Shop – California Water Library

Page

Showing
661-671 of 1020

Per Page

Sort By

Owens River Water Trail

Inyo County | September 1st, 2015

Summary

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.

View Document Download Now Email

Passage of fiproles and imidacloprid from urban pest control uses through wastewater treatment plants in northern California, USA

Society of Environmental Toxicology and Chemistry (SETAC) | November 3rd, 2017

Summary

Urban pest control insecticides—specifically fipronil and its 4 major degradates (fipronil sulfone, sulfide, desulfinyl, and amide), as well as imidacloprid—were moni

View Document Download Now Email

Patterns and magnitude of flow alteration in California, USA

Freshwater Biology (Wiley) | December 27th, 2017

Summary

The importance of the natural flow regime to stream and river health has received growing attention over the last two decades. Quantifying natural river flows has become

View Document Download Now Email

Per and Polyfluoroalkyl Substances (PFASs) in San Francisco Bay: Synthesis and Strategy

San Francisco Estuary Institute (SFEI) | June 1st, 2018

Summary

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a broad class of fluorine-rich specialty chemicals. Some types of PFASs, and in particular the perfluoroalkyl f

View Document Download Now Email

Per- and polyfluoroalkyl substances (PFASs) in San Francisco Bay wildlife: Temporal trends, exposure pathways, and notable presence of precursor compounds

Chemosphere (Elsevier) | April 21st, 2017

Summary

Concentrations of perfluorooctane sulfonate (PFOS) in San Francisco Bay (SF Bay) wildlife have historically been among the highest reported globally. To track continuing

View Document Download Now Email

Persistent spatial structuring of coastal ocean acidification in the California Current System

Nature Portfolio (Springer Nature) | May 31st, 2017

Summary

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA

View Document Download Now Email

Persistent spatial structuring of coastal ocean acidification in the California Current System

Nature Portfolio (Springer Nature) | May 31st, 2017

Summary

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA e

View Document Download Now Email

Pesticide Concentrations Associated with Augmented Flow Pulses in the Yolo Bypass and Cache Slough Complex, California

U.S. Geological Survey (USGS) | July 23rd, 2020

Summary

Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approx

Surface-water and suspended-sediment samples were collected and analyzed by the U.S. Geological Survey for multiple current-use pesticides and pesticide degradates approximately every 2 weeks at up to five sites in the Yolo Bypass and Cache Slough Complex before, during, and after augmented flow pulses in summer and fall 2016 and 2018 as well as during ambient flow conditions in summer and fall 2017 (no flow pulse). In 2016, augmented flows occurred during the summer (July) and required the pumping of Sacramento River water by local Reclamation Districts into the Colusa Basin Drain and Yolo Bypass Toe Drain. In contrast, augmented flows in 2018 occurred in the fall (August–September) and used agricultural tailwater (primarily rice field discharge water) to create the flow pulse. Water samples were analyzed by the U.S. Geological Survey for a suite of 175 current-use pesticides and pesticide degradates using gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry laboratory methods. Suspended sediments filtered from the water samples were analyzed for 143 pesticides and degradates by gas chromatography with mass spectrometry. During the study, 53 pesticides were detected, and all the samples contained mixtures of multiple pesticides at concentrations ranging from below method detection limits to 8,780 nanograms per liter. Pesticides used in growing rice were the dominant pesticides present at four of the five sites sampled and urban-use pesticides dominated at the remaining site. Overall, total pesticide concentrations tended to be higher at sites in the northern part of the Yolo Bypass and lower at southern sites, except for the farthest downstream site which received additional pesticide inputs from the Sacramento River. Flow-pulse water source influenced total pesticide concentrations in the Yolo Bypass and Cache Slough Complex, and the highest total pesticide concentrations at each site were detected either immediately before or during the flow pulse generated with agricultural tailwater in 2018. Data gathered during this study will aid the California Department of Water Resources and other agencies working in the region in adaptively managing pulse flows in the Yolo Bypass and Cache Slough Complex, as one of several California Natural Resources Agency’s Delta Smelt Resiliency strategies.

View Document Download Now Email

Pesticide contamination detected across five wildlife refuges in the Sacramento Valley of California

Science of the Total Environment (Elsevier) | March 1st, 2025

Summary

An important goal for the applied ecological sciences is to understand the extent to which the biodiversity on conserved or managed lands is exposed to anthropogenic stre

An important goal for the applied ecological sciences is to understand the extent to which the biodiversity on conserved or managed lands is exposed to anthropogenic stressors. Among the various categories of conserved lands in the United States, the National Wildlife Refuge System is focused on the protection and management of native wildlife and plant populations. Refuge lands can be associated with wetlands and, especially in California, tend to be near areas of intense human use, including agriculture. The proximity of refuges to cultivated lands results in potential exposure to pesticide drift, which increases the possibility of non-target effects on plants and wildlife. We used a passive sampler approach to quantify aerial pesticide deposition during 28 days in spring of 2023, across five refuges in the Sacramento Valley of California. Pesticides were detected across all refuges and plots within the study area, with 36 individual compounds identified, including insecticides, herbicides, and fungicides, from 176 silicone bands from 49 plots. Distance to agriculture was not an important predictor in our models for most indices of contamination. However, our models revealed that the nearest crop type was an important mediator of the importance of distance to agriculture, as fungicide contamination decreased with distance to agriculture only when orchards were the nearest crop type. The overall lack of distance effects suggests that the interior of refuges in the study area do not necessarily provide more protection from pesticides than refuge edges, although larger refuges could offer more protection. We currently lack information on how the level of contamination found herein is biologically relevant to wildlife, and ongoing monitoring efforts have found productive communities of insects in the study area. The results of this study provide a foundation for future investigations on refuges to analyze impacts of specific pesticide compounds on plants and wildlife.

View Document Download Now Email

Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program

U.S. Geological Survey (USGS) | July 11th, 2018

Summary

Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality

Emergent hypotheses about causes of the pelagic organism decline in the Sacramento–San Joaquin Delta (Delta) indicate that a more complete understanding of the quality of water entering the Delta is needed. Less than half of all pesticides used in the Delta watershed are measured in samples collected for routine monitoring, and with new pesticides continually being registered for use, the concentrations of unmonitored pesticides in the Delta ecosystem are unknown. In response, a multi-year, cooperative effort to improve monitoring of mercury, nutrients, pathogens, and pesticides was begun by the Delta Regional Monitoring Program (RMP). In July 2015, the U.S. Geological Survey in cooperation with the Delta RMP began measuring concentrations of 154 pesticide compounds in monthly samples of surface water and suspended sediment collected at five major inputs to the Sacramento–San Joaquin Delta from July 2015 to June 2016. In addition to pesticide concentration measurements, field water-quality indicators (water temperature, specific conductance, dissolved oxygen, pH, and turbidity) were measured at each site and samples were collected for the analysis of dissolved organic carbon, dissolved copper, particulate organic carbon, particulate inorganic carbon, total particulate carbon, and total particulate nitrogen. Pesticide concentrations in particulates were measured in collected suspended-sediment samples by gas chromatography with mass spectrometry, whereas concentrations measured in surface-water samples utilized a combination of gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry. Samples were collected from two sites in the San Joaquin River watershed and at one site for each of the Mokelumne River, Sacramento River, and Ulatis Creek watersheds. All water samples contained mixtures of 2–25 pesticides. Pesticides were detected in 100 percent of surface-water samples. A total of 54 pesticide compounds were detected in water samples during the study period (19 fungicides, 18 herbicides, 9 insecticides, 7 breakdown products, and 1 synergist). The most frequently detected pesticide compounds were the herbicides hexazinone (95 percent) and diuron (73 percent) and the fungicides boscalid (93 percent) and azoxystrobin (75 percent). Pesticide concentrations ranged from below the method detection limits to 2,630 nanograms per liter for the herbicide metolachlor. A total of 11 pesticide compounds were detected in the suspended sediments filtered from water samples (6 herbicides, 3 insecticides, 1 fungicide, and 1 breakdown product). The most frequently detected compounds were the insecticides permethrin (7 percent) and bifenthrin (5 percent) and the herbicide pendimethalin (5 percent). Pesticide concentrations in the suspended-sediment ranged from below the method detection limit to 265 nanograms per liter for the herbicide pendimethalin.

View Document Download Now Email

← Prev

Page : 67

Owens River Water Trail

Passage of fiproles and imidacloprid from urban pest control uses through wastewater treatment plants in northern California, USA

Patterns and magnitude of flow alteration in California, USA

Per and Polyfluoroalkyl Substances (PFASs) in San Francisco Bay: Synthesis and Strategy

Per- and polyfluoroalkyl substances (PFASs) in San Francisco Bay wildlife: Temporal trends, exposure pathways, and notable presence of precursor compounds

Persistent spatial structuring of coastal ocean acidification in the California Current System

Persistent spatial structuring of coastal ocean acidification in the California Current System

Pesticide Concentrations Associated with Augmented Flow Pulses in the Yolo Bypass and Cache Slough Complex, California

Pesticide contamination detected across five wildlife refuges in the Sacramento Valley of California

Pesticide inputs to the Sacramento–San Joaquin Delta, 2015–16: Results from the Delta Regional Monitoring Program

Filter Results

Type

Topic

Keywords

Publisher

Basin

Hydrological Region

Search for:

Search the California Water Library

Type

Topic

Keywords

Hydrological Region

Basin