Ruling on Plaintiffs’ Motion for Preliminary Injunction, Case No. Bcv-22-103220-Gap, Bring Back the Kern et al v. City of Bakersfield et al

Superior Court of California, County of Kern | October 30th, 2023

Scott Valley Integrated Hydrologic Model: Data Collection, Analysis, and Water Budget Final Report

University of California, Davis (UC Davis) | November 14th, 2017

The Scott Valley is an agricultural groundwater basin in Northern California, within the Scott River watershed and part of the much larger Klamath Basin watershed straddl

The Scott Valley is an agricultural groundwater basin in Northern California, within the Scott River watershed and part of the much larger Klamath Basin watershed straddling the California-Oregon border. The Scott River provides important habitat for salmonid fish, including spawning and rearing habitat for coho and fall-run Chinook salmon and steelhead trout. Sufficient flows at adequately low temperatures during summer, for rearing, and fall, for spawning, are critical for healthy fish habitat in the mainstem and tributaries. This report presents the data assembled and the methods used for data analysis and data modeling to prepare the Scott Valley Integrated Hydrologic Model Version 2, which is currently under development. The report includes precipitation data analysis, streamflow data analysis and modeling, geology and groundwater data review and analysis, evapotranspiration and soils data analysis, and preparation of relevant watershed, land use, topography, and irrigation data. The data collection and analysis efforts culminate in the development of a spatio-temporally distributed soil water budget model for the Scott Valley. The soil water budget model is used to determine spatially and temporally varying groundwater pumping rates, surface water diversion rates, and groundwater recharge across the groundwater basin. The spatial resolution of the soil water budget model is by individual fields (land use polygons). Temporal discretization is in daily time steps for the period from October 1, 1990 to September 30, 2011. This period includes several dry years, average years, and wet year periods. Methods and results of the soil water budget model are presented in this report. This report represents the next step toward a better understanding of the interactions between groundwater, surface water, land-use, and agricultural practices with a specific focus on the seasonal impacts of groundwater pumping on streamflow during critical low flow periods. The work presented here relies on an extensive data collection facilitated by the voluntary and active collaboration of communities, landowners, the Scott River Watershed Council (SRWC), the Siskiyou Resource Conservation District (SRCD), and the Scott Valley Groundwater Advisory Committee (GWAC) which has been appointed by the Board of Supervisors in January 2011, meeting monthly since April 2011 and advising UC Davis on its data collection and modeling efforts. In the data analysis and during the model development, numerous assumptions have been made as is common in building a conceptual and numerical integrated hydrologic model. Models cannot represent the complexity of the real system, but are an effort to capture salient hydrologic features with sufficient accuracy to develop modeling results that are useful for a better understanding of the watershed dynamics and water balance.

Sediment Mobility and River Corridor Assessment for a 140-Kilometer Segment of the Main-Stem Klamath River Below Iron Gate Dam, California

U.S. Geological Survey (USGS) | January 26th, 2021

This river corridor assessment documents sediment mobility and river response to flood disturbance along a 140-kilometer segment of the main-stem Klamath River below Iron

This river corridor assessment documents sediment mobility and river response to flood disturbance along a 140-kilometer segment of the main-stem Klamath River below Iron Gate Dam, California. Field and remote sensing methods were used to assess fundamental indicators of active sediment transport and river response to a combination of natural runoff events and reservoir releases during the study period from 2005 to 2019. Discharge measurements at two gaged sites and bed-material samples at two ungaged sites provided direct and indirect evidence of mobile bed conditions, scour and fill, and surface flushing of fine sediment. Available remote-sensing datasets collected in 2005, 2009, 2010, and 2016 were used to determine sediment storage, flood inundation boundaries, and provide indirect evidence of flood-induced scour. These datasets validate channel-maintenance flows defined by Shea and others (2016). During the study period, flows greater than or equal to 6,030 cubic feet per second mobilized the substrate, caused localized scour, and flushed fine sediment from bar surfaces. Flows greater than or equal to 10,400 cubic feet per second stripped vegetation from bars and floodplains and produced deeper scour. Flood disturbance within the study reach is produced by the combined effect of natural flows and reservoir releases, which resulted in mobile bed conditions during the study period. Periodic scour and substrate disturbance are considered by the U.S. Fish and Wildlife Service to be integral for managing disease-induced mortality of juvenile and adult salmonids. Substrate conditions conducive to parasites that host infectious diseases, particularly Ceratonova shasta, occur periodically. Additional studies are required to determine whether disease prevalence can be mitigated by well-timed reservoir releases. Study results are useful for interpreting linkages among physical and biological processes and for evaluating the effectiveness of flow management targeted to improve river bed conditions for endangered salmonid populations.

Storing and managing water for the environment is more efficient than mimicking natural flows

Nature Portfolio (Springer Nature) | June 27th, 2024

Strategic stream gauging network design for sustainable water management

Nature Portfolio (Springer Nature) | June 3rd, 2024

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compo

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compounded by gauge deactivations, limit our ability to track river flows and address global water challenges. Here we introduce an approach for identifying gauging sites to efficiently fill gaps in monitoring coverage within river networks while also addressing water management priorities, including reservoir operations, biodiversity conservation and hydroclimatic monitoring. Applying this approach to gauges in California, United States, we found substantial gaps in the stream monitoring network. Hypothetically reconfiguring gauges to locations that maximize coverage and representation of management objectives highlights the current network’s biases. Through the strategic reactivation and placement of additional gauges, we demonstrate how stream gauging networks can be designed to support sustainable water management.

Synthesis of Studies in the Fall Low-Salinity Zone of the San Francisco Estuary, September–December 2011

U.S. Geological Survey (USGS) | July 14th, 2014

In fall 2011, a large-scale investigation (fall low-salinity habitat investigation) was implemented by the Bureau of Reclamation in cooperation with the Interagency Ecolo

In fall 2011, a large-scale investigation (fall low-salinity habitat investigation) was implemented by the Bureau of Reclamation in cooperation with the Interagency Ecological Program to explore hypotheses about the ecological role of low-salinity habitat in the San Francisco Estuary—specifically, hypotheses about the importance of fall low-salinity habitat to the biology of delta smelt Hypomesus transpacificus, a species endemic to the San Francisco Estuary and listed as threatened or endangered under federal and state endangered species legislation. The Interagency Ecological Program is a consortium of 10 agencies that work together to develop a better understanding of the ecology of the Estuary and the effects of the State Water Project and Federal Central Valley Project operations on the physical, chemical, and biological conditions of the San Francisco Estuary. The fall low-salinity habitat investigation constitutes one of the actions stipulated in the Reasonable and Prudent Alternative issued with the 2008 Biological Opinion of the U.S. Fish and Wildlife Service, which called for adaptive management of fall Sacramento-San Joaquin Delta outflow following “wet” and “above normal” water years to alleviate jeopardy to delta smelt and adverse modification of delta smelt critical habitat. The basic hypothesis of the adaptive management of fall low-salinity habitat is that greater outflows move the low-salinity zone (salinity 1–6), an important component of delta smelt habitat, westward and that moving the low-salinity zone westward of its position in the fall of recent years will benefit delta smelt, although the specific mechanisms providing such benefit are uncertain. An adaptive management plan was prepared to guide implementation of the adaptive management of fall low-salinity habitat and to reduce uncertainty. This report has three major objectives: •To provide a summary of the results from the first year of coordinated fall low-salinity habitat studies and monitoring. •To provide a synthesis of the results of the fall low-salinity habitat studies and other ongoing research and monitoring, to determine if the available information supports the hypotheses behind the adaptive management of fall low-salinity habitat as set forth in the adaptive management plan. •To begin to put the results from the fall low-salinity habitat studies into context within the larger body of knowledge regarding the San Francisco Estuary and, in particular, the upper San Francisco Estuary, including the Sacramento-San Joaquin Delta, Suisun Bay, and associated embayments.

Synthetic Streamflows

American Geophysical Union (AGU) | January 1st, 1971

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 1. This monograph contains virtually no mathematical derivations an

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 1. This monograph contains virtually no mathematical derivations and little statistical theory, but a large number of formulas, examples, and their phenomenological justification. Moreover, many references are cited so that interested readers can locate some of the missing details and study them from their source documents. The purpose of this monograph is to summarize many of the proposals for generating synthetic streamflows, to present numerical calculations that show the step-by-step calculations, and to offer proposals for their application in a variety of hydrologic engineering problems. This monograph is the first of a series of monographs emphasizing procedural aspects of hydrologic analysis.

Systematic Screening of Dams for Environmental Flow Assessment and Implementation

Bioscience (Oxford University Press) | November 30th, 2014

The Hardest Working River in the West: Common-Sense Solutions for a Reliable Water Future for the Colorado River Basin

Western Resource Advocates | July 14th, 2014

The majestic Colorado River cuts a 1,450-mile path through the American West before drying up well short of its natural finish line at the Gulf of California. Reservoirs

The majestic Colorado River cuts a 1,450-mile path through the American West before drying up well short of its natural finish line at the Gulf of California. Reservoirs once filled to the brim from the river and its tributaries are at historic lows due to an unprecedented drought and growing human demands. Diminished stream flows now pose serious challenges for wildlife and recreation, as well as cities, farms, and others who rely upon the river. Steps currently being taken to improve the situation are not up to the task of bringing the river system back into balance and providing a reliable water supply for all the communities who depend upon the Colorado River. Fortunately, we have five feasible, affordable, common-sense solutions that can be implemented now to protect the flow of the river, ensure greater economic vitality, and secure water resources for millions of Americans.

The Instream Flow Incremental Methodology: A Primer for IFIM

U.S. Department of the Interior (DOI) | March 1st, 1995

This booklet is a primer on the Instream Flow Incremental Methodology (IFIM). Our objective for this primer is to give you a short but comprehensive introduction to the b

This booklet is a primer on the Instream Flow Incremental Methodology (IFIM). Our objective for this primer is to give you a short but comprehensive introduction to the background, philosophical and ecological underpinnings, individual components, and steps in applying IFIM. As a primer, we have tried to keep it simple. Scientific names and other technical details have been avoided, but the primer includes relevant definitions (with key words or phrases indicated in italics for their first use), summaries of the literature where you may wish to turn for further reading, and explanations to increase your understanding of what IFIM is all about and how it works. The primer should reinforce your growing knowledge and provide the necessary stepping stones into more advanced, certified training in IFIM methods. This primer is divided into five more or less independent sections. The first section reviews the history of instream flow problems in the United States. Reading this section should provide you with an understanding ofwhy IFIM emerged to solve certain complex water management problems and hint at future directions. The second section discusses the choice of instream flow methods and, more importantly, provides a framework for deciding whether IFIM is appropriate for the kind of problems you might be facing. The third section reviews the ecological underpinnings of IFIM from a historical perspective. This section is meant to show you the degree to which IFIM components, or models, represent the essence of the biological systems that we are attempting to understand. It is more detailed than the other sections and meant specifically to be of interest to biologists and ecologists. Section four delves into the broader philosophical, problem-solving approach embodied in IFIM.  This perspective is important because the 'facts' alone rarely dictate good decisions; it is how we employ those facts to resolve instream flow problems in an interdisciplinary decision making arena that is important. The fifth section outlines the logical steps in applying IFIM and the information flow that holds them together. Here you will learn how to navigate through the IFIM process from tentative problem identification to problem resolution.