A local utility company’s proposed rate increase has been approved. Alliant Energy’s settlement agreement to adjust natural gas rates was approved Monday by the Iowa Utilities Board. According to Justin Foss with Alliant the rate increase will take effect in the first quarter of 2013. The increase will reimburse the company for the around $70 million they’ve invested in infrastructure. Foss says customers won’t see a change in their bill until 2016, due to a cost management plan that will use tax benefits Alliant is entitled to, to offset the increase and actually lower bills over the next three years.