Voters in Storm Lake and Sergeant Bluff-Luton will vote tomorrow on school bond issues. School officials say growing enrollment means the districts will run out of space. The bond issues require a 60 percent "supermajority" to win approval. In Sergeant Bluff, the $33 million bond issue is smaller than three previous referendums and those failed overwhelmingly. The proposal calls for $26.6 million for a new lower elementary school and around $4.7 million for a new athletic complex. About $1.6 million, would go for site improvements.