South Lahontan

Off-Lake Sources of Airborne Dust in Owens Valley, California

National Academy of Sciences (NAS) | June 17th, 2025

Since 2017, the District has used additional information to attribute PM10 exceedances to specific sources within the Owens Valley Planning Area. This information include

Since 2017, the District has used additional information to attribute PM10 exceedances to specific sources within the Owens Valley Planning Area. This information includes particulate and meteorological data, modeling, cameras, field observations, and media reports of dust storms. These data are compiled into the District’s exceedance database. Based on these data, the District classifies each exceedance as one of the following: 1) dust—primarily on-lake sources, 2) dust—primarily local off-lake sources, 3) dust—primarily regional event, 4) wildfire smoke, or 5) mixed—dust and wildfire sources.

Optimizing the dammed: Water supply losses and fish habitat gains from dam removal in California

Journal of Environmental Management (Elsevier) | April 1st, 2014

Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic an

Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate removing rim dams in California's Central Valley to highlight promising habitat and unpromising economic use tradeoffs for water supply and hydropower. CALVIN, an economic-engineering optimization model, is used to evaluate water storage and scarcity from removing dams. A warm and dry climate model for a 30-year period centered at 2085, and a population growth scenario for year 2050 water demands represent future conditions. Tradeoffs between hydropower generation and water scarcity to urban, agricultural, and instream flow requirements were compared with additional river kilometers of habitat accessible to anadromous fish species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Removing individual dams decreases statewide delivered water by 0–2282 million cubic meters and provides access to 0 to 3200 km of salmonid habitat upstream of dams. The method described here can help prioritize dam removal, although more detailed, project-specific studies also are needed. Similarly, improving environmental protection can come at substantially lower economic cost, when evaluated and operated as a system.

Ordinary High Flows and the Stage–Discharge Relationship in the Arid West Region

U.S. Army Corps of Engineers (USACE) | July 14th, 2011

The Ordinary High Water Mark (OHWM) defines the lateral extent of non-wetland waters and is regulated as “Waters of the United States” under Sec. 404 of the Clean Wat

The Ordinary High Water Mark (OHWM) defines the lateral extent of non-wetland waters and is regulated as “Waters of the United States” under Sec. 404 of the Clean Water Act. Previous research has developed a reliable and repeatable methodology for identifying the OHWM on ephemeral and intermittent streams in the Arid West using the physical features of the channel (Lichvar and McColley 2008, Curtis and Lichvar 2010). This study expands upon the previous reports by providing an analysis of how gage data may be utilized in OHW determinations. We clarify the methodology for using gage data, review the potential errors encountered in developing a stage–discharge relationship, compare the position of the gage-predicted OHWM to the field OHW signature, and determine the recurrence interval and flow duration of OHW events. The field OHW signature often is not associated with a 2-year flood event like many assume, but ranges from <1- to 15.5-year flood event. This large variation in recurrence intervals for the field OHWMs makes it impossible to define the frequency of the ordinary high flow from gage data because the OHW event is unique to each channel.

Origins of Extreme Climate States during the 1982–83 ENSO Winter

American Meteorological Society (AMS) | November 1st, 1997

Owens River Water Trail

Inyo County | September 1st, 2015

The Owens River Water Trail is a signature recreation project—the first dedicated water trail on a river in California. The project creates a 6.3 mile water trail on th

The Owens River Water Trail is a signature recreation project—the first dedicated water trail on a river in California. The project creates a 6.3 mile water trail on the newly re-watered Lower Owens River in the scenic Owens Valley that is solely dedicated to kayaks, canoes, and other paddlecraft. Recreationists will find well designed parking areas, accessible paths to the river, and formal paddlecraft entry and exit points.  The Owens River Water Trail is also improves aquatic habitat; opening up the river and improving transport of organic sediments. The Lower Owens River is a component of the Lower Owens River Project (LORP) which, in addition to ecosystem recovery promotes sustainable recreation. The area of the proposed water trail has a moderately wide channel characterized by large areas of open water separated by relatively short lengths of channel that are obstructed or bridged by bulrush and cattail (collectively referred to as tules). Tules and coyote willow line the margins of the open water channel; ponds open to salt grass meadow.  Tree willow is the dominate overstory. The river has a sustained 40 cfs flow and a yearly seasonal habitat flow of up to 200 cfs. The project is expected to improve water quality. Years of low flows prior to 2006 allowed tules to colonize the channel. In places, thick beds of tule roots completely cover the river bottom and vegetation blocks the channel. The seasonal habitat flows meant to move muck out the system are diminished in the vegetation and the buildup of organic material, derived from decaying tules, cannot be effectively flushed by the habitat flow. The project improves water quality by opening these blockages. The newly established channel will better fit the river’s hydrograph and is expected to improve flushing of organic sediment and protect the fishery. Inyo County and LADWP jointly manage the LORP. A preferred Recreation use plan for the LORP, which has at its core a river trail, has the support of LADWP and parties to the MOU, and was developed by a diverse range of stakeholders including the LADWP, conservation organizations, ranchers, anglers, students, area Indian Tribes, local, state, and federal agencies, local businesses, and the general public. A water trail on the Lower Owens River has popular support, and now area businesses, local agencies and NGOs are meeting to discuss forming a Lower Owens River stewardship group. The entire project area is owned by the City of Los Angeles and is open to daytime use by the public. The Owens River Water Trail is 2.5 miles from the center of Lone Pine, easily accessible by bike or car. Lone Pine aspires to be identified as a River Town; this project establishes that connection. The Lone Pine economic plan associated with the project includes a concessionaire running regularly scheduled drop-offs and pick-ups of boaters between the river and the many local hotels.

Owens Valley Groundwater Basin Final Groundwater Sustainability Plan

Owens Valley Groundwater Authority | December 9th, 2021

The Owens Valley Groundwater Basin and Fish Slough subbasin (Basin) were assigned a low priority status by the California Department of Water Resources (DWR) and are not

The Owens Valley Groundwater Basin and Fish Slough subbasin (Basin) were assigned a low priority status by the California Department of Water Resources (DWR) and are not required to be managed by a Groundwater Sustainability Agency (GSA). GSAs in low priority basins are encouraged to complete a GSP. Following the adoption of the Sustainable Groundwater Management Act (SGMA), the Basin was originally ranked as medium priority, but DWR proposed it be assigned high priority and ultimately ranked the Basin as low priority in December 2019. Despite the uncertainty in the Basin ranking before the final ranking was announced the Owens Valley Groundwater Authority (OVGA) elected to prepare a GSP for the Basin. This document is the GSP, and it was developed in accordance with Sustainable Groundwater Management Act (SGMA) statutory and regulatory requirements. This GSP describes the Basin, develops quantifiable management objectives that account for the interests of beneficial groundwater uses and users, and identifies a group of management actions that will maintain sustainable conditions in the Basin for 20 years after plan adoption. This GSP also contains steps a GSA could undertake to manage pumping to address declining water levels in a portion of the Basin. Preparation and implementation of the GSP by the OVGA is discretionary as long as the Basin remains very low or low priority. This GSP does not pertain to lands in the Basin that are exempt from SGMA, e.g. Federal and state owned lands, Tribal Reservations, and Los Angeles Department of Water and Power (LADWP) lands managed pursuant to the Long Term Water Agreement (LTWA). LADWP lands in Inyo County are referred to as adjudicated; other lands in the Basin are referred to as GSP lands in this document. Los Angeles-owned lands in the Basin in Mono County are not exempt from SGMA. Due to size, the file has been divided into five parts. Part 1, Part 2, Part 3, Part 4, Part 5

Paying for California's Water System

Public Policy Institute of California (PPIC) | May 31st, 2021

Paying it Forward: The Path Toward Climate-Safe Infrastructure in California

Climate-Safe Infrastructure Working Group | September 1st, 2018

Performance of Fire Danger Indices and Their Utility in Predicting Future Wildfire Danger Over the Conterminous United States

American Geophysical Union (AGU) | November 20th, 2023

Petition for 2023 Drought Emergency Regulation or Other Emergency Action to Protect Nesting Birds, Water Quality, and other Public Trust Resources at Mono Lake

Mono Lake Committee | December 16th, 2022