Monitoring Data

The Commission on Water Resource Management’s Survey Branch is responsible for collecting basic hydrologic data and conducting water availability and sustainable yield analyses statewide. The information presented below highlights some of the Commission’s monitoring activities essential to the protection of Hawaii’s water resources.  The U.S. Geological Survey also collects water level and deep monitor well data through cooperative agreements with CWRM and other government agencies. The Honolulu Board of Water Supply also has a network of water level and deep monitor wells on Oahu.

Deep Monitor Well Data

Kunia Middle Deep Monitor WellA deep monitor well penetrates the freshwater basal aquifer into the underlying brackish and salt water. It is used to estimate the thickness of the freshwater part of the aquifer (freshwater lens) and the freshwater-saltwater transition zone. For convenience, the vertical profile is divided into three parts: the upper fresh water zone (less than 2% sea water), the transition zone (2% to 50% sea water), and into the saline zone (greater than 50% sea water). The data are presented as graphs of the changes in elevation (feet, mean sea level) of the top of the transition zone (2% seawater) and the midpoint of the transition zone (50% seawater) over time.

Cross Section of a Typical Island Aquifer

Click to view the documents below to learn more about deep monitor wells.

Deep Monitor Well Conductivity / Water Level Data

The Commission on Water Resource Management owns a number of deep monitor wells on the islands of Oahu, Maui, and Hawaii. CWRM staff collects conductivity and water level data for each of these deep monitor wells (DMW). Click on the desired well on the maps below to view a time series of the conductivity and water level data collected at the well. Data for certain Oahu DMWs have been combined into a single graph. Efforts are being made to update the remaining Oahu, Maui, and Hawaii DMWs.


Kunia Mauka
Kunia Middle
Waipio Mauka




Ouli 1
Ouli Kawamata
USGS Waiaka Tank

DWS Pahoehoe
Kahaluu DMW
– Kainaliu
Keauhou A
– Keopu DMW
USGS Kealakekua