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Waverley Borough Council Committee System - Committee Document

Meeting of the Executive held on 28/08/2001
Critical Watercourse Failure- 27 St Christopher's Road, Haslemere



This report gives details of the July flooding incident at St. Christopher’s Road, Haslemere, refers to legal, policy and budgetary considerations, and recommends a possible response. The purpose of the report is to enable members to consider and select the appropriate level of further action to be undertaken by the Council.
APPENDIX - G

WAVERLEY BOROUGH COUNCIL

EXECUTIVE COMMITTEE – 28TH AUGUST 2001

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Title:

CRITICAL WATERCOURSE FAILURE -
ST CHRISTOPHER'S ROAD, HASLEMERE

[Wards Affected: Haslemere North & Grayswood and Shottermill]
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Note pursuant to Section 100B(5) of the Local Government Act 1972

The Annexes to this report contain exempt information by virtue of which the public is likely to be excluded during the item to which the report relates, as specified in Part I of Schedule 12A to the Local Government Act 1972, namely:-

(Exempt) Annexe 1

Information relating to the financial or business affairs of any particular person (other than the authority) (Paragraph 7);

Any instructions to counsel and any opinion of counsel (whether or not in connection with any proceedings) and any advice received, information obtained or action to be taken in connection with:-

(a) any legal proceedings by or against the authority, or

(b) the determination of any matter affecting the authority,

(whether, in either case, proceedings have been commenced or are in contemplation) (Paragraph 12); and

Information which, if disclosed to the public, would reveal that the authority proposes:-

(a) to give under any enactment a notice under or by virtue of which requirements are imposed on a person; or

(b) to make an order or direction under any enactment,

as disclosure to the public might afford an opportunity to a person affected by the notice, order or direction or defeat the purpose or one of the purposes for which the notice, order or direction is to be given or made (Paragraph 13).

(Exempt) Annexe 2

Information relating to the financial or business affairs of any particular person (other than the authority) (Paragraph 7).

Summary and Purpose

This report gives details of the July flooding incident at St. Christopher’s Road, Haslemere, refers to legal, policy and budgetary considerations, and recommends a possible response. The purpose of the report is to enable members to consider and select the appropriate level of further action to be undertaken by the Council.
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Background

Flooding in Haslemere – July 2001

1. On Saturday 7th July 2001 an exceptionally intense and concentrated rain storm struck the Haslemere area. Over 50 mm (2 inches) of rain (i.e. the normal monthly rainfall) fell in less than one hour. The majority of the local drainage systems were overwhelmed. Dozens of homes, shops and highways were subject to flooding, the magnitude of which had not be experienced for over 30 years. Much of the flooding resulted from the unprecedented volume of surface water run-off but, in St Christopher's Road, at least six properties were flooded internally, in one case up to 1 metre deep, following the breach of an underground brick-built culvert of Victorian origin.

2 The history of the culvert is indeterminate. A drainage plan dated 1897 suggests that an open watercourse existed in this location at that date. One of the landowners has claimed that by the time the houses were built, in the first few years of the last century, the stream had been culverted. The next available (chronologically) Ordnance Survey map of the area, published in 1917, indicates that the stream was no longer an open watercourse at that time. It is probable therefore that the culvert was constructed in a period around 1900. Weyhill (then Clay Hill) was a major centre of brick making activity at that time and it is more likely that the culvert was constructed by the brick maker or other landowner for the greater convenience of the development of the land.

3 It is known that flooding in St Christopher's Road and Meadow Vale was a frequent occurrence until Waverley replaced the inadequate culvert under the railway line in 1986/87. It is believed that, historically, regular maintenance was required to remove the silt and other debris which accumulated due to the restriction under the railway. Waverley also regularly maintains the trash screen (grill) at the entrance to the culvert in Weyhill to prevent the ingress of storm debris which might otherwise cause an intractable blockage within the culvert.

Land Drainage – Powers and responsibilities

4. The Council is defined as a "drainage body" in the Land Drainage Act 1991, which gives it powers in relation to land drainage, flood prevention, and the maintenance of flows in watercourses. It has the power to maintain and improve existing ordinary watercourses and to construct new works. It also has the power to serve notice on landowners requiring them to carry out necessary works to maintain the flow of an ordinary watercourse. Powers given to local authorities are, in general, permissive, giving such authorities a degree of discretion over public expenditure priority.

5. There is a degree of public confusion on the attribution of responsibility for the management of watercourses. The Department of the Environment, Farming and Rural Affairs (DEFRA) has policy responsibility for flood and coastal defence in England. It asserts that responsibility for delivering that policy rests with the flood defence "operating authorities". The Environment Agency (EA) is charged by DEFRA with exercising general supervision over all matters relating to flood defence and is defined as the "principal operating authority". Local authorities are defined by DEFRA as "operating authorities" for their areas in respect of flood defence.

6. Following a number of serious flooding incidents across the country in the last few years, the Government published a series of "high-level targets" for flood defence operating authorities with a view to ensuring "a more certain delivery of its aims and objectives" to reduce the effects of flooding. DEFRA has charged the EA with delivering on those targets. The EA, which states that it has "jurisdiction" over designated main rivers (as defined on a statutory map), maintains that district/borough authorities have "jurisdiction" over all ordinary watercourses. It has identified a category of watercourse which it designates as a "critical ordinary watercourse", defined as an ordinary watercourse which has the potential to put at risk from flooding large numbers of people and property. The EA, in seeking delivery of the Government's targets, has requested that local authorities should identify the critical ordinary watercourses in their areas and ensure that a regular programme of inspection is in place.

7. The watercourse at St. Christopher’s Road is an ordinary watercourse as defined in the Land Drainage Act 1991, i.e. not a “main river”. Whilst it is one of the many tributaries of the River Wey, that does not affect its status. The EA has jurisdiction over designated main rivers, including the River Wey, but its main river status commences some kilometres downstream, at Bramshott. The EA does not accept responsibility for carrying out works on ordinary watercourses.

8. The culverted watercourse in question drains a large part of the southern slopes of Hindhead including the Polecat Valley and the developed areas of Lion Lane, Farnham Lane and Weyhill. It is a "Critical Ordinary Watercourse" as defined by the Environment Agency (“EA”) in that its failure would result in the flooding of many properties. It is the category of watercourse which the Government, through the Ministry of Agriculture, Fisheries and Food (MAFF) (now the Department of the Environment, Farming and Rural Affairs – “DEFRA”) and the EA are urging and expect district authorities to inspect, and to ensure is maintained in accordance with the Government's targets for improved flood defence activity.

Waverley's Policy on Flood Defence

9. Waverley, and its predecessor authorities, has maintained a policy of seeking to reduce the incidence and the effect of flooding in its area and have constructed an extensive amount of flood relief works throughout the Borough, both in public areas and on private land. Waverley not only maintains the flood defence infrastructure which it has constructed but maintains other parts of critical watercourses where failure to do so would result in an increased risk of flooding to property

Flood Defence Policy Review

10. The Executive Committee at its meeting on 16th February 2001 considered an item "Land Drainage and Flood Defence Policy Review" which sought to establish the Council's policy on this subject into the future. The report followed a prolonged period of exceptionally inclement weather and consequent wide-spread flooding in the Borough. It explained the targets set by the Government for an improved response by local authorities in flood defence matters and specifically in their
11. The Committee resolved that a policy statement based on the current practice of Waverley should be prepared and submitted to the Ministry of Agriculture Fisheries and Food (MAFF). That policy statement was accordingly prepared and submitted and was presented to the Committee at its meeting of 12th June 2001 for noting.

12. The Committee further resolved that the Land Drainage function should be the subject of a policy review within the current financial year. The recommendations of this report accord with the existing policy of the Council in flood defence matters and will not prejudice the wider consideration of its future policy on this function.

WBC Policy Statement on Flood Defence

13. WBC's published statement on its flood defence policy which was forwarded to MAFF and the EA earlier this year states;

The Council's policy is to reduce and manage flood risk in the Borough by:

1. Regularly inspecting and maintaining the flood defence works which have been installed by Waverley and its predecessors.

2. Monitoring those ordinary watercourses which have proved to be critical in terms of flood risk and taking action to maintain the critical parts.

3. Regularly maintaining those ordinary watercourses for which Waverley is the riparian owner.

4. Advising riparian owners of their duty to maintain watercourses.

5. Investigating flooding incidence and where practicable and where resources permit, carrying out works to reduce the flooding risk or persuading riparian owners to carry out remedial works, where appropriate.

6. Providing a 24 hour emergency response service for the provision of sandbags to those in immediate risk of flooding and for the emergency clearance of critical watercourses and the structures thereon. The "out-of-hours" response to the public is delivered through an emergency call centre service which is contracted out.

Waverley's Best Value Performance Plan 2001/02

14. The Council's Performance Plan on Flood Management states that the Council's aim is to minimise the risk of flooding in the Borough by;

i. identifying properties at risk and, where practicable, designing and implementing schemes to provide flood relief and protection;

ii. maintaining the culverts, pipe lines and channels constructed by Waverley and its predecessor authorities;

iii. informing the owners of land on the banks of any watercourse or land through which a watercourse flows of their duties to maintain and protect watercourses on or adjacent to their land;

iv. identifying and maintaining watercourses other than main rivers (main rivers are the responsibility of the Environment Agency) and critical structures which, if not adequately maintained by the owners or those who are directly responsible for drainage on the land, would result in the flooding of property;

v. requiring developers to make adequate provision for storm water run-off from new development to protect downstream properties from flooding;

vi. liaising with the Environment Agency on development control and flood warning systems.

15. It can be seen from the above that the Council has a published policy on flood defence and a published Performance Plan both of which include the intention that the Council will take action to reduce the risk of flooding in the Borough, subject to consideration of available resources.

16. Waverley Borough Council has previously replaced un-safe and inadequate sections of this culvert both upstream and downstream of the section in question and, under its policy, would have progressed to the replacement of this section, as part of its rolling programme of flood relief, according to priorities across the Borough. Waverley owns or maintains the 500 m of underground culvert downstream of this point and 60 m of it upstream. All are concrete pipes of robust construction and anticipated design life of 60 to 100 years.

Budget Issues

17. After addressing the most severe and persistent flooding problems, Council reduced its capital expenditure to a rolling programme of 30,000 per annum to be expended on the construction of new works for the relief of flooding to property. That programme is continuing.

18. In response to the increased level of flooding in the Borough, the Operations Committee, at its meeting of 15th January 2001, recommended that the capital budget provision be increased by 15,000, for the financial year 2001/2002 initially, the additional sum to be used to provide an enhanced level of maintenance for the Council's land drainage infrastructure. Under the existing policy, the base sum of 30,000 per annum continues to be expended on new works, or enhancement to existing works, for the relief of flooding. Maintenance of the existing infrastructure is largely funded through the Land Drainage Revenue Budget which currently provides 35,000 per annum for "hired and contracted services".

19. The Council has a land drainage rolling capital programme budget for the purpose of carrying out works for the relief of flooding. It has a land drainage revenue budget allocation for the maintenance of both the flood relief infrastructure which the Council has installed and for the maintenance of critical parts of other watercourses where there is a risk of flooding of property.

20. The Council has carried out an extensive programme of flood relief works on private land throughout its history and continues with a programme of minor works for this purpose. To undertake the work at St Christopher Road, if resources allow, could
21. In its policy statements, in previous consultations papers and in dealing with other requests for co-operation in flood defence issued by MAFF and the EA, the Council limits its policy of carrying out flood relief and maintenance works with the proviso that it is done within the resources currently available. No commitment is made to carrying out works beyond the budget provision and therefore the Council's other spending priorities and its Council's tax minimisation ambitions are not compromised.

Financial Implications

22. The Land Drainage revenue budget is judged to provide for the required maintenance works to the Council’s drainage infrastructure and for the emergency response to flooding incidents for normal conditions. The budget has recently been increased to 35,000 per annum to reflect the increase in unusually inclement weather and corresponding increase in flooding problems. It is anticipated that the short-term remedial works, estimated at 5,000, can be accommodated within this year’s revenue budget without compromising the planned maintenance works. However, if wholly exceptional levels of flooding were to be experienced, as in the Autumn of 2000, additional funding would need to be sought.

23. There are various methods of culvert renovation available, each requiring detailed internal survey information, which cannot be obtained until the culvert is made safe by the short-term remedial works, for a reliable estimate of cost. As a guide, however, a 160 metre length of similar sized culvert (more than three times the length of the brick culvert), immediately downstream in the Kings Road Industrial Site, was relined by Waverley in 1996 at a cost of 50,000. It may be more practicable and economic, however, to construct a replacement culvert either on the existing or on a new alignment. It is proposed that the capital programme provision of 30,000 for 2002/03 be identified for this scheme. A further report will be presented to the Executive Committee which will also cover detailed proposals for funding.

Confidential Professional Advice – Please refer to (Exempt) Annexe 1
Risk Assessment – Please refer to (Exempt) Annexe 2

Conclusion

24. A number of properties in St Christopher's Road, Haslemere have suffered flooding and there is a high risk of its repeat together with more widespread flooding in the Weyhill area, due to the condition of an aged brick-built culvert which conveys a critical ordinary watercourse. This is part of the strategic drainage infrastructure in Haslemere. It is concluded that the most practicable and effective way to reduce the risk of flooding to properties in St Christopher's Road, Meadow Vale and Weyhill, both in the short and long term, is for the Council to use its powers to take immediate remedial action and to investigate the cost of rehabilitation or replacement of the culvert in the longer term.


Recommendation

It is recommended that

1. the Director of Environment and Leisure be authorised to undertake the required short-term remedial works to the culvert within the existing Land Drainage Budget provision for 2001/2002; and

2. the Director of Environment and Leisure be authorised to develop a plan and investigate the cost of the rehabilitation or renewal of this length of culvert and report back to the Executive Committee.
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Background Papers (DoEL)

There are no background papers (as defined by Section 100D(5) of the Local Government Act 1972) relating to this report.
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CONTACT OFFICERS:

Name: Robin Ellks Telephone: 01483 869411
E-mail: rellks@waverley.gov.uk
Name: Sara Whitmarsh Telephone: 01483 869233
E-mail: swhitmarsh@waverley.gov.uk