Upper Helemano Reservoir near Wahiawa, Oahu water level

Name: Upper Helemano Reservoir near Wahiawa, Oahu water level (U.S. Geological Survey)
Creator: U.S. Geological Survey
License: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits

Reservoir, Upper Helemano Reservoir, Hawaii, United States

Directions

Very high for mid-October

Water level

42.79ft Down 0.16 ft over the last 24 hours

Measured Oct 20, 2026, 10:10 AM HST (37 min ago)

History

What this means

There is plenty of water in Upper Helemano Reservoir near Wahiawa, Oahu: 42.79 ft, well above normal for mid-October.

The median for mid-October is 35.89 ft, based on 7 years of readings, so the lake level is 6.90 ft above typical.

The level is falling, down 0.16 ft over the past 24 hours. Over the past 30 days it has moved between 42.63 ft and 44.40 ft.

Many reservoirs are drawn down through summer and fall; most of the refill comes later, with winter rain or spring snowmelt.

Compared with 7 years of daily readings for this time of year. How to read levels

Key numbers

Median for this date: 35.89 ft6.90 ft above the median for this date
Normal for this date: 35.70 ft – 40.48 ft8 years in 10 fall in this range (7 years of records)
Lowest and highest in 30 days: 42.63 ft – 44.40 ft
Lowest and highest in 12 months: 33.25 ft – 46.16 ft

Swimming and boating at Upper Helemano Reservoir near Wahiawa, Oahu

High water can flood ramps, parking areas and shoreline campsites, and it carries floating debris. Expect some no-wake zones to be extended.

If you swim, pick a spot with an easy way out, and remember that drop-offs move as the level changes.

Weather at the gauge

Rain in the last 3 days: 0.68 in.

20 Tue 79° 68° 0.21 in, 92% Wind 16 mph

21 Wed 78° 68° – Wind 12 mph

22 Thu 79° 65° – Wind 7 mph

23 Fri 78° 64° 0.04 in, 26% Wind 9 mph

24 Sat 78° 65° 0.01 in, 27% Wind 8 mph

25 Sun 76° 64° 0.08 in, 49% Wind 7 mph

26 Mon 79° 63° – Wind 5 mph

Forecast: Open-Meteo

Sunrise 06:31 AM Sunset 06:05 PM Daylight 11 hr, 34 min Waxing gibbous 71%

Map

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
Wahiawa Ditch at Wahiawa, OahuCanal gauge, Wahiawa Ditch	9.8 cfs	Normal	+0.3 cfs	2.3 mi
Kaukonahua Stream below Wahiawa Reservoir, OahuRiver gauge, Kaukonahua Stream	52.2 cfs	Normal	+19.3 cfs	2.3 mi
Wahiawa Reservoir at Spillway at Wahiawa, OahuReservoir, Wahiawa Reservoir	55.72 ft	Very low	+1.00 ft	2.5 mi
Helemano 6 Reservoir, OahuReservoir	22.88 ft	Normal	+0.04 ft	3.0 mi
Opaeula Str near Wahiawa, OahuRiver gauge, Opaeula Str	1.88 ft	Below flood stage	−0.02 ft	3.1 mi
SF Kaukonahua Str at E pump, near Wahiawa, OahuRiver gauge, SF Kaukonahua Str	2.00 ft	Below flood stage	−0.08 ft	3.3 mi
Ku Tree Reservoir near Wahiawa, OahuReservoir, Ku Tree Reservoir	17.19 ft	Low	±0	3.6 mi
Koolau Reservoir near Wahiawa, OahuReservoir, Koolau Reservoir	6.67 ft	Very high	+0.21 ft	4.4 mi

Questions and answers

What is a normal level for Upper Helemano Reservoir near Wahiawa, Oahu in mid-October?

The median for mid-October is 35.89 ft. In 8 years out of 10 the reading falls between 35.70 ft and 40.48 ft, based on 7 years of records.

What is the water level of Upper Helemano Reservoir near Wahiawa, Oahu today?

On Oct 20, 2026, 10:10 AM HST, the water level was 42.79 ft. Down 0.16 ft over the last 24 hours.

Is Upper Helemano Reservoir near Wahiawa, Oahu rising or falling?

Down 0.16 ft over the last 24 hours. Down 0.77 ft over the last 7 days.

Is the level of Upper Helemano Reservoir near Wahiawa, Oahu normal?

Very high for mid-October. Compared with 7 years of daily readings for this time of year.

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.

Where does this data come from?

The values come directly from the U.S. Geological Survey, the official operator of this gauge, and are in the public domain. We do not estimate or model live values.

For specialists

Station codes, datum, parameters, data quality and downloads

Operator: U.S. Geological Survey
Station code: usgs:213133158014201 (Agency page)
Coordinates: 21.52591, -158.02842 (WGS84)
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	42.79 ft	2026-10-20 20:10	Provisional

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How to cite

U.S. Geological Survey: Upper Helemano Reservoir near Wahiawa, Oahu (usgs:213133158014201). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/united-states/hawaii/upper-helemano-reservoir-near-wahiawa-oahu

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