In 1978, California voters passed Prop 13, giving homeowners, landlords, and commercial property owners across the state a huge tax cut. The new constitutional amendment froze the assessed value of each home at the 1975 market price and then capped tax payments at one percent of that value, allowing for only a small annual increase ever after.

That below-market assessment is only reset if the owner sells the property or makes improvements upon it. Such “new construction” might include adding on a new room or building a deck, but certain modifications are excluded, like solar panels, fire sprinkler systems, and improvements for disability access.

What it would do:
Exempt the addition of rainwater capture system from the list of home improvements that would trigger a property tax reassessment.

What it would cost the government: No much (assuming rain capture systems don’t suddenly get really popular).

Why it’s on the ballot: State Sen. Steve Glazer, an Orinda Democrat, introduced a bill last fall to put the proposition on the ballot. He says he was inspired by a rain collecting homeowner at a Walnut Creek community meeting. But the last few years of weather offers its own inspiration: years of drought, followed by torrential downpour.


Arguments in Favor:

State lawmakers should encouraging residents to conserve water, collecting rain when it falls and using it to water their grass when it doesn’t. But right now, state property tax rules actively discourage that behavior, by sticking new rain harvesters with potentially massive property tax hikes.

Arguments Against:

No opposition.



  • California Democratic Party
  • League of Women Voters of California
  • California Chamber of Commerce
  • League of California Cities
  • Save the Bay
  • Howard Jarvis Taxpayers Association


  • No Opponents


Campaign contributions for and against Prop. 72

Going Deeper