Tag: groundwater dependent ecosystems

Groundwater Resource Hub

February 2, 2023 No Comments

The purpose of the Groundwater Resource Hub is to help local agencies achieve sustainable groundwater management by providing the science and tools needed to help address nature’s water needs. Over time, the goal is to improve statewide and local understanding of nature’s groundwater needs to reduce uncertainties and therefore enhance sustainable groundwater management.

Groundwater dependent ecosystems (GDEs) are plant and animal communities that require groundwater to meet some or all of their water needs. California is home to a diverse range of GDEs including palm oases in the Sonoran Desert, hot springs in the Mojave Desert, seasonal wetlands in the Central Valley, perennial riparian forests along the Sacramento and San Joaquin rivers, and estuaries along the coast and in the Delta. These ecosystems rely on groundwater in California’s semi-arid climate, especially during dry summers and periods of drought. GDEs provide important benefits to California including habitat for animals, water supply, water purification, flood mitigation, erosion control, recreational opportunities and general enjoyment of California’s natural landscape.

Groundwater Dependent Ecosystems under the Sustainable Groundwater Management Act

February 2, 2023 No Comments

This guidance provides a systematic and defensible approach to identify GDEs, determine whether potential effects on GDEs are occurring or may occur due to groundwater conditions, and consider GDEs when setting sustainable management criteria. This guidance recommends setting sustainable management criteria based on the conditions necessary to avoid adverse impacts to GDEs and undesirable results in the basin, especially where conservation of species and habitats within GDEs is required by other laws, such as the Endangered Species Act.

This document is designed to inform local decision making, consistent with SGMA’s emphasis on local control. Rather than prescribing approaches or outcomes, this guidance provides a flexible process meant to enable GSAs and stakeholders to make decisions based on the best available science in a manner that promotes transparency and accountability.

Groundwater and Stream Interaction in California’s Central Valley: Insights for Sustainable Groundwater Management

February 2, 2023 No Comments

This report was undertaken to provide technical information on the state of streams and groundwater resources in the Central Valley. The findings of this report were used to support the need for what is now known as the Sustainable Groundwater Management Act (SGMA). The intent was to illustrate the physical inter-relationship between the surface and groundwater resources and the potential impacts that groundwater pumping has had and is currently having on our rivers and streams to demonstrate the need for sustainable groundwater management.

Based on the scale of the data used in this study, the findings contained herein should not be used as a definitive source in determining whether a particular stream or river reach should or should not be considered as an interconnected surface water for SGMA purposes. Further study at a finer scale would be necessary for such a determination.

ICONS: Interconnected Surface Water in California’s Central Valley

February 2, 2023 No Comments

Sustainable groundwater management in California requires an understanding of how groundwater pumping affects surface water features. Groundwater seeps into many river and lake beds in California, providing a steady source of cool clean water. This source of water is crucial for people and nature because it remains steady throughout the year even after the winter rains stop. Under the Sustainable Groundwater Management Act (SGMA),
interconnected surface water (ISW) is defined as “surface water that is hydraulically connected at any point by a continuous saturated zone to the underlying aquifer and the overlying surface water is not completely depleted” (Groundwater Sustainability Plan Emergency Regulations).

SGMA requires special treatment of ISW, but in many parts of the state, ISW is poorly understood. This dataset categories rivers and stream segments on the likelihood that they are ISW, using groundwater depth as a proxy to determine ISW. This data is available to view in an interactive online map at: http://icons.codefornature.org/.