FLUCTUATIONS IN GROUNDWATER LEVELS OF THE NORTHERN POMONA BASIN FROM 1900-1985: IMPLICATIONS FOR FUTURE WATER CONSUMPTION

Groundwater is a tightly regulated commodity because it is a necessary and limited resource. This study focuses on changes in groundwater levels of the northern part of the Pomona Basin, located south of California's San Gabriel Mountains, encompassing parts of the cities of La Verne, Claremont, and Pomona.

The purpose of this research is to determine the extent to which urban development and municipal and agricultural water use have impacted groundwater levels and flow within the basin. Fluctuations in groundwater levels will be evaluated using a linear regression of these data. Groundwater flow paths will be examined through maps of equipotential surfaces, generated from historic well levels. Additionally, stratigraphy and the location and characteristics of aquifers are being investigated through cores documented in well logs from the California Department of Water Resources. The project will also examine how the importation of water into the basin influenced the groundwater system.

Identifying key factors contributing to changes in groundwater levels over this 85-year period will help to target the sources that could potentially exhaust groundwater reserves today. Thus, water consumption can be more efficiently monitored in the context of current patterns of municipal and agricultural water consumption and land development.