Handbook for Developing Watershed Plans to Restore and Protect Our Waters

U.S. Environmental Protection Agency (EPA) | March 20th, 2008

This handbook provides information on developing and implementing watershed management plans that help to restore and protect water quality. A watershed is the area of la

This handbook provides information on developing and implementing watershed management plans that help to restore and protect water quality. A watershed is the area of land that contributes runoff to a lake, river, stream, wetland, estuary, or bay. A watershed management plan defines and addresses existing or future water quality problems from both point sources and nonpoint sources of pollutants. Experience over the past decade has shown that effective watershed management includes active participation from stakeholders, analysis and quantification of the specific causes and sources of water quality problems, identification of measurable water quality goals, and implementation of specific actions needed to  solve those problems. This handbook is intended to serve as the basis for developing and implementing watershed plans to meet water quality standards and protect water resources. Although watershed plans are useful for all watersheds to protect and restore water resources, as well as to meet other community resource goals, they are critical for impaired or threatened waterbodies. The most recent national water quality assessment reported that 40 to 50 percent of the nation’s assessed waterbodies are impaired or threatened. 3/20This handbook is designed to provide a framework to help you develop a scientifically defensible plan that will lead to measurable results and an overall improvement in the water quality and watershed conditions that are important to your community.

Harnessing California's Waters: The Completion of the First Stage of the Pit River Power Project

Scientific American | April 1st, 1923

California is now the greatest hydro-electric power State in the Union. Over one-fifth of all the electric power generated by American water is produced in Californi

California is now the greatest hydro-electric power State in the Union. Over one-fifth of all the electric power generated by American water is produced in California. Last year, according to figures announced by Engineer H. D. McGlashan of the water resources branch of the United States Geological Survey, 3,227,262,000 kilowatt-hours were produced by water power in California. New York, which comes next with 14.72 per cent of the total. made 2,203,564,000 kilowatthours. On Saturday, September 30, 1922, an important step in California's electrification was carried out. On this date the constantly flowing waters of the Fall River were diverted through a tunnel and dropped 454 feet through steel penstocks to the Pit River Power Plant No. 1 .

Harnessing the Power of Geophysical Imaging to Recharge California's Groundwater

American Geophysical Union (AGU) | April 17th, 2025

Motivated by the availability of 20,000 line-km of airborne electromagnetic (AEM) data covering the Central Valley of California, we developed a workflow that uses resist

Motivated by the availability of 20,000 line-km of airborne electromagnetic (AEM) data covering the Central Valley of California, we developed a workflow that uses resistivity profiles from electromagnetic (EM) data to assess the suitability of areas for groundwater recharge. We defined a suitable area as one where “fastpaths” of coarse-grained material could efficiently move water from the ground surface to the water table. We defined recharge metrics and generated the corresponding maps by integrating resistivity profiles from AEM data, sediment type (from driller's logs), water level measurements, and water quality measurements. The workflow is publicly available through a web-based application, fastpath. We produced maps displaying recharge metrics on a 400 m × 400 m grid covering the Central Valley, with 80% of the cells sufficiently close to an AEM resistivity profile (within ∼3 km) to be assessed for recharge. Various decisions are made in the workflow that result in a range of values for determined metrics at any given location. The maps summarizing all metrics show that between 19% (2,000,000 acres) and 56% (7,000,000 acres) of the total area in the valley is land suitable for recharge. The landcover with the largest total area of land classified as suitable is cultivated crops. We estimated the total space available for recharge water to be ∼170 km3 which is two orders of magnitude greater than an estimate of the total volume of water likely to be available for recharge.

Haven or Hazard: The Ecology and Future of the Salton Sea

Pacific Institute | February 1st, 1999

California’s Salton Sea is a fertile oasis in the hostile desert of south-eastern California. It has been adopted by millions of birds migrating along the Pacific Flywa

California’s Salton Sea is a fertile oasis in the hostile desert of south-eastern California. It has been adopted by millions of birds migrating along the Pacific Flyway and also attracts human anglers and boaters. Rehabilitating the Salton Sea presents a huge challenge to the local, state, and federal officials that share responsibility for its health, as well as the health of those in surrounding communities. Originally published in February 1999,  Haven or Hazard: The Ecology and Future of the Salton Sea looks in detail at the condition of the Sea, the threats to the area, and possible solutions to protect its value for animals and people.

Hazard: The Future of the Salton Sea With No Restoration Project

Pacific Institute | May 1st, 2006

The Salton Sea lies on the brink of catastrophic change. The amount of water flowing into the Sea in the next twenty years will decrease by more than 40%, causing

The Salton Sea lies on the brink of catastrophic change. The amount of water flowing into the Sea in the next twenty years will decrease by more than 40%, causing its surface elevation to drop by more than 20 feet, rapidly shrinking its volume by more than 60%, tripling its salinity, and exposing more than 100 square miles of dusty lakebed to the desert’s blowing winds. These changes will cause four major impacts: Human health in the Imperial and Coachella valleys – currently home to more than 400,000 people and growing quickly – will be harmed by the estimated 33% increase in the amount of fine windblown dust in the basin. The Imperial Valley already suffers from the highest childhood asthma hospitalization rate in the state; the growing number of retirees living in both valleys are especially susceptible to poor air quality. Air quality in these two valleys – which already fails to meet state and federal air quality standards – would get much worse, increasing the cost of bringing these areas into compliance. Air quality-related litigation and state liability will increase. California has assumed ultimate responsibility for managing only those lands exposed due to a recent set of water transfers, constituting about half of the estimated 134 square miles exposed in 30 years. Responsibility for managing any dust blowing off the other 60 or so square miles will rest with the individual property owner. However, there is no clear way to determine which lands will be exposed due to the water transfers and which will be exposed due to other actions. Total air quality management costs at Owens Lake have exceeded $400 million. Costs at the Salton Sea could be higher. Many – if not most – of the hundreds of thousands of birds that currently use the Sea will lose their roosting and breeding habitats and their sources of food. The Sea’s fish will be almost entirely gone within a dozen years. Those birds that remain will suffer from disease and the reproductive deformities and failures that plagued the Kesterson National Wildlife Refuge twenty years ago. Some of the endangered and threatened species that use the Sea may be able to find other habitats, but others could suffer significant population losses. The tremendous scale of the Sea adds to its complexity, and the difficulty of finding a viable solution. The Sea currently runs almost 35 miles long, and 15 miles at its widest point, covering about 365 square miles. It has the largest surface area of any lake in California, yet is barely 50 feet at its deepest point. The Sea is 1/3 saltier than the ocean, and, fed by the fertilizers running off of neighboring fields, sustains incredible levels of biological productivity. Until recently, the amount of water entering the Sea was roughly balanced by the amount of water evaporating from its broad surface. Stabilizing the Sea at its current salinity would require the removal of more than four million tons of salt each year, assuming flows to the Sea do not change. But they will change. Under a set of agreements signed in 2003, the Imperial Valley has begun to transfer water to San Diego County, ultimately reducing flows to the Salton Sea. Other actions, including actions in Mexico, will also reduce the amount of water flowing to the Sea, by 45% or more in the next 30-40 years. These changes will dramatically decrease the size of the Salton Sea and the quality of its water. In September, 2003, the California legislature passed a set of laws that implement the 2003 water agreements and provide a 15-year reprieve for the Sea. The legislation offers the prospect of more than $300 million of restoration funds, but it does not guarantee a long-term restoration project for the Salton Sea. California’s Resources Agency will submit a Salton Sea Ecosystem Restoration Plan and related documents to the state legislature by December 31, 2006. The cost of any long-term restoration plan will almost certainly exceed a billion dollars. Although various private-public partnerships have been suggested, funding and implementation of any restoration plan is far from certain, especially given the lack of consensus on a preferred alternative.

Hazard’s Toll: The Costs of Inaction at the Salton Sea

Pacific Institute | September 3rd, 2014

The declining Salton Sea will impose massive public health and environmental costs on local residents and Californians generally, as described in the Pacific Institute re

The declining Salton Sea will impose massive public health and environmental costs on local residents and Californians generally, as described in the Pacific Institute report Hazard’s Toll. The continued failure to protect and preserve the Salton Sea, worsening air quality and the loss of valuable ecological habitat – combined with diminished recreational revenue and property devaluation – could cost as much as $70 billion over the next 30 years. The high costs of California’s 2007 plan for the Salton Sea have inhibited deliberation and deterred any meaningful investment in revitalizing the Salton Sea. Many decision-makers assume that delaying action at the Salton Sea will result in business as usual, with no additional costs. Hazard’s Toll makes clear that this is not the case. Because the Salton Sea has changed over the past decade and will soon enter a period of very rapid decline, the costs of inaction are escalating rapidly. Even at the low end of the costs estimated in Hazard’s Toll, the long-term social and economic costs of a deteriorating Salton Sea could approach $29 billion, well in excess of the project cost of the state’s plan. The consequences of continued inaction at the Salton Sea will be felt most directly by the 650,000 people who live in harm’s way of the Salton Sea’s dust, as well as by the birds and other life that depend on the lake. Hazard’s Toll estimates the costs of these consequences, for the first time. These considerable costs demonstrate the urgent need for action at the Salton Sea. The report also highlights a large number of important data gaps that should be addressed in the near future. Despite many decades of study and the impending decline of the Salton Sea, we still lack information on many factors affecting life and the economy in the region. These factors, combined with general uncertainty about population growth rates, climate change, and changing hydrologic conditions, suggest that the above estimates indicate a general magnitude of potential future costs, rather than precise projections.

Hazy Futures: Projecting the local impacts of global warming is a stubborn challenge. But cities need answers fast

American Association for the Advancement of Science (AAAS) | June 5th, 2025

A wastewater treatment plant isn’t top on everyone’s sightseeing itinerary. But on a cloudless, breezy day in April, Agmed Weber, operations manager for the Walnut Cr

A wastewater treatment plant isn’t top on everyone’s sightseeing itinerary. But on a cloudless, breezy day in April, Agmed Weber, operations manager for the Walnut Creek plant—which handles more than half of the sewage here in Texas’s booming capital city—is an enthusiastic tour guide. He marvels at the foresight of those who built the jumbo plant a half-century ago, when Austin was a third of its current size. “They were really thinking about the future,” he says. Weber feels a similar pressure—to prepare for not only continued population growth, but also a hotter future. Austin is “in a tight space where we need to think ahead,” he says.

Health of Native Riparian Vegetation and its Relation to Hydrologic Conditions along the Mojave River, Southern California

U.S. Geological Survey (USGS) | July 15th, 1999

Healthy, Fair, and Profitable: A Win-Win Pesticide Policy

Pacific Institute | January 1st, 2002

A new report released by the Pacific Institute and the California Green Scissors project makes the case for changing the way pesticides are regulated in California. Acc

A new report released by the Pacific Institute and the California Green Scissors project makes the case for changing the way pesticides are regulated in California. According to the report, if California significantly increased its funding for sustainable agriculture — instead of just spending money to regulate pesticide usage — we could aid California farmers, improve the public health and save millions of dollars in associated costs.

Heavily polluted Tijuana River drives regional air quality crisis

American Association for the Advancement of Science (AAAS) | August 28th, 2025

Intense industrial and urban wastewater pollution has plagued the Tijuana River for decades, causing long-term closure of neighboring beaches. Rico et al. showed that sur

Intense industrial and urban wastewater pollution has plagued the Tijuana River for decades, causing long-term closure of neighboring beaches. Rico et al. showed that surging wastewater flows in the summer of 2024 enhanced water-to-air hydrogen sulfide (H2S) transfer at a turbulent hotspot, leading to nighttime atmospheric H2S peaks thousands of times greater than typical urban levels. This example makes it clear that poor water quality can drastically affect air quality—an observation with important implications for global waterways.