Pilarcitos C A Half Moon Bay water level

Name: Pilarcitos C A Half Moon Bay water level (U.S. Geological Survey)
Creator: U.S. Geological Survey
License: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits

River gauge, California, United States

Directions

Below flood stage

Water level

2.73ft Steady over the last 24 hours

Measured Oct 20, 2026, 01:00 AM PDT (43 min ago)

Flow: 2.5 cfs

History

7 days

Water level Minor flood stage

What this means

Pilarcitos C A Half Moon Bay is at 2.73 ft, in the normal range.

It is 6.37 ft below the flood stage of 9.10 ft.

It has barely moved over the past 24 hours. In the last month it has stayed between 2.53 ft and 2.79 ft.

Fall is often low-water season on rivers, until steadier rain returns.

Judged against the official flood stage for this gauge. How to read levels

Key numbers

Highest on record: 13.08 ftJanuary 4, 1982

Floating and fishing near Pilarcitos C A Half Moon Bay

Normal flows mean predictable rapids and good access at most put-ins.

Flood stage here is 9.10 ft, 6.37 ft above the current reading. Beyond it, the National Weather Service also defines moderate and major flood stages.

What happens at each level

24.00 ft: Major flood stage. Major flooding of adjacent neighborhoods. Highway 1 backwatered and flooded at Pilarcitos Creek.
17.00 ft: Moderate flood stage. Homes along Willow/Pilarcitos/Oak Avenue begin to flood. Water is about 3 feet below Highway 1 bridge chord. NWS will issue a Flash Flood Warning if not yet already issued.
9.10 ft: Minor flood stage. Water begins to flood Naomi Patridge Trail. NWS will issue an urban/small stream advisory if not yet already issued.
7.50 ft: Action Stage. Water is 1.5 feet below Naomi Patridge Trail.
2.73 ft: Right now

Impact statements from the U.S. National Weather Service.

Highest crests on record

Rank	Level	Date
1	13.08 ft	January 4, 1982
2	12.27 ft	February 3, 1998

Weather at the gauge

No rain in the last 3 days.

18 Sun 61° 54° – Wind 9 mph

19 Mon 62° 53° – Wind 11 mph

20 Tue 68° 52° – Wind 6 mph

21 Wed 65° 56° 0.61 in, 52% Wind 7 mph

22 Thu 65° 57° 0.01 in, 28% Wind 8 mph

23 Fri 70° 55° – Wind 9 mph

24 Sat 77° 55° – Wind 8 mph

Forecast: Open-Meteo

Sunrise 07:23 AM Sunset 06:27 PM Daylight 11 hr, 4 min First quarter 67%

Map

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
Pilarcitos Creek below Stone Dam near HillsboroughRiver gauge, Pilarcitos Creek	1.5 cfs	Normal	±0	4.4 mi
Pilarcitos Creek above Stone Dam near HillsboroughRiver gauge, Pilarcitos Creek	3.4 cfs	Normal	±0	4.6 mi
Pilarcitos Creek below Spillway near HillsboroughRiver gauge, Pilarcitos Creek	2.8 cfs	Normal	±0	5.7 mi
Pilarcitos Lake near HillsboroughLake, Pilarcitos Lake	679.70 ft	Below flood stage	−0.05 ft	5.7 mi
San Mateo Creek below Lo Crystal Sp Reservoir near San MateoRiver gauge, San Mateo Creek	4.0 cfs	High	+0.3 cfs	6.0 mi
San Gregorio C A San GregorioRiver gauge	3.67 ft	Below flood stage	±0	10 mi
San Francisquito C A Stanford UniversityRiver gauge	0.18 ft	Below flood stage	+0.01 ft	14 mi
Pescadero Creek near PescaderoRiver gauge, Pescadero Creek	2.2 cfs	Normal	−0.2 cfs	15 mi

Questions and answers

What is flood stage for Pilarcitos C A Half Moon Bay?

The official flood stage is 9.10 ft. The level is currently 6.37 ft below it.

Is gage height the same as water depth?

No. Gage height is measured from a fixed reference point chosen by the agency, so a reading of 10 ft does not mean the river is 10 ft deep.

What is the water level of Pilarcitos C A Half Moon Bay today?

On Oct 20, 2026, 01:00 AM PDT, the water level was 2.73 ft. Steady over the last 24 hours.

Is Pilarcitos C A Half Moon Bay rising or falling?

Steady over the last 24 hours.

Is the level of Pilarcitos C A Half Moon Bay normal?

Below flood stage. Judged against the official flood stage for this gauge.

What is the highest water level ever recorded at Pilarcitos C A Half Moon Bay?

The highest level on record is 13.08 ft on January 4, 1982.

How often is this data updated?

The U.S. Geological Survey publishes a new reading every 15 minutes. This page refreshes within minutes of each update.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: U.S. Geological Survey
Station code: usgs:11162630 (Agency page)
Coordinates: 37.46656, -122.43410 (WGS84)
Vertical datum: NAVD88
Update interval: every 15 minutes
Licence: Public domain. Data: U.S. Geological Survey (USGS), provisional data subject to revision

Published series

Parameter	Last value	Time (UTC)	Quality
Water level	2.73 ft	2026-10-20 08:00	Provisional
Flow	2.5 cfs	2026-10-20 08:00	Provisional

Download

Embed this gauge

Add a live card for this gauge to your website. It updates on its own and links back here.

<iframe src="https://nivelmap.com/embed/11969?lang=en" width="360" height="230" style="border:0;max-width:100%" loading="lazy" title="Pilarcitos C A Half Moon Bay water level"></iframe>

How to cite

U.S. Geological Survey: Pilarcitos C A Half Moon Bay (usgs:11162630). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/united-states/california/pilarcitos-c-a-half-moon-bay

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer