Minutes:
With reference to article 20 of the minute of the meeting of the Enterprise, Planning and Infrastructure Committee of 12 January 2010, the Committee had before it a report by the Director of Enterprise, Planning and Infrastructure which informed of the work carried out to date to redesign the flood prevention scheme and that the estimated cost of constructing the redesigned scheme exceeds the approved scheme budget.
By way of background, the report provided an overview of the long standing flooding problem in Lochside Drive and of the design scheme installed to resolve this issue. It was advised that in 2006, the Council had employed a company to design and construct a flood prevention scheme for this area and that this was completed in November 2008. However, in September 2009, the scheme failed and the area was again flooded.
Following the flood in 2009, an investigation by Council engineers was undertaken and concluded that the flood prevention scheme was inadequate to deal with the volume of water in the Glashieburn on the morning of 04 September. The investigation also concluded that the scheme could not cope with the estimated 1 in 200 year storm event; the required standard in the design brief. Details of the failings of the scheme were outlined; in particular attention was focused on the limited capacity of the 900mm diameter culvert which ran from the new attenuation pond under the gardens of 28 to 38 Lochside Drive, discharging into the open burn east of Lochside Road. The culvert under the gardens lay almost flat and could not carry the volume of water discharged from the attenuation pond.
To give protection to the properties either the pond had to be considerably bigger or the culvert capacity has to be increased. The simplest and most effective solution would be to increase the culvert capacity. An additional 200m of 1200mm diameter culvert and connections to the existing system, was required. The provision of this auxiliary culvert would give the required discharge capacity to allow the attenuation pond to function without overflowing and to prevent flooding of Lochside Drive by surcharging of the 900mm culvert.
As such, the company responsible for the design of and the supervision of the construction of the scheme have redesigned the scheme in light of its failure to contain the floods of 2009. Their recommendations include the installation of a 1200mm diameter culvert as described in 6.2 above. The scheme differs from the earlier model in that the 900 mm diameter pipe which crosses Lochside Road was considered incapable of carrying the 1 in 200 year flood criteria and that a 1200 mm diameter pipe would need to be taken across the road discharging directly into the loch. Their estimated cost for the scheme including the above additional works is £275,000. Discussions were ongoing between the Council and the company, with a view to reducing the cost of the works to a minimum. A meeting had also been held with the residents of Lochside Drive and agreement in principal had been established to allow access to their gardens for the construction of the new culvert. Formal written agreements with the residents would now be progressed. It was also highlighted that in terms of the revised scheme approval from SEPA would be required to discharge the new storm overflow culvert into the loch and this is being progressed.
With regards financial implications for the Council, the report advised that a sum of £175,000 was included in the 2010/2011 capital budget for completion of the scheme. Although it was expected that some costs would be recovered from the company responsible for constructing the scheme, it was likely that these would comprise largely of payment in kind. Other costs were currently under discussion. Monies recovered from the company would be used to offset the rise in cost of the scheme but as these figures had not been agreed as yet and there was not currently a timescale on these monies it would be beneficial to have the total scheme costs available prior to tender. As such the Committee was requested to refer the report to the next meeting of the Finance and Resources Committee with a request for provisional gap funding of £100,000, to ensure that the scheme can be implemented at the earliest possible opportunity, provided the lowest competent tender was both within 10% of the pre-tender estimate and the approved scheme budget. The work would be awarded at the earliest opportunity thus limiting the exposure of affected properties to future flooding.
The Committee heard for Mr. Cheyne Roads Manager, who provided an update on the current negotiations and agreements made to date with regards financing of the new scheme.
The Committee resolved:-
(i) to note that he company responsible for constructing the scheme, had redesigned the Glashieburn flood prevention scheme in light of its failure to contain the floods of 2009 and had recommended significant enhancements;
(ii) to note that the enhancements recommended were estimated by the company responsible for constructing the scheme, to cost £275,000 to construct, significantly more than the approved capital budget for 2010/11 of £175,000;
(iii) to note that council officers were working with the company responsible for constructing the scheme, to streamline the design and reduce the cost of the improvements to a minimum.
(iv) to note that the construction industry in the north east was competitive at present and that tenders for this work could be less than estimated;
(v) to instruct officers to proceed to tender at the earliest possible opportunity;
(vii) to refer the matter to the Finance and Resources Committee for consideration of the additional gap capital funding considered necessary at this stage to progress the scheme and to request that officers submit an updated report to that Committee detailing all negotiations and agreements made to date; and
(viii) to authorise the Head of Asset Management and Operations to accept the lowest competent tender for the works, provided it was both within the approved scheme budget and within 10% of the pre-tender estimate.