X0508 4 2023-09-01 0001035201 CALIFORNIA WATER SERVICE GROUP CWT 0001615551 Webb Ronald D 1720 NORTH FIRST STREET SAN JOSE CA 95112 1 VP, Human Resources 0 Common Stock 2023-09-01 4 D 0 50 50.10 D 23522 D Common Stock 2023-09-03 4 D 0 51 50.10 D 23471 D Represents the number of shares withheld by and surrendered to the Issuer to satisfy the tax withholding obligations that arose in connection with the vesting of the Restricted Stock Award (RSA) Award #649. Represents the number of shares withheld by and surrendered to the Issuer to satisfy the tax withholding obligations that arose in connection with the vesting of the Restricted Stock Award (RSA) Award #607. /s/ Michelle Mortensen on behalf of Ronald Webb 2023-09-06