PORTLAND — Supporters of a proposal to renovate the Cumberland County Civic Center kicked off their effort this morning with an unveiling of illustrations showing how the outside of the upgraded arena would appear.

The drawings by architect Paul Stevens of SMRT Inc. shows the indented corners of the arena squared off and street level entrances from both Spring and Free streets.

The extension of the building would provide more room for the concourses around the exterior of the seating “bowl,” and additional space for concessions, said Neal Pratt, chairman of the Cumberland County Civic Center Board of Trustees.

County voters will decide in November whether to float a $33 million bond to pay for the renovations, which will also include new seating – including a premium seating section – and improved “back of house” areas, such as the loading dock and dressing rooms.

Pratt said voters would not see bigger tax bills as a result of the bond – although a likely reduction will not be realized.

The county earlier this year paid off a bond that financed construction of a jail. Pratt said the roughly $1 million a year that had gone to paying off that loan will be redirected to the Civic Center. That will go toward bond payments, along with higher revenues being projected for the center.