Sacramento Central Groundwater Authority, GEI Consultants Inc. | April 1, 2018...
Summary
The Sacramento Central Groundwater Authority (SCGA) has prepared an Annual Report describing groundwater conditions in the South American Subbasin for the 2017 Water...
The Sacramento Central Groundwater Authority (SCGA) has prepared an Annual Report describing groundwater conditions in the South American Subbasin for the 2017 Water Year (i.e., inclusive of months October 2016 to September 2017) in support of their pending Alternative Submittal. The Annual Report is intended for conveying monitoring and water use data to the State DWR on an annual basis to gauge performance of the groundwater subbasin relative to the sustainability goal set forth in a Groundwater Sustainability Plan (GSP) or, for SCGA, the Alternative Submittal. As such, SCGA is including sufficient information to provide interested parties with sufficient background and supporting details to serve as a public communications document for subbasin management and to take the place of historic biennial reporting available on the SCGA website.
The Sustainable Groundwater Management Act (SGMA) requires groundwater sustainability agencies (GSAs) to develop groundwater sustainability plans (GSPs) that achieve sustainable groundwater management within...
The Sustainable Groundwater Management Act (SGMA) requires groundwater sustainability agencies (GSAs) to develop groundwater sustainability plans (GSPs) that achieve sustainable groundwater management within 20 years of adoption. All critically overdrafted basins must adopt GSPs by January 31, 2020; all other medium and high priority basins must complete GSPs by January 31, 2022. Since many subbasins are hydrologically connected to adjoining subbasins, sustainable groundwater management will require accounting for groundwater interactions with adjoining subbasins. Often, adjoining subbasins will use different analytical methods or apply different levels of technical rigor. Many GSAs are concerned that different methodologies for developing interbasin flows can lead to different results that will call into question the ability to achieve sustainability and would potentially create issues with SGMA compliance.
This effort evaluated opportunities and barriers for agencies to account for interconnected basin dynamics through the collaboration of technical experts focused on a portion of the northern Sacramento Valley Integrated Regional Water Management (NSVIRWM) Plan area. As interbasin flows (i.e., groundwater flow between interconnected basins) cannot be directly measured, the project reviewed available tools to investigate how they may or may not be suitable for use in estimating interbasin flows within the region. This process highlighted areas for local agencies to consider in addressing interbasin issues, developed a framework for analysis in other areas of the state, and identified areas where the state and federal government can assist local agencies implementing SGMA. This report is developed to provide summary level information appropriate for decision makers, with more detailed technical information and examples provided in the appendices or by reference.
Interbasin flow is groundwater entering or exiting a defined subbasin through its boundaries in the subsurface and may vary significantly in space and time based on the dynamics of inflow and outflow from the basins. Interbasin flows are driven by differences in groundwater levels (i.e. head gradients) across the basin boundary. Groundwater levels are, in turn, impacted by processes on the land surface. Land use and crop acreages drive water demand in a subbasin and indirectly drive groundwater pumping, which has a direct effect on groundwater levels (i.e., groundwater heads). The direction and magnitude of interbasin flow depends on the groundwater head gradient across the basin boundary and the conductivity of the aquifer materials.
It is widely recognized that the groundwater subbasins in the Sacramento Valley, and throughout the Central Valley, are interconnected to varying degrees. The Sacramento Valley Groundwater Basin includes many subbasins, extends over a wide geographic area, and includes numerous established and eligible GSAs. With interconnected subbasins, management decisions and actions in one subbasin may influence one or more adjoining subbasins. Such influence may positively or negatively impact sustainability. Thus, interbasin flows become critical to both GSAs’ development of GSPs and to DWR reviewing GSPs.
Groundwater Resources Association of California | October 3, 2017...
Summary
In basins with complex spatial and temporal variations in water budget components, integrated groundwater-surface water modeling is the best approach to quantify and...
In basins with complex spatial and temporal variations in water budget components, integrated groundwater-surface water modeling is the best approach to quantify and evaluate interbasin groundwater flows.
California Department of Water Resources (DWR) | October 16, 2015...
Summary
In September 2014, the Governor signed into law the Sustainable Groundwater Management Act (SGMA). The Department has developed a program and is currently...
In September 2014, the Governor signed into law the Sustainable Groundwater Management Act (SGMA). The Department has developed a program and is currently implementing new and expanded responsibilities identified in SGMA. One of these responsibilities is developing emergency regulations to modify groundwater basin boundaries. SGMA established a process for local agencies to request that DWR revise the boundaries of a groundwater basin or subbasin, including the creation of new subbasins.
California’s Sustainable Groundwater Management Act (SGMA) establishes milestones that high- and medium-priority basins in a critical state of overdraft must meet to become...
California’s Sustainable Groundwater Management Act (SGMA) establishes milestones that high- and medium-priority basins in a critical state of overdraft must meet to become sustainable. BasinScout can assist managers in building an objective allocation plan that reflects the needs of various stakeholders in shaping how sustainability is achieved.
California Department of Water Resources (DWR) | October 7, 2015...
Summary
These regulations specify the information a local agency is required to provide when requesting that the Department revise the boundaries of a basin...
These regulations specify the information a local agency is required to provide when requesting that the Department revise the boundaries of a basin or subbasin, including the establishment of new subbasins, and the methodology and criteria used by the Department to evaluate a modification to existing basin or subbasin boundaries.
California Department of Water Resources | May 17, 2016...
Summary
ARTICLE 1. Introductory Provisions § 350. Authority and Purpose These regulations specify the components of groundwater sustainability plans, alternatives to groundwater sustainability plans,...
ARTICLE 1. Introductory Provisions
§ 350. Authority and Purpose
These regulations specify the components of groundwater sustainability plans, alternatives to groundwater sustainability plans, and coordination agreements prepared pursuant to the Sustainable Groundwater Management Act (Part 2.74 of Division 6 of the Water Code, beginning with Section 10720), and the methods and criteria used by the Department to evaluate those plans, alternatives, and coordination agreements, and information required by the Department to facilitate that evaluation.
Note: Authority cited: Section 10733.2, Water Code. Reference: Sections 10733.2 and 10733.4, Water Code.
The California Groundwater Units dataset classifies and delineates areas within the State of California into one of three groundwater-based polygon units: (1) those...
The California Groundwater Units dataset classifies and delineates areas within the State of California into one of three groundwater-based polygon units: (1) those areas previously defined as alluvial groundwater basins or subbasins, (2) highland areas that are adjacent to and topographically upgradient of groundwater basins, and (3) highland areas not associated with a groundwater basin, only a hydrogeologic province.
In total, 938 Groundwater Units are represented. The Groundwater Units dataset relates existing groundwater basins with their newly delineated highland areas which can be used in subsequent hydrologic studies. The methods used to delineate groundwater-basin-associated highland areas are similar to those used to delineate a contributing area (such as for a lake or water body); the difference is that highland areas are constrained to the immediately surrounding upslope (upstream) area. Upslope basins have their own delineated highland.
A geoprocessing tool was created to facilitate delineation of highland areas for groundwater basins and subbasins and is available for download.
California Irrigation Institute | January 30, 2017...
Summary
I have been asked to discuss my thoughts on the effect of SGMA upon the dairy industry. As the General Manager of Stevinson...
I have been asked to discuss my thoughts on the effect of SGMA upon the dairy industry. As the General Manager of Stevinson Water District in Merced County, and from a six-generation California dairy farming family, I have been quite involved in both in dairy farming, the production of milk and the rapidly changing agricultural water business. Most recently, I have been involved in the development of Groundwater Sustainable Agency in the Merced Basin. My comments are based both from my experiences and from information gathered from CDFA agricultural statistics, House of Representative Devin Nunes presentation to his constituencies in September 2016, and from conversations with civil water engineers in the south San Joaquin Valley.
Ventura County, located in California’s south coast, is one of United States’ most productive agricultural counties (ranked 10th in California and 11th in the...
Ventura County, located in California’s south coast, is one of United States’ most productive agricultural counties (ranked 10th in California and 11th in the US)1, with agricultural production valued at $2.1B in 2016.2 California’s landmark groundwater law, the Sustainable Groundwater Management Act (SGMA), requires that 127 groundwater basins, including those in Ventura County, develop Groundwater Sustainability Plans that ensure pumping within sustainable limits. In western Ventura County, where over 70 percent of groundwater use is agricultural, the California Department of Water Resources has designated two groundwater basins as being in critical overdraft under SGMA.
The local management agency may have to reduce groundwater use in these basins by as much as 40 percent to achieve a sustainable yield. While these reductions are critical to achieving long-term sustainability of water use, which includes nature’s needs, they also pose significant challenges to wisely managing reduced water allocations to keep irrigated agricultural land in production. The Nature Conservancy (TNC) has a vested interest in preserving farming in the county because it buffers important river and wetland habitat from nearby urban lands.
Growers in the region quickly identified water markets as an important tool for managing limited groundwater resources.
