Urban Water Use Efficiency (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

During the past few decades, Californians have made great progress in urban water use efficiency. Once viewed and invoked primarily as a temporary strategy in response to

During the past few decades, Californians have made great progress in urban water use efficiency. Once viewed and invoked primarily as a temporary strategy in response to a drought or emergency water shortage situation, water use efficiency has become a permanent part of the long-term management of California’s water supply. At the individual level, the benefits of water use efficiency may appear small, incremental, or difficult to see, but when Californians act together as a community to conserve water, the cumulative effect is significant, and the benefits are widespread. There are several factors that have contributed to increased water use efficiency: outreach efforts that have increased awareness and changed behaviors; urban water suppliers’ implementation of demand management measures (DMMs); plumbing codes requiring more efficient fixtures; the Model Water Efficient Landscape Ordinance (MWELO); advances in irrigation technology; new technologies in the commercial, institutional, and industrial (CII) sectors; and mandates requiring that unmetered connections become metered. But, with tighter environmental constraints on the Sacramento-San Joaquin River Delta (Delta), increasing population, and the necessity of adapting to climate change, even greater efficiencies will be needed and are achievable. When faced with an increasing demand for water, water agencies can consider options for increasing supplies or reducing demand, or a combination of both, to meet this need. Increasing water supply can be expensive and can include costs of purchasing additional water, capital cost of production and distribution systems, water supply treatment facilities, energy costs, and wastewater treatment facilities. Reducing demand through increased water use efficiency is generally lower cost and quicker to implement.

User Manual for the California Central Valley Groundwater-Surface Water Simulation Model

California Department of Water Resources (DWR) | June 13th, 2013

This report describes the input and output files for the California Central Valley Groundwater-Surface Water Simulation Model (C2VSim). C2VSim is an integrated numeri

This report describes the input and output files for the California Central Valley Groundwater-Surface Water Simulation Model (C2VSim). C2VSim is an integrated numerical model simulating land surface processes and groundwater and surface water flows in the main alluvial aquifer system of California’s Central Valley (figure 1). C2VSim was developed using the Integrated Water Flow Model (IWFM) application, which couples a three-dimensional finite element groundwater simulation process with one-dimensional land surface, stream flow, lake, unsaturated zone and smallstream watershed simulation processes. The C2VSim version described in this report runs under IWFM version 3.02 and utilizes a coarse grid, and is thus referred to as version 3.02-CG. In addition, the input files for the C2VSim model are regularly updated to correct errors, incorporate improved input data or extend the simulation time period. These updates are referred to as revisions; this report describes the data in revision R374, released in June 2013. The C2VSim model inputs include monthly historical precipitation, stream inflows, surface water diversions, land use and crop acreages for the simulation period, October 1921 through September 2009. C2VSim dynamically calculates crop water demands, allocates contributions from precipitation, soil moisture and surface water diversions, and calculates the groundwater pumpage required to meet the remaining demand. The coarse grid version of the C2VSim model incorporates a finite element grid with 1392 elements, grouped into 21 water budget subregions (figure 1), which are further grouped by drainage basin into five hydrologic regions. The model subregions are based on Depletion Study Areas (DSAs), originally created by the DWR Division of Planning for estimating regional water supplies and demands. Hydrologic parameters (including hydraulic conductivities, storage parameters and recession coefficients) were calibrated to match observed values including groundwater heads, groundwater head differences between well pairs, surface water flows, and stream-groundwater flows for the period between September 1975 and October 2003. The model simulates the historical response of the Central Valley’s groundwater flow system to historical stresses, and can also be used to simulate the response to projected future stresses. Agricultural groundwater pumping is not monitored in the Central Valley, and the C2VSim model provides pumpage estimates that are considered robust because they are constrained spatially and temporally by the estimated demand and surface water supplies. The calibrated model is also being used as the basis for the groundwater flow component of CalSim 3, a water resources planning model for simulating operation of the California State Water Project (SWP) and Federal Central Valley Project (CVP).

User’s Manual for the Draper Climate-Distribution Software Suite with Data-Evaluation Tools

U.S. Geological Survey (USGS) | March 20th, 2019

Development of a time series of spatially distributed climate data is an important step in the process of developing physically based environmental models requiri

Development of a time series of spatially distributed climate data is an important step in the process of developing physically based environmental models requiring distributed inputs of climate data beyond what is available from observations collected at climate stations. To prepare inputs required for model-mapping units across the study area, climate data (temperature and precipitation) are distributed by combining data from gridded surfaces of mean-monthly climate-data values with (often) widely spaced daily pointobservations. Examples of climate-data files used to develop PRMS-formatted input files for the Merced River Basin Precipitation-Runoff Modeling System (PRMS) are includedin this manual. The Draper Climate-Distribution Software Suite (Draper Suite) consists of the Draper climate-distribution program (Draper) and several supporting pre- and post-processing applications. Draper combines spatially distributed input in the form of monthly averaged values for precipitation, maximum temperature, and minimum temperature with daily observed data from climate stations to estimate distributed climate-data values at predefined locations across a study area (typically adrainage basin) on a daily time step. Alternative methods are used when station data are limited or missing for a particular day. Draper uses a set of required and optional input andoutput files with defined formats and naming conventions. Ashell application also is available to manage multiple runs of the Draper application. Other applications in the Draper Suite include (1) a toolto find and interactively remove outliers in the input data, (2) atool to check and enforce a minimum daily temperature range, and (3) a tool to view output diagnostic information as time- series graphs. These tools can be used iteratively to evaluate and improve the results from Draper as part of a work flow involving physically-based environmental models, such as the Precipitation-Runoff Modeling System (PRMS).

Using Landsat and MODIS satellite collections to examine extent, timing, and potential impacts of surface water inundation in California croplands

Remote Sensing Applications: Society and Environment (RSASE) | October 1st, 2022

The state of California, United States of America produces many crop products that are both utilized domestically and exported throughout the world. With nearly 39,000 km

The state of California, United States of America produces many crop products that are both utilized domestically and exported throughout the world. With nearly 39,000 km2 of croplands, monitoring unintentional and intentional surface water inundation is important for water resource management and flood hazard readiness. We examine inundation dynamics in California croplands from 2003 to 2020 by intersecting monthly surface water maps (n = 216 months) derived using two satellite remote sensing platforms (Landsat and Moderate Resolution Imaging Spectroradiometer [MODIS]) with a high-quality cropland map generated by the California Department of Water Resources. Surface water maps were produced using the Dynamic Surface Water Extent model, in which satellite image pixels are classified into different levels of detection confidence. Our analysis focused on calculating monthly and annual occurrence of “high confidence” water for each satellite collection across eight cropland types and 58 counties. Results indicate that 49.9% (MODIS) to 56.4% (Landsat) of croplands were inundated at least once during the 18-year timespan. Rice crops, due to their unique need of consistent surface water and dominance as a crop type in CA, had the highest proportion of and mean annual inundation area, while citrus crops had the lowest. Mean monthly inundation patterns in most croplands followed California's precipitation patterns with high inundation during the winter and spring rainy season. At the county level, croplands in the southern Central Valley typically had high occurrences of inundation in conjunction with large crop areas. Exposure and sensitivity of inundation for three crop types (citrus, deciduous, and vineyards) that are typically less associated with intentional inundation were geographically variable, but overall were generally highest in counties in the southern Central Valley, California's primary agricultural region. Flood and precipitation related crop insurance claims indicated that rice had the highest mean indemnity payout for any month with damages typically occurring in March and April. Insurance claims were also high in deciduous fruit and nut crops, which had peak damages in February. A comparison between inundation results and insurance claims suggests that the inundation mapped by our process coincides with claim activity. These data elucidate water inundation patterns across the state that can serve to inform farmers, insurers, decision makers, resource managers, and flood mitigation professionals.

Utah's Land, Water and Air 2022 Report to the Governor

Utah State University | November 30th, 2022

Utah's Land, Water and Air 2023 Report to the Governor and Legislature

Utah State University | October 19th, 2023

This report serves as a 2023 snapshot of key issues and concerns with Utah’s shared resources. It highlights gathered data that is available to provide context to thes

This report serves as a 2023 snapshot of key issues and concerns with Utah’s shared resources. It highlights gathered data that is available to provide context to these issues, as well as identifies areas where more study is needed. Addressing these challenges will enable Utah policymakers to make informed decisions for the future. Under the authorship of 43 researchers and experts and the general guidance of 49 advisory committee members, the report outlines 32 issues and trends to pay attention to in the coming months and years.

Valuing energy flexibility from water systems

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

From Maven's Notebook preview: * The researchers suggest a way to measure the value of using water systems to help manage energy needs. * Water systems are generall

From Maven's Notebook preview: * The researchers suggest a way to measure the value of using water systems to help manage energy needs. * Water systems are generally very efficient at adjusting their energy use, but with current designs, they can only provide a moderate amount of power and energy under typical conditions. * Upgrading facilities to improve their energy flexibility is often a good investment and is usually cheaper than adding battery storage on-site. * Different pricing systems for energy in the U.S. and around the world have the biggest impact on whether these upgrades will be profitable. * Recognizing the value of energy flexibility is the first step to encouraging energy storage, flexible energy use, and renewable biogas generation in the water industry.

Valuing Water for Better Governance: How To Promote Dialogue To Balance Social, Environmental, And Economic Values?

Pacific Institute | March 10th, 2007

Solving the freshwater crisis requires significantly more investment and spending in the water sector. But getting more money requires broader agreement among stakehol

Solving the freshwater crisis requires significantly more investment and spending in the water sector. But getting more money requires broader agreement among stakeholders than exists at present. A powerful way of obtaining broader agreement is to clarify through dialogues our values, value differences, and common ground. When this is done, people and businesses are willing to pay more for water systems and their governance, which in turn enables water systems and their managers to deliver more value to people and businesses. Dialogue about values also strengthens the legitimacy and sustainability of formal political decisions; many of which have been reversed or deferred at great cost because underlying value issues were ignored. Dialogue about values is essential to create a “virtuous circle” of progress in the water sector. This paper develops an initial intellectual framework for such dialogue.This paper was sponsored by the Business and Industry CEO Panel for Water and was originally presented at the 3rd World Water Forum, March 2003.

Ventura County and Upper Santa Clara River Drainage Area Land and Water Use Survey, 1961

California Department of Water Resources (DWR) | April 15th, 1965

The pastoral rolling hills and  agricultural valleys of  Ventura County and the Upper Santa Clara River Drainage  Area are  experiencing rapid changes in land and 

The pastoral rolling hills and  agricultural valleys of  Ventura County and the Upper Santa Clara River Drainage  Area are  experiencing rapid changes in land and  water use. The rural character of the landscape had remained somewhat stable until the expanding perimeter of urban development of Los Angeles County spilled over into the area. Increasing industrial  decentralization in the Los Angeles area has also  brought light industry to Ventura County, and the resulting increase in employee population has afforded new opportunity for commercial service and  supply enterprises to develop. The increased momentum of industrial and residential development is paralleled by  an equivalent rise in  water utilization. As a result, additional water supplies must be developed to meet the  current and expanding needs of this area. This bulletin is one of a series presenting the results of land and water use studies made by the Department of Water Resources. It contains the results of a land and water use survey conducted in 1961 in Ventura County and the Upper Santa Clara River  Drainage Area in Los Angeles County. This report presents information on  urban and agricultural development in the study area, and the present and projected water requirements for this  cultural development.  

Ventura Regional Groundwater Flow Model and Updated Hydrogeologic Conceptual Model: Oxnard Plain, Oxnard Forebay, Pleasant Valley, West Las Posas, and Mound Groundwater Basins

United Water Conservation District (UWCD) | July 2nd, 2018

United Water Conservation District’s (United) effort of the past six years to develop a significantly improved groundwater flow model for the Oxnard Plain and adjacent

United Water Conservation District’s (United) effort of the past six years to develop a significantly improved groundwater flow model for the Oxnard Plain and adjacent basins, as described in this report, is part of a broader effort by United and other agencies in the region to better understand the key factors that affect availability and usability of our area’s groundwater resources. Use of these resources, which have been supplemented for the past 90 years by spreading (artificial recharge) of surface water diverted from the Santa Clara River, has been key to the past growth and the future sustainability of cities and agriculture on the Oxnard coastal plain. Groundwater of suitable quality for a wide range of beneficial uses can be withdrawn from wells and delivered to cities or farms on the Oxnard coastal plain and in the Santa Clara River valley without construction of extensive, costly infrastructure projects (such as the aqueducts and surface reservoirs of the State Water Project), and provides a reliable water supply and resilience against potential major disruptions such as earthquakes and droughts. Although imported surface water from northern California began contributing significantly to the region’s municipal water-supply portfolio over the past half century, and desalination of brackish water or seawater may play an important water-supply role for the region in the future, neither of these alternative sources of water-supply can match the low cost and small environmental footprint of the existing groundwater resources, as enhanced by United’s recharge operations. Unfortunately, the relative accessibility, reliability, and low cost of groundwater for water supply has resulted in it being extracted from the aquifers underlying the Oxnard coastal plain at a faster rate than it has been replenished over the long term. This “overdraft” has resulted in corresponding groundwater-level declines in regional aquifers that have only been partly reversed during wet climatic cycles. In turn, these groundwater-level declines have resulted in seawater intrusion into the regional aquifers near the coast (since the 1930s), and could potentially exacerbate other water-quality problems or cause subsidence of land surface if allowed to continue. United coordinated with other regional water-supply stakeholders to plan and implement major projects in the 1950s, 1980s, and 1990s to mitigate the effects of overdraft, and these efforts have been partially successful. However, under California’s Sustainable Groundwater Management Act (SGMA) of 2015, groundwater sustainability plans (GSPs) must be developed and implemented by 2020 to provide long-term solutions that will prevent further negative impacts in “critically overdrafted basins,” including the Oxnard Plain and Pleasant Valley basins, and by 2022 for other groundwater basins in United’s service area. The geometry and physical characteristics of the aquifers, combined with the interactions of the stresses acting on those aquifers, within the regional groundwater basins are complex. The complexity is compounded by spatial and temporal variability of groundwater recharge and discharge. In order to forecast the effects of potential future water-supply alternatives with a sufficient level of certainty to evaluate and design new projects, it became evident to United in 2011 that the region needed a numerical groundwater-flow model that could discretely simulate each of the seven individual aquifer systems and six intervening aquitards that comprise the multi-layered regional aquifer system beneath the Oxnard and Pleasant Valley groundwater basins. The California Department of Water Resources notes that “while models are, by definition, a simplification of a more complex reality, they have proven to be useful tools over several decades for addressing a range of groundwater problems and supporting the decision-making process. Models can be useful tools for estimating the potential hydrologic effects of proposed water management activities” (Joseph and others, 2016). Numerical models of local groundwater basins developed by California Department of Water Resources in the 1970s, and by the U.S. Geological Survey in the 1990s, were useful for answering the questions about groundwater being asked at those times. However, these models assumed a greatly simplified hydrologic system, consisting of one, two, or three “lumped” aquifers, rather than explicitly modeling the seven aquifers (and six aquitards) that actually exist in the region. This oversimplification was necessary at the time due to limitations in available data, as well as limitations in computer processing power. Consequently, these models produced simulated groundwater elevations that did not always match measured groundwater elevations very well in some key areas, including near the coast and in recharge zones, reducing the reliability and increasing the uncertainty of forecasts for future conditions. Therefore, in 2012 United initiated, with financial and technical support from regional stakeholders, development of the numerical model described in this report (“Ventura Regional Groundwater Flow Model,” or VRGWFM), which discretely simulates each aquifer and aquitard underlying the Oxnard coastal plain as a distinct “layer” (in modeling terminology). The goal of this effort is to achieve significant improvement in calibration compared to previous models, allowing simulation of a greater range of natural and man-made hydrogeologic processes that have occurred in the past, and thereby increase the reliability of model predictions for the future. That said, the California Department of Water Resources warns, “there should be no expectation that a single ‘true’ model exists. All models and model results will have some level of uncertainty” (Joseph and others, 2016). For this reason, United is committed to continuous improvement of the VRGWFM as new data and improved methods become available, to minimize potential uncertainty. United would like to acknowledge the financial support provided by the Fox Canyon Groundwater Management Agency (FCGMA) and the Santa Clara River Watershed Committee, as well as the technical input and assistance provided by the FCGMA Technical Advisory Group (TAG), the Calleguas Municipal Water District’s technical staff and consultants, and the participants of the Expert Panel convened by United to review and provide guidance for improving the model (Dr. Sorab Panday, James Rumbaugh, and John Porcello). United would also like to acknowledge the various water and sanitation districts (including Ventura County Watershed Protection District), municipalities, and individuals that provided data to support development of the VRGWFM. We especially want to acknowledge the importance of the U.S. Geological Survey effort in the 1990s and 2000s to establish a regional groundwater monitoring-well network and construct the first MODFLOW model for the basins underlying the entire Santa Clara River and Calleguas Creek watersheds; their model was a critical “jumping-off point” for the VRGWFM. Finally, United’s Groundwater Department staff would like to recognize the foresight and patience of United’s Board of Directors, previous and present General Managers, and—most notably—former Groundwater Department Manager Tony Morgan, for their efforts in kicking off this modeling effort six years ago and guiding/pushing staff to completion of “Version 1.0” today.