Busy as they are with their lives, California citizens can probably only be asked to concentrate on one part of the state’s prismatic double-rainbow of water issues at a time.

When it was the killer drought, it was pretty much only the drought, until a rainy mid-winter of 2017 got us off the hook, sort of. This rainy season, when it finally came, was only a drop or two above plunging us back into formally defined drought, and the Sierra snowpack is still lousy.

In recent weeks the water story for Southern Californians had been the pending vote on the proposed Sacramento Delta tunnels by the powerful Metropolitan Water District, and then the surprisingly strong affirmative vote by over 60 percent of the MWD’s local agencies to spend a stunning near $11 billion to back the mammoth twin-tunnel plan. The strange-bedfellow opponents to that plan — progressive ardent environmentalists, fiscal conservatives and delta natives — saw their concerns pushed aside by the district in hopes the project can guarantee tap and garden-irrigation water for many generations of Southlanders to come.

But there’s another twin tunnel of California water issues bearing down on California voters, about which little has so far been said: Not just one but two separate bond issues coming our way on the June and November ballots.

Proposition 68 in June, authored by Senate President Pro Tem Kevin de Leon in the Legislature as SB5, includes $1.5 billion for parks, $1.5 billion for drought contingency/water supply and $500 million for flood protection for a grand total of $4.1 billion in bonded indebtedness.

The November bond, which doesn’t have a number assigned yet, is now known as the Water Supply and Water Quality Act of 2018 and is both not as much of a grab-bag and yet is twice as large: $8.9 billion in bond debt. Some $750 million of that goes to provide, backers say, safe drinking water and wastewater treatment for disadvantaged communities, especially in the Central Valley, and another $750 million goes to restoring lost capacity to Friant Kern Canal.

The first bond issue is built the way it is because it was written by legislators and includes lots of constituent-serving open-space recreational area spending and clean-water projects. The fall measure is more of a Big Water-serving one, repairing parts of the huge engineering infrastructure that moves water around vast California.

Voters will approach the issues with concerns about their own pocketbooks, and both of these measures would spend big taxpayer dollars. But the fact is, bond issuances is how California throughout the past and present centuries have chosen to finance upkeep of the state’s giant waterworks. And voters have a history of supporting the bonds, including several times doing it twice in the same calendar year. Tim Quinn, executive director of the Association of California Water Agencies, which represents both urban and agricultural water agencies, told the wonky nonprofit Water Education Foundation that what bonds leverage now is developing sustainable water supplies at the regional level with financial help from the state.

Maybe, but it is still a lot of money. But then maybe even frequent bond votes are better than a Brown administration proposal to put a tax on drinking water at 95 cents per month per household.