Water Management

Proper management of the District's water is critical to ensuring a stable and reliable supply for irrigation customers, especially in dry years. The District works cooperatively with other local agencies to promote long-term sustainability of this precious resource. Proper planning as well as efficient use of water benefits both the local urban and agricultural communities.

Groundwater Management

Groundwater within the District is supplied by the Turlock Groundwater Basin, which is a subunit of the larger San Joaquin Valley Groundwater Basin. The District utilizes a combination of surface water and groundwater to supply irrigation water to its growers. In dry years, groundwater pumping helps meet irrigation demand that cannot be supplied by surface water. In normal and wetter years, surface water makes up the bulk of the supply with groundwater being drawn upon to a lesser extent. This practice of utilizing surface and ground water to meet local requirements is known as conjunctive use.

The District's conjunctive use strategy is vital to maintaining a stable water supply. Deep percolation of surface water past the root zone is the primary method of groundwater recharge in the Turlock Groundwater Basin. This water is stored and then becomes part of the District's water supply in dry years. Groundwater is also the source of municipal water for Turlock, Ceres, South Modesto, Hilmar, Hickman, Hughson, Denair, Delhi, Keyes, Ballico, and rural residences in the Turlock Groundwater Basin. Agricultural areas extending from the eastern boundary of TID to the Sierra Nevada foothills also rely exclusively upon groundwater for irrigation water.

The District's use of groundwater also plays an important role in water conservation. TID-owned and -rented pumps (distributed throughout the District) not only provide an additional source of water, they are used to help control flow fluctuations in the canal system. This helps the Water Distribution Operators conserve water by reducing spills at the end of the canal system.

Groundwater Leadership

TID has long been a leader in the management of local groundwater resources. The District first developed a groundwater model to predict the behavior of the underground aquifer under a variety of conditions over twenty-five years ago. Since that time, TID has continued to update and improve its model. The model has proved to be a useful tool for evaluating the potential future impacts of land use changes, the sustainability of groundwater supplies, and drought planning efforts.

The District has also taken an active role in local groundwater management and planning. The District has a long-standing program of groundwater level monitoring throughout its boundaries, and cooperates with other state and local entities to monitor the larger basin area. TID was the first local entity to adopt a Groundwater Management Plan in 1993, and is a member of the Turlock Groundwater Basin Association (TGBA), which has collaborated on groundwater issues since 1995. The TGBA developed basin-wide Groundwater Management Plans in 1997 and January 2008. The TID Board of Directors adopted the latest Groundwater Management Plan, on March 18, 2008.

Agricultural Water Management Plan

The District became a member of the Agricultural Water Management Council (AWMC) in April 1997. The AWMC is a non-profit organization consisting of water suppliers, public agencies, and members of the farming, academic, and environmental communities, dedicated to improving agricultural water efficiency through a voluntary planning process. The AWMC has established guidelines for evaluating and improving efficiency through the implementation of water management plans.

As an agricultural water supplier member of the AWMC, TID is committed to developing and implementing an Agricultural Water Management Plan. TID was one of the first agricultural water suppliers to complete an Agricultural Water Management Plan. The Plan was first submitted to the AWMC in 1999, and was officially endorsed by the council in May 2001 after a rigorous review and evaluation. Our Plan includes a description of the district, its current operational practices, and the analyses for implementing 17 "Efficient Water Management Practices."

In developing the Plan, the District has devoted considerable effort to analyzing water management in the District and to developing a program aimed at sustaining sound water management practices where they are already in place, while improving practices that can be strengthened. The District is currently updating its Agricultural Water Management Plan, and will provide copies of the draft for public review and comment when completed.

California Irrigation Management Information System

The California Irrigation Management Information System (CIMIS) is designed to help growers develop efficient water budgets and irrigation strategies. CIMIS is a standardized way of accounting for water consumed through evapotranspiration (ET) by the soil and plants. The main purpose of CIMIS is to provide information for irrigation scheduling by matching the amount of water applied to a crop with needs of the plant.

The CIMIS stations in this area are:

For more information about how to use CIMIS, visit the Department of Water Resources CIMIS website.

For more information about these programs, please contact Keith Larson at (209) 883-8386.