Rainfall events prove costly

11 October 2012

Waipa District Council has been left with a repair bill of over $1.5 million following two major storms in July that caused significant damage to the roading and stormwater networks.

Last week the council's Service Delivery Committee heard that repairs to the roading network as a result of the storms would be in the order of $516,000 while permanent stormwater repairs would cost over $1.2 million.

As these costs were unforeseen, the committee was asked to consider whether the council should fund the works from existing budgets by deferring other works, or loan fund the repairs where they were capital in nature and use existing budgets for operating costs.

Road Corridor Manager Dawn Inglis said while the New Zealand Transport Agency had indicated it would support a claim for 49 percent of the repair costs, the council would still need to find $263,000 to make up the balance.

The damage was significant and the intensity and duration of the events, particularly in areas where the ground was already saturated, caused a number of significant slips and culvert collapses, she said.

Water services manager Lorraine Kendrick said the affect of the storms had been compounded by an elevated water table and ground saturation.

This in turn caused localised flooding and the failure of some of the water drainage systems and while some repair work has already been undertaken some badly affected areas in Cambridge will require more extensive restoration, she said.

Furthermore damage to a stormwater pipe in the Kihikihi landfill had resulted in leachate being detected in monitoring samples. Investigations had confirmed the pipeline would need to be completely replaced to prevent leachate entering the pipeline and discharging into the drain.

The Committee upheld the staff recommendation for the repair works to be funded from existing budgets and for certain planned capital works to be deferred to avoid and mitigate any effect on ratepayers.