	Introduction

The Sacramento-San Joaquin River Delta (the Delta) is formed by the confluence of the north-flowing San Joaquin River, the south-flowing Sacramento River, and the San Francisco Bay, to which the delta of the two rivers is linked. The 1,153-square-mile estuary is the hub of California's extensive water supply system. The Delta provides water to more than 25 million people and habitat for various species, including the threatened delta smelt and endangered chinook salmon. As such, the Delta has endured decades of competing water demands. During this time, the Delta ecosystem has experienced environmental degradation, increasing regional water demands, and a decrease in reliable water supplies for urban, agricultural, and natural areas. Numerous categories of stakeholders have an interest in water flowing through the Delta, including agricultural, urban, industrial, environmental, and recreational interests. Fish and Wildlife Service completed consultations and issued a new biological opinion in late 2008. This decision required federal and state entities to reduce pumping water in two large water projects and therefore has had significant effects on the water supply of California. California follows a dual system of water rights, recognizing both the riparian and prior appropriation doctrines. Modification of Water Rights and the No Injury Rule

Water rights may be modified under certain circumstances. The Water Projects and Water Rights

Two major water projects transfer water throughout the state. Litigation of Water Rights and Management in the Delta

Over the decades since the construction of the water projects, there has been extensive litigation regarding water rights, Delta water management, and the regulation of permits and standards for water in the Delta. The court noted that the Board must not disregard the effects of other users and instead must look at the impacts to the system comprehensively, including "past, present, and probable future beneficial uses of water as well as water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area." In other cases, courts have addressed reductions due to environmental conditions. In 2007, the federal district court for the Eastern District of California addressed the issue of threatened species in the Delta by issuing an interim order that required specified water flows for management of the Delta's resources to protect the delta smelt. In May 2008, a House Natural Resources Committee subcommittee held a hearing on the management of salmon fisheries in the Delta. The groups claim that the diversions have violated of the public trust doctrine, the rule of reasonable use, and water quality requirements.
The Sacramento-San Joaquin River Delta (the Delta) is formed by the confluence of the north-flowing San Joaquin River, the south-flowing Sacramento River, and the San Francisco Bay, to which the delta of the two rivers is linked. The 1,153-square-mile estuary is the hub of California's extensive water supply system. The Delta provides water to more than 25 million people and habitat for various species, including the threatened delta smelt and endangered chinook salmon. As such, the Delta has endured decades of competing water demands. During this time, the Delta ecosystem has experienced environmental degradation, increasing regional water demands, and a decrease in reliable water supplies for urban, agricultural, and natural areas.
The numerous stakeholders associated with the Delta include agricultural, urban, industrial, environmental, and recreational interests. In order to provide water to the various users, two major water projects were created: the federal Central Valley Project and the State Water Project. Concerns have been raised about the effectiveness of the regulation of these projects and the Delta waters generally, both to meet the needs of water users and to avoid environmental impacts to water quality and species. Specifically, in late 2007, a federal judge ordered a reduction in the amount of water pumped out of the Delta in order to preserve the habitat of endangered fish in the Delta, meaning less water would be available for areas that depend on the water projects for their water supply. In 2008, those restrictions were continued under a newly issued biological opinion, and another judicial decision was issued that indicates similar restrictions may be required for other species. Furthermore, Governor Schwarzenegger declared a state of drought for the entire State of California in June 2008 and declared a state of emergency in California due to drought in February 2009. These events pose significant impacts on California's water supply. As a matter of overseeing the impacts of water flow and water management in the Delta, the House Natural Resources Committee held a subcommittee hearing on the effect conditions in the Delta have on the endangered species there in 2008.
This report provides a summary of California's dual system of water rights, which includes riparian and prior appropriation doctrines, and regulation of those rights by the state. In particular, the report discusses considerations used in the process of regulating water usage, including the public trust doctrine, the rule of beneficial use, and the no injury rule. The report discusses the California water projects, the projects' rights, and access to water by other users. Significant court decisions and relevant statutes that affect the Delta are explained as well.