Exhibit 99.1 DATE: July 29, 2026 CONTACT: Jim Lynch, (408) 367-8200 (analysts) Shannon Dean (408) 367-8243 (media) For Immediate Release California Water Service Group Reports Strong Second Quarter 2026 Financial Results SAN JOSE, Calif., July 29, 2026 (GLOBE NEWSWIRE) -- California Water Service Group (Group or the Company, NYSE: CWT), a leading publicly traded water utility serving California, Hawaii, New Mexico, Washington, and Texas, today reported strong second quarter 2026 results. Second Quarter 2026 ...