Groundwater Legislation Update
In September, Governor Jerry Brown signed The Sustainable Groundwater Management Act of 2014 (SGMA). The SGMA is a comprehensive three bill package that includes AB 1739 (Dickinson), SB 1168 (Pavely) and SB 1319 (Pavely). From MID’s perspective, the SGMA sets the framework for statewide sustainable groundwater management by local agencies. The SGMA requires, among other items, the formation of Groundwater Sustainability Agencies (GSA) and the preparation of Groundwater Sustainability Plans (GSP) with a focus on long-term sustainability in the sub-basin.
As you know, MID has been actively engaged in sustainable groundwater management within our irrigation service area for more than 20 years. We will continue to represent your best interests through a multitude of local groundwater organizations and we are optimistic that through State law and the continued cooperation of local water purveyors we will bring careful, deliberate and coordinated action to continued groundwater sustainability moving forward. If you have any questions or concerns related to this issue, please contact John Davids, MID's Irrigation Operations Manager, at (209) 526-7564.
Groundwater in the Modesto Irrigation District
Water that is found beneath the surface of the Earth in saturated rock formations is called groundwater. It is a very important and valuable water supply for much of the world and particularly in the Central Valley of California. Groundwater is poorly understood yet represents a very significant component of our overall water supply. In fact, many of the cities in the Central Valley rely 100% on groundwater for their drinking water supply, as did the City of Modesto for most of its history.
According to information contained in California Department of Water Resources Bulletin 118, the estimated amount of groundwater stored within the Modesto Subbasin, in just 100 feet of saturated thickness, is 5 million acre feet or 2.5 times greater than the maximum storage capacity of Don Pedro Reservoir. The Modesto Subbasin is defined as that area of land lying between the Stanislaus River on the north, the Tuolumne River on the south, the Sierra Nevada Mountain foothills on the east and the San Joaquin River on the west. The MID water service boundary is entirely located within the Modesto Subbasin. The primary source of recharge (60%) in the basin occurs through agricultural irrigation using surface water supplied by the MID. Other sources of recharge in the basin occur via rainfall and seepage from surface water bodies such as Modesto Reservoir. Some reaches of the Tuolumne River are supplemented with groundwater inflows.
MID Operations – Conjunctive Use
Modesto Regional Water Treatment Plant
Integrated Regional Groundwater Management Plan
The U.S. Geological Survey (USGS) is conducting a thorough, multi-phased study of the Modesto Groundwater Sub-Basin. The first phase of this study resulted in a document titled “Hydrogeologic Characterization of the Modesto Area, San Joaquin Valley, California.” One of the key findings of this report is that the primary means of recharge in the Modesto Subbasin is via the application of surface water for agricultural irrigation purposes. Ultimately the USGS evaluation will:
Wellfield Optimization Project
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