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San Francisquito Creek is small for most of the year. In August you can stand in its bed near Middlefield Road and see only gravel and willow roots. In a wet winter it can rise several feet in a night and spill into the streets of Crescent Park and East Palo Alto. That split personality has shaped Palo Alto from the start. The creek gave the city its namesake tree, its northern border and its worst floods.
This page follows the creek from Ohlone villages through Spanish maps, Stanford's dams and the flood of 1998 to the flood projects under way in 2026. It does not repeat the full story of the tree itself, which is on our page about El Palo Alto.
A perched creek on a county line
The creek begins just below Searsville Lake in Stanford's Jasper Ridge preserve, where Bear Creek and Corte Madera Creek meet. From there the mainstem runs about 12.9 miles to the bay, according to measurements cited by Wikipedia. Los Trancos Creek joins it near Alpine Road. The whole watershed covers roughly 40 to 45 square miles, depending on which source you use and how much of the upper hills it counts.
For much of its length the creek is a boundary. It separates Palo Alto from Menlo Park and East Palo Alto. Together with Los Trancos Creek it forms the line between Santa Clara and San Mateo counties. That line goes back to the mission era, when the creek divided the grazing lands of Mission San Francisco de Asís from those of Mission Santa Clara.
The creek authority calls San Francisquito the last free-flowing urban creek on the southern Peninsula. Once it leaves the foothills, it runs across an alluvial fan it built itself over thousands of years. The channel sits high on that fan, a "perched creek" with natural banks taller than the land around it. When the water tops those banks it does not drain back into the channel. It runs downhill and away, across streets and yards. That geography explains why floods here spread so widely.
Ohlone life along the creek
People lived along this creek for thousands of years before Europeans arrived. Our page on the Ohlone covers the region's first peoples in depth. Sources name different local groups. This site follows historians who place the Puichon along the lower creek, while the creek authority describes the watershed as home to the Lamchin. Both were Ohlone communities with ties across the Peninsula.
The creek offered fresh water in winter and spring, shade from oaks and willows and a route between the bay marshes and the hills. Steelhead ran up it from the bay. Archaeologists have found remains of salmon or trout at sites in the watershed. Oral histories describe coho salmon in the creek as late as the 1940s. Shellfish, waterfowl and tule reeds came from the tidal marsh at its mouth. In 1857 a federal survey mapped about 1,142 acres of tidal marsh there.
El Palo Alto and the Spanish maps
In November 1769 the Portolá expedition camped beside the creek for several days after its scouts first saw San Francisco Bay. Near the camp stood the tall redwood the Spanish called El Palo Alto. Our Spanish and Mexican era page tells the rest of that story.
Later expeditions kept returning to the creek. In 1774 Father Francisco Palóu raised a cross near the tree to mark a possible mission site. Juan Bautista de Anza's party crossed in 1776 and called the stream the Arroyo de San Francisco. The mission was never built here. The creek's summer flow was judged too low to support one. The mission went to Santa Clara instead. The name the creek kept, San Francisquito, means "little San Francisco."
Stanford's dams and the steelhead
The university shaped the upper creek more than anyone. Searsville Dam went up in 1892, a 65-foot concrete wall that formed Searsville Lake. Stanford built the Lagunita Diversion Dam in 1899 and 1900 to send winter water into Lake Lagunita. A Los Trancos diversion followed in 1929 to fill Felt Reservoir. Our pages on Jasper Ridge and Lake Lagunita cover those landscapes today.
The dams blocked steelhead, which still spawn in the watershed and are federally listed as threatened. Over the last two decades Stanford has removed or eased several barriers. It built a new fish ladder on Los Trancos Creek in 2009. In late 2018 it removed the 119-year-old Lagunita diversion and restored 480 feet of channel. It also replaced a low weir at the Jasper Ridge road crossing with a bridge. Searsville Dam is still standing. Its reservoir has lost most of its storage to sediment. Stanford is studying a plan to open a passage through the base of the dam.
Taming the lower creek
Down in the flats, Palo Alto pushed the creek into a narrower course. In the late 1920s levees rerouted its mouth away from the old channel near today's Baylands toward a new engineered outlet. Filling for the airport and golf course shrank the tidal marsh at the mouth to about 352 acres by 2004. Our page on the history of the Baylands picks up that story.
Bridges came next. The Newell Road bridge dates to 1911. The Pope-Chaucer bridge, between Palo Alto and Menlo Park, has a small culvert-style opening that backs water up in big storms. Residents built houses close to the banks in Crescent Park and Duveneck/St. Francis on the Palo Alto side and in the Willows on the Menlo Park side. Concrete and wooden floodwalls went up piece by piece along the top of the banks. Many of them are now old and need repair.
Floods: 1955 to 2022
The U.S. Geological Survey has measured flows at a gauge on the Stanford golf course since 1930, with a gap in the 1940s. The creek authority publishes the ranked list. The five highest peaks:
| Date | Peak flow (cubic feet per second) |
|---|---|
| February 3, 1998 | 7,200 |
| December 31, 2022 | 6,340 |
| December 22, 1955 | 5,560 |
| December 23, 2012 | 5,400 |
| January 4, 1982 | 5,220 |
The 1998 storm was the flood of record. During that El Niño winter the creek burst its banks and damaged its levees. The creek authority puts the toll at about 1,700 damaged properties across Palo Alto, Menlo Park and East Palo Alto. Water spread through neighborhoods near the creek on both sides. Our history of the 1998 flood covers that night in detail.
The New Year's Eve storm of 2022 was a smaller event by return period, about a 30-year storm by the authority's updated analysis. It still taught engineers a hard lesson. Better gauges showed that the creek overtopped at several spots above and below the Pope-Chaucer bridge, not just at the bridge itself. Valley Water's review found that observed water levels ran up to two feet higher than the old model predicted. The channel holds about 25 percent less water than planners had assumed.
The creek authority
The 1998 flood finally broke a long stalemate. Because the creek divides two counties, neither county's water district had been willing to pay to rebuild it alone. In 1999 five agencies formed the San Francisquito Creek Joint Powers Authority, known as the SFCJPA: the cities of Palo Alto, Menlo Park and East Palo Alto, San Mateo County and the Santa Clara Valley Water District, now called Valley Water. San Mateo County now takes part through its flood and sea level rise district, known as OneShoreline. Elected officials from each member sit on the board. A small staff runs the projects with help from consultants and the member agencies.
The authority works upstream from the bay, one segment or "reach" at a time. That order matters. California law forbids a project from moving flood risk onto someone else, so the lower creek has to carry more water before the upper creek can send it more.
Flood projects as published in 2026
The authority's project pages give this picture as of late October 2026. Check the SFCJPA website for updates, because schedules move.
- Reach 1, the bay to Highway 101: Completed in 2019. Crews widened the channel, built larger levees and added floodwalls where there was no room to widen. The work created more than 22 acres of new or improved marsh and new levee-top trails linking to the Bay Trail. The authority says it protects more than 1,700 properties from a 100-year creek flood during a king tide and allows for three feet of sea level rise.
- Newell Road Bridge: The City of Palo Alto is replacing the 1911 bridge with funding from Caltrans and Valley Water. Hoodline reported in October 2026 that ground was broken in May 2026 and put the cost at $16.12 million.
- Reach 2, Highway 101 to Middlefield Road: Plans include widening the channel at choke points through a U.S. Army Corps of Engineers study, repairing or replacing old floodwalls, replacing a temporary wooden floodwall along Woodland Avenue and finally replacing the Pope-Chaucer bridge. The authority studied a tunnel to divert high flows and decided in August 2026 to stop evaluating it.
- SAFER Bay: A shoreline project to protect East Palo Alto and Menlo Park's Belle Haven from tidal flooding and rising seas. Its board certified the environmental impact report on May 28, 2026.
Good to know
- The creek is usually dry in summer. In winter storms, stay off the banks and out of the channel.
- The creek authority posts rain and streamflow gauges and a sandbag location map each winter.
- For storm and evacuation planning, see our guide to emergency preparedness.
Seeing the creek today
The easiest place to start is El Palo Alto Park at Alma Street and Palo Alto Avenue, where the tree leans over the bank beside the railroad bridge. Hopkins Creekside Park runs along the creek in a narrow strip near Palo Alto Avenue and is a good place to see the banks and the floodwalls up close. Most accounts say Timothy Hopkins gave it to the city in 1907, but a 2001 creek marker at El Palo Alto Park says he left the land to the city at his death in 1936.
Downstream of Highway 101, the levee trails built for the Reach 1 project let you walk the widened channel to the bay. New interpretive signs on the Friendship Bridge there describe the creek's human and natural history, with panels written for children. Across the water lie East Palo Alto and the Belle Haven side of Menlo Park, the neighbors who share the creek's risks and its repairs.
Frequently asked questions
When did San Francisquito Creek last flood?
The creek overtopped its banks on December 31, 2022, with a peak flow of about 6,340 cubic feet per second at the Stanford gauge. That was the second highest flow on record. The flood of record came on February 3, 1998, at about 7,200 cubic feet per second.
How many properties flooded in 1998?
The San Francisquito Creek Joint Powers Authority says the 1998 flood damaged about 1,700 properties in Palo Alto, Menlo Park and East Palo Alto. That flood led the cities and the two counties' water agencies to form the authority in 1999.
What is being done about the Pope-Chaucer Bridge?
The creek authority plans to replace the bridge, which has an undersized opening that backs water up in big storms. Work downstream must be finished first so that the new bridge does not push more water onto neighborhoods below it. The authority's Reach 2 page lists the current status.
Does Searsville Dam cause flooding in Palo Alto?
No, according to the creek authority. The dam is still in place and does not provide flood control. Stanford is studying a plan to open a passage through its base for fish. It must also manage the sediment stored behind it as part of that project.
Who is in charge of San Francisquito Creek?
No single agency. The SFCJPA coordinates flood projects for Palo Alto, Menlo Park, East Palo Alto, Valley Water and San Mateo County. Stanford owns the upper watershed dams and the cities handle bridges and local emergency response.