Water Resources


View the 2020 Annual Water Quality Report(PDF, 5MB). Also available in Spanish(PDF, 5MB) and Mandarin(PDF, 6MB).

Local Water Supply

Palo Alto’s water comes from the San Francisco Public Utilities Commission (SFPUC). This high quality water supply consists almost entirely of Sierra Nevada snowmelt delivered through the Hetch Hetchy water distribution system.  Precipitation levels can vary greatly within any given year. Even though we may experience periods of wet weather, a warm dry spell can affect water supplies later in the year. These climate conditions, along with our limited long-term water supplies, mean it is in our best interest to use water as efficiently as possible, regardless of drought conditions. Learn more about the City of Palo Alto's Urban Water Management Plan.

Update on Current Water Conditions

California is experiencing dry weather conditions, and the Governor is asking water customers to reduce usage by 15% compared to 2020. There are currently no mandatory water use restrictions or drought surcharges in effect at this time for Palo Alto.

Water waste is still prohibited. Read about the City's water use regulations in the municipal code.

On June 9, the water supplier for the rest of Santa Clara County, Valley Water, declared a water shortage emergency and adopted a 15% mandatory water use reduction for water retailers its agency serves. The County of Santa Clara also proclaimed a local emergency as there is significant uncertainty about local and statewide water supply conditions. Santa Clara County relies on imported water supplies which have been negatively impacted by low snowpack levels and a couple of years of consecutive drought. Valley Water also has limited water storage capabilities due to surface water reservoir constraints.

The City recognizes the importance of Making Water Conservation a California Way of Life at all times. We partner with Valley Water and the Bay Area Water Supply and Conservation Agency (BAWSCA) to deliver rebates for water efficient landscaping upgrades as well as products and projects that conserve water and reduce storm water runoff. Visit our Save Energy & Water page to view available water efficiency resources. 

Helpful Information about Your Water Supply

This new video from our friends at BAWSCA talks about our precious water supply & how membership in this agency has helped CPAU, among other member agencies, protect our high-quality water at a fair price. 

Water Quality & Annual Consumer Confidence Report

The City of Palo Alto Utilities and our water supplier are required by law to adhere to strict health and safety standards for potable drinking water. Every year we publish an Annual Consumer Confidence Report which informs customers about the City's water quality. Past annual reports are provided below on this page.  If you would like a copy of the report mailed to you, please email us at utilitiescommunications@cityofpaloalto.org or call (650) 329-2479 to submit a request. Click here for the 2016 Public Health Goals ReportRead about tap water quality versus bottled water. 

View the 2020 Annual Water Quality Report(PDF, 5MB). Also available in Spanish(PDF, 5MB) and Mandarin(PDF, 6MB).

View the 2020 Annual Water Quality Postcard(PDF, 1MB)

Parameter As of June 9, 2021 As of June 10, 2021
 HH Flow (MGD)  245 245 
HTWTP Flow (MGD) 25 25 
 SVWTP Flow (MGD) 25 
 Total Chlorine Residual (mg/L) 3.3  3.3 
 Free Ammonia-N (mg/L) 0.05  0.04 
 pH 9.4  9.6 
 Turbidity (NTU) 0.21  0.20 
 Conductivity (uS/cm) 46  51 
 Hardness (mg/L) 7.5  14 
 Alkalinity (mg/L) 11  13 
 TOC (mg/L) 1.6  1.6 

Previous Palo Alto Annual Water Quality Reports

Recycled Water & Other Alternative Water Sources

  • Recycled water is available from the Regional Water Quality Control Plant for use with construction activities and landscape irrigation.
  • Read information on how to use Recycled Water here, including how to obtain the necessary permit.
  • Interested in opportunities for reusing water that is "dewatered" or pumped from the ground during construction projects? Read our FAQs.

Water Distribution System Flushing

City staff need to periodically flush water mains and hydrants with fresh water to prevent the water quality from degrading. This is more frequently needed in areas where a cul-de-sac or end-of-the-line piping tend to accumulate vegetation, algae or sediment. Flushing is necessary to keep debris out of customers' service line. We post signs at each site to let people know that this is being done.  We monitor our water quality every day to ensure that it meets all State and Federal guidelines for drinking water quality standards. If a customer experiences discoloration or sediment in water coming from the tap, they should flush the cold (not hot) water for a minute or more until the water clears.

Flushing Guidance for Buildings Following Shutdown

Businesses are returning to work after an extended shutdown due to COVID-19 public health shelter in place orders. If a building has been vacant and dormant, water use has been reduced, which could result in a degradation in water quality. Stagnant water can harbor bacteria, so it is important to flush your water system before you begin using the water again. Our water supplier has provided guidance with steps to take when restoring water service.  


The City of Palo Alto takes its responsibility to protect customers from lead exposure very seriously. Palo Alto Utilities does not have lead services or other equipment in our system, though we still perform sampling to ensure clean, safe drinking water quality. The City of Palo Alto’s lead sampling technique uses best practices for accurate water quality testing. If you have questions about the City's lead or other water quality testing procedures, please contact our Water Transmission Staff at (650) 496-6967.


Get the facts about fluoride in drinking water. Read more from the Centers for Disease ControlAmerican Dental Association, and DrinkTap.org. You also read more at the SFPUC fluoridation page

Chromium 6

Chromium is an abundant element in the Earth’s crust, found naturally in rocks, plants, soil and volcanic dust, humans and animals. One form, hexavalent chromium, is widely found in waters, including source waters for drinking water, typically at VERY low concentration levels. Chromium 6 is not a concern in Palo Alto. The water supplies we receive from the SFPUC fully comply with the new California Chromium 6 MCL standard finalized in July 2014.

Permanent Water Use Restrictions

Using water more efficiently is important every day, regardless of drought or rain conditions.

  • Flooding or runoff is prohibited
  • Broken or defective plumbing and irrigation systems must be repaired or replaced within a reasonable period
  • Turf and ornamental landscape* irrigation is not allowed between 10am and 6pm, except for hand watering with a bucket or a hose with a shut-off valve
  • A shut-off valve is required for hoses used to wash vehicles, buildings, etc
  • Potable water for construction uses is prohibited if non-potable water is available
  • Water in fountains or other decorative water features must be recirculate
  • Commercial car washes must use recycled water systems if economically feasible
  • Potable water for street sweepers/washers is prohibited if non-potable water is available

*"Ornamental landscape” refers to landscaping for purely decorative purposes, which is distinguished from edible gardens or landscapes that are functional as well as aesthetic.

Help save water by reporting water waste through Palo Alto 311

Email: drought@cityofpaloalto.org or leave a voice message at (650) 496-6968