News Details


 2014 Drought Updates Here

Water Distribution System Flushing
City of Palo Alto Water Transmission staff are currently flushing the City’s water distribution system to prevent degradation of water quality. Due to drought conditions this past year and request for conservation from our water supplier, the San Francisco Public Utilities Commission (SFPUC), City staff had limited some of the routine flushing of hydrants and main water distribution system. This, in addition to overall reduced water consumption has decreased the volume of water flowing through our distribution system. We must flush it with fresh water to prevent the water quality from degrading.

Read more about the drought and Palo Alto's response.

Update 2/25/15 - The Hetch Hetchy supply was restored to service at a rate of 105 MGD on 2/6/2015. The Sunol Valley Water Treatment Plant reduced its rate to about 25 Million gallons a day (MGD).  On 2/17/2015, the Hetch Hetchy rate was further increased to 165 MGD.

The following table compares water quality parameters at Irvington Portal. This data is based on the most recent sampling results and represents an estimate of how the blend parameters will change.

Water Quality
Chlorine levels in our water supply are currently higher than normal. Due to decreased water demand and lower volumes of water flowing through the system, SFPUC has had to increase the amount of chlorine in the water it supplies Palo Alto and other SFPUC customers for disinfection purposes. This increase in chlorine, coupled with the system flushing may create slight changes in taste and odor. Please rest assured that the water is absolutely safe to drink. If anyone has any significant concerns, they can contact our Water Transmission division at (650) 496-6967.

As a reminder, we 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 water quality report, which informs customers about the City's water quality. 

General questions or concerns? Call us at (650) 329-2161 to report issues or request information.

Water Blend Changes
Sometimes our water intake may come from a local storage reservoir, rather than straight from Hetch Hetchy.  This can create some changes in taste, appearance and odor. Right now, Palo Alto and other SFPUC customers in surrounding cities are receiving water from the Sunol Valley Water Treatment Plant and Reservoir. Some customers may be sensitive to changes in the water, so we post updates here.

If you experience discoloration or sediment in water coming from your tap, flush the water for a minute or more until the water clears. There may be more oxygen in the water, which can give a cloudy appearance. This is not harmful to drink. If problems persist or seem different than these conditions, please notify us right away, take precautions, and do not drink the water.

Stay Informed

    • Stay abreast of breaking news about any water disruptions or quality issues by following us on Twitter:@PAUtilities
  • To report a substantial leak, break or other emergency, call (650) 329-2579
  • To report over-watering or runoff infractions, call (650)329-2261 
  • Water Rate & Supply Status information is here.
  • City Water Quality Annual Report available here.
  • SFPUC Water Supply project status (slide presentation) available here
  • Backflow prevention surveys--get the full scoop about what is going on and why here. 
  • Highly Sensitive Customers---since occasional minor fluctuations in water quality do occur, people with high-sensitivity to water quality issues (e.g. those with compromised immune systems) should consult with their health care provider to determine in general if they should be taking precautionary measures such as adding filtration devices.

    SFPUC (Hetch-Hetchy) Water Supply Updates

    2014 DROUGHT: Details can be found

    RIM FIRE---
    The Rim Fire had no operational or water quality impact to the SFPUC water system. The water system is being monitored very closely and should things change, the SFPUC has back-up plans ready to go. 

    CHROMIUM 6 Not a Concern---The water supplies we receive from the SFPUC fully comply with the new California Chromium 6 MCL standard expected to be finalized in July 2014.  Click here for the latest SFPUC report on 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.

ALGAE---Long-term Actions: The SFPUC is developing an early warning monitoring program to better identify any future algae bloom events and exploring other improvements.  

SFPUC Hetch-Hetchy System Operations

Click here for a reference map of the SFPUC Hetch-Hetchy System. 

Click read about how the Hetch-Hetchy system uses gravity, not electricity, to deliver your water.

Planned Disruptions are no longer posted to respect the privacy of the impacted customers, all of whom receive direct notification of the disruption. 

Why are any planned disruptions necessary? 
Currently the City is in the process of performing system and seismic upgrades, along with increasing the storage capacity for the City's water distribution system. This work may cause some customers to experience lower than normal water pressures during high demand times of the year, such as warmer months and high usage times of day. You may also experience some cloudy water due to valving modifications done to support the affected areas. There are two primary reasons for water quality changes and planned disruptions:

  • San Francisco Public Utility Commission (SFPUC)'s Routine Maintenance on the Hetch-Hetchy supply system.  While most of the time we are getting our water supply straight from the Hetch-Hetchy aqueduct, periodically that aqueduct must be closed for maintenance and our supply is mixed with water from other reservoirs in the system.  In those cases, the water is still high quality and meets all standards, but may be cloudy (due to air bubbles) or have a slightly different smell or taste.
  • The City's Ongoing Aggressive Maintenance Program to test ("exercise") and replace old water valves.  An average of 100 valves per month are exercised and as many as 12 per month are replaced.  Everyone benefits from these improvements to the water distribution system, and we thank our customers for any inconvenience they must experience while their water is briefly turned off.  Customers always receive advance notice of these shut-offs.

Last Updated February 25, 2015