Monday, November 30, 2009

Ojai Groundwater Studies

A recent article in the Ojai Valley News describes a study of the Ojai groundwater basin that recently gained funding from the State Dept of Water Resources (DWR.) The $219,000 grant administered by the Ojai Basin Groundwater Management Agency (OBGMA) will help advance the understanding of how the Ojai groundwater basin works. The study will help plan for water management, especially under the drought conditions that create conflict in the valley.

The project consultant gave an overview of the evolving understanding of the groundwater basin at the October meeting of the Ventura River Watershed Council. These graphics are courtesy of Jordan Kear.

The Ojai valley relies upon groundwater for much of its water supply. Under natural conditions, rainfall soaks into the ground filling in spaces within the soil and rock. This groundwater reserve is called an aquifer. Over 200 wells extract water for agriculture, residential, and other uses such as the two golf courses in the valley.

The modeling effort is aimed at providing a better understanding of how the basin recharges during the short rainy season, and how the many wells interact. With better understanding, it is hoped that well operators may cooperate to enhance the overall basin yield. (When wells run dry, users have to purchase water from Casitas Water District, which provides a backup supply of 254,000 acre-feet in Lake Casitas.)

Since aquifers are often connected to surface water, wells can also reduce flows in nearby rivers and streams, which downstream uses rely upon. So groundwater management is also a critical piece of overall ecosystem-based management for the watershed.