With a five-year drought and then a winter of floods having exposed the limits of California’s vast network of reservoirs, dams and canals, voters are likely to have the chance next year to decide whether to pay for major upgrades to the state’s waterworks.  Two multibillion-dollar bonds are expected to go before voters that promise to boost water supplies, offer flood protection and restore rivers and streams. One measure, sponsored by the Legislature, also would fund new parks and hiking trails.