North East Fife Area Committee
16 February 2011
Agenda Item No. 6
Report by: Dr Bob McLellan, Head of Transportation Services
Wards Affected: 19
Purpose
The purpose of this report is to advise committee about the findings of the focused flooding study into the effects on water levels by radical reduction or complete removal of naturally occurring silt berms in the Kinness Burn between Maggie Murray’s Bridge and Greenside
Place Bridge and to seek agreement on the way forward for the delivery of flooding mitigation measures, subject to completion of all necessary statutory processes.
Recommendation(s)
It is recommended that Committee instructs the Head of Transportation Services to:-
(i) Submit a licence application to SEPA (Scottish Environmental Protection
Agency) under CAR (Controlled Activity Regulations) to carry out the Option
(2) package of works as follows:
 Radically reduce the height of the berms between the Smaller
Footbridge at Dempster Terrace and Greenside Place Bridge;
 Remove unstable sections of existing berms;

Instigate an ongoing rigorous maintenance regime to maintain the b erms in ‘after works’ condition;
 Complete recommended minor works to further help alleviate flood risk;
(ii) Continue to investigate options in relation to the Smaller Footbridge and report findings to North East Fife Area Committee in due course.
Resource Implications
Costs associated with the short term flood alleviation proposals, including SEPA licence application / approval will be met from existing budgets. Provision has been made in the North East Fife ATWP(Area Transportation Works Programme) 2011/12 for the proposed works in the watercourse in the Kinnessburn Road area. Bids for taking forward a longer term flood alleviation scheme will continue to be submitted for possible capital funding approval.

Legal & Risk Implications
Any proposed watercourse maintenance works require to be assessed and approved by SEPA (Scottish Environment Protection Agency). Whilst a full flood alleviation scheme is required at this location, the proposed measures will go some way to mitigate the localised risk of flooding in certain water flow situations.
Policy & Impact Assessment
Kinness Burn is a high priority scheme for potential flood alleviation works in Fife and this location has a long history of flooding. As part of the flood study, the consultants have taken into account the associated environmental and ecological impacts of the proposed measures.
Consultation
It was agreed following a public meeting with local residents and others on 28
January 2010 to progress a detailed flood study exercise at the Kinness Burn between Maggie Murray’s Bridge and Greenside Place Bridge. The purpose of this exercise was to investigate proposed options for more active sediment management of the burn and also for the total removal of naturally occurring silt berms in the engineered section of the Kinness Burn. The latter aspect was the most popular option with the public however it would require very detailed and convincing evidence as justification in the SEPA licence application process. The Consultants engaged to complete the exercise have kept in liaison with SEPA throughout the study work and have also been consulting with Scottish Water and Scottish Natural Heritage.
1.0 Background
1.1 A report was presented to the East Area Services Committee on 8 March 2006 (para
439 of 2006.EAS.150) refers. This report outlined the findings of a formal Flood Study of the Kinness Burn catchment and it identified the potential of flooding risk based on different levels of tide/river flow/storm events and provided a number of costed flood alleviation schemes for consideration. The study found that for the 1 in 200 year joint probability return period, and adding the predicted effects of climate change, there are potentially 136 properties at risk to flooding. Whilst this study supported the economic justification of providing a Flood Prevention Scheme, the cost of the scheme (up to circa £10m) has proved prohibitive at a time of reduced capital resources.
1.2 Following the public meeting mentioned above, a report was presented to the North
East Fife Area Committee on 24 February 2010 (para 405 of 2010 NEFAC.415) refers. Committee agreed to firstly, develop options to remove in part and in full naturally occurring silt berms as part of short term flood alleviation measures and secondly to continue to develop longer term flood alleviation measures.

1.3 Once further investigation work had been carried out including discussions with
SEPA, the scope of a focussed project brief was determined. A specialist consultant was then appointed to take forward a detailed flood study at the section of watercourse between Maggie Murray’s Bridge and Greenside Place Bridge.
1.4 A progress report on the flood study was presented to the North East Fife Area
Committee on 27 October 2010 (para 503 of 2010 NEFAC.482) refers. This report updated the committee on progress being made by the consultant and outlined a programme t o bring the completed study’s recommendations to committee.
2.0 Flood Study - Option Appraisal
2.1 The effect on flooding or otherwise of the naturally occurring silt berms was a subject of great public conjecture and it was vital that this issue was analysed in sufficient detail to fully clarify any such related impact of the berms. This would be a crucial aspect in relation to SEPA’s consideration of any proposals arising from the study.
Therefore the main objective of the study was to undertake flood risk assessments of the impact that berms have on flooding between Maggie Murray’s Bridge and
Greenside Place Bridge and to recommend a short-term solution to mitigate flooding at Kinnessburn Road.
2.2 To achieve this objective, the study entailed data gathering, topographic survey of the watercourse, visual condition survey of the hydraulic structures, berms and river banks, hydrological assessment, hydraulic modelling and environmental appraisal which includes a geomorphologic assessment. A plan showing the locations of existing berms is attached as Appendix 1 of this report and a larger scale plan will also be displayed at the committee meeting.
2.3 Three main options were assessed to ascertain the impact that the berms have upon the water levels and consequently on flood risks. They were as follows:
2.3.1 Option (1):
– Do Nothing – Leave Alone in Natural Condition
This option presents the current situation at Kinness Burn, which in hydrodynamic modelling provides the base case model.
2.3.2 Option (2): – Radical Sediment Management – Berm Reduction and
Maintenance.
The approach carried out for the berm reduction consisted of reducing the current height of each berm by 25% and 50%. Starting from berm one
(upstream of study reach
Maggie Murray’s Bridge) – to Berm nine (at downstream of study reach Greenside Place Bridge) two model runs, (for 25% and 50% berm removal) were undertaken for each of these berms.
2.3.3 Option (3): – River Restoration to Engineered Condition – Remove All
Berms to Bed Level.
This option simulates that all berms within the study reach are 100% removed.
The model results of this option provided a set of minimum water levels to which the other options were compared.

2.4 Environmental appraisals and geomorphology assessments examined existing baseline conditions along the study reach of the Kinness Burn where engineering works are proposed. These identified any environmental and ecological constraints associated with any proposed works and carried out an appraisal of potential implications of the works and provided recommendations for their implementation.
3.0 Flood Study - Findings
3.1 The study report provides Fife Council with clear and concise details of all assessments undertaken and presents conclusions and recommendations to carry out some engineering works. The report can be used to support an application for authorisation to carry out proposed engineering works in the Kinness Burn under the
Water Environment (Controlled Activities)(Scotland) Regulations 2005 (as amended).
Discussions have been undertaken with SEPA between September and November
2010 in respect of the report findings and any likely CAR licence application(s).
3.2 The principal objective of this study was to undertake flood risk assessment to analyse the impact that berms have on increasing flooding and based on these assessments to recommend a short term solution of mitigating flooding at
Kinnessburn Road. In order to achieve this objective, topographic and condition assessment survey, hydrological and hydraulic modelling, environment appraisal and geomorphology assessment have been undertaken.
3.3 The three options detailed above were analysed to ascertain the impact of berms upon peak design flood levels and consequently on flood risks. The key findings of the study report are as follows:
3.4 Option (1) Do-Nothing - is not recommended due to the morphological and ecological risks associated with the potential destabilisation of the berms. In addition, the flooding problem would persist and likely increase as the berms would continue to grow, further reducing the hydraulic capacity of the channel to contain high flood event flows.
3.5 Option (3) River Restoration to Engineered Condition is not recommended due to the significantly detrimental impact on the ecology of the burn. Although this option reduces flood levels slightly more than Option (2) between Dempster Court Bridge and the Dempster Terrace Smaller Footbridge there is little enhanced benefit downstream. The same benefit could possibly be gained by removing the Smaller
Footbridge. The ecological value of this reach of the Kinness Burn is not particularly high in terms of its existing modified characteristics, but it does provide a wildlife corridor used by birds and otter and is of potential value for fish migration/spawning.
There would be significant disturbance to the bed and banks of the burn which, even with mitigation measures in place, would result in local deterioration in water quality within the immediate area and also further downstream.
3.6 Option (2) Radical Sediment Management and Maintenance - the conclusion of this study based on all assessments, optimisation and costing identified that Option
(2) is the most feasible and cost effective option.

3.7 In relation to Option (2), the works proposed include the reduction of berms by 50% to approximately 100mm above normal water level from berms 5 to 9, between
Dempster Terrace and Greenside Place Bridge. The removal of unstable berms
(currently berm 3, parts of 4 and 5) which can be dislodged by flood waters and potentially cause restriction to flow with possible blockage downstream and consequently increase of flooding. The banks and timber revetments in some locations have deteriorated to a poor condition these should be repaired and strengthened as part of the works.
3.8 By implementing Option (2), the flood water levels, between Maggie Murray’s Bridge and Greenside Place Bridge, will reduce and consequently will achieve a short term flood mitigation at Kinnessburn Road during certain water flows.
3.9 In terms of environmental aspects Option (2), (50% reduction of berms 5 to 9) is also the preferred option. Although Option (2) is the preferred solution, it will not prevent siltation occurring in this reach of the watercourse. Therefore a rigorous maintenance regime of cutting the vegetation and repeat skimming at an interval sufficient to prevent significant silt build-up will be instigated upon completion of the works.
3.10 Two plans of the Kinness Burn between berms 5 to 9, which represent all recommended works, based on condition assessment survey, detailed hydrodynamic modelling, environmental appraisal and geomorphology assessment are attached as
Appendices 2 and 3 of this report. In addition a photomontage to give a visualisation of the before and after scenario of delivering Option (2) is attached in Appendix 4.
3.11 On receipt of committee approval, a CAR licence application for Option (2) could be submitted by early March. The application will require to be advertised and it is anticipated that it could be subject to objections. Due to the high level of liaison with
SEPA during the flood study process and our subsequent discussions it would not be unreasonable to hope for licence approval by the end of June. This would allow delivery of the works to be carried out from August/September 2011.
3.12 The report does not support the case for full dredging of the burn due to the limited flooding benefits which are more than overcome by the severity of the ecological impact on the watercourse. Given the contents of the flood study report and the dialogue with SEPA it can be anticipated that a CAR licence application for Option (3) would not be sustained during the application process. There is a view that the
Council should still submit such an application if agreed by Committee.
3.13 Whilst it was not raised as a crucial issue within the study, the Dempster Terrace
Smaller Footbridge is known to contribute on occasions to flooding problems due to its low soffit level. This bridge is not the responsibility of the Council and ownership of this bridge is not clear. Any proposals to alter or remove this bridge could lead to a lengthy consultation process and ownership searches and it is not seen as viable to take this issue forward within the Option (2) package of works. Options in relation to this issue will continue to be taken forward by Transportation Services for future consideration by Committee.

4.0 Conclusions
4.1 The findings of the flood study shows that Option (2) provides the optimum package of measures to provide a degree of localised flood mitigation without such serious environmental and ecological impacts that would stand the test of the CAR application process and allowing for objections etc the works could be delivered by
September/October 2011.
4.2 Options in relation to the Smaller Footbridge at Dempster Terrace will require further investigation and review by Transportation Services.
List of Appendices
1.
Drawing No 1021201-01-011 plan showing berms
2.
Indicative works layout drawing No 1021201-01-014
3.
4.
Report Contact
Indicative works layout drawing No 1021201-01-015
Photomontage
– Before / After Option (2) Implementation
Author Name Iain Smith
Author’s Job Title Consultant Engineer
Workplace
Telephone:
Email –
County Buildings
08451 55 55 55 + 44 46 47 iainj.smith@fife.gov.uk