Old and Middle River Flow Review: USGS Gauge Readings versus Index Calculations for 2011 through 2017

California Department of Water Resources (DWR) | November 17th, 2017

This report will demonstrate the strong flow correlation between the United States Geological Survey gages at the Old and Middle Rivers (USGS OMR), and the OMR Index calc

This report will demonstrate the strong flow correlation between the United States Geological Survey gages at the Old and Middle Rivers (USGS OMR), and the OMR Index calculations, which have been used by the State Water Project and the Central Valley Project (the Projects) to operate to, and comply with, Old and Middle River (OMR) flow requirements. The results of the two different methodologies for determining OMR will be compared with daily, 5-day average, and 14-day average values, and will demonstrate a close correlation and tracking between the two methodologies. The time-span will be from December to June of the Water Years 2011 to 2017 and gives a background view and general effectiveness of using the OMR Index. The difference between the methodologies is that the USGS OMR values are based on tidally filtered hourly flow values of Old and Middle Rivers near Bacon Island, whereas the Index methodology uses an empirical equation based on net flows into and out of the Southern Delta. The USGS OMR flow values have been difficult for the Projects to operate to, in large part because the tidally filtering calculation is lagged by three days. What’s more, atmospheric conditions exert an unpredictable influence on OMR values and missing data introduces errors. By contrast, the OMR Index is much easier to work with because the San Joaquin River at Vernalis (VNS) gage used in the OMR Index equation is located upstream of the Delta and is therefore not affected significantly by tidal effects or atmospheric conditions and has only a one-day delay in the OMR Index equation. Using prior day flows from the VNS gage allows the Projects’ operations to be more predictable since current day exports can be closely controlled. Through regression analysis and empirical graphs, this report will show that the OMR Index method produces results that are closely correlated with values from the USGS OMR. And since the Index method can be used to closely approximate the USGS OMR flow values over an averaging period, the Index method is a satisfactory alternative to using the lagged USGS OMR flow data for real-time operations.

One Water LA 2040 Plan

City of Los Angeles | April 30th, 2018

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two p

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two primary goals: 1. Develop a vision and implementation strategy to more sustainably and cost-effectively manage water. 2. Identify ways for City departments and regional agencies to integrate their water management strategies. Los Angeles Sanitation (LASAN) and the Los Angeles Department of Water and Power (LADWP) led the Plan's development, partnering with other City departments, regional agencies, academia, the business community, and other stakeholders. The Plan provides a comprehensive strategy for managing water in a more integrated, collaborative, and sustainable way through new project, program, and policy opportunities. The Implementation Strategy provides a roadmap to make the One Water LA Vision a reality. Additional water projects, programs, or policies that are the sole responsibility of one agency, including LADWP's aqueduct or groundwater remediation project, are contained in each agency's appropriate plans. This plan is divided into an Executive Summary and ten sections. Executive Summary Volume One: Summary Report Volume Two: Wastewater Facilities Plan Volume Three: Stormwater and Urban Runoff Facilities Plan Volume Four: Los Angeles River Flow Study Volume Five: Integration Opportunities Analysis Volume Six: Climate Risk and Resilience Assessment for Wastewater and Stormwater Infrastructure Volume Seven: Implementation Strategy Supporting Documents Volume Eight: Technical Support Materials Volume Nine: Stakeholder Engagement Materials, Part 1, Part 2, Part 3 Volume Ten: Programmatic Environmental Impact Report (in progress)

Pacific Coast Federation of Fishermen’s Associations et al v. Wilbur Ross et al

U.S. District Court, Northern District of California | December 12th, 2019

Passage and Flow Considered Anew: Wild Salmon Restoration Via Hyrdo Relicensing

University of Montana | May 24th, 2016

Patterns and magnitude of flow alteration in California, USA

Freshwater Biology (Wiley) | December 27th, 2017

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

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 an essential component of water resource planning, including assessments of water supplies (Vicuna,Maurer, Joyce, Dracup, & Purkey, 2007; Wurbs, 2005), reservoir operations (Hejazi, Cai, & Ruddell, 2008) and drought risk (Meko,Therrell, Baisan, & Hughes, 2001). Understanding the natural flow regime is also crucial for managing stream ecosystems.

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

Petition for Extension of Time to Perfect Conditional Water Rights Under the State Water Project Permits (SWP) 16478, 16479, 16481, and 16482 for Water Supply and Permits 16477 and 16480 for Hydropower Operations

California Department of Water Resources (DWR) | January 21st, 2025

Click here for DWR press release and related correspondence.

Click here for DWR press release and related correspondence.

Phenomenological vs. biophysical models of thermal stress in aquatic eggs

Ecology Letters (Wiley) | January 1st, 2017

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between temperature and fitness metrics. We tested one of these relationships using the embryonic stage of a Chinook salmon population. We parameterised the model with laboratory data, applied it to predict survival in the field, and found that it significantly underestimated field-derived estimates of thermal mortality. We used a biophysical model based on mass transfer theory to show that the discrepancy was due to the differences in water flow velocities between the lab and the field. This mechanistic approach provides testable predictions for how the thermal tolerance of embryos depends on egg size and flow velocity of the surrounding water. We found support for these predictions across more than 180 fish species, suggesting that flow and temperature mediated oxygen limitation is a general mechanism underlying the thermal tolerance of embryos.

Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead – Draft Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | January 16th, 2026

The Secretary of the Department of the Interior, acting through the Bureau of Reclamation, proposes the adoption of new guidelines and coordinated management strategies t

The Secretary of the Department of the Interior, acting through the Bureau of Reclamation, proposes the adoption of new guidelines and coordinated management strategies to address Lake Powell and Lake Mead through their full operating range to take effect when the current agreements expire in 2026. Management strategies will primarily focus on the operation of Glen Canyon Dam and Hoover Dam, but may include actions upstream and downstream of these facilities to protect critical reservoir elevations. This Draft EIS has been prepared to inform the Secretary’s timely adoption of a new set of guidelines that would be sufficiently robust and provide improved predictability to all water users and managers in the Colorado River Basin. This Draft EIS has been prepared pursuant to the National Environmental Policy Act to address the formulation and evaluation of specific interim criteria and to identify the potential environmental impacts of implementing such criteria.

Preface to the Environmental Assessment for 2019 Ocean Salmon Fisheries Management Measures

National Marine Fisheries Service (NMFS) | April 1st, 2019