Resources · How it works
Understanding your allocation
Your groundwater allocation is the amount of water your parcel is permitted to pump from underground in a given period. Here's how the number is arrived at and what it means in practice.
Allocations replace “pump as much as you want”
Before SGMA, groundwater was essentially unmetered. Under the GSA’s Pumping Cap Policy, each parcel now has an allocation: a specific, measurable ceiling on how much groundwater can be pumped from it during a given water year (October 1 – September 30).
The allocation isn’t a target — it’s a limit. You can use less. What you can’t do is exceed the limit without consequence.
What goes into the number
The allocation for a specific parcel depends on a few things:
- Parcel acreage. The starting point. Larger parcels have larger base allocations.
- Land-use category. Agricultural, municipal, industrial, and domestic parcels each have different baseline calculations.
- Sustainable yield.The GSP’s calculation of how much groundwater the subbasin can produce annually without causing the undesirable results SGMA tracks.
- Transition schedule.The GSP includes a phased reduction schedule — allocations decrease over time toward the sustainable yield, not overnight.
- Tier adjustments.The Pumping Cap Policy includes tiers that can modify a parcel’s base allocation up or down based on historical use and other factors.
Where to find your number
- Watermark is the fastest source of truth for your parcel’s current allocation.
- The Pumping Cap Policy spells out the methodology in full.
- Board meetings are where allocation adjustments and tier changes are discussed.