help to indicate this trend.
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Table 8.2 – Overall trigger matrix for September 2003 scenario Company Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Drought Trigger drought Region Resources Status Recharge Demand/ Bulk region GW Reservoirs Forecast supplies score demand / Shared sources Moderate Drought - 2 Reservoir levels extremely low, with Eastern 1 2-3 2 2 0 groundwater levels 2 (1-3) falling. Recharge forecasts are low and demand remains high. Developing Drought - 1 Western 0-1 NA 1 1 0 Overall triggers 1 (4-5) indicate a developing drought. Developing Drought - 1 Overall triggers indicate a developing drought Eastern but if recharge 0 NA 2 2 0 1 (6-8) remains low and demand high, this drought region could move to moderate drought in the fairly near future. Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Figure 8.1 – Trigger schematic tool – Eastern (W) 2003
H 3 2 to 1
Aug
Sep Demand
Apr Oct Jan Nov 2 Dec 1 to 0 L L H Resources / Recharge
0 1 2 3 Normal Developing Moderate Severe Drought Drought Drought Status
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To present the full 2003 scenario a timeline table (see Table 8.3) has been developed to show when each drought region would change drought status and set out some of the key actions that would be implemented as per the Drought Action Plan. The main points are:
The Drought Management team would have been convened in February / March 2003 for all drought regions and developing drought actions commenced; Eastern (1-3) drought region would have been the only drought region to step up to a moderate drought status during July–October; In Eastern (1-3) drought region a temporary use ban Phase 1 would have been put in place in August (at the latest) to curb the high demands. It is likely they would have been considered in June and July and may have been implemented then, depending on whether adjacent water companies were implementing restrictions. In early September, with the reservoirs indicating a moderate / severe drought, it is thought likely that a temporary use ban Phase 2 would also have been implemented to assist with applications if drought permits/orders are required for winter refill; Drought permit/order applications would likely be submitted in October (when both Ardingly and Arlington indicate a severe drought status) to assist with winter refill.
The scenario has demonstrated that drought permits/orders for winter refill may be required when overall Eastern (1-3) drought region is only at moderate drought, which was not covered in the drought plan. In the development of the revised draft drought plan, we have made alterations to the drought permit/order triggers as a result of this.
In a comparison of this scenario to actual actions that were implemented in 2003, there are some discrepancies. In reality, no hosepipe or sprinkler bans were implemented during 2003. Drought permits to assist with winter reservoir water conservation and refill were applied for The Upper and Lower Ouse, and the Cuckmere in October / November 2003 and were granted in December 2003. The scenario suggests that the updated triggers lead to some actions commencing slightly earlier than might have occurred previously under the former South East Water or Mid Kent Water.
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Table 8.3 – 2003 Drought scenario regional drought scores and summary of actions likely to be implemented East West East Scenario (selected) actions likely to be
(1-3) (4-5) (6-8) implemented Jan 2003 0-1 Drought Management Team convened Feb 2003 East (1-3) and East (6-8) commence developing drought actions Mar 2003 West (4-5) commence developing drought actions Arlington Reservoir at severe drought status (there are Apr 2003 no drought permits linked to this reservoir for summer use) May 2003 Jun 2003 1-2 East (1-3) moderate actions commence, including phase 1 temporary bans likely to be advertised in very Jul 2003 1-2 early August and implemented in mid-August when demand is highest (they would have been considered in June and July and may have been implemented Aug 2003 1-2 immediately depending on whether adjacent water companies were implementing them) East (1-3): consider putting phase 2 temporary use bans in place. This is likely to have been imposed in Sep 2003 order to apply for winter refill drought permits. Arlington reservoir at severe drought status. East (1-3) Arlington and Ardingly Reservoirs at severe Oct 2003 drought status. Lower Ouse and Cuckmere winter refill drought permits/orders applied for. Nov 2003 Dec 2003 Key Normal drought status Developing drought status Moderate drought status 0-1 Normal / developing drought status boundary 1-2 Developing / Moderate drought status boundary
When considering the potential impacts on drought status of our override trigger having been activated during this drought, we can conclude that in this scenario, it would have had limited impact until June 2003 when we reached the 1-2 status boundary. This is because prior to that point, the status of our triggers was such that even with the potential loss of a bulk supply, we would likely be able to accommodate that with output from our own sources. However, as our triggers approach the 1-2 status boundary, we would likely use the override trigger to move our drought status from level 1 (developing drought) to level 2 (moderate drought). This would escalate our action plan to take account of a neighbouring water company’s bulk supply reduction earlier. In this way, we see the true benefit of the override trigger and how it would have worked really well in practice.
8.1.2 Medium duration, multi season drought (1995-1997) 1995 to 1997 was selected because of the sequential years of hot dry weather with below average recharge. The 1995-1997 scenario is considered to have a greater than one per cent probability of occurrence in any given year, i.e. a return period of greater than one in 100 years. As per the 2003 drought scenario, trigger scores were collated and entered into the drought assessment matrices for each month. An example for August 1996 is shown below (Table 8.4, Table 8.5, and Figure 8.2), which indicates
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Eastern (1-3) and Eastern (6-8) drought regions are both at moderate drought and Western (4-5) is at developing drought status.
Table 8.4 – Initial trigger matrix for August 1996 scenario
Surface Groundwater Recharge Demand Water Elphicks Farm Trial Goudhurst (Ashdown Beds) 0 Ardingly (Ashdown Beds) (32%) 2 (32%) 0
3) - Cornish (Chalk S Downs) Poverty Bottom (Chalk South 2 (44%) Downs) (44%) 0 East (1-3) 2 Arlington 2 Ryarsh (Gs W of Cramptons (Greensand West of East (1 Medway) (20%) 1 Medway) (20%) 1
Hambledon Old Schl (Gs Cleve (Chalk Maidenhead) 1 0
6) Wy+Lod) (37%) (25%)
- Stonor Park (Maidenhead Basingstoke (East Hants Chalk) (25%) 1 n/a Downs) (38%) 0 West (4-6) 2 Winslade Farm (E Hants Borden (Wey Loddon West (4 Downs) (38%) 1 Greensand and HB) (37%) 1 Charing No 7 (Gs E of Goudhurst (Ashdown Beds) Medway) (23%) 0 (5%) 0 Dane Court (Chalk Stour) Cramptons (Greensand West of (43%) 2 Medway) (7%) 1 Duckpit Farm (Chalk N Boughton (Chalk North Downs) Downs) (22%) 2 n/a (22%) 1 East (7-8) 3
8) - Elphicks (Ashdown Beds) Charing (Greensand East of (5%) 0 Medway) (23%) 1 Ryarsh (Gs W of
East (7 Boughton (Chalk Stour) (43%) Medway) (7%) 1 1 Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Table 8.5 – Overall trigger matrix for August 1996 scenario Company Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Drought Trigger drought Region Resources Status Recharge Demand/ Bulk region score GW Reservoirs Forecast supplies demand / Shared sources Moderate Drought - 2 Reservoir levels indicate a moderate Eastern drought and 1 2 0 2 0 2 (1-3) groundwater levels falling. Recharge forecasts are ok but demand is high. Developing Drought - 1 Current GW Western 1 NA 0 2 0 indicates a 1 (4-5) developing drought and demand is high.
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Company Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Drought Trigger drought Region Resources Status Recharge Demand/ Bulk region score GW Reservoirs Forecast supplies demand / Shared sources Moderate Drought - 2 Overall triggers indicate a developing Eastern 1-2 NA 1 3 0 progressing to 2 (6-8) moderate drought. Demand is exceptionally high. Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Figure 8.2 – Trigger schematic tool – all drought regions August 1996
H 3 E (6-8) 2 to 1
E (1-3)
W (4-6) Demand
2 1 to 0 L L H Resources / Recharge
0 1 2 3 Normal Developing Moderate Severe Status Drought Drought Drought
A timeline table (see Table 8.6) has been developed to show when each drought region would change drought status and set out some of the key actions that would be implemented as per the drought action plan. A comparison with what happened in reality is also made, however it should be noted that some of the discrepancies may be because the scenario is based on a 2003 demand profile. The main points are:
Eastern (1-3) drought region would have been the first drought region to go into a developing drought status in May 1995 As the drought continues in August 1995 Eastern (6-8) would have reached developing drought status, and Eastern (1-3) would have stepped up to moderate drought status. Western (4-5) drought region would have remained at normal status A temporary use ban on water use (Phase1) would have been implemented in August 1995 which is consistent with what happened in reality By October 1995 all three drought regions would have been at developing drought status and would stay at or above this status until late December 1997 In late August the Company would have been considering applying for the Upper / Lower Ouse drought permit/order to assist with Ardingly Reservoir water
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conservation and refill (because Ardingly crossed the severe drought trigger in August). In reality the drought permit/order (if granted) would probably not have been used until December 1995. We would have applied again in December if the drought permit/order had not previously been granted earlier in autumn. This is consistent with the actual winter 1996 drought permit used A temporary use ban (Phase1) is likely to have been kept in place over the winter period but would be lifted in February because of rising reservoir levels and in case of need later in the summer. (A re-application of a restriction is likely to have greater demand savings and allow fresh communications messages) The July 1996 temporary use bans (Phase1) in both Eastern (6-8) and Eastern (1- 3) are also consistent with what actually happened. Because of the extended duration of the drought it is likely they would have been maintained over winter 1996-97 so that the drought message communicated remains constant In July 1996 the Ardingly Reservoir severe drought trigger was crossed so we would have been preparing and considering a Summer Lower Ouse drought permit/order application in mid-late July. It is however unlikely to have been applied for because the Eastern (1-3) drought region status was only moderate. (During summer a severe drought status is the trigger for drought permit/order application) The timing of crossing the Ardingly Reservoir severe trigger has an impact on the drought permit/order type applied for and when an application would be submitted. For example in summer 1995 the Ardingly severe drought trigger was not crossed until August. This would have prompted Autumn Ouse drought permit/order application to help refill Ardingly Reservoir, even though the drought region status was only moderate. This is because the drought permit/order application process takes about 6 weeks and if a summer Lower Ouse drought permit/order were applied for in mid-August, by October it would be attained too late to be of use In September 1996 an application for the Upper / Lower Ouse drought permit/order to assist with Ardingly Reservoir water conservation and refill would have been considered, and is likely to have been submitted, because the reservoir crossed the severe drought trigger In February 1997 Eastern (6-8) would have moved to moderate drought status. In reality the former Mid Kent Water drought team had only just been convened. It appears these triggers are prompting initial drought actions sooner than the former Mid Kent Water drought plan would have done. Phase 2 temporary use bans are likely to be implemented in Eastern (1-3) to reduce demand and a Phase 3 drought order also applied for. Restrictions were not put in place in reality, although they were considered at the time In October 1997 Western (4-5) drought region reaches moderate drought but temporary use bans (Phase 1) would not be implemented this late in the year Post drought actions, including the lifting of the Phase 1 and 2 temporary use ban restrictions would commence in early 1998
Table 8.6 – 1995–97 Drought scenario regional drought scores and summary of actions likely to be implemented East West East Scenario (selected) actions 1995-1997 Actions (1-3) (4-5) (6-8) likely to be implemented Jan 1995 0-1 Feb 1995 0-1 Mar 1995 Apr 1995 Drought management team May 1995 convened
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East West East Scenario (selected) actions 1995-1997 Actions (1-3) (4-5) (6-8) likely to be implemented East (1-3) developing actions commence Jun 1995 East (1-3) Ardingly reservoir trigger at moderate drought approaching severe. Permutations of the Ouse drought permit/order would be prepared (these would not have Jul 1995 1-2 been submitted until the region was at severe drought status and/or the severe Ardingly reservoir trigger has been crossed in late summer when an East (1-3) and West (4-5) autumn refill could be applied sprinkler ban. for) East (1-3) hosepipe ban) East (1-3) moderate actions commence, including phase 1 Aug 1995 temporary use bans advertised in late July/early August and implemented by mid-August. Ardingly reservoir severe drought trigger crossed in Sep 1995 August, Upper / Lower Ouse drought permit/order applications in enable abstraction and autumn refill submitted in late August. Oct 1995 East (6-8) and West (4-5) developing drought actions commence. Nov 1995 East (1-3) Ardingly reservoir trigger moderate drought, approaching severe drought. Assumed that drought Dec 1995 permits/orders for the River Ouse are in place. If not, we would reapply in December as Ardingly is approaching severe drought trigger. Jan 1996 0-1 East (1-3) winter reservoir conservation and refill drought permit/order assumed to be in East (1-3) drought permit use. Likely to have revoked the to allow additional Feb 1996 phase 1 temporary ban abstraction from the River restrictions in case of need later Ouse in summer. East (6-8) DMT Mar 1996 established in early 1996 Apr 1996 May 1996 East (1-3) Ardingly reservoir trigger at moderate drought, approaching serve drought. Permutations of the Ouse Jun 1996 1-2 1-2 drought permits/orders would be prepared (these would not be submitted until the severe drought trigger is reached.
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East West East Scenario (selected) actions 1995-1997 Actions (1-3) (4-5) (6-8) likely to be implemented East (1-3) and East (6-8) temporary bans on water use phase 1 likely to be implemented in July (even though East (6-8) Jul 1996 has not yet reached moderate drought status) Ardingly reservoir severe drought trigger crossed in mid- July, but because the drought region status is only moderate, a summer Lower drought permit/order application is Aug 1996 unlikely to have been submitted. Permutations of the Ouse autumn refill drought permit/order would be prepared (these would not have been submitted until the Ardingly severe drought trigger reached in September, if considered East (1-3) sprinkler ban Sep 1996 required at all. Under this and hosepipe ban scenario it is quite likely that we would have decided that a drought permit/order would not have been necessary). Oct 1996 1-2 1-2 East (1-3) and East (6-8) phase Nov 1996 1 restrictions kept in place over Dec 1996 1-2 winter and into 1997 – likely to have been kept in place over Jan 1997 1-2 summer 1997 in both regions Feb 1997 East (6-8) moderate drought East (6-8) DMT actions commence (for example: concluded developing Mar 1997 increase in transfer from East (1- drought with possibility of 3) to East (6-8), prepare Halling moving into moderate Apr 1997 No.8 drought permit/order in drought. Water use case required (unlikely that it restrictions considered May 1997 would have been submitted), but not put in place. Jun 1997 1-2 1-2 consider phase 2 temporary bans on water use, restrictions Jul 1997 1-2 may have been put in place in mid-summer. If so, a phase 3 Aug 1997 drought order would also have Sep 1997 been applied for) West (4-5) moderate drought Oct 1997 actions (phase 1 restrictions unlikely to be put on during Nov 1997 0-1 Autumn) East (6-8) and East (1-3) Dec 1997 temporary ban phase 1 and phase 2 restrictions lifted. Jan 1998 0-1 Commence post drought actions. Key Normal drought status Developing drought status Moderate drought status 0-1 Normal / developing drought status boundary 1-2 Developing / Moderate drought status boundary
Activation of our override trigger would have had limited impact on our drought status until we came close to reaching our level 1-2 status boundary. Therefore, if another
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company hit its triggers, then it would escalate our actions to take account of a reduction in a neighbouring water company’s bulk supply earlier than would otherwise have been the case. In this way, we see the true benefit of the override trigger and how it would have worked really well in practice.
8.1.3 Long term drought (2003-2006) 2003 to 2006 was selected because of sequential years of below average recharge and high forecast demands, which for the South East of England it was recorded as a one in 40-80 year event7, i.e. with a 1.25-2.5 per cent probability of occurrence in any given year. The Centre for Ecology and Hydrology stated that the ‘combined November-February rainfall deficiencies are the lowest for successive winters since 1932-1934 in much of central and south eastern England’ (Mid Kent Water, March 2006).
As per the 2003 and 1995-97 scenarios, trigger scores were collated and entered into the drought assessment matrices for each month. An example for December 2004 is shown below (Table 8.7, Table 8.8, and Figure 8.3), which indicates the first time in the scenario when all regions are at Moderate drought, with Eastern (1-3) experiencing the worst drought conditions during that month.
Table 8.7 – Initial trigger matrix for December 2004 scenario
Surface Groundwater Recharge Demand Water Elphicks Farm Trial Goudhurst (Ashdown Beds) 1 Ardingly (Ashdown Beds) (32%) 2 (32%) 1
3) - Cornish (Chalk S Downs) Poverty Bottom (Chalk South 2 (44%) Downs) (44%) 1 East (1-3) 1 Arlington 2 Ryarsh (Gs W of Cramptons (Greensand West of East (1 Medway) (20%) 2 Medway) (20%) 2
Hambledon Old Schl (Gs Cleve (Chalk Maidenhead) 1 2
6) Wy+Lod) (37%) (25%)
- Stonor Park (Maidenhead Basingstoke (East Hants Chalk) (25%) 1 n/a Downs) (38%) 2 West (4-6) 2 Winslade Farm (E Hants Borden (Wey Loddon West (4 Downs) (38%) 1 Greensand and HB) (37%) 1 Charing No 7 (Gs E of Goudhurst (Ashdown Beds) Medway) (23%) 1 (5%) 1 Dane Court (Chalk Stour) Cramptons (Greensand West of (43%) 0 Medway) (7%) 2 Duckpit Farm (Chalk N Boughton (Chalk North Downs) Downs) (22%) 1 n/a (22%) 2 East (7-8) 2
8) - Elphicks (Ashdown Beds) Charing (Greensand East of (5%) 0 Medway) (23%) 2 Ryarsh (Gs W of
East (7 Boughton (Chalk Stour) (43%) Medway) (7%) 2 2 Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
7 Return period estimates for 2003 -2006 are based on non-essential use submissions by Southern Water Services made in Spring 2006. References: Southern Water Services, March 2006 a, and Southern Water Services March 2006b.
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Table 8.8 – Overall trigger matrix for December 2004 scenario Company Trigger 1 Trigger 2 Trigger 3 Trigger 4 Override Comment Overall Drought Trigger drought Region Resources Status Recharge Demand/ Bulk region GW Reservoirs Forecast supplies score demand / Shared sources Moderate Drought - 2 Reservoir levels and Eastern groundwater indicates a 2 2 1-2 1 0 2 (1-3) Moderate drought, and recharge forecasts are low. Moderate Drought - 1- 2 Current GW indicates a Western Developing drought (but 1 NA 2 2 0 1-2 (4-5) increasing in severity), but recharge forecasts are low and demand is high. Moderate Drought - 1- 2 Current GW indicates a Eastern Developing drought (but 1 NA 2 2 0 1-2 (6-8) increasing in severity), but recharge forecasts are low and demand is high. Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Figure 8.3 – Trigger schematic tool – all drought regions December 2004
H 3 2 to 1
E (E) W
Demand E (W)
2 1 to 0 L L H Resources / Recharge
0 1 2 3 Normal Developing Moderate Severe Status Drought Drought Drought
A timeline table (see Table 8.9) has been developed to show when each drought region would change drought status and set out some of the key actions that would be implemented as per the drought action plan. A comparison with what happened in reality is also made, however it should be noted that some of the discrepancies may be because the scenario is based wholly on a 2003 demand profile. The drought year
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2003 has already been discussed in Section 8.1.1 and so details for that year are not mentioned in the discussion below. The main points for the 2004-2006 period are:
Over the 2004 winter all drought regions would have been at developing drought status. Drought permits/orders for Ardingly (Lower Ouse) and Arlington (Cuckmere) would have been in place to assist with refill of the reservoirs and temporary and a Phase 1 temporary use ban would have remained in place for Eastern (1-3) drought region. During this we would have also been discussing whether there were any schemes that could be accelerated to assist with the drought should it continue over the next 12 months or longer. In early spring 2004 we would have considered whether to lift the temporary use ban Phase 1 restrictions for Eastern (1-3) drought region because the drought is of a similar severity across the company area and the other drought regions have not reached the trigger for it to be implemented. The temporary use ban Phase 1 restrictions would have been advertised in September 2005, and subsequently implemented in early October 2004. This is probably the latest time of year we would consider putting these restrictions on, under this situation. This is generally consistent with the sprinkler and hosepipe ban that was actually implemented in summer 2004. In December 2004 all drought regions were at a moderate drought status. Winter refill drought permits/orders would not have been applied for because the Reservoir curves had not reached the severe drought trigger. In late March 2005 the Eastern (6-8) drought region would have advertised and then implemented the temporary use ban Phase 1 restrictions. The Western (4-5) drought region would have been the last implement a temporary use ban. This would have been advertised in early August, to be closely followed by a whole company Phase 2 restriction in late August. During August a Phase 4 drought order application would have been prepared and applied for at the same time that the Phase 2 restriction was put in place. Phase 3 would have been omitted because of the speed of the worsening severity of the drought. Drought permit/order applications to assist with Ardingly and Arlington winter refill would have been considered in October because even though both reservoirs indicate only a moderate drought status and overall Eastern (1-3) drought status is moderate; the reservoir levels were not looking like they would quickly recover. If granted they may not have been used until December or January. If a decision was taken not to apply for them, then they would have been applied for in January 2006 when Arlington reached severe drought status and reservoir storage was close to crossing the drought trigger. All drought regions remained at moderate drought status until at least December 2005 and the drought actions would have continued until normal status was resumed.
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Table 8.9 – 2003–2006 Drought scenario regional drought scores and summary of actions likely to be implemented East West East Scenario (selected) actions likely 2003-2006 summary of
(1-3) (4-5) (6-8) to be implemented key actions Jan 2003 0-1 Drought management team convened. Feb 2003 East (1-3) & East (6-8) commence developing drought actions. West (4-6) commence developing Mar 2003 drought actions. Arlington reservoir at severe drought status. (There are no April 2003 drought permits/orders linked to this reservoir for summer use). May 2003 Jun 2003 1-2 Jul 2003 1-2 East (1-3) moderate actions commence, including: Phase 1 temporary bans likely to be advertised in very early August and implemented in mid-August, when demand is highest. (They would Aug 2003 1-2 have been considered in June and July and may have been implemented then, depending on whether adjacent water companies were implementing them). East (1-3) consider putting on Phase 2 temporary bans – likely to have been imposed in order to Sep 2003 apply for winter refill drought permits/orders. Arlington reservoir at severe drought. East (1-3) Arlington and Ardingly East (1-2) winter reservoirs at severe drought. Apply reservoir conservation Oct 2003 for Lower Ouse and Cuckmere and refill drought permits winter refill drought permits/orders. (Lower and Upper Ouse and Cuckmere) applied Nov 2003 for. East (1-3) Drought Dec 2003 permits granted. East (1-3) Phase 2 temporary bans lifted because surface water Jan 2004 resource status is improving. Phase 1 temporary bans kept in place. All Regions: consider accelerating infrastructural connectivity or source Feb 2004 improvement schemes that could be brought online in the next 6 months. Mar 2004 East (1-3) consider lifting Phase 1 April 2004 temporary bans this spring because May 2004 East (1-3) is at same drought status Jun 2004 then rest of company. Jul 2004 Aug 2004 East (1-3) moderate actions East (1-3) sprinkler ban commence, including: Phase 1 East (1-3) hosepipe ban Sep 2004 temporary bans advertised mid- September and put in place early October.
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East West East Scenario (selected) actions likely 2003-2006 summary of
(1-3) (4-5) (6-8) to be implemented key actions Oct 2004 Nov 2004 East (6-8) & West (4-5) moderate actions commence, including: Dec 2004 1-2 1-2 reviewing operational use and delivery programme (S1b) and operational works (D2b). Jan 2005 East (6-8) drought Feb 2005 1-2 management team convened. East (6-8) Phase 1 temporary bans Mar 2005 1-2 advertised in late March and implemented in early April. April 2005 May 2005 Jun 2005 East (6-8) Sprinkler ban.
West (4-5) Phase 1 temporary bans Jul 2005 1-2 advertised in early August and implemented by late August. East (1-3) sprinkler ban. All regions – Phase 2 temporary East (1-3) and East (6-8) ban advertised late August and hosepipe ban. implemented early September. East (1-3) River Ouse Aug 2005 - Phase 4 drought order applied for drought permit applied in late August. for July 2005. - Prepare summer and winter West (4-5) considered a drought permits/orders for use in all drought permit for three drought regions (Lower River Greatham in 2005. Sep 2005 Ouse, Cuckmere, Southland and Oaklands, Halling No.8).
Would have considered applying for Upper Ouse and Cuckmere drought permits/orders to enable reservoir Oct 2005 1-2 refill this autumn even though severe reservoir drought triggers were not crossed. Nov 2005 1-2 1-2 Dec 2005 1-2 East (1-3) Arlington reservoir at severe drought. Apply for Cuckmere winter reservoir conservation and refill drought permits/orders if not already done so this autumn. (Also Jan 2006 1-2 likely to have submitted a Lower Ouse drought permits/orders application to refill Ardingly Reservoir). All regions – continue with drought actions until normal status is resumed. Key Normal drought status Developing drought status Moderate drought status 0-1 Normal / developing drought status boundary 1-2 Developing / moderate drought status boundary
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Note – Mid Kent Water i.e. the former East (6-8) drought region applied for a Drought Order to ban the non-essential use of water in March 2006.
Application of our override trigger during the 2003-06 drought would mean we would have reached moderate drought status in drought region East (1-3) a few months earlier in 2003 and retained moderate status all the way through to January 2006. We would have been preparing to take action a little earlier in West (4-5) and East (6-8), but not significantly different to action being taken in any case on a prudent basis. In this way, if another company hit its triggers then it would escalate our action to plan with a neighbouring water companies bulk supply impacts earlier. Therefore, we see the true benefit of the override trigger and how it would have worked really well in practice.
8.1.4 Two dry winter drought (2010-2012) The 2010-2012 drought is considered to be the worst experienced in the South East Water company area in the historic record back to 1920, with a return period of approximately 1 in 100 years (or a 1 per cent probability of occurrence in any one year). As per the 2003, 1995-1997 and 2003-2006 scenarios, trigger scores were collated and entered into the drought assessment matrices for each month. An example for June 2012 is shown below (Table 8.10), which indicates when overall company drought status is severe, following the second dry winter. Eastern (1-3) experienced the worst drought conditions during that month.
As has been mentioned previously, the 2010-2012 drought has been illustrated using modelled operation of our two reservoirs (Ardingly and Arlington, as presented in and Figure 8.6) in response to observed rainfall-runoff sequences during that drought event, as opposed to observed storage level data. This is because our two reservoirs were operated abnormally during this period and hence using observed storage levels would be misleading and inappropriate. The trigger matrix has been adapted accordingly, with results from the reservoir modelling rather than operational data.
Table 8.10 – Initial trigger matrix for June 2012
Surface Recharge (2-year cumulative Groundwater Demand Water recharge) Elphicks Farm Trial Goudhurst (Ashdown Beds) Ardingly (Ashdown Beds) (32%) 3 0 (32%) 3
3) - Cornish (Chalk S Downs) Poverty Bottom (Chalk South East (1- (44%) 2 Downs) (44%) 3 0 Arlington 0 3) Ryarsh (Gs W of Cramptons (Greensand West of East (1 Medway) (20%) 2 Medway) (20%) 3
Hambledon Old Schl (Gs Cleve (Chalk Maidenhead) 1 3
6) Wy+Lod) (37%) (25%)
- Stonor Park (Maidenhead Basingstoke (East Hants West (4- 2 n/a 1-2 0 Chalk) (25%) Downs) (38%) 6) Winslade Farm (E Hants Borden (Wey Loddon West (4 Downs) (38%) 1 Greensand and HB) (37%) 3 Charing No 7 (Gs E of Goudhurst (Ashdown Beds) Medway) (23%) 2 (5%) 3 Dane Court (Chalk Stour) Cramptons (Greensand West of (43%) 2 Medway) (7%) 3 Duckpit Farm (Chalk N Boughton (Chalk North Downs) East (7- Downs) (22%) 2 n/a (22%) 3 0
8) 8) - Elphicks (Ashdown Beds) Charing (Greensand East of (5%) 3 Medway) (23%) 3 Ryarsh (Gs W of
East (7 Boughton (Chalk Stour) (43%) Medway) (7%) 2 3
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Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status. Table 8.11 – Overall trigger matrix for June 2012 Company Trigger 1 Trigger 2 Trigger 3a Trigger 3b Trigger 4 Comment Overall Region Resources Status Three Year Two Year Demand/ Drought GW Reservoirs Cumulative Cumulative Forecast Region Recharge Recharge demand score 2 Moderate Drought (although (Both reservoirs are currently Eastern Elphicks 0 1 3 0 full, Elphicks (Ashdown) 2 (W) is groundwater levels severely critically low (32% of GW)) severe) Developing to Moderate Drought (Groundwater levels have increased to developing drought status in the East Western 1-2 2 3 0 1-2 Hants Downs and Wey Loddon Greensand. Groundwater levels are still low at Stoner, however these are increasing) 2 Moderate Drought (although (Chalk groundwater levels Eastern Elphicks have increased to moderate 1 3 0 2 (E) is drought status. Elphicks critically (Ashdown) groundwater levels severe) severely low (5% of GW)) Key: (0) normal drought status, (1) developing drought status, (2) moderate drought status, (3) severe drought status.
Figure 8.4 – Trigger schematic tool showing 11 June 2012 to 30 June 2012
H 3 2 to 1 E (W)
E (E)
W Demand
2 1 to 0 L L H Resources / Recharge
0 1 2 3 Normal Mild Moderate Severe Status Drought Drought Drought
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Figure 8.5 – Storage at Ardingly Reservoir during the 2010-2012 drought event
Figure 8.6 – Storage at Arlington Reservoir during the 2010-2012 drought event
It can be seen from Figure 8.5 and Figure 8.6 that reservoir levels during the 2010- 2012 drought were in fact not badly affected by the low rainfall. This is due to the fact that the drought was characterised by a prolonged period of low rainfall covering two dry winters, which has a more significant impact on groundwater levels than reservoir
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storage (volume and recovery/refill), which can be refilled quickly even at such low rainfall levels, e.g. during its refill season, Arlington only requires three months of 30 per cent of LTA rainfall to reach capacity. As such, our reservoirs are more vulnerable to short, sharp drought events which result in high demands being placed on the system, such as the 2003 drought event described earlier in section 8.1.1.
Our actions during this type of drought event are set out in Table 8.12. The summary of key actions in this table show only the new drought actions that were initiated each month: when a new drought management action is initiated, the preceding actions are continued unless otherwise stated, but are not repeated in each row of the table for presentational reasons. These actions are aligned with those we would initiate based on section 3 of this drought plan. The regional drought scores shown in Table 8.12 demonstrate that although groundwater levels were impacted by the two dry winter drought, the overall picture across the regional triggers, showed only the East (1-3) region reaching severe drought (level 3) during the latter stages of the event, in late winter/early spring 2012. Illustration of our actions and the progression and recession through our drought trigger levels shows that across most of our area we were able to balance supply and demand without recourse to all of our surface water drought permits/orders, or to a drought order to restrict the non-essential use of water. The drought broke in summer 2012. However, this drought highlighted to us that a third dry winter could have the potential to move all our regions into the level 3 ‘severe’ drought trigger zone, requiring preparation for additional drought permits/orders. This initiated consideration of a third dry winter drought scenario, which has been described in section 8.2 below.
Table 8.12 – 2010-2012 Drought scenario regional drought scores and summary of actions implemented East West East 2010-2012 summary of key actions (1-3) (4-5) (6-8) Oct 2010 1 1 0 Nov 2010 1 1 0 Based on the current drought status, watching brief is Dec 2010 1 2 0 maintained on a monthly basis. Jan 2011 0 1 1 Feb 2011 0 1 1 Developing drought conditions observed, although the Mar 2011 1 1 1 Company’s resources position remains good. Developing drought status closely monitored given the low Apr 2011 1 1 1 rainfall and higher demands. Consideration given to media messages to customers during May reminding everyone to use water wisely during the good weather. Media messages deployed reminding everyone to use water wisely during the good weather. South East Water started to assess the impacts for next summer, under a scenario of a dry May 2011 1 1 1 summer this year followed by a dry winter with low recharge, this includes reviewing current site output capacities and potential capital schemes/other measures. June 2011 1 1 1 July 2011 1 1 1 August 1 1 1 2011 September 2 1 1 2011
October Initiation of weekly reservoir drought meeting, continuation of 2 1 1 2011 formal drought meetings, sources optimised to increase output, additional sources being investigated including
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East West East 2010-2012 summary of key actions (1-3) (4-5) (6-8) reinstatement of disused sources, enhanced leakage detection programme being implemented, high demand commercial users being investigated and water efficiency audits being taken Communication plans on-going.
November Drought order submitted to the Environment Agency and Defra 2-3 2 2 2011 to reduce the Lower Ouse MRF and conserve storage; drought permit for Arlington Reservoir considered, to be submitted to the Environment Agency during December.
Summer drought permits/orders reviewed. Drought permit for December 2-3 2 2 Arlington Reservoir considered, but due to the high river levels 2011 and the ability to refill the reservoir the application is put on hold. Planning for worst case conditions through the summer / into January 3 2 2 early next autumn. This includes potential imposition of 2012 customer restrictions, from as early as April 2012. Summer drought permits/orders reviewed. Proposed customer restrictions published for representation. February 3 2 2-3 Additional drought permit/order for Ardingly Reservoir 2012 prepared. Work to assess impacts of a third consecutive dry winter scenario commenced. March 3 2 2-3 2012 Temporary use ban restrictions in place from 5th April 2012.
Drought permit to lower the MRF at Barcombe prepared and the draft circulated to the Environment Agency and April 2012 3 2 2-3 stakeholders for review. This drought permit has been drafted for implementation under worst case scenario from the 1st July. Additional drought permits considered, in discussion with the Environment Agency. The drought permit prepared no longer required given May 2012 2-3 1-2 2-3 improvements is storage levels at Ardingly Reservoir. Further restrictions and drought permits/orders now unlikely as June 2012 2 1-2 2 drought recovery commenced. July 2012 2 0-1 1-2 Review of lessons learned during the recent drought Prudently proceeded with a number of drought management August 1-2 0-1 1-2 schemes that offer benefit next spring should there be a dry 2012 winter. September 1-2 0-1 1-2 2012 De-escalation of drought activity: Formal drought management team stood down. But meetings retained in diaries should the need to re-enact the team be required. Enhanced leakage detection programme remains in place but level of October 0-1 0 1-2 enhancement continuously under review. Further pressure 2012 management work that commenced during drought continues to completion. Progress continues on a number of schemes that were originally being progressed to mitigate for a further dry winter. Review of lessons learned during the recent drought is continuing. Normal drought status Developing drought status Moderate drought status Severe drought status 0-1 Normal / developing drought status boundary 1-2 Developing / moderate drought status boundary
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East West East 2010-2012 summary of key actions (1-3) (4-5) (6-8) 2-3 Moderate / severe drought status boundary
8.1.5 Overall findings from the historic scenarios As would be expected, each of the drought scenarios has a slightly different effect on the three drought regions. They have demonstrated that the trigger and actions methodology proposed is flexible enough to help make drought decisions in a timely manner.
The key findings demonstrated that:
Winter refill drought permits/orders may need to be applied for when overall the drought region is at a moderate drought status. The trigger that we will use for submitting a reservoir refill drought permit/order application is when the reservoir falls below the severe drought curve. The application for this type of drought permit/order would be submitted between August and February inclusive. The preparation of this type of drought permit/order would be undertaken during the early/middle stages of the drought, for example when the reservoir falls below the moderate drought curve, in order to allow sufficient time for the necessary environmental assessments to be undertaken in support of the Permit application. Preparation of surface water drought permits/orders is estimated to take 1-2 months. Wherever possible we would look to base permit/order applications on previous applications we have submitted, in order to expedite the process. Drought permits/orders for both reservoir refill during spring to early autumn, and for the drought permits/orders to increase supply, are not likely to be applied for until each drought region as a whole is at severe drought status (however applications would be prepared in advance of submission during the early and middle stages of the drought). The latest time we are likely to implement temporary use bans over the autumn to winter period is in October. Demands are generally higher in spring / summer so this type of action will have a greater effect at this time of year. In winter demand saving reductions from temporary use bans are considered to be negligible. If we are faced with a longer-term drought which fluctuates between developing – moderate – developing status, once temporary use ban restrictions have been implemented they are likely to be kept in place because we consider it important to maintain a consistent drought message until the drought is in recession. Constant lifting and re-implementation of temporary use ban restrictions would create confusing communications messages. However, as shown during the 2004 drought scenario year, there may be a case for lifting restrictions during a long drought, to ensure consistency in communications about the severity of the drought. In this case only one drought region had temporary use ban restrictions in place for the previous summer and by the following spring all drought regions were at a similar drought situation. It would not be justifiable to customers to, in that situation, be implementing inconsistent actions. In each of the scenarios (with the exception of the 2010-2012 drought during which the temporary use ban restrictions were already in place in their current form), the application for the temporary use ban restrictions appeared to have been triggered (using this new methodology) slightly before the former hosepipe ban was applied for in reality. Our new Phase 1 restriction primarily restricts domestic hosepipe use but does offer concession to some users (e.g. disabled customers) and for several
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uses (e.g. watering food crops) and some small businesses. It is not as restrictive as the former hosepipe ban and so we consider that it is justifiable to bring in these restrictions slightly earlier. If the drought is increasing in severity quickly, as it did in August 2005, a Phase 3 drought order may be omitted and the Phase 4 drought order applied for directly.
8.1.6 Historic scenario testing conclusion We have tested the drought plan approach against the most significant low rainfall events since the 1930s and have shown that it is sufficiently robust and is in line with the requirements to ensure customer water needs are protected during such events. The modelling confirms that even under the three to four-year duration droughts (that were considered most severe during the last 20 years), the severity in terms of overall drought region drought status is only developing – moderate. The 2010-2012 drought did, however, take our drought region status into severe following the second dry winter. We have taken this analysis a stage further in section 8.3 where we test our plan against a third dry winter scenario.
It is worth noting that our 1 in 10 year level of service on demand restrictions was imposed twice in the last 10 years. We found it necessary to impose temporary restrictions on customers’ water use to maintain security of supplies during the 2004- 2006 and 2010-2012 droughts. However, in the 2010-2012 drought our two reservoirs were operated abnormally which meant the restrictions would have been avoided otherwise. The 2010-2012 drought also revealed some distribution issues with our system which we have since investigated in our dWRMP19. To ensure we are more likely to operate to our planned level of service, we have explored how more resilience can be built and we would now expect to meet our levels of service in this drought plan. This is discussed in section 8.4.
8.2 Testing against a range of alternative drought scenarios
An alternative range of drought scenarios was generated using the stochastic weather generator that was created for the Water Resources in the South East (WRSE) group project. The approach to drought development using a weather generator follows the new EA and Defra guidance on water resource planning and is consistent with the Water UK National Long Term Planning Framework project.
The weather generator is capable of producing a large number of artificial droughts of known relative severity through the direct generation of daily rainfall and Potential Evapotranspiration (PET). Because the output is daily rainfall and PET, it was possible to run the outputs through the same recharge, rainfall-runoff, groundwater modelling and water resources simulation tools that we have used for our dWRMP19. This means all of the stochastically generated drought inputs could be plotted against the same triggers as described for the historic droughts above (sections 8.1.1 to 8.1.4).
The weather generator produced 200 stochastic drought events for each of our eight Water Resource Zones (WRZs). These droughts were then ranked by deployable output, and the following three drought scenarios were chosen:
A ‘design’ drought, which represents the worst historic impact drought (1 in 100 return period on average, or one per cent probability of occurring each year) – equivalent in severity to the worst drought seen in the historic record back to 1920, considered to be 2010-2012.
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A severe impact drought (1 in 200 return period on average, or 0.5 per cent probability of occurring each year) – equivalent in severity to a drought that might be expected to occur once every couple of centuries. In the context of shorter (12 and 18 month) events, this represents a drought similar to 1976, but where dry conditions persisted through until November, or 1921, but where the early winter before the drought was somewhat drier (the 1921 drought actually had reasonable rainfall totals in December 1920).
An extreme impact drought (1 in 500 return period on average, or 0.2 per cent probability of occurring each year) – a plausible drought, but very rare and of a type that might only be expected to occur a couple of times in a thousand years. Long term academic studies have shown the existence of this type of event in Northern Europe within long term historic analyses.
The stochastically generated drought scenarios presented in our draft drought plan have been updated for our revised draft drought plan to reflect the very latest work we have undertaken for our dWRMP19. The stochastic drought events that have been selected to exemplify how we would respond to such events are the same as those used to inform our dWRMP19, thus bringing consistency across our two plans. These drought events have been selected based on WRZ level deployable output impacts, i.e. the severity of the drought event on our whole area rather than simply level/flow metrics at specific points.
We have modelled 9 drought scenarios for WRZs 2 and 3 (which include our surface water sources): these included 12, 18 and 24 month drought durations (i.e. where the maximum rainfall deficit occurs 12, 18 and 24 months after the start of the drought respectively) under each of the following three levels of drought impact:
Worst historic (1 in 100 year, one per cent probability of occurring each year);
Severe (1 in 200 year, 0.5 per cent probability of occurring each year); and
Extreme (1 in 500 year, 0.2 per cent probability of occurring each year).
For our groundwater dominated WRZs (all except WRZ2 and WRZ3), since groundwater takes longer to respond to reduced recharge than surface water sources, drought durations of less than 24 months do not present the same level of risk as would be the case for surface water sources. This duration formed the basis of the scenario testing for each groundwater trigger site under each of the three drought severities (worst historic, severe and extreme).
When producing the drought scenario regional drought scores, the nature of the regional drought was simulated based on the assumption that all WRZs would experience events of the relevant severity at the same time (e.g. the ‘severe’ event was made up of approximately 1 in 200 year droughts occurring simultaneously across the region in all WRZs). In reality, most droughts would demonstrate more regional variability than this, with severity in each WRZ varying around the overall scenario severity. However, as demonstrated in the 2016 Water UK ‘Long Term Water Resources Planning Framework’ document, the overall drought coherence is strong across the region, so the generated scenario is statistically representative for planning purposes. In other words, the scenarios presented are a good way to test our drought response for planning purposes.
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The full set of results of the recharge, reservoir and groundwater level outputs for the three levels of drought severity (and duration for surface water dominated WRZs) are provided in Error! Reference source not found., with specific outputs also presented later in this section where useful to help illustrate our timeline of drought actions.
The drought scenario regional drought scores and associated timelines of actions for each scenario are provided in Table 8.13 to Table 8.17 below. It should be noted that the response timelines only show drought actions as far as it is possible to pre- determine the actual response the company would take in a real drought event (please refer back to section 3 for further detail regarding the need to retain flexibility in our drought actions to respond to different drought events).
Further evidence has been provided in the form of the reservoir storage plots for Ardingly and Arlington reservoirs. Plots of groundwater levels at all the groundwater trigger sites are provided in Error! Reference source not found..
It should be noted that the demands placed on the reservoir system model for the drought scenarios shown here show the response of the reservoirs not only to the stochastically generated rainfall-runoff sequences, but also to ‘design’ demands placed on the system that are consistent with the demands used to determine the deployable output of the reservoir. In this way, there is consistency between how the reservoir operation is modelled between our drought plan and dWRMP19, but it does mean that the reservoirs are likely being placed under potentially higher demand than would be experienced during each different drought event. We consider this to be a conservative way of modelling the reservoir system during drought events, and provides a sensible precautionary approach to plan for resilience to such high demands during similar drought events.
During an actual drought event, Trigger Schematic Tools would also be used, as demonstrated for the historic drought events presented in section 8.1. However, their value is in being able to plot demand variability against the supply side indicators. As demand did not form part of the ‘plausible drought’ analysis, the illustration of the management timeline has been limited to the drought scenario regional drought scores. The timeline descriptions are at a higher level than the drought events described in Section 8.1. This is because the scenario modelling that was carried out was only on a monthly basis for the recharge and groundwater triggers, with some interpolation between annual minimum values for the groundwater. However, there is sufficient detail to allow key conclusions to be drawn about the nature of drought response under the three different levels of severity.
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Table 8.13 – Worst historic drought scenario regional drought scores
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Table 8.14 – Worst historic drought scenario timeline of actions
Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Reservoir status fluctuates East (1-3) Rapidly between developing and moderate recharge worsening drought and West (4- groundwater Ongoing severe drought Summary of Moderate and developing drought evident in 5) and East situation – some Some improvement in East (1-3) conditions in East (6-8) GWL, groundwater and recharge monitoring respectively (6-8) GWL groundwater monitoring status groundwater levels, but West (4-5) but other regions recovering move to sites in severe and East (6-8) move more firmly moderate drought status into severe drought status at the drought (L3) start of autumn Media and Implement progressive messaging with temporary use bans (Phase 1 customers to raise then Phase 2). These are awareness of the likely to be most effective developing Apply for and implement drought order to restrict non-essential use Actions likely to be during summer months, so Remove non-essential use drought status their implementation will be drought order followed by implemented Continue temporary use bans to avoid confusion considered at an early stage temporary use bans (demand) Plan for
implementation of Prepare for drought order to progressive restrict non-essential use (2-3 temporary use months duration) bans Communications with neighbouring water companies on bulk supplies: overall drought Implement winter status likely to be developing, refill drought Apply for therefore override trigger could be permit/order (East winter implemented if neighbouring 1-3) Apply for and refill Continue drought permits/orders Actions likely to be companies are in a worse drought implement drought into the winter period to maximise situation Preparatory work summer refill End drought permits/orders implemented permit/or reservoir refill and enable for summer refill drought (supply) der groundwater sources to be rested Meetings with Environment drought permits/orders (East 1- Agency and Natural England permit/order 3) applications (1-2 Preparatory work for winter refill months duration) drought permit/order applications (1-2 months duration)
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Figure 8.7 – Storage levels at Ardingly and Arlington Reservoirs during the worst historic drought scenario
It can be seen from Figure 8.7 that reservoir levels at Ardingly are drawn down to a greater extent than Arlington. This pattern of behaviour is mirrored in the severe, extreme and third dry winter drought scenarios shown in Figure 8.7, Figure 8.8 and
Figure 8.9. Ardingly is drawn down into severe (level 3) drought status during the first winter of this worst historic drought, while Arlington only just dips into moderate (level 2) drought status. The regional drought scores (for the reservoirs, the East (1-3) Reservoirs score) do not show the level 3 status, because the overall zonal value is calculated as an average of the two reservoirs’ drought statuses (there is a 50 per cent weighting assigned to each reservoir).
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Table 8.15 – Severe drought scenario regional drought scores
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Table 8.16 – Severe drought scenario timeline of actions
Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Worsening GWL and reservoir Rapidly worsening situation at indicators: GWLs in West (4-5) and both reservoirs in autumn Returning East (6-8) reach severe (level 3) Level 3 (severe) drought Reservoir status to normal Summary of Overall moderate drought status evident in drought status in late winter/early status at both reservoirs mid- improving, but drought groundwater and recharge monitoring spring, and reservoirs reach moderate winter. Numerous concerns remain monitoring status status at drought in spring. GWLs reach level 3 groundwater sites at Level 3 for groundwater most sites drought status earlier than in worst (severe) drought status - worst historic drought scenario in East (6-8) drought region Media and Implement progressive messaging with Remove temporary use bans (Phase 1 customers to raise non- then Phase 2). These are likely awareness of the essential to be most effective during developing Apply for and implement drought order to restrict non-essential use use Actions likely to be summer months, so their drought status drought implementation will be implemented Continue temporary use bans to avoid confusion order considered at an early stage (demand) Plan for followed
implementation of by Prepare for drought order to progressive temporary restrict non-essential use (2-3 temporary use use bans months duration) bans Apply for Communications with Implement winter refill neighbouring water companies on winter refill drought Apply for and bulk supplies: we would already be drought permits/or implement speaking to the other companies permits/orders ders summer drought about bulk supplies – so override (East 1-3) (East 1-3) permits/orders Re-apply for winter refill drought trigger would not result in a Actions likely to be permits/orders (East 1-3) to different approach or actions Preparatory End drought permits/orders Operation maximise reservoir refill and implemented work for al Prepare for winter enable groundwater sources to be (supply) Meetings with Environment summer refill conservati refill drought rested Agency and Natural England drought on permit/order permit/order measures applications (1-2 Preparatory work for winter refill applications for months duration) drought permit/order applications (1-2 months Arlington (1-2 months duration) duration) Reservoir
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Figure 8.8 – Storage levels at Ardingly and Arlington Reservoirs during the severe drought scenario
It can be seen that storage at Ardingly Reservoir has been drawn down to zero, i.e. well into emergency storage, under this modelled scenario. Arlington, as has been observed in Figure 8.7, is more resilient to droughts of this nature as it can be refilled more quickly under low rainfall levels.
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Table 8.17 – Extreme drought scenario regional drought scores
The key difference between this drought and the severe drought scenario regional drought scores is the longevity of the scores remaining at severe drought status (level 3), both for GWLs and reservoir levels. It is likely that as a result, South East Water would need to consider preparing to implement their groundwater drought permits, and potentially recourse to emergency drought orders. This is reflected in Table 8.18 below.
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Table 8.18 – Extreme drought scenario timeline of actions
Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 1 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 2 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year 3 Year
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Moderate drought evident in groundwater Severe drought status Level 3 (severe) drought status All region showing Surface Water improving, Summary of and recharge monitoring, with East (6-8) (level 3) reached for at both reservoirs, numerous recovery, returning but concerns remain for region already having breached severe East (1-3) and West (4- groundwater sites at Level 3 to normal at most monitoring status groundwater drought status (level 3) trigger for recharge 5) regions (severe) drought status sites by October Implement progressive Media and temporary use bans messaging with Remove (Phase 1 then Phase 2). customers to raise non- These are likely to be most awareness of the Apply for and implement drought order to restrict non-essential use essential effective during summer developing use Actions likely to be months, so their drought status Continue temporary use bans to avoid confusion drought implementation will be implemented order considered at an early (demand) Plan for Consideration to be given to possible recourse to emergency drought orders. Refer to South East followed stage implementation of Water’s Emergency Plan for procedure. by
progressive temporary Prepare for drought order temporary use use bans to restrict non-essential bans use (2-3 months duration) Implement winter refill Permits Communications with (E1-3) neighbouring water companies Apply for
on bulk supplies: we would and Apply for Preparatory work for already be speaking to the implement winter refill summer refill Re-apply for winter refill drought other companies about bulk summer drought drought permit/order permits/orders (East 1-3) to supplies – so override trigger drought permits/orders applications (1-2 maximise reservoir refill and would not result in a different permits/orde Actions likely to be (East 1-3) months duration) enable groundwater sources to be approach or actions rs rested End drought permits/orders implemented Prepare for Operational Extent of severe (supply) Meetings with Environment winter refill conservation drought status (level Consider submitting applications Agency and Natural England drought measures for 3) across the for groundwater drought permit/order Arlington company area would permits/orders Preparatory work for winter applications Reservoir initiate preparation refill drought permit/order (1-2 months of groundwater applications (1-2 months duration) drought duration) permits/orders (6-12 months duration)
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Figure 8.9 – Storage levels at Ardingly and Arlington Reservoirs during the extreme drought scenario
Figure 8.9 indicates that during an extreme drought, reservoir levels at both Ardingly and Arlington are drawn down to zero (under unrestricted demands). This follows incomplete refill during in the first winter period, followed by a second low refill season (i.e. a dry winter). In reality, this is unlikely to occur, because South East Water would have taken steps to reduce demands and supplement supplies through drought permit/order applications, as set out in Table 8.18.
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8.2.1 Summary of worst historic, severe and extreme drought scenarios The analysis presented above provides valuable insight into the nature of drought risk and response that we might face under these types of drought event. These are summarised in Table 8.19, below. This table follows a similar format to that of Table 10: ‘Drought Planning Links’ in dWRMP19. Table 10 goes further to define the impact on deployable output and to specify the benefits of drought permits/orders. This information is provided earlier in this report, in Table 3.1, Table 3.2 and Table 3.6.
It should be noted that all of the quoted yield impacts and intervention benefits are based on findings from dWRMP19 studies; these will change as model constraints are refined and developments are made to consider conjunctive use in WRZ2 and WRZ3. Moreover, the deployable outputs used in the drought plan, specifically for the groundwater sources, are based on unrestricted demand and therefore some of the benefits realised through demand measures might be underestimated. So the results presented here are considered to represent a worst-case assessment.
Overall the analysis indicates that the drought plan is robust to events up to and including the severe impact scenario. The most uncertain scenario appears to be a shorter duration severe impact drought in the Eastern (1-3) drought region as there may be limited warning for the implementation of winter drought permits/orders prior to the critical summer/autumn in such a severe drought. The analysis indicates that we would not be able to meet our stated levels of service in an extreme impact drought. Managing our response to such an extreme drought could require the implementation of measures beyond those described within this drought plan which we do not currently believe to be proportionate and in our customers’ interest.
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Table 8.19 - Summary Findings from the scenario testing Scenario Effectiveness of drought response under different drought Effectiveness of drought response under different drought durations scenarios Worst There is generally sufficient system resilience to cope with Short (12 month) droughts may limit the effectiveness of winter refill Drought historic this level of drought and interventions can be introduced in Orders and Permits for the Eastern (1-3) region, as reservoir storage risks will impact a timely manner according to this drought plan. Should only tend to be visible at Arlington and may only breach Level 2 in February of the override trigger have been initiated during this the drought year. Although the specific 18 month scenario tested here would (1per cent drought, it would only have escalated actions while we have breached the trigger threshold early in the winter, the outputs from the probability were in developing drought (level 1). severe impact scenario described below indicates that 18 month worst historic of events could occur that do not breach the triggers until the end of winter. This occurring could reduce the effectiveness of supply side interventions during such an in a given event. However, for the worst historic scenario the system is able to cope year) without having to rely on such measures in any case, and summer Permits and Orders would be available Severe Without supply side interventions, this level of drought The 18 month event that was tested would not necessarily trigger a winter impact would be sufficient to threaten emergency storage during refill Permit until very late in the refill season. This indicates that a severe the critical year in East (1-3). However, analyses carried impact event may not trigger all of the Drought Order and Permit benefits (0.5 per out for WRMP14 show that the potential benefit from calculated for WRMP14. The analysis indicates that availability of summer cent Drought Orders and Permits is in excess of 13 Ml/d across Permits/Orders would provide resilience, and there would be sufficient time to probability the WRZs. This compares to a loss of yield of around prepare for and implement them, as the trigger breaches occur in late of 8 Ml/d in the droughts that were analysed for this Plan. winter/early spring. However, these shorter ‘severe’ events appear to present occurring the greatest risk to the Eastern (1-3) Region. in a given The interventions available in the other regions are limited year) (4 Ml/d and 2 Ml/d benefit respectively), but the analysis Longer duration (24 month) events appear to be more manageable as there is indicates that the risk to groundwater yield is also limited a greater warning and winter refill interventions would be more reliable. (around 7 Ml/d for West (4-5) and only 1 or 2 Ml/d for East (6-8)), so the combination of supply and demand interventions appear to be sufficient. As shown in Table 8.15 and Table 8.16, there is enough warning to allow the timely implementation of measures in order to prevent emergency plans being needed.
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Scenario Effectiveness of drought response under different drought Effectiveness of drought response under different drought durations scenarios Extreme The analysis indicates that extreme droughts would The ‘short, sharp’ 12 month extreme impact event provides sufficient warning impact provide sufficient warning to allow the deployment of all to allow the full deployment of all drought interventions. The duration is not effective measures, including groundwater drought therefore particularly significant to risk presented by this severity of scenario, (0.2 per permits/orders as the failure of winter recharge is extreme although it is possible that measures would be more effective for the 24 month cent and triggers would be breached very early. For the East event in the East (1-3) region, as refill could be maximised throughout the probability (1-3) and West (4-5) regions there is a risk that the whole of a full winter recharge season. of measures would not be sufficient to address all of the occurring yield impacts from such a drought (particularly in the in a given West) and we would have to consider measures beyond year) those described within this drought plan, such as emergency drought orders.
We consider that the references made throughout this scenario testing section to use of our override trigger shows that whilst implementation of the override trigger would have had little impact on drought status across the scenarios examined, it does confirm the value of the override trigger in providing an early and effective response mechanism to potential bulk supply risks, where a donor company has alerted us that it has hit its own triggers, even though our own triggers might not necessarily warrant this escalated action.
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8.3 Testing against a third dry winter drought scenario
As noted in Section 8.2, the main drought scenario analyses concentrated on 18 to 24 month events, as this was thought to represent the highest risk to our supply systems. Although longer events might seem to represent a higher level of risk, the random nature of our weather and the probabilities involved suggest that shorter events will tend to be more intense, which means they represent a larger risk. However, in order to test the system against a longer 36-month or third dry winter drought, a different scenario was run. This scenario was based on the 2010-2012 two dry winter drought event (as described in section 8.1.4), and presented a ‘what if’ scenario to test what would have happened if the longest historical drought had continued.
The 2010-2012 drought contained two dry winters, so we used data from April 2010 to March 2012, then repeated the second 12 months from April 2011 to March 2012 (i.e. added to that drought) to generate the 36-month event. The 18-month period up to March 2012 was the most severe on record, therefore this represents a very challenging, low probability long duration event. As with the main scenario testing, the drought scenario regional drought scores are provided in Table 8.20 below, along with a summary of the reservoir drawdown response in Ardingly and Arlington reservoirs.
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Table 8.20 – Third dry winter drought scenario regional drought scores
Overall this analysis shows that, in terms of the overall yield and resource risk, this third dry winter event would represent a drought situation between the severe and extreme drought events in the East (1-3) and West (4-5) regions. Our response would be similar to the 24 month events described in Section 8.2 and our response to the 2010-2012 historic drought scenario presented in section 8.1.4. The long duration of the drought allows us time to implement all our drought permit/order options, even those groundwater options that require the longest lead-in time. The analysis indicates that this third dry winter event could therefore be managed through the measures described in our drought plan, and may represent less of a threat to water resources than a shorter high impact event such as the 2003 historic drought scenario set out in section 8.1.1.
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Figure 8.10 – Storage levels at Ardingly and Arlington Reservoirs during the third dry winter drought scenario
Ardingly Reservoir storage for 3DW drought Arlington Reservoir storage for 3DW drought 6 4
5
3
4
3 2
Volume (Mm3) Volume Volume (Mm3) Volume
2
1
1
0 0
Apr Oct Jul Jan Jul Jan Apr Jul Jan Jul Jan Apr Oct Apr Oct Oct
Jan Apr Oct Jan Jul Jul Oct Jan Apr Jul Oct Jul Apr Oct Jan Apr
Developing Moderate Severe 3DW Restricted 3DW Unrestricted Developing Moderate Severe 3DW Restricted 3DW Unrestricted
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8.4 Conclusions and linkages with our water resources management plan
Our dWRMP19 sets out our plans to maintain the balance between supply and demand over a 60-year timescale. Since our supply capability in the dWRMP19 is evaluated under drought conditions and demand is assumed to be that which would be experienced in a dry year, our performance during drought is closely linked with the combined effectiveness of our dWRMP19 and drought plan. The two plans therefore are linked and, wherever practicably possible, based on the same operational and planning assumptions.
The historical and plausible drought testing assumes that all our drought actions including drought orders/permits (allowing us to temporarily take more water from the environment for short periods during drought) can be applied in all scenarios.
An overview of our plan’s performance against the historic and alternative droughts generated is illustrated in Table 8.21. It states when the plan is sufficient for us to meet our stated levels of service or otherwise and shows how the use of drought management actions increases resilience to some of the drought events.
Table 8.21 –Drought plan performance against alternative plausible droughts
Plan in which Is drought plan able scenario is used to meet stated level of Drought Drought (highlights overlaps) service... Description Severity
Drought …with …without
Scenarios Drought WRMP drought drought Plan actions? actions?
>1% chance in 2003 No Yes Yes Yes any given year >1% chance in 1995 - 1997 No Yes Yes Yes any given year
Droughts Between 1.25 and 2.5% 2003 - 2006 No Yes Yes Yes chance in any Historic given year
Worst Historic 1% chance in No Yes Yes Yes (stochastic 1 any given year in 100) Severe 0.5% chance (stochastic 1 in any given Yes Yes Yes No in 200) year Extreme 0.2% chance (stochastic 1 in any given Yes Yes No No in 500) year Third dry Between 0.5 winter (36 and 0.2% Yes Yes Yes No month chance in any
AdditionalDrought Scenarios drought) given year
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Revised Draft Drought Plan December 2017
Our assessments, especially to the severe drought scenario, identified that without also improving levels of resilience there is a high reliance on drought permits/orders (more so than we and some others who have made representation on our plan feel is acceptable). There is an uncertainty associated with obtaining these drought permits/orders especially under more severe drought scenarios. Reducing the reliance on them would result in a more robust plan.
Our initial testing of the drought plan (ahead of dWRMP19) made the assumption that our current network infrastructure is capable of being operated flexibly under the more challenging range drought conditions we tested. We acknowledged in the draft drought plan that this might not be the case under certain drought conditions, so additional drought resilience options to increase connectivity have been considered in our dWRMP19.
Since we published our draft drought plan, we have revisited all of the assumptions concerning drought permits/orders, and the capability of our network infrastructure under more severe drought scenarios, as part of the preparation of our dWRMP19 (to be published for wider public consultation in early 2018).
Through further scenario modelling, application of our decision-making processes and consideration of customers’ preferences as part of our dWRMP19, we have proposed moving from current levels of supply resilience i.e. meeting worst historic droughts on record i.e. 1 in 100 year (1 per cent probability of occurrence each year), to be more robust 1 in 200 year level of supply resilience (0.5 per cent probability of occurrence each year).
We have explained our reasons for moving our levels of resilience to 1 in 200 year (0.5 per cent probability of occurrence each year) in the dRWMP19, which we believe can achieve during the period 2020 to 2025.
The improvements in levels of supply resilience will reduce our reliance on drought permits/orders to levels considered more acceptable by customers and stakeholders, and is based on some modest further investment in a combination of network improvements and new sources.
At this stage, we cannot prejudge the outcome of the consultation on our dWRMP19 or the subsequent acceptance of our dWRMP19 by the Secretary of State for Defra in 2018.
However, once our WRMP19 has been approved in its final form, we will review the latest version of our drought plan and take steps that are necessary to ensure both plans remain aligned.
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