2014 Drought Plan Appendix 1 Resource Zone Characteristics & Drought Measures Drought Plan 2014anglianwater.co.uk Appendix 1 Contents

Resource Zone Characteristics & Drought Measures Resource Zone Characteristcs & Drought Measures 2 Central 4 Characteristics 4 Previous drought 5 Drought Measures 6 East Lincolnshire 8 Characteristics 8 Previous Droughts 9 Drought Measures 10 West Lincolnshire 13 Characteristics 13 Previous Droughts 14 Drought Measures 14 Hunstanton 16 Characteristics 16 Previous Drought 16 Drought Measures 16 Fenland 18 Characteristics 18 Previous Drought 19 Drought Measures 19 North Norfolk Coast 22 Characteristics 22 Previous Drought 23 Drought Measures 23 Norwich & The Broads 25 Characteristics 25 Previous Drought 25 Drought Measures 26 Norfolk Rural 28 Characteristics 28 Previous Drought 28 Drought Measures 29 Cheveley, Ely, Newmarket, Sudbury & West Suffolk 31 Characteristics 31 Previous Drought 32 Drought Measures 32 East Suffolk 34 Characteristics 34 Previous Drought 35 Drought Measures 35 Drought Plan 2014 Appendixanglianwater.co.uk 1 South Essex 37 Characteristics 37 Previous Drought 38 Drought Measures 38 Central Essex 40 Characteristics 40 Previous Drought 40 Drought Measures 40 Ruthamford North 42 Characteristics 42 Previous Drought 43 Drought Measures 43 Ruthamford South 45 Characteristics 45 Previous Drought 45 Drought Measures 46 Hartlepool 48 Characteristics 48 Previous Drought 48 Drought Measures 48 Contents Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Resource Zone Characteristcs & Drought Measures 2 Resource Zone Characteristics & Drought Measures Resource Zone Characteristcs & Drought Measures

Resource Zone Characteristcs & Drought Measures

The resource zones (RZ) have been assessed in our Water resources Management Plan and a number of the zones have been divided. The revised list of RZs are presented in Table A1. For each RZ we describe the characteristics of the zone, any details from previous droughts and the drought measures that we would take in each zone.

Resource Zones (RZs)

Central Lincolnshire

East Lincolnshire

West Lincolnshire

Hunstanton

Fenland

North Norfolk Coast

Norwich & Broads

Norfolk Rural

Ely

Newmarket

Cheveley

Sudbury

West Suffolk

East Suffolk

South Essex

Central Essex

Ruthamford North

Ruthamford South

Hartlepool Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Central Lincolnshire 4 Resource Zone Characteristics & Drought Measures Central Lincolnshire

Central Lincolnshire

Central Lincolnshire RZ

Characteristics

The Central Lincolnshire RZ extends south from the and is based on the supply systems for Scunthorpe, Lincoln, and Sleaford. The main water resource for the zone is Lincolnshire Limestone aquifer. There are also groundwater abstractions from the Sherwood Sandstone and the Chalk. Surface water is abstracted from the , which is supported with water from the and the . Customers to the Drought Plan 2014 Appendixanglianwater.co.uk 1 5

south of this zone are also supplied with raw water supplies from Rutland Water. The new Hall WTW was opened in July 2014, which will treat water abstracted directly from the River Trent for supply to customers in Lincoln.

The zone includes five drought vulnerable groundwater sources.

Increasing nitrate levels in the Lincolnshire Limestone aquifer have been managed by developing satellite groundwater sources in the confined limestone aquifer, which have also secured source reliable outputs and hence deployable outputs under low groundwater level conditions.

The Elsham WTW is reliant on augmentation of the flow of the River Ancholme by the ’s Trent-Witham-Ancholme (TWA) transfer scheme during lower summer flows. The TWA scheme is managed by the Environment Agency under a section 20 agreement.

Previous drought

The Northern Chalk was most affected with the early 1990’s groundwater drought, during which the Section 20 Agreement (see East Lincolnshire RZ for more details) was fully invoked by the National Rivers Authority and use of both the TWA and transfers was maximised.

The drought of the early 1990’s affected the Lincolnshire Limestone aquifer in this zone. This was addressed by the development of satellite boreholes and additional boreholes were drilled during the 2011-12 drought to help further improve the security of supply.

Groundwater levels in the Lincolnshire Limestone reached historic lows during the 2011-12 drought, but recovered remarkably quickly as a result of the extended period of rain that followed (in some instances levels in the Lincolnshire Limestone recovered by 10 metres in less than 2 weeks).

Despite the vulnerability of these groundwater sources to drought, we do not envisage any problems in maintaining deployable outputs from groundwater sources during a drought. Under current demands there is both average and peak headroom capacity in this zone.

The raw water transfer from Rutland Water to the zone was constructed in response to the 1976 drought.

In 1976, the TWA transfer licence from the River Trent was found to be the limiting factor for our direct intake from the River Ancholme. This period has been used to define the reliable yield of the source.

Whilst the RZ as a whole has a surplus of potable water available, the proposed development of non-potable supplies to meet increasing industrial demand has driven the extension of our Elsham WTW. Minor investment is also being delivered to maintain the security of supplies through local enhancement to the trunk main and local distribution systems to facilitate increased internal transfers within the RZ. 6 Resource Zone Characteristics & Drought Measures Central Lincolnshire

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. would look to increase Elsham sourceworks output to the daily licensed quantity, which would require continued support through the TWA scheme. Additional resources from this scheme would only be available under a Drought Order to change the Environment Agency abstraction licence from the River Trent.

The option exists to re-commission the intake on the River Witham and install the required treatment, however, the low flows experienced during drought conditions would not make this a particularly reliable option.

We will routinely monitor our drought vulnerable boreholes to identify the onset of potential drought conditions. On a local scale replacement / satellite boreholes would be developed if required to sustain source reliable outputs and hence deployable outputs from the Limestone aquifer sourceworks. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures East Lincolnshire 8 Resource Zone Characteristics & Drought Measures East Lincolnshire

East Lincolnshire

East Lincolnshire Resource Zone

Characteristics

The East Lincolnshire RZ extends from the Humber to and is based on the supply systems for , Louth, Skegness, Boston, Bourne, Spalding and Stamford.

In the northern part of this zone, the main water resources are abstractions from the Chalk and Spilsby Sandstone. A Section 20 Water Resource Management Agreement with the Environment Agency serves to protect and limit the use of the Northern Lincolnshire Chalk aquifer during periods of naturally low groundwater levels, which can result in low spring flows from the and saline intrusion along the south bank of the Humber Drought Plan 2014 Appendixanglianwater.co.uk 1 9

Estuary. The Section 20 Agreement restricts abstraction from the Chalk during drought to protect groundwater quality. This restriction limits the average deployable outputs of 13 of our groundwater sources and is accounted for in our water resource management planning process. We are currently investigating the potential impact of a number of our Northern Lincolnshire Chalk groundwater sources on low flow rivers and streams, as part of the AMP5 National Environment Programme.

A downward trend in groundwater levels in the confined Spilsby Sandstone over the last decade has led to a voluntary reduction of the previously increased licensed abstraction quantities from the aquifer, with an increase of surface water being transferred south. This has been supported by investment into reinforcement of trunk mains.

We abstract from the Louth Canal to fill Covenham reservoir. We also have the option to operate the Great Eau transfer scheme to provide a significant increase to the contributory catchment and augment the yield of Covenham reservoir during drought periods. The Great Eau scheme is managed with the Environment Agency under a section 20 agreement.

In the southern part of this zone we abstract groundwater from the Southern Lincolnshire Limestone aquifer. Abstraction boreholes are all located in the confined aquifer beneath , which receives recharge through the narrow band of outcrop that runs north south through Stamford and Sleaford. The zone has historically exported water to , however as demand has grown this has ceased and water is now imported from Rutland Water.

Borehole yields in the confined aquifer are prolific and abstractions are only limited by the need to restrict drawdown in the aquifer to maintain confined discharges from natural springs known locally as blow wells. It is necessary to protect the aquifer against inducing the flow of connate saline water from the east during periods of low groundwater recharge and hence low groundwater levels. The area has been extensively modelled to define a safe level of abstraction and is now embodied in the current abstraction licences. The water quality in the aquifer is monitored by the Environment Agency and some licences include conditions that restrict abstractions in the event of increased salinity levels, low groundwater levels or low spring flows.

There are environmental concerns about the impact of abstractions on the West and East Glen streams that rise along the Lincolnshire Limestone aquifer outcrop and then turn east to flow across the Fens. The flow of the lower reaches of the River Glen is supported by pumping through the Environment Agency’s Gwash-Glen transfer scheme which was commissioned in the early 1990’s and is managed under a section 20 agreement between Anglian Water and the Environment Agency. This transfers water released into the from Rutland Water to the lower River Glen during periods of low flows.

Previous Droughts

The Spilsby Sandstone abstraction licences have a condition to reduce the annual licensed quantity if aquifer levels in an observation borehole fall below a specified level. This condition was enforced for the first time in 2003, although was subsequently lifted as groundwater levels recovered. The condition reinforces the need to meet a base load of demand by importing water from Covenham to ensure local sourceworks are able to meet peak demands and any outage. 10 Resource Zone Characteristics & Drought Measures East Lincolnshire

The northern part of the zone experiences a low planning peak demand due to the high percentage of industrial demand and its local socio-economic and geographic characteristics. Historically the chalk sourceworks were developed to meet peak demand with limited treated water storage. The construction of the Irby reservoir to provide blending for nitrate compliance has increased security of supplies.

Abstraction from Lincolnshire Limestone sources have been restricted in past drought periods. These sources are restricted under licence conditions when low levels are recorded in the Environment Agency’s observation borehole. The condition was most recently triggered in 2011.

The aquifer was over-abstracted during the 1976 drought to maintain supplies to Peterborough, prior to the commissioning of Rutland Water. This identified the need for river support in the lower reaches of the River Glen that was addressed through the commissioning of the Gwash-Glen transfer scheme in 1991. The scheme is operated by the Environment Agency through a Section 20 Agreement with Anglian Water by which water is released from Rutland Water on request. This secures an increased level of abstraction from the Southern Limestone aquifer.

Work by the University of Birmingham and later investment as part of the AMP3 and AMP4 National Environment Programme (NEP) investigations has shown that the Glens are ephemeral in some reaches being vulnerable to drying out during a prolonged drought, which effects hydrological continuity. Changes to land management and land drainage improvements have exacerbated this further. The Environment Agency is currently reviewing Gwash-Glen transfer arrangements through further investigation, to include a trial to reduce the transfer quantities from Rutland Water.

Historical experience of the management of the limestone aquifer also led to the implementation by the Environment Agency of a programme for sealing or controlling the flow of wild bores to Fenland drains. This has conserved water resources and secured more reliable environmental flows.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. The Great Eau transfer link with Covenham provides security against forecast demands and could be developed in the longer term by the augmentation of water resources at Covenham WTW through effluent re-use or raw water transfers through extension of the TWA scheme. It is unlikely that these measures would be introduced as measures during a drought.

Anglian Water would look to protect the Lincolnshire Northern Chalk aquifer against saline intrusion under the Section 20 Agreement by reducing abstractions from the Chalk boreholes and replace supplies with the increased use of Covenham and Elsham sourceworks.

During periods of low flow, in liaison with the Environment Agency our support borehole would support flows in Beck and the .

The Environment Agency’s Gwash-Glen transfer scheme is used within the limits of the Section 20 Agreement with Anglian Water to support the flow of the lower reaches of the River Glen, beyond the confluence of the two ephemeral headwater streams of the West and East Glen. Any changes to the agreement would require a Drought Order to change the existing Environment Agency transfer licence conditions. Drought Plan 2014 Appendixanglianwater.co.uk 1 11

In terms of groundwater, on a local scale replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from the impacted groundwater sources. There are no drought vulnerable boreholes in this zone and no identified schemes in the current investment period. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Resource Zone Characteristics & Drought Measures West Lincolnshire 13

West Lincolnshire

West Lincolnshire Resource Zone

Characteristics

The West Lincolnshire RZ lies to the west of the River Trent and is based on the supply systems for Gainsborough and Retford. The water resource in this zone is groundwater abstracted from the Sherwood Sandstone.

The Environment Agency has expressed concern that the Sherwood Sandstone aquifer is over licensed. Investigative work is progressing under the AMP5 National Environment Programme into the potential impact of our abstractions on the Ranskill Brook and the River Poulter. Further investigations are planned for AMP6. 14 Resource Zone Characteristics & Drought Measures West Lincolnshire

A small bulk supply is imported to the village of Finningley from Yorkshire Water Services. This is a discrete area of our supply system.

Previous Droughts

The groundwater sources in this resource zone have not been historically impacted by drought.

Drought Measures

If there were any future drought concerns, we would look to optimise conjunctive use of groundwater and surface water sources in the RZ. There may be future options to supply customers in this zone from our new abstraction from the River Trent. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains.

In our WRMP we have identified the Sherwood Sandstone as a potential location to trial an aquifer storage and recovery (ASR) system. ASR could be used to provide additional drought security to this and neighbouring zones. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Hunstanton 16 Resource Zone Characteristics & Drought Measures Hunstanton

Hunstanton

Hunstanton Resource Zone

Characteristics

The Hunstanton RZ lies to the east of the Wash and is based on the supply systems for Hunstanton town. The water resource in this zone is groundwater abstracted from the Chalk.

Chalk sources supplying this zone have a theoretical impact on the wetlands along the western end of the North Norfolk Coast Special Protection Area and Special Area of Conservation. We have accepted a sustainability change in AMP4 and will be promoting a new transfer into the zone during AMP6.

Previous Drought

The groundwater sources in this resource zone have not been historically impacted by drought.

Drought Measures

There are no drought vulnerable boreholes in this zone and no identified schemes in the current investment period. On a local scale replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from the impacted groundwater sources. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Fenland 18 Resource Zone Characteristics & Drought Measures Fenland

Fenland

Fenland Resource Zone

Characteristics

The Fenland RZ lies to the south and east of the Wash and is based on the supply systems for Wisbech, Downham Market and Kings Lynn.

The central area of the Fens is supplied from the Chalk aquifer either directly by abstractions from borehole sources on the western margin of the Chalk aquifer or indirectly from the chalk fed rivers of the Wissey and the Nar before they enter the Fens. Secure water resources are available in the north from the thickening Chalk aquifer. The Sandringham Sands aquifer was developed in the early 1990’s in order to address increasing nitrate levels in the Chalk Drought Plan 2014 Appendixanglianwater.co.uk 1 19

groundwater and is used in conjunction with the overlying Chalk aquifer in northwest Norfolk in order to maintain water quality compliance. The west of the zone is supplied by surface water from Rutland Water transferred via Peterborough.

The development of trunk mains and service reservoirs close to customers within the RZ has meant that flexibility in the use of alternative sourceworks serves to enhance the security of supplies during off peak periods.

A number of environmental issues have been linked to the impact of abstractions on chalk spring flows, for example Foulden Common and Great Cressingham Fen SAC. Anglian Water investigated these under the NEP/AMP3 programme. In the north of the zone there exists a potential impact of abstractions on the wetlands along the Wash and western end if the North Norfolk Coast Special Protection Area (SPA) and Special Area of Conservation (SAC). These have been investigated under Habitats Directive Review of Consents (HDRoC) in line with the Environment Agency’s AMP4 / Water Resources Environment Programme (WREP) programme. This resulted in a sustainability reduction at a groundwater source. The River Nar is currently under investigation through the Environment Agency’s Restoring Sustainable Abstraction programme.

The zone includes the drought vulnerable groundwater sources.

Previous Drought

With its dependence upon the relatively thin unconfined Chalk aquifer, water supplies to the Fenland RZ were stressed during the 1988 to 1992 drought. This was addressed by the construction of satellite boreholes at a number of sites and the development of a link from Peterborough to the towns in the west of the zone.

The development of new sources for nitrate blending in the from of the Sandringham Sands Wellfield in northwest Norfolk and the Wellington Wellfield in the Chalk aquifer improved the resilience of the supplies. Further work to extend the Welllington Wellfield was identified as a severe drought option during the 2011-12 drought and is due to complete in 2015. Development of the existing licensed intake point on the Cut-Off Channel is also being progressed.

Low groundwater levels recorded in 2011 resulted in the restriction of abstraction at a groundwater source in accordance with licence conditions.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. We are licensed to abstract water from both the River Wissey and the Cut-Off Channel, which forms part of the Ely-Ouse to Essex transfer scheme. During periods of low flows in the River Wissey, water is transferred from the Cut-Off Channel to the Wissey in order to maintain the required minimum residual flow downstream of the intake. We are currently progressing the option to advance one of our supply-demand options to develop the intake to allow for direct abstraction form the Cut-Off Channel.

As part of our Environmental Assessment to support a Drought Permit at this WTW, we would look to approach the Environment Agency to relax the Wellington Wellfield groundwater licence and provide temporary additional supplies from this source. 20 Resource Zone Characteristics & Drought Measures Fenland

As part of our draft Drought Plan 2012 submission, we completed an environmental assessment to support a drought permit to support river flows in the River Nar through the emergency support groundwater source drilled by the National Rivers Authority during the 1990-91 drought. The Environment Agency has indicated that there is currently insufficient information available to support this option. During the 2011-12 drought we focussed our efforts on use of the Cut-Off Channel at Stoke Ferry and the Wellington Wellfield extension. Our assessments indicate that these should be sufficient to allow us to meet any forecast drought deficit as a result of low flows in the River Wissey and River Nar, and low groundwater levels at Marham.

In terms of groundwater, on a local scale replacement / satellite boreholes would be developed if required and we would seek to progress the extension of the Wellington Wellfield, to sustain source reliable outputs. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures North Norfolk Coast 22 Resource Zone Characteristics & Drought Measures North Norfolk Coast

North Norfolk Coast

North Norfolk Coast Resource Zone

Characteristics

The North Norfolk Coast RZ extends eastwards from the Wash to the Norfolk Broads and is based on the supply systems for Wells, Fakenham, Sheringham, Aylsham, North Walsham and Ludham. The water resource for this zone is groundwater abstracted from the Chalk aquifer in the North Norfolk area. The RZ has trunk main interconnections between sourceworks, and there are only limited connections to adjacent zones.

The Sheringham sourceworks was included in the AMP3 / NEP programme which included the investigation of the impact of abstraction on Sheringham and Beeston Common SAC. This has resulted in a sustainability reduction of 2 Ml/d and funding was secured in AMP5 to develop satellite boreholes.

The AMP4 WREP included an investigation of the impact of abstractions on the North Norfolk Coast. Historical concerns on the reduction of low flows in the River Stiffkey by the Houghton St Giles abstraction have been addressed by the provision of a dedicated river support borehole at the sourceworks.

The zone includes one drought vulnerable groundwater source.

The demand in the RZ comes from small coastal holiday resorts towns and some rural market towns. There is limited industrial demand and the zone’s demand characteristics are governed by seasonal holiday use with the potential for high peak demands in hot dry weather, particularly if this coincides with a holiday weekend. The planning peak demand factor is the highest in the region reflecting both holiday use and garden watering by resident population, which has a high proportion of retired households. Drought Plan 2014 Appendixanglianwater.co.uk 1 23

Previous Drought

The Chalk aquifer is semi-confined by thick glacial deposits and deep borehole yields are little affected by a recession of groundwater levels. As a result the impact of peak demands during short periods of hot dry weather that can occur any summer can have more significance than a prolonged period of low rainfall. Many of the boreholes require treatment for iron removal and periodic replacement due to deterioration due to encrustation. This can become evident during periods of higher pumping to meet peak demands.

There are a number of private wells in both the drift and chalk deposits. These were often constructed to the minimum depth required to secure a supply and are vulnerable to a fall in rest water level. A number the Anglian Water abstraction licences include provision to provide remedial works in the event of failure due to low water levels that can result from the combined effects of drought and water abstraction. As a result a number of private wells were deepened or replaced during the 1990s droughts.

A satellite borehole for the Metton/Matlaske source was drilled and commissioned in 2009, to secure the deployable output from these sources.

Drought Measures

The important wetland sites in the zone are sensitive to a reduction in rainfall and in recharge to the shallow drift aquifers. Hydrological and ecological monitoring has shown that chalk groundwater abstractions do not have a significant effect; nevertheless concerns remain over the potential of adverse impacts. Ongoing monitoring and investigations during a future drought should provide further insight into the issue.

The use of the river support borehole at Houghton St Giles is triggered by flows measured in the River Stiffkey. There are no plans to provide any further remedial works although environmental information will be reviewed with regulators to determine if any actions are appropriate.

Any reports of failure of private water supplies will be investigated and the need for remedial works agreed with the owners and the Environment Agency.

In terms of groundwater, on a local scale replacement / satellite boreholes would be developed if required, although the borehole at Bessingham has secured the deployable output from the only drought vulnerable source in the zone. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Resource Zone Characteristics & Drought Measures Norwich & The Broads 25

Norwich & The Broads

Norwich & The Broads Resource Zone

Characteristics

The Norwich and the Broads RZ is centred on the City of Norwich and the surrounding area. The water resources for the zone rely upon water storage within the Chalk aquifer to provide a reliable base flow to the intakes on the River Wensum in the Norwich area as well as for direct abstraction from Chalk boreholes. The Chalk boreholes have considerable variation in yield and raw water quality requiring different treatments. There is one groundwater source that abstracts from the Crag aquifer. Many of the sources in this zone are at high risk of contamination from industrial and agricultural sources.

Concerns on the environmental impact of abstractions have been investigated under the NEP/WREP programme with solutions including the relocation of abstractions. The River Wensum intake is currently subject to a 20Ml/d sustainability reduction in AMP5 and further investment is planned during AMP6. Due to environmental concerns we have closed and replaced a groundwater source which is due to be commissioned during AMP6.

Previous Drought

The droughts of the 1990's showed that the abstraction from the River Wensum could not be sustained while passing the required Minimum Residual Flow (MRF). The development of river augmentation boreholes was investigated and boreholes were drilled and tested at three sites, however these were not developed due to environmental concerns and there are no plans to do so. The need to maintain supplies was addressed through the ability to transfer to a downstream intake. 26 Resource Zone Characteristics & Drought Measures Norwich & The Broads

The use of the river support boreholes is triggered by flows measured in the River Tas. We also operate a support scheme to the West Earlham and Bowthorpe Marshes.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. The need to maintain headroom in Norwich is being addressed by investment through the Supply-Demand programme to secure the fully licensed output of existing sourceworks at peak demand and to provide the flexibility to meet planned growth in the city of Norwich.

We have included the option for a drought permit application to increase abstraction from the Costessey groundwater source if required during a drought to support supplies to Norwich. This option remains under investigation and we will continue to work with the Environment Agency to review the outcome of testing in 2013. We have given our commitment to the Environment Agency and Natural that we will not make an application for a drought permit until we have completed the additional work. If we are unable to conclude 'no adverse impact' on the River Wensum SAC, we will remove the groundwater option from the drought plan and will set out measures of alternative options to be further assessed. Elements of the options identification process have already been undertaken as part of the project to identify feasible solutions to address the sustainability reduction scheme in the WRMP .

In terms of groundwater, on a local scale replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs. There are no drought vulnerable boreholes in this zone and no identified schemes in the current investment period. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Norfolk Rural 28 Resource Zone Characteristics & Drought Measures Norfolk Rural

Norfolk Rural

Norfolk Rural Resource Zone

Characteristics

The Norfolk Rural RZ lies to the est of Norwich and includes the supply systems for Swafham, Dereham, Wymondham, Attleborough and Diss. The water resource for this zone are entirely groundwater abstraction from the Chalk aquifer, with some borehole sources dating back to the 19th Century. Most current sourceworks were in use by the 1970s with more recent developments undertaken to meet growth in local demand, improvements to security during low groundwater level conditions and blending to meet drinking water standards. There are poor interconnections between sourceworks in this RZ.

The zone contains a large number of small wetland conservation sites and concerns over the risk of impact of abstractions on these sites have been investigated in the NEP/WREP programme and are well documented.

Previous Drought

The impact of previous droughts has been seen through the need to develop satellite boreholes to support or replace those with deteriorating yield due to age. The Chalk aquifer itself holds a very large quantity of water in storage and is generally considered secure against a prolonged drought. The number of single source supply zones and the treated water storage available in the event of a plant or network failure limits the resilience of the zone to drought and peak demands during a period of peak demand. The impact of a period of low rainfall on the large number of conservation sites in the zone has resulted in concerns on the contribution that abstraction makes to environmental stress during drought. Drought Plan 2014 Appendixanglianwater.co.uk 1 29

The zone includes a groundwater source where abstraction can be reduced for 12 months when low groundwater levels are recorded at the Environment Agency’s observation borehole.

There are a number of private wells in both the drift and chalk deposits. These were often constructed to the minimum depth required to secure a supply and are vulnerable to a fall in rest water level. Anglian Water has deepened or replaced a number of private wells during the 1990s droughts.

Groundwater levels at two drought vulnerable sources in the zone were impacted during the 2011-12 drought. The Drought Management Team opted to advance AMP5 capital investment to drill replacement boreholes at both of these sources.

The use of the river support borehole is triggered by low flows measured in the River Waveney.

Drought Measures

New boreholes were drilled and commissioned during 2012.

Any reports of failure of private water supplies will be investigated and the need for remedial works agreed with the owners and the Agency.

Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Resource Zone Characteristics & Drought Measures Cheveley, Ely, Newmarket, Sudbury & West Suffolk 31

Cheveley, Ely, Newmarket, Sudbury & West Suffolk

Cheveley, Ely, Newmarket, Sudbury & West Suffolk

orough (B) Key to Map: Breckland District

DistrictFenland Council Boundaries District Resource Zones South Norfolk District

ELY

nshire District Forest Heath District East Cambridgeshire District

NEWMARKET Mid Suffolk District St. Edmundsbury District (B) WEST SUFFOLK CHEVELEY District (B) Suffolk Co South Cambridgeshire District

Ipswich District (B) Babergh District SUDBURY

ertfordshire District Braintree District Uttlesford District © Crown Copyright 2014. All rights reserved. Ordnance Survey License Number 100022432.

Characteristics

The Cambridgeshire and West Suffolk RZ has been divided into five smaller zones: Ely RZ, Newmarket RZ, Cheveley RZ, Sudbury RZ and West Suffolk RZ. These zones are located in the centre of East Anglia and are based on the supply systems for Ely, Newmarket, Bury St Edmunds, Haverhill, Thetford and Sudbury. The water resource for these zones is entirely dependent on abstractions from the Chalk aquifer.

The Ely RZ is devoid of reliable local water resources and is supplied by boreholes in the thinning Chalk aquifer close to the Fens. Further east, boreholes have been developed in the thicker Chalk aquifer where water resources are more resilient to drought. Investment to meet growth in demand from new housing development, improvement to security of supplies during low ground water level conditions in the 1990s droughts and for blending to meet drinking water standards for nitrate has improved the overall security of supplies. There are local trunk main networks linking sourceworks and treated water storage in the larger planning zones, but no strategic links between these zones or with adjacent RZs. We have increased the treated water storage at Ely and a trunk main from Mildenhall to Littleport has improved local security of supplies during peak demands.

Environmental concerns exist over the impact of abstractions at a small number of conservation sites, mostly on the edge of the Chalk outcrop and on the impact of abstractions on the River Lark and Chippenham Fen in the Ely and Newmarket RZs. These are being investigated as part of the AMP5 NEP programme.

Many of the chalk groundwater sources contain significant nitrate levels and are subject to treatment or blending arrangements.

These zones includes five drought vulnerable groundwater sources. 32 Resource Zone Characteristics & Drought Measures Cheveley, Ely, Newmarket, Sudbury & West Suffolk

Previous Drought

The borehole sources in the Ely and Newmarket RZs were severely affected by the 1988-92 drought and as a result satellite boreholes were developed for the sourceworks centred on Mildenhall and Newmarket. Cambridge Water Company developed its Thetford Wellfield during the same period and the Thetford to Cambridge pipeline bisects these zones. We have a formal agreement for a supply from Cambridge Water if required during a drought.

A new groundwater source has been commissioned in Newmarket to support the drought vulnerable sources.

Drought Measures

Works undertaken during the 1990s droughts improved the resilience of these zones to low groundwater levels, particularly in the west. Further replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from these sourceworks. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains.

We have a formal drought agreement for a bulk supply from Cambridge Water during a period of drought. The use of cross connections requires the installation of temporary booster pumps and chlorination equipment would be considered in the event of local operational emergencies or potentially during drought. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures East Suffolk 34 Resource Zone Characteristics & Drought Measures East Suffolk

East Suffolk

East Suffolk Resource Zone

Characteristics

The East Suffolk RZ extends inland from the Stour, Orwell and Deben estuaries and includes the supply systems for Ipswich, Felixstowe, Hadleigh, Stowmarket and Woodbridge. The water resources for the zone are a combination of groundwater abstraction from the Chalk and surface water from Alton Water.

The Chalk groundwater sources are mostly semi-confined by glacial drift deposits or fully confined beneath the Tertiary silts and clays of the London Basin. The effective separation of the Chalk aquifer from the surface waters has allowed a higher percentage of the available aquifer resources to be developed than in other zones to the north of East Anglia because of minimal environmental impact.

This zone includes three drought vulnerable groundwater sources.

Alton Water reservoir is filled from the Gipping catchment, which has a relatively low base flow from groundwater in the catchment and limited input from the return of treated effluents upstream. The river intake is licensed to require a relatively small residual flow to be passed during abstraction and has large capacity pumps to be able to abstract peak river flows during periods of heavy rainfall. A transfer from the Mill River augments the yield.

We also operate a river support borehole for the River Deben.

Our AMP5 Business Plan included an aquifer storage and recharge supply-demand scheme at Bucklesham, to utilise surplus resources in the Mill River. The scheme is not progressing following a re-assessment of river flows by the Environment Agency. Drought Plan 2014 Appendixanglianwater.co.uk 1 35

Previous Drought

Water supplies to Ipswich were severely restricted during the 1976 drought and the 1985 ‘mini-drought’. The commissioning of Alton Water WTW prior to the 1990s droughts significantly improved the security of supplies, however the limitations of the River Gipping to refill the reservoir during periods of low flows were demonstrated and the transfer from Bucklesham WTW under the Orwell Estuary to Alton Water was developed. When in operational use during the 1980s, the Bucklesham WTW was itself augmented by the use of a chalk borehole upstream of the Mill River intake, commonly referred to as the ‘Waddling Duck’. Use of the Waddling Duck borehole for river augmentation was included as a drought permit option in our previous drought plan. Following our review of the resource availability in the Mill River, this is no longer considered applicable.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. We would use the Bucklesham WTW transfer scheme to augment Alton Water during low flow conditions.

An option to reduce of the minimum residual flow in the River Gipping has been included as a contingency measure requiring an application to the Environment Agency for a drought permit.

The use of the river support borehole at Debenham is triggered by low flow conditions in the River Deben.

Further replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from impacted sourceworks. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Resource Zone Characteristics & Drought Measures South Essex 37

South Essex

South Essex Resource Zone

Characteristics

The South Essex RZ extends inland from Colchester and is based on the supply systems for Colchester and Braintree. The water resources for the zone are a combination of groundwater abstraction from the Chalk and surface water from Ardleigh Water.

The Chalk groundwater sources are fully confined beneath the Tertiary silts and clays of the London Basin. The effective separation of the Chalk aquifer from the surface waters has allowed a higher percentage of the available aquifer resources to be developed than in other zones to the north of East Anglia because of minimal environmental impact.

Ardleigh reservoir is jointly operated with Affinity East through the Ardleigh reservoir committee. This is currently based on a 70:30 split of resources. Ardleigh reservoir has a very short retention period and relies upon the return of treated effluent from towns along the Colne Valley and base flow from the extensive area of glacial sand and gravel aquifer overlying the London Clay. There is no residual flow released to tide under low flow conditions other than the compensation release from Ardleigh reservoir to Salary Brook. There are river augmentation boreholes to support the River Colne.

Anglian Water is entitled to a bulk supply from the Essex and Suffolk Water Company (E&SWC) at points in the Colchester, Tiptree and Braintree PZs. The E&SWC potable water main to Tiptree passes round the north of Colchester. A link between the reservoirs for Colchester and Braintree was constructed in the late 1990s to secure supplies against projected growth. 38 Resource Zone Characteristics & Drought Measures South Essex

Previous Drought

As a result of low flows during the 1995-97 drought the groundwater licences were varied to authorise river augmentation of the Colne. Further investment was identified following the 2011-12 drought to commission a permanent washout to the River Colne from the Aldham groundwater source.

Following the 1976 drought Anglian Water Authority sought powers to augment the flow of the River Colne for subsequent abstraction to Ardleigh Reservoir using the Ely-Ouse to Essex transfer scheme, as now operated by the Environment Agency. However this part of the scheme is not operational due to high losses from the Toppesfield Brook in the upper reaches of the River Colne. Any plans to re-use this transfer option would require careful consideration, close liaison with the Ardleigh Reservoir Committee, E&SWC and application for a Drought Order to vary the Environment Agency transfer licence.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in the RZ. We would use the borehole augmentation options to support Ardleigh reservoir during low flow conditions.

An option to increase the output from the augmentation boreholes has been included as a contingency measure requiring an application to the Environment Agency for a drought permit.

We would look to optimise any potential bulk supplies via existing cross connections from Essex and Suffolk Water Company.

Trials have taken place to prove that water could be transferred to Ardleigh reservoir, providing a means to augment the reservoir from the Ely-Ouse to Essex transfer scheme. No formal agreement exists between E&SWC, Ardleigh Reservoir Committee and the Environment Agency; and the option would most likely require an application for a Drought Order. Through the Ardleigh Reservoir Committee we are also reviewing the trading options with E&SWC to take a supply from the pipeline transfer to Abberton reservoir.

Further replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from impacted sourceworks. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Central Essex 40 Resource Zone Characteristics & Drought Measures Central Essex

Central Essex

Central Essex Resource Zone

Characteristics

The Central Essex RZ is based on the supply system for Halstead. The water resource for this zone is entirely groundwater abstraction from the Chalk. There are no drought vulnerable boreholes in this zone.

We operate river support boreholes for the Upper Colne and Cornard Mere.

Previous Drought

The groundwater sources in this resource zone have not been historically impacted by drought.

Drought Measures

There are no drought vulnerable boreholes in this zone and no identified schemes in the current investment period. On a local scale replacement / satellite boreholes would be developed if required, to sustain source reliable outputs and hence deployable outputs from the impacted groundwater sources. Intra-Zonal transfers would be used to balance supplies with demands using existing or new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Ruthamford North 42 Resource Zone Characteristics & Drought Measures Ruthamford North

Ruthamford North

Ruthamford North Resource Zone

Characteristics

The Ruthamford North RZ is located to the west of our region and is based on the supply systems for March, Peterborough, Corby, Kettering, Wellingborough, Northampton and Daventry. The water resources in this zone are from the surface reservoirs of Rutland Water, Pitsford, Ravensthorpe and Hollowell.

Pitsford reservoir and Rutland Water are both pumped storage reservoir that abstract water from the and , primarily during periods of high winter flow. Ravensthorpe and Hollowell are much smaller reservoirs that both rely on natural inflow from their catchments.

Treated and raw water supplies are exported from this RZ to the East Lincolnshire and Central Lincolnshire RZs. There is also an export agreement with Severn Trent Water, under a longstanding statutory agreement.

Rutland Water is designated as a Special Protection Area for birds which would be affected by increased drawdown during a severe drought. This has been addressed through a scheme to create additional habitat for birds within and adjacent to the reservoir in the formation of lagoons. These environmental mitigation measures allowed us to invest in additional treatment works to realise the full yield potential of Rutland Water and to ensure that we have been able to secure supplies to date. Drought Plan 2014 Appendixanglianwater.co.uk 1 43

All reservoirs benefit from long retention periods and have been managed during previous droughts to avoid problems with water quality due to high nitrate during refill. During the 2011-12 drought, additional investment was identified to improve interconnections between the Ruthamford zones via the installation of booster pumps.

Previous Drought

During the 2011-12 drought we took the precautionary measure of applying for a winter drought permits to refill Rutland Water and Pitsford reservoir. The permits enabled us to abstract more water than we would otherwise have been able to and to recover levels ahead of the higher demand summer period. The drought permits were judged not to have had any serious environmental or socio-economic impacts.

The 2011-12 drought further highlighted the lack of connectivity between the major reservoirs in the Ruthamford RZs.

Drought Measures

The main drought measures for this zone would be the application for drought permits to reduce the minimum residual flow condition associated with the abstraction licences for the River Nene intakes to Rutland Water and/or Pitsford reservoir. We could potentially also consider relaxation of the Gwash-Glen transfer arrangement from Rutland Water, if appropriate, although this would require an application for a Drought Order to vary the Environment Agency transfer licence. A permanent solution to make the Gwash-Glen transfer licence more flexible is currently under investigation.

During the 2011-12 drought we have also considered other options to support this zone in a severe drought including a water reuse scheme, canal transfer options and additional interconnectivity within and between RZs. Resource Zone Characteristics & Drought Measures Ruthamford South 45

Ruthamford South

Ruthamford South Resource Zone

Characteristics

The Ruthamford South RZ is located in the south west of our region and is based on the supply systems for Milton Keynes, Leighton Buzzard, Bedford, Biggleswade, St Neots and Huntingdon. The water resources to the zone are a combination of surface water abstractions from the River Great Ouse and groundwater from the Lower Greensand.

Water from the River Great Ouse is pumped both directly into supply and is stored in Grafham Water. Treated water is exported from the zone to Affinity Central under the terms defined in the Great Ouse Water Act 1961.

Environmental concerns have been associated with the management of the surface water resources in the large Special Protection Area wetlands of the Wash and Ouse Washes. The Ouse and Nene Strategic Study were commissioned following the 1997 Drought Order applications to help refill Grafham Water and Pitsford reservoirs. This work forms the basis for our Environmental Assessments for these reservoirs.

The Lower Greensand boreholes are not considered to be vulnerable to the impacts of drought.

Previous Drought

The 1995-97 drought closely followed after the previous one, giving the worst combination of droughts this century. The prospect of the more intense drought continuing for a third year led to a precautionary application for two Drought Orders in September 1997 to assist 46 Resource Zone Characteristics & Drought Measures Ruthamford South

with the winter refill of Grafham and Pitsford reservoirs. The above average rainfall of the summer continued into the winter and it was possible to withdraw the applications in February 1998.

Drought Measures

We would look to optimise conjunctive use of groundwater and surface water sources in this RZ. The main drought measure is the potential to reduce the minimum residual flow condition at the intakes from the River Great Ouse to Grafham Water, to allow for increase abstraction.

During the 2011-12 drought we identified the option to advance one of our AMP6 supply-demand schemes to re-commission the Foxcote Reservoir. The decision was taken not to advance this scheme at the time due to the need to first address a number of environmental factors, but the option remains in the WRMP to meet future demands.

During 2012 we invested to drill replacement boreholes and we are also currently re-commissioning a groundwater source.

In terms of groundwater, no vulnerable boreholes have been identified in this zone. On a local scale replacement / satellite boreholes would be used if required, to sustain source reliable outputs and hence deployable outputs from the Greensand aquifer sourceworks. Intra zone transfers would be used to balance supplies with demands using existing of new trunk mains. Drought Plan 2014 Appendixanglianwater.co.uk 1 Resource Zone Characteristics & Drought Measures Hartlepool 48 Resource Zone Characteristics & Drought Measures Hartlepool

Hartlepool

Hartlepool Resource Zone

Characteristics

The Hartlepool RZ comprises the entire area supplied by Hartlepool Water, in the North-East of England and is geographically separate from the other RZs in the Anglian region. The water resources are entirely groundwater abstracted from the Magnesian Limestone aquifer. All of the groundwater sources pump to a strategic treated water storage reservoir where they can be blended to maintain consistent and compliant water quality. This is a well-integrated system.

The two small surface water reservoirs at Crookfoot and Hurworth Burn previously used to provide non-potable industrial supplies have been sold.

A new groundwater source has been developed at Hopper House. This will provide a contingency for drought management, if required.

Previous Drought

There have never been any recorded historical periods of droughts in this area. There are water level conditions associated with the abstraction licences at Hope House and Hopper House, but neither are understood to have ever been implemented.

Drought Measures

There are no specific drought measures other than the communication of the prevailing situation and the response to customers through the media. Drought Plan 2014 Appendixanglianwater.co.uk 1 49

A new satellite borehole is drilled, tested and licensed but presently not commissioned. There is presently a large surplus of available headroom in the Hartlepool RZ and the need for commissioning the borehole remains under review.

The provision of a bulk supply from the neighbouring company, Northumbrian Water, could be used in a severe event to provide local emergency supplies via pipes and boosters. However there are no current opportunities for trading between the two companies, or the need to invest in the required infrastructure, as both supply systems are currently in surplus.