Groundwater replenishment happens through direct recharge and in-lieu recharge. Water used for direct recharge most often comes from flood flows, water conservation, recycled water, desalination and water transfers.

California’s “Mediterranean” climate, characterized by warm, dry summers and mild winters, is considered one of its great attractions, but it also can be unpredictable with flooding followed by drought and few years of “normal” precipitation.  [See also Hydrologic Cycle].

Wastewater management in California centers on the collection, conveyance, treatment, reuse and disposal of wastewater. This process is conducted largely by public agencies, though there are also private systems in places where a publicly owned treatment plant is not feasible.

In California, wastewater treatment takes place through 100,000 miles of sanitary sewer lines and at more than 900 wastewater treatment plants that manage the roughly 4 billion gallons of wastewater generated in the state each day.

Liability for levee failure in California took a new turn after a court ruling found the state liable for hundreds of millions of dollars from the 1986 Linda Levee collapse in Yuba County. The levee failure killed two people and destroyed or damaged about 3,000 homes.

The collapse also had long-term legal ramifications.

The Paterno Decision

California’s Supreme Court found that, “when a public entity operates a flood management system built by someone else, it accepts liability as if it had planned and built the system itself.”

The federal Safe Drinking Water Act sets standards for drinking water quality in the United States.

Launched in 1974 and administered by the U.S. Environmental Protection Agency, the Safe Drinking Water Act oversees states, communities, and water suppliers who implement the drinking water standards at the local level.

The act’s regulations apply to every public water system in the United States but do not include private wells serving less than 25 people.

According to the EPA, there are more than 160,000 public water systems in the United States.

Overdraft occurs when, over a period of years, more water is pumped from a groundwater basin than is replaced from all sources – such as rainfall, irrigation water, streams fed by mountain runoff and intentional recharge. [See also Hydrologic Cycle.]

While many of its individual aquifers are not overdrafted, California as a whole uses more groundwater than is replaced.

The treatment of groundwater— the primary source of drinking water and irrigation water in many parts of the United States — varies from community to community, and even from well to well within a city depending on what contaminants the water contains.

In California, one-half of the state’s population drinks water drawn from underground sources [the remainder is provided by surface water].

California has considered, but not implemented, a comprehensive groundwater strategy many times over the last century.

One hundred years ago, the California Conservation Commission considered adding  groundwater regulation into the Water Commission Act of 1913.  After hearings were held, it was decided to leave groundwater rights out of the Water Code.

Groundwater banking is a process of diverting floodwaters or other surface water into an aquifer where it can be stored until it is needed later. In a twist of fate, the space made available by emptying some aquifers opened the door for the banking activities used so extensively today.

Recurrent droughts and uncertainties about future water supplies have led several California communities to look to treat salty water for supplemental supplies through a process known as desalination.

Desalination removes salt and other dissolved minerals from water and is one method to reclaim water for other uses. This can occur with ocean water along the coast and in the interior at spots that draw from ancient salt water deep under the surface or where groundwater has been tainted by too much salt.

The Central Valley Project Improvement Act supports a major federal effort to store and transport water in California’s Central Valley.

The 1992 Act changed operations of Central Valley Project; a major project that addresses flooding, storage and irrigation issues in the valley [see also Central Valley Project].

California’s Legislature passed the Wild and Scenic Rivers Act in 1972, following the passage of the federal Wild and Scenic Rivers Act by Congress in 1968. Under California law, “[c]ertain rivers which possess extraordinary scenic, recreational, fishery, or wildlife values shall be preserved in their free-flowing state, together with their immediate environments, for the benefit and enjoyment of the people of the state.”

Rivers are classified as:

More than 100 years ago, California’s Gold Rush left a toxic legacy that continues to cause problems in Northern California watersheds.

The discovery of gold in John Sutter’s millrace at Coloma in the 1840s drew people from around the globe.

Over the course of decades, intense efforts were focused on washing and prying gold from the hills of the Sierra Nevada.

California was the first state in the nation to protect fish, flora and fauna with the enactment of the California Endangered Species Act in 1970. (Congress followed suit in 1973 by passing the federal Endangered Species Act. See also the Convention on International Trade in Endangered Species of Wild Fauna and Flora, or CITES.)

The legal term “area-of-origin” dates back to 1931 in California.

At that time, concerns over water transfers prompted enactment of four “area-of-origin” statutes. With water transfers from Yosemite’s Hetch Hetchy Valley to supply water for San Francisco and from Owens Valley to Los Angeles fresh in mind, the California statutes were intended to protect local areas against export of water.

In particular, counties in Northern California had concerns about the state tapping their water to develop California’s supply.

Agriculture drainage issues date back to the earliest farming. In ancient times, farmers let fields stay fallow hoping rain would flush out salt.

Today, salt and other contaminants continue to cause agricultural drainage problems, particularly in California. Whether a field is adequately drained, or saturated with water, the water still has to be removed.

The disposal of this often-contaminated water continues to be a challenge in California, with the environmental effects of selenium and other drainage-related elements changing the course of drainage planning.