Tools
Calculators and maps for your roof, your well and your address.
Wells and groundwaterWell test planner: what is due on your wellTell us when you last tested. We show what is due now, using Sonoma County Environmental Health's schedule.
Tap water and supplyWater map: your supplier, watershed and groundwaterEnter an address or click the map. We show who supplies your water, which watershed you live in, and which groundwater basin is under you.
Rain and storageWater storage tank size calculatorAnswer a few questions about your household, animals and garden. The calculator works out your daily use, then the tank size for the days you want to cover, and whether one tank or several fits.