Replacement Water Cost Adjustment Factor


The Replacement Water Cost Adjustment Factor (RWCAF) has been established to recover the costs of imported water required to fulfill the water systems requirements under the judgment of the adjudication of the Main San Gabriel Basin Watermaster.

Each year in May the Main San Gabriel Basin Watermaster recommends to the Superior Courts of California the adoption of a basin safe yield. This safe yield fluctuates annually from a historic low of 140,000 acre feet of allowable extraction to a historic high of 230,000 acre feet of extraction.

This variable results in fluctuations of purchased imported water requirements for the City of Azusa. When the safe yield is high, the RWCAF is reduced, and when the safe yield is low, the RWCAF is set higher.

Determining the RWCAF

The Azusa Light and Water determines the RWCAF at the beginning of each year for the City's water system. The Director of Utilities then notifies the City Council of the new RWCAF. It is then applied to all water bills beginning the 1st billing cycle of the new fiscal year.

Azusa Light and Water will determine the RWCAF to the following methodology:

  • Determine Azusa's Integrated Production Rights (R) for the following fiscal year based on the Safe Yield declared by the Main San Gabriel Basin Watermaster in the spring of each year.
  • Project Azusa's total water production (P) based on estimated sales (S) in units (CCF) of water for the following year.
  • Derive the amount of Replacement Water (W) required by subtracting (R) from (P).
  • Derive the costs ($) associated with (W) from the Main San Gabriel Basin Watermaster which includes replacement water costs from the responsible agencies, administrative charges, and in-lieu fees.
  • Derive RWCAF by dividing ($) by (S).
  • If the RWCAF is less than $0.01/CCF, then apply $0.01/CCF commencing in July until the month ($) is attained, then discontinue the charge.