The Orange County Water District was created in 1933 and its primary responsibility is managing the vast groundwater basin under northern and central Orange County that supplies water to more than 20 cities and water agencies, serving more than 2.3 million Orange County residents.

With one of the most sophisticated groundwater protection programs in the country, OCWD uses more than 700 wells providing more than 1,400 sampling points—from which OCWD takes more than 18,000 water samples and conducts more than 350,000 analyses every year

One of the primary challenges of pumping so much fresh water out of the ground is making sure that it is not replaced by salt water from the Pacific Ocean as water supplies draw down. When salt water overtakes freshwater, this is known as salt water intrusion and it’s been a primary issue for the district for the last decade. Once salt water overtakes fresh water it is nearly impossible to ever fully regain fresh water dominance in the basin. The district uses a series of measures to make sure this doesn’t happen, including a combination of In-Situ, Inc.’s LevelTROLL pressure transducers and AquaTROLL level/conductivity sensors.

Currently, the OCWD has over 100 of these devices set up strategically in their groundwater basins to collect important level information in the basin and conductivity readings (conductivity can also detect how much saltwater is in a specific location) along the coastline next to huge pumps that are constantly turning off and on to keep the seawater out.

The staff at OCWD uses the information supplied by the LevelTROLL’s and AquaTROLL’s to determine how stable the groundwater basin is and whether or not any saltwater is creeping in to their freshwater supply.

With the valuable information supplied by these data collection devices, the district can make the proper recommendations to their staff and make sure that millions of people in Orange County will continue to have a steady supply of fresh water without the worry of sea water mixing with its most important resource.

OCWD Website