Checked August 27, 2026
How California watering rules work
The rules behind the numbers, in plain English. Every claim in these guides cites the adopted state text, the statute, or our verified datasets.
Water budgetsThe Two Numbers That Decide Your Landscape Water BudgetEstimated water use vs the budget cap: what feeds each number, why plants and drip matter most, and what happens when a plan runs over.The climate numberWhat Is ETo? California Reference EvapotranspirationWhat reference evapotranspiration (ETo) measures, why it runs from the high 30s on the coast to the 90s in the desert, and how watering scales from it.Small projectsThe Prescriptive Path for Small California LandscapesSmall California landscape projects can skip the water budget math and follow the section 492 checklist instead. Every requirement, in plain language.HOA rulesCan Your HOA Fine You for a Brown Lawn in California?Civil Code 4735 blocks HOA fines for cutting back lawn watering during a declared drought emergency. What is void, what still applies, and one exception.Irrigation mathDrip vs Sprinklers in a California Water BudgetWhy California's landscape water budget credits drip at 0.81 efficiency vs 0.75 for spray, and how that 7 percent gap helps a yard pass its budget.Edible areasEdible Gardens in a California Water BudgetVegetable gardens and orchards count at a full 1.0 in a California landscape water budget instead of 0.55. What qualifies and how to claim it.