READING BOROUGH COUNCIL

REPORT BY DIRECTOR OF ENVIRONMENT AND NEIGHBOURHOOD SERVICES TO: POLICY COMMITTEE

DATE: 15 FEBRUARY 2016

AGENDA ITEM: 14

TITLE: WORKS TO WHITEKNIGHTS RESERVOIR

LEAD COUNCILLOR:

COUNCILLOR PAGE

PORTFOLIO: STRATEGIC ENVIRONMENT, PLANNING & TRANSPORT

SERVICE: TRANSPORTATION & STREETCARE

WARDS: PARK

LEAD OFFICER: SAM SHEAN TEL: 0118 937 3374 0118 937 2138

JOB TITLE: STREETCARE SERVICES MANAGER

E-MAIL: sam.shean@reading.gov.uk

1. EXECUTIVE SUMMARY 1.1 Whiteknights Reservoir is located within the University of Reading grounds and

borders Whiteknights Road and the Borough boundary.

1.2 This report summarises the progress to date on the scheme to improve the reservoir retaining wall required by the Environment Agency, and sets out the additional costs of that scheme, following recent technical assessments.

1.3 The proposal is to seek approval to a revised and expanded repair scheme and to seek additional capital spend approval of up to £450k, (further to that already obtained from the Strategic Environment, Planning & Transport Committee in July 2015).

2. RECOMMENDED ACTION 2.1 That the committee approve the revised and expanded Whiteknights

Reservoir repair scheme. 2.2 That Policy Committee approve the additional spend of up to £450k.

3. POLICY CONTEXT

3.1 To discharge the Council’s duty as a Statutory Undertaker under the Reservoirs

Act 1975. 4. BACKGROUND 3.1 Whiteknights Lake is a 70,000m3 capacity reservoir retained by an earthfill

embankment dam. There are three ‘Statutory Undertakers’ that own land

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forming part of the reservoir, as set out in The Reservoirs Act 1975; the University of Reading, Reading Borough Council (both in its highway and land owning capacity) and B & M Care.

3.2 The University of Reading (UoR) commissioned the Section 10 of the Reservoirs

Act 1975 report which was completed in July 2012. This study was jointly funded by the UoR and Reading Borough Council.

3.3 There were five mandatory recommendations set out in the Section 10 report,

four relating to B & M Care home site and one for Reading Borough Council to protect the allotment side embankment to withstand Probable Maximum Flood (PMF) discharge during a 1 in 1000 year flood event. In effect the works are required to channel any overflow from the dam to a designated spillway.

3.4 Further to the report to the Strategic Environment Planning & Transport

Committee dated 15th July 2015, the progress to date and funding proposal are listed in section 4 & 5 respectively.

4. PROGRESS TO DATE 4.1 Since the Flood Study was completed in February 2015, the Council has

commissioned John Gosden as the Qualified Civil Engineer under the Reservoirs Act 1975 to oversee the improvement work and to certify the works once completed.

4.2 Building on from the Flood Study, Peter Brett Associates LLP (PBA) has completed a detailed assessment of the catchment area and undertaken a hydrological review. This review indicated a larger Probable Maximum Flood discharge, and therefore a greater extent of flooding once the wave wall is over-topped. As a result a longer length of retaining wall is now required to direct this flood water over the existing Care Home spillway. 4.3 The proposed allotment retaining wall also needs to be slightly higher than first

envisaged as it will both retain the flood water and also act as a vehicle and pedestrian restraint barrier. This in turn impacts upon the foundation requirements for the retaining wall.

4.4 The original Engineer’s estimate for the works was based on the 2012 Flood Study information available and proposed a 40m long retaining wall, 610mm high with gabion baskets at the toe of the allotment embankment to be employed to stabilise the embankment. 4.5 The proposed retaining wall now has to be 72m long and will be at least 1.1m high at the highway boundary in order to contain and control the Probable Maximum Flood. Piles are being used to stabilise the embankment in order to keep work on the highway edge rather than within the allotment site where access and working space is limited.

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4.6 As the proposed retaining wall is longer, it encompasses the existing pedestrian entrance to the allotments and therefore provision needs to be made for a new pedestrian entrance that prevents flooding into the site. 4.7 The current cost estimate for the construction works is approximately £ 462k, with an overall scheme cost of approximately £750k, which includes for £120k of risk allowance. 4.8 The Environment Agency has issued a Non-Compliance Enforcement Notice on

The Statutory Undertakers of the Reservoir dated 29th September 2015 for not completing the modification works to the downstream slope of the Allotment embankment, as set out in the July 2012 Section 10 report. The deadline for completing these works was originally set for 17th July 2015.

4.9 The Environment Agency acknowledged the work done to date and the Council’s commitment to complying with this enforcement notice and has now set a revised Enforcement Notice deadline date for completing these works at 29th March 2017. Regular update discussions with the Environment Agency continue to take place between officers. 4.10 The Planning Application for the works was submitted during December 2015 and is due for determination on 10th February 2016. 4.11 Detailed design has been completed and necessary procurement processes have commenced. 4.12 Works are programmed to commence in late spring 2016 and to be completed in late summer 2016. 5. FUNDING PROPSALS 5.1 Depending on the competitive tender process the estimated cost of the revised

and expanded scheme is between £600,000 and £ 750,000 5.2 The original scheme cost estimate of up to £ 300,000, (reported to SEPT

Committee in July 2015), prior to the revised specification, was to be covered by the approved Council Capital programme for 2015/16.The Council had set aside a total of £ 375,000 to cover the original scheme costs including a contingency amount of £ 75,000.

Due to the limited time available to design, procure and construct the

necessary works within the statutory compliance period, there are limited opportunities to bid for suitable external funding.

Whilst we have been working in partnership with the UoR and the Care Home as

the Reservoir’s joint Statutory Undertakers, funding for these works falls solely to Reading Borough Council. The UoR has contributed funding towards the initial Flood Study but are not in a position to further fund these essential flood protection works.

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5.3 Officers have been in contact with the Department for Transport to explore capital funding opportunities, however, the next Capital Highway Maintenance Challenge Fund bidding round will not take place until 2017/2018 by which time the Environment Agency Enforcement Notice deadline of March 2017 would have passed. 5.4 It is therefore proposed to fund the costs of the revised and expanded scheme

from planned resources identified in the Council’s Capital programme. Along with an increased allocation from the Health and Safety Works budget, the additional costs will also utilise some of the LTP 2016/2017 Bridges & Carriageways Capital award.

6. CONTRIBUTION TO STRATEGIC AIMS 6.1 Corporate Plan Service priority: Keeping the town clean, safe, green and active. 7. COMMUNITY ENGAGEMENT AND INFORMATION 7.1 Work on the Whiteknights Reservoir will be placed in the public domain via the

planning application process. 7.2 Advance information notice boards will be erected at Whiteknights Road and

the Allotment site detailing the scope of the scheme prior to the commencement of the works.

7.3 A number of neighbours to the proposed development have been consulted

formally by the Council as the Local Planning Authority; further consultation will be undertaken where considered appropriate to ensure that stakeholders affected by the proposal are engaged.

8. LEGAL IMPLICATIONS 8.1 The Reservoirs Act 1975 requires ‘Statutory Undertakers’ of the reservoir to

reduce the risk of failure and the consequences should it fail. 8.2 The Flood and Water Management Act 2010 requires the Borough Council to take

the leadership role for ensuring significant risk from all sources of flooding is identified and managed

8.3 Schedule 2 of the Flood and Water Management Act 2010 amends other Acts and

under the amended Section 14A of the Land Drainage Act 1991, LLFA’s have the power to carry out works to manage flood risk from surface water runoff, groundwater and ordinary watercourses, where the work is desirable having regard to the ‘local strategy for flood risk management’.

8.4 If an option involves the relocation of allotment holders then this will require

requisite notices and potentially compensation to be paid.

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9. FINANCIAL IMPLICATIONS 9.1 The estimated cost of the revised and expanded scheme is estimated to be

between £600,000 and £750,000. 9.2 £375,000 (which includes the original estimated £ 300,000 cost of the works

before the change in the specification) has already been identified in the capital programme for 2015/16.

9.3 The additional funding for the revised specification has been built into the

capital programme for 16/17 and will be funded by an increased allocation from the Health & Safety works budget, along with the use of some funds from the LTP 2016/2017 Bridges & Carriageways Capital award.

10. Risk Assessment. 10.1 ‘Statutory Undertakers’ of the reservoir are required to reduce the risk of

failure and the consequences should it fail. 10.2 Lead Local Flood Authority Councils are required to carry out their designated statutory duties, as described in the Flood and Water Management Act 2010. 11. BACKGROUND PAPERS 11.1 The Reservoirs Act 1975 Section 10 report for Whiteknights Dam dated July 2012. 11.2 The Whiteknights Dam Flood Study report dated February 2015. 11.3 Environment Agency Biennial Report on Reservoir Safety (1st April 2013 – 31st December 2014) 11.4 Strategic Environment Planning & Transport Committee report of 15th July 2015. 11.5 The Environment Agency Enforcement Notice of 29th September 2015.

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WHITEKNIGHTSRESERVOIR

WHITEKNIGHTS ROAD

LAKESIDE RESIDENTIAL CARE HOME

ALLOTMENT GARDENS

EXISTING SPILLWAY

THE GATE LODGE - ACCESS TO BE MAINTAINEDFOR LODGE AND EMERGENCY EXIT

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Drawing Issue Status

Date of 1st Issue

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DrawnMark Revision ChkdDate

File Location: j:\27560 rbc llfa support\4001 whiteknights reservoir\cad\dwgs\27560_4001_101.dwg

UTILITIES NOTE: The position of any existing public or private sewers, utility services, plant or apparatus shown on this

drawing is believed to be correct, but no warranty to this is expressed or implied. Other such plant or apparatus may also

be present but not shown. The Contractor is therefore advised to undertake his own investigation where the presence of

any existing sewers, services, plant or apparatus may affect his operations.

SCALING NOTE: Do not scale from this drawing. If in doubt, ask.

Reproduced from/based upon Ordnance Survey material with the permission of Ordnance Survey ®on behalf of The Controller of Her Majesty's Stationery Office. © Crown Copyright.

Unauthorised reproduction infringes Crown Copyright and may lead to prosecution or civil proceedings.

Licence No. Year of Publication Owner/Purchaser of Mapping

user name: alex wray

Offices throughoutthe UK and Europe

© Peter Brett Associates LLPwww.peterbrett.com

READINGTel: 0118 950 0761

Approved

Appd

Drawn

RBC LLFA SUPPORT

WHITEKNIGHTS RESERVOIR

LOCATION PLAN - 1:1250

FOR PLANNING

27560/4001/101 A

19.11.2015

1:1250

- jfds

AEW CWD

A MINOR AMENDMENTS 23.11.15 AEW NKA CWD

RBC100019672 2013

Client

A3 Scale

NOTES:

1. THIS DRAWING IS TO BE READ IN CONJUNCTION WITHPBA DRAWINGS 27560/4001/100-106 AND 27560/4001/200.

KEY:

RED LINE PLANNING BOUNDARY

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1800

MIN

1000

MIN

SINGLE LEAF RED BRICKWORK CLADDING

1:40 CROSSFALL

2.0m

CONCRETE COPING SLABSBLACK RAILINGS TO MATCH STYLE OF EXISTING CARE HOME WALL

EXISTING FOOTPATH TO BE REGRADEDNEW BEANY BLOCK DRAINAGE KERB

STEEL SHEET PILE

ANDERTON STEPOC PRECAST CONCRETE BLOCKS

REINFORCED CONCRETE BASE

REINFORCED CONCRETE CORE18

00 M

IN

SINGLE LEAF RED BRICKWORK CLADDING TO BOTH FACES

1:40 CROSSFALL

1.5 - 2.0m

CONCRETE COPING SLABS

BLACK RAILINGS TO MATCH STYLE OF EXISTING CARE HOME WALL

EXISTING FOOTPATH TO BE REGRADEDNEW BEANY BLOCK DRAINAGE KERB REINFORCED CONCRETE CORE AND BASE

NEW HEDGE TO BE ESTABLISHED

WHITEKNIGHTSRESERVOIR

END OF CARE HOME WALL RE-BUILT BANK TO BE HYDROSEEDED WITH GRASS / WILDFLOWER MIX

NEW HEDGEROW TO REAR OF WALL

FOOTPATH RE-CONSTRUCTED

EXTENT OF NEW WALL - SEE NOTE 4

WHITEKNIGHTS ROADRBC ALLOTMENTS

LAKESIDERESIDENTIALCARE HOME

RELOCATED GATE (1.2m WIDE) - SEE PHOTOS 1 AND 2

NEW BEANY BLOCK BRAINAGE

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2

DETAIL 2

DETAIL 1

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Drawing Issue Status

Date of 1st Issue

Drawing Number

Designed

Revision

DrawnMark Revision ChkdDate

File Location: j:\27560 rbc llfa support\4001 whiteknights reservoir\cad\dwgs\27560_4001_103.dwg

UTILITIES NOTE: The position of any existing public or private sewers, utility services, plant or apparatus shown on this

drawing is believed to be correct, but no warranty to this is expressed or implied. Other such plant or apparatus may also

be present but not shown. The Contractor is therefore advised to undertake his own investigation where the presence of

any existing sewers, services, plant or apparatus may affect his operations.

SCALING NOTE: Do not scale from this drawing. If in doubt, ask.

user name: alex wray

Offices throughoutthe UK and Europe

© Peter Brett Associates LLPwww.peterbrett.com

READINGTel: 0118 950 0761

Approved

Appd

Drawn

RBC LLFA SUPPORT

WHITEKNIGHTS RESERVOIR

GENERAL ARRANGEMENT - PROPOSED

FOR PLANNING

27560/4001/103 A

18.11.2015

1:500

AEW jfds

NKA CWD

A DETAIL 2 ADDED 03.12.15 AEW NKA CWD

Client

A2 Scale

NOTES:

1. THIS DRAWING IS TO BE READ IN CONJUNCTION WITH PBA DRAWINGS27560/4001/100-106 AND 27560/4001/200.

2. ALL LEVELS ARE IN METRES AND RELATIVE TO ORDNANCE SURVEY DATUM(NEWLYN).

3. THIS DRAWING IS BASED ON SURVEY INFORMATION SUPPLIED BY LONGDINAND BROWNING SURVEYS DATED 01.07.15.

4. NEW FLOOD WALL TO EXTEND APPROXIMATELY 72m EAST FROM CONNECTIONWITH EXISTING CAREHOME WALL. FIRST 58m OF FLOOD WALL TOINCORPORATE VEHICULAR RESTRAINT SYSTEM - SEE DETAIL 1. LOW LEVELFLOOD WALL TO CONTINUE TO CH 72m - SEE DETAIL 2. FOR FURTHERINFORMATION SEE PBA DRAWING 27560/4001/104.

EXTENT OF HYDRO-SEEDING

NEW NATIVE HEDGEROW INCLUDING HOLLY, HAWTHORN &HORNBEAM

KEY:

EXTENT OF FOOTWAY RE-CONSTRUCTION INCLUDING NEW KERBDRAINAGE SYSTEM

PROPOSEDPEDESTRIAN GATE

PHOTO 2

DETAIL 1SUBJECT TO DETAILED DESIGN

1:50

EXTENT OF NEW WALL

NEW DRAINAGE SYSTEM (SEE DRAWING No. 27560/4001/200)

PLAN1:500

DETAIL 2SUBJECT TO DETAILED DESIGN

1:50

1

PHOTO 1

PHOTO LOCATION MARKER

PROPOSED PEDESTRIAN GATE

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