A proposal on the November ballot to borrow billions of dollars to build reservoirs and restore watersheds has divided California's environmentalists.
Opponents fear Proposition 1 could open the way for salmon-killing dams or giveaways to corporate growers.
Adam Scow of Food & Water Watch calls the proposal a bad deal for taxpayers that won't solve California's water problems.
The group held a protest against the bond in Beverly Hills Thursday.
The Natural Resources Defense Council, the California League of Conservation Voters and other supporters say the plan will steer money to vital projects as California struggles in a punishing drought.
NRDC staff attorney Doug Obegi says a vote for the $7.5 billion plan is not a vote for big, new dams.