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Turn on a tap in Palo Alto and the water most likely fell as snow in the Sierra Nevada. It melted into the Tuolumne River, collected behind O'Shaughnessy Dam at Hetch Hetchy Reservoir in Yosemite and then traveled by aqueduct across the Central Valley to the Bay Area. That system belongs to the San Francisco Public Utilities Commission, known as the SFPUC. Palo Alto buys its water from the SFPUC and City of Palo Alto Utilities delivers it.
The water is high quality and relatively affordable, but it is not unlimited. California swings between wet years and droughts and outdoor watering makes up a big share of what homes use in summer. This guide explains the supply, the rules that apply every year, how to spot leaks and what help is available to replace a thirsty lawn. For bills and accounts, see our utilities guide.
Where the water comes from
The city's water resources page says Palo Alto's water is almost entirely Sierra Nevada snowmelt delivered through the Hetch Hetchy system. The SFPUC's regional water system serves 2.7 million residents. Besides San Francisco itself it sells water wholesale to 27 cities and water agencies in Alameda, Santa Clara and San Mateo counties. Palo Alto is one of them.
Hetch Hetchy Reservoir sits in Yosemite National Park, which our Yosemite day trip guide covers. Its water passes through hydroelectric powerhouses on the way down from the mountains. Local reservoirs add storage closer to home. The SFPUC lists Calaveras and San Antonio in the East Bay hills and Crystal Springs, Pilarcitos and San Andreas on the Peninsula.
Supply sources shift during maintenance. The city's page showed a planned change in fall 2026 in which the SFPUC's Sunol Valley treatment plant began contributing water while the Hetch Hetchy share dropped somewhat. These changes are planned by the SFPUC and are usually invisible at the tap.
Recycled water and wholesale partners
Palo Alto also produces recycled water at its Regional Water Quality Control Plant near the Baylands. It is used for landscape irrigation and construction, not drinking. The city belongs to the Bay Area Water Supply and Conservation Agency, which represents the SFPUC's wholesale customers. Valley Water, the Santa Clara County water district, runs the regional conservation and rebate programs that Palo Alto residents can use.
Watering rules that apply all year
Palo Alto has permanent water use rules in Chapter 12.32 of the municipal code. They apply in wet years too. These are the main points of section 12.32.010:
| Rule | What it means |
|---|---|
| Watering hours | No drinking water on lawns or purely decorative landscaping between 10 a.m. and 6 p.m. |
| Exemptions to the hours | Trees, edible gardens and landscapes with more than a decorative purpose. Hand watering with a bucket or a hose with a working shut-off valve is also allowed. |
| No runoff | Water may not flood or run off into gutters, driveways, sidewalks or streets. |
| Hoses | Washing cars, sidewalks or buildings requires a hose with an automatic shut-off valve. |
| Leaks | Broken plumbing, sprinklers and irrigation systems must be repaired as soon as possible. |
| Fountains | Decorative fountains and water features must recirculate. |
The code does not set watering days. In a drought the rules can tighten. The city's Urban Water Management Plan includes a four-stage drought response plan and its utility rules include a water shortage emergency regulation. If the SFPUC or the state calls for cuts, the city announces which stage applies.
The state turf ban
California's AB 1572 limits the use of drinking water on nonfunctional turf, meaning grass that is purely decorative. The city's turf ban page gives a simple test: if the only time anyone walks on the grass is to mow it, it is probably nonfunctional. Street strips, parking lot islands and lawns in front of office buildings are typical examples.
- Public properties: from January 1, 2027
- Commercial, industrial and institutional properties: from January 1, 2028
- HOA common areas and community service organizations: from January 1, 2029
Single-family home landscapes are excluded. So are sports fields, parks, school grounds and other turf people actually use. Landscapes watered only with recycled water are excluded too. Trees can still be watered with drinking water.
Rebates for lawns and landscapes
Valley Water runs landscape rebates in partnership with the city. When we checked the city's turf ban page in October 2026 it listed two:
| Program | Listed amount | What it covers |
|---|---|---|
| Landscape Conversion Rebate | Up to $4 per square foot on the city page (Valley Water base rate $2) | Replacing lawn with water-efficient landscaping |
| Lawn to Mulch Rebate | Up to $2 per square foot | Replacing lawn with mulch at commercial, institutional, industrial and multifamily (5 or more units) sites; not single-family homes |
Rebate programs have rules about plant coverage, irrigation and photos. Most require approval before you start. Read the current requirements on Valley Water's rebate portal before you tear anything out. Valley Water also offers a free Water Wise Outdoor Survey, in which a specialist reviews your irrigation system and suggests fixes. The city's water programs line is (650) 329-2241 or [email protected].
Native and drought-tolerant plants are the usual replacement. They also support birds and pollinators. Our wildflowers guide and Gamble Garden page are good places for planting ideas. If you want to grow food instead, our community gardens guide explains the city's plots.
Track your use with WaterSmart
The city's WaterSmart portal, reached through MyCPAU, shows how much water you use and where. Homes with the city's smart meters can see hourly, daily and weekly use. You can compare your use with similar households, update a household profile for better estimates and download hourly data.
Leak alerts
Single-family homes with smart meters have received courtesy leak alerts by email since October 2024. An alert goes out when the meter sees continuous use that suggests a leak. The city lists two triggers:
- 5 gallons an hour of continuous use for 24 hours, which often means a running toilet or a slow drip
- 75 gallons an hour for 8 hours, which points to a broken pipe or a stuck irrigation valve
Homes without smart meters get alerts after the bill if use jumps sharply. You can also set your own daily thresholds in the portal. If you need a plumber, the city links to a directory of contractors trained in leak detection and repair. It does not endorse them.
Simple ways to use less
Most savings come from outdoors and from fixing leaks. These steps cost little.
- Water early. Run sprinklers before 10 a.m. or after 6 p.m., as the rules require. Less water evaporates.
- Skip watering after rain. Turn the controller off from the first winter storms until spring. Our weather guide shows when the rain falls.
- Fix runoff. Adjust sprinkler heads that spray the sidewalk and shorten run times if water pools.
- Mulch beds. A few inches of mulch keep soil moist longer.
- Check the toilet. A few drops of food coloring in the tank will show up in the bowl if the flapper leaks.
- Use a shut-off nozzle. It is required for washing cars and paving anyway.
Indoors, efficient fixtures and full loads in the washer and dishwasher add up. If you are replacing a water heater, the city's heat pump water heater program, described in our utilities guide, saves energy too.
Water quality
The city publishes an annual water quality report and says Palo Alto Utilities has no lead service lines or other lead equipment in its system. If tap water looks discolored after nearby work, the city advises running the cold tap for a minute or more until it clears. Water quality questions go to the water transmission staff at (650) 496-6967. Questions about storm runoff and creeks belong to a different system, covered in our rain and storm guide.
Good to know
- No lawn watering between 10 a.m. and 6 p.m., all year.
- Runoff into the street is against city code.
- Turn on WaterSmart leak alerts through MyCPAU.
- Get rebate approval from Valley Water before removing a lawn.
- Single-family homes are excluded from the state turf ban.
Frequently asked questions
Where does Palo Alto get its water?
Palo Alto buys its water from the San Francisco Public Utilities Commission. The city says the supply is almost entirely Sierra Nevada snowmelt delivered through the Hetch Hetchy system from Hetch Hetchy Reservoir in Yosemite National Park. City of Palo Alto Utilities then delivers it to homes and businesses.
What are Palo Alto's watering rules?
Under municipal code section 12.32.010, you may not water lawns or purely decorative landscaping with drinking water between 10 a.m. and 6 p.m. Runoff onto sidewalks, driveways and streets is banned, hoses used to wash cars or hard surfaces need an automatic shut-off nozzle and decorative fountains must recirculate. Trees, edible gardens and hand watering with a bucket or shut-off hose are exempt from the hours rule.
Are there rebates for removing a lawn in Palo Alto?
Yes, through Valley Water in partnership with the city. When the city checked in October 2026, its turf ban page listed a Landscape Conversion Rebate of up to $4 per square foot. Valley Water's own page gives a base rate of $2 per square foot. Lawn to Mulch is only for commercial, institutional, industrial and multifamily (5 or more units) properties, so homeowners use Landscape Conversion. Read the program requirements and get approval before you remove anything.
Does the state ban on watering nonfunctional turf apply to my house?
No. California's AB 1572 restricts drinking water on decorative grass at public, commercial, industrial and institutional sites and HOA common areas, starting in 2027 and phasing in through 2029. The city's page says single-family residential landscapes are excluded.
How can I tell if I have a water leak in Palo Alto?
Log in to WaterSmart through MyCPAU to see hourly and daily use. Single-family homes with smart meters get courtesy email alerts when continuous use suggests a leak, such as 5 gallons an hour for 24 hours. You can also set your own high-use alerts in the portal.