Valley Water, which supplies surface water to our Los Altos Suburban system (serving Los Altos and portions of Cupertino, Los Altos Hills, Mountain View, and Sunnyvale), will begin a major pipeline repair project this fall. This project, which will begin on Thursday, Oct. 30 and last through April 2026, will affect Cal Water customers as we move to 100 percent groundwater. We do not expect that water service will be interrupted, but the source of your water will temporarily change.

During the span of this project, we remind all customers:

• You may experience hard water as we move to meet system demand with more groundwater sources than usual. Hard water is caused by naturally occurring minerals and does not pose a health risk; however, it can cause spots on glasses and fixtures. You can minimize spotting by hand-washing dishes or towel drying them immediately after the dishwasher rinse cycle. If you already have spots on your glasses, soak them in white vinegar for 5 to 10 minutes.
• Please conserve water as much as possible and use water wisely. Your conservation efforts will help us continue providing the appropriate water supply for health, safety, and firefighting capabilities.
• Turn off sprinkler systems when it rains. Turn off your sprinkler systems during and for 48 hours after rainfall to conserve water and prevent overwatering.

We will be closely monitoring our water supply for customers, which we also provide through groundwater wells and our own storage facilities.

We will let you know when Valley Water’s project is complete so that you can resume normal water use. We apologize for any inconvenience this may cause and thank you for your cooperation.