Voters in Ottumwa head to the polls today to decide whether to extend a local-option sales tax for 12 and-a-half more years. At stake is 7-point-five million dollars in Vision Iowa funds with more than four million from private contributions and donations, for a new special events center and much-needed improvements to streets and sewers in Ottumwa. The community’s split over the issue, and voter turnout is expected to be heavy.