The Ahwahnee Water Principles

Local Government Commission | July 1st, 2006

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at

In 2004,the Local Government Commission set out to identify effective,least-cost economically and politically viable options for sustainable water resources management at the local level. The LGC invited respected water resource policy, management and planning professionals – with experience at the federal,state and local levels – to craft a set of land use principles which would provide guidance to local officials and communities concerned about sustaining future water supplies. The process of developing the Ahwahnee Water Principles mirrored the LGC’s earlier Ahwahnee Principles for Resource-Efficient Communities, which were released in 1991. The Ahwahnee Principles presented a blueprint for elected officials to create compact, mixed-use,walkable,transit-oriented developments in their local communities,and have since paved the way for growing acceptance and inclusion of “smart growth”and the “New Urbanism”in local and regional land-use policies and practices.

The Alkaline and Boracic Lakes of California

Scientific American | July 7th, 1877

Immediately east of the range of the Sierra Nevada is an extensive region of alkaline lakes and hot springs, of which very large areas are almost totally barren, the onl

Immediately east of the range of the Sierra Nevada is an extensive region of alkaline lakes and hot springs, of which very large areas are almost totally barren, the only vegetation consisting of wild sage, yucca, a few cacti, and scanty tufts of bunch-grass. This district affords, in its many extensive craters and in its lavas, basalts, and obsidians, the most conclusive evidence of its volcanic origin, while its solfataras and boiling springs may be regarded as the last representatives of active volcanicity. Although this region is one of great scientific interest, and may eventually become industrially important, it appears to be but little known in this country, and it has therefore been thought that a brief description of the district, as well as that of the borax lakes, lying on the western side of the Sierra, might not be without interest to English readers. The most remarkable of the alkaline lakes of this portion of California are Mono and Owens Lakes.

The Anatomy of a Drought in the Upper San Francisco Estuary: Water Quality and Lower-Trophic Responses to Multi-Year Droughts Over a Long-Term Record (1975-2021)

University of California, Davis (UC Davis) | December 23rd, 2024

The Ancient Lakes of Western America, their Deposits and Drainage

Nature Portfolio (Springer Nature) | September 8th, 1870

By continental elevation the whole country west of the Mississippi was raised out of the cretaceous sea, and these estnaries became lakes inclosed by raised dry land. The

By continental elevation the whole country west of the Mississippi was raised out of the cretaceous sea, and these estnaries became lakes inclosed by raised dry land. The knowledge of this country from the Mississippi to the Pacific Ocean has been accumulated by various explorers besides the writer, as Dr. Hayden, Mr. George Gibbs, Professors W. P. Blake and Thomas Antisell, and Prof. J. D. Whitney and the State Geological Survey of California, and Baron Richtofen, the lamented Rémond, Drs. Shiel, Wislizenus, and others. Besides Mr. Clarence King has explored a large tract of this country, but his very important contributions have not, as yet, been made public. The general character of the topography of the region west of the Mississippi has been given by these great lines of elevation traversing the country from north to south. There are the Rocky Mountains, the Sierra Nevada, and the Coast Ranges. The last is the most modern, and is composed, for the most part, of Miocene Tertiary rocks. Parallel with this lies a narrow trough, in California traversed by the Sacramento and San Joachin Rivers, encroached on by the mountains at places, but still in Oregon and Washington, traversed by the Willamette and Cowletz Rivers. These two sections are drained through the Golden Gate and Columbia.

The Application of Ground-Water Flow Models as Predictive Tools—A Review of Two Ground-Water Models of Eastern Honey Lake Valley, California-Nevada

Geological Society of America (GSA) | January 9th, 1992

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of

In the late 1980's Washoe County, Nevada, entered into an agreement with a private water development company to develop and export groundwater from the Nevada portion of the arid Honey Lake Valley to the rapidly growing Reno-Sparks area. The proposed project is known as the Truckee Meadows Project (TMP). Honey Lake Valley is 35 mi north of Reno, Nevada; but is located predominantly in California. Computer groundwater models of the valley were prepared by the USGS and the TMP proponents and presented to the Nevada State Engineer to evaluate the impacts of the proposed exportation of 15,000 ac-ft annually from eastern Honey Lake Valley. By using assumptions, numbers, and data which are not justified by the scientific data, both models place unreasonable and, in some instances, artificial constraints on the geology and hydrogeology of the groundwater system rather than allowing the geology and hydrogeology to constrain the models. Neither model is useful as a predictive tool. However, the major problems with the two models fall into two fundamentally different classes. The USGS model exceeded the technical limitations of the model code and made large, inappropriate adjustments to the water budget to compensate for these undetected errors. The TMP model used a water budget that was not technically justified or explained and placed the spatial distribution of ground-water recharge and discharge beyond the realm of hydrogeologic reality.  

The approaching obsolescence of 137Cs dating of wetland soils in North America

Quaternary Science Reviews (Elsevier) | September 24th, 2018

The peak fallout in 1963 of the radionuclide 137Cs has been used to date lake, reservoir, continental shelf, and wetland sedimentary deposits. In wetlands such dating is

The peak fallout in 1963 of the radionuclide 137Cs has been used to date lake, reservoir, continental shelf, and wetland sedimentary deposits. In wetlands such dating is used to project the ability of wetlands to keep pace with sea level rise and develop strategies for mitigating carbon pollution using biological carbon sequestration. Here we demonstrate that reliable 137Cs profiles are increasingly difficult to obtain from wetland soils. Among 58 soil cores recently collected from a range of wetland types and 137Cs fallout densities across the United States, 25% contain no identifiable 137Cs peaks. Less than 40% of 137Cs ages are consistent with 210Pb dating. We provide a new measure of 137Cs peak clarity (t) for our core dataset by comparing the 50% interquartile range of data around the 137Cs peak for “ideal” cores profiles determined using 137Cs fallout data to that of observed core profiles. Our results show that overall t is approximately 10 times greater for observed cores than ideal cores. The deterioration in the 137Cs peak has occurred due to radionuclide decay, 137Cs migration in situ, which is ubiquitous in this study, and 137Cs amendments from surface waters. Such deterioration likely extends to both Mexican and non-permafrost, Canadian wetlands. We recommend continued use of 137Cs only if the full bound of dating uncertainty for both 137Cs and an additional method such as 210Pb is propagated into estimates of wetland vertical accretion and carbon sequestration.

The Basin Characterization Model—A Regional Water Balance Software Package

U.S. Geological Survey (USGS) | March 22nd, 2021

This report documents the computer software package, Basin Characterization Model, version 8 (BCMv8)—a monthly, gridded, regional water-balance model—and provides det

This report documents the computer software package, Basin Characterization Model, version 8 (BCMv8)—a monthly, gridded, regional water-balance model—and provides detailed operational instructions and example applications. After several years of many applications and uses of a previous version, CA-BCM, published in 2014, the BCMv8 was refined to improve the accuracy of the water-balance components, particularly the recharge estimate, which is the most difficult to accurately assess. The improvement of the various water-balance components targeted the actual evapotranspiration component, which, in turn, reduced the uncertainty of the recharge estimate. The improvement of this component was enabled by the availability of a national, gridded actual-evapotranspiration product from the U.S. Geological Survey that was unique in its scope to combine remotely sensed spatial variability and ground-based long-term water-balance constraints. This dataset provided the ability to assess monthly actual evapotranspiration for 62 vegetation types and to perform regional calibration in watersheds throughout California with the objective of closing the water balance using improved estimates for each component. The refinements, including vegetation-specific evapotranspiration, enabled the development of applications that could explore various aspects of landscape disturbance, such as wildfire, forest management, or urbanization. The improvements to BCMv8 also provided the ability to assess long-term sustainability of water resources under a variety of management applications or future climate projections.

The Bay Delta Conveyance Facility: Affordability and Financing Considerations

California Debt and Investment Advisory Commission (CDIAC) | November 1st, 2014

The Bay Delta Conservation Plan (BDCP) is a collaborative effort involving numerous state and federal agencies with the goal of restoring and protecting the environmental

The Bay Delta Conservation Plan (BDCP) is a collaborative effort involving numerous state and federal agencies with the goal of restoring and protecting the environmental health of the Sacramento-San Joaquin Delta while also improving the reliability of an important source of California’s water supply. Currently, the Delta provides vital water supplies to municipal, industrial and agricultural water users in the Central Valley and coastal and Southern California. These water deliveries are crucial to the state’s economy and represent a critical source of water for more than 25 million California residents. According to the BDCP documents, in the absence of the various conservation measures proposed in the plan, Delta water supplies are expected to become increasingly unreliable, water quality in the Delta would be vulnerable due to sea level rise and associated saltwater intrusion, and the state would be exposed to potentially severe public health consequences resulting from a major seismic event that could damage Delta facilities and temporarily halt water exports. This report provides a preliminary assessment of the affordability and financing considerations of the Delta conveyance facility. The report does not address the merits of the BDCP per se or the question of whether the state and other parties involved in the project should proceed with this project.

The Benefits of Headwater Forest Management

Public Policy Institute of California (PPIC) | April 1st, 2020

Forests in California are increasingly vulnerable to major wildfires and droughts that threaten the benefits they provide. Improving the health of headwater forests in th

Forests in California are increasingly vulnerable to major wildfires and droughts that threaten the benefits they provide. Improving the health of headwater forests in the Sierra, in particular—where most of the state’s surface water supplies originate—will provide an array of social, economic, and environmental benefits across multiple sectors and geographies. Research by forest ecologists and wildfire behavior experts finds that the best way to realize these benefits is to reestablish and maintain lower densities of trees, which will help make these forests more resilient to fire, drought, and pests.  Healthier forests can support rural communities, reduce air quality impacts from wildfires, securely store carbon and reduce greenhouse gas emissions, protect water quality from post-fire erosion, and increase water supply. The broad base of beneficiaries of headwater forest management includes rural communities in the headwater region, regions that are vulnerable to smoke impacts from major wildfires, and major urban areas and agricultural regions that receive water and hydropower from headwater forests.  Improving forest health will require a substantial lift from an array of private and public entities—along with new policies and sources of funding to facilitate complex, collaborative management. Clarifying the benefits and beneficiaries of forest management is a critical step in motivating long-term stewardship, and will inform efforts to craft financial tools, policies, and other governance solutions needed to make this heavy lift. By assessing what is known about the benefits of forest management, this report provides crucial information for ongoing policy discussions on long-term stewardship of California’s headwater forests. 

The Big Water Supply Shift: Groundwater Key to Water Security in California's Changing Climate

Union of Concerned Scientists | November 1st, 2015

For more than a century, California has relied on its snowmelt-fed reservoirs, rivers, and streams for the majority of its water, but drought and climate chang

For more than a century, California has relied on its snowmelt-fed reservoirs, rivers, and streams for the majority of its water, but drought and climate change are depleting those traditional supplies. Snow is already melting as many as 30 days earlier than in the mid-twentieth century, meaning less water is available during the hotter months when water demand is highest. California is increasingly turning to groundwater to meet its water needs. Today, groundwater supplies up to 50 percent of California’s water, but California’s prolonged drought has led to the over-pumping of groundwater, overdrafting the Central Valley’s aquifers. Sustainable groundwater management will allow the state to adapt to climate change while increasing water reliability in the future.