Complex sentence: It was owned by community-owned Winnipeg Enterprises Corporation, headed by prominent businessman Culver Riley, which had borrowed about $2.5 million, most of it from the City of Winnipeg, to build the Stadium and Arena.
Split into simpler sentences: It was owned by community-owned Winnipeg Enterprises Corporation. At the time of the arena's construction, Enterprises was headed by prominent businessman Culver Riley and had borrowed about $2.5 million, most of it from the City of Winnipeg, to build the Stadium and Arena.