Nibi Metrics
Real-time water levels, forecasts, and alerts for lakes and rivers across Canada and the US. Built on official government data.
Nibi Metrics turns raw gauge readings from official hydrometric networks into something a person standing on a dock can actually use: is the water high or low for today, which way is it moving, and how unusual is this? This page explains where every number on the platform comes from and what we do to it along the way.
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Koolau Reservoir near Wahiawa, Oahu Water Level
Live lake level, flow, historical records and forecast for Koolau Reservoir near Wahiawa, Oahu in HI, United States, built from official government gauge data.
- Location HI, United States
- Watershed oahu
- Primary gauge 16206600 (USGS)
About Koolau Reservoir near Wahiawa, Oahu
Koolau Reservoir - A vital water source on Oahu.
Nestled within the Oahu watershed, Koolau Reservoir near Wahiawa is a significant body of water on the island of Oahu, Hawaii. Known for its responsiveness to rainfall-driven inflows, this reservoir plays an essential role in managing water resources in an area that experiences rapid hydrological changes.
The watershed context
Koolau Reservoir is situated in an area characterized by its tropical island hydrology. Rainfall has the power to dramatically elevate water levels in a short time, making the management of this reservoir crucial. The nearby Heeia Stream and other small water bodies serve as peers to this reservoir, underscoring the interconnected nature of water flow across Oahu. Rather than a seasonal snowmelt, Oahu's water level fluctuations depend heavily on local rainfall patterns and trade-wind storms, which can lead to flash floods, particularly in the steeper basins found throughout the region.
The absence of record-high snowmelt seasons sets the stage for a unique hydrological environment where rainfall is the primary driver for inflow and outflow. This system can result in swift water level changes, posing both opportunities and challenges for local ecosystems and water management strategies.
Why the data matters here
The monitoring station at Koolau Reservoir, operated by the U.S. Geological Survey (USGS), provides crucial data on water levels in the reservoir. Today's reading reflects current conditions in relation to historical trends, comparing today's elevation against the median for this calendar day across the station's historical record of over four years. This comparison is vital, as it gives context beyond raw elevation and helps assess the reservoir's response amid the island's dynamic rainfall patterns.
How this page is built
Readings come from official government gauges and are rolled into daily records: the daily mean, high and low for every day on record. Each calendar day gets its own baseline from the full history, so the level you see is compared against what this specific date usually looks like rather than an annual average.
How Nibi Metrics works · Water stories
