X0609 4 2026-09-04 0 0001035201 CALIFORNIA WATER SERVICE GROUP CWT 0001763820 Mares Michael S JR false 1720 NORTH FIRST STREET SAN JOSE CA 95112 0 1 0 0 SVP Operations 0 Common Stock 2026-09-04 4 F 0 69 50.03 D 8318.915 D Common Stock 2026-09-05 4 F 0 67 50.03 D 8251.915 D Represents the number of shares withheld and surrendered to the issuer to satisfy the tax withholding obligations that arose in connection with the vesting of Restricted Stock (RSA) Award granted on March 4,2025 Represents the number of shares withheld and surrendered to the issuer to satisfy the tax withholding obligations that arose in connection with the vesting of Restricted Stock (RSA) Award granted on June 5, 2024. By: /s/ Michelle R. Mortensen For: Michael S Mares 2026-09-08