Updating and recalibrating the integrated Santa Rosa Plain Hydrologic Model to assess stream depletion and to simulate future climate and management scenarios in Santa Rosa, Sonoma County, California

U.S. Geological Survey (USGS) | March 10th, 2025

The Santa Rosa Plain Hydrologic Model (SRPHM) was developed and published in 2014 through a collaboration between the U.S. Geological Survey (USGS) and Sonoma Water to an

The Santa Rosa Plain Hydrologic Model (SRPHM) was developed and published in 2014 through a collaboration between the U.S. Geological Survey (USGS) and Sonoma Water to analyze the hydrologic system in the Santa Rosa Plain watershed, help meet the increasing demand for fresh water, and prepare for future uncertainties in water resources. The original model simulated hydrological conditions and water use from water years 1975 to 2010. Recently (2023), the USGS, in cooperation with the California State Water Resources Control Board and Sonoma Water, updated the SRPHM model to extend its simulation period to the end of the 2018 calendar year, incorporate new estimates of rural and agricultural water use, and use an efficient input format for climate variables. The updated model was recalibrated, and evaluation of the new model calibration is included in this report. This report presents the results of comparing the hydraulic heads, streamflow, and groundwater budget simulated by the updated model with those generated by the original model and observed data. The main difference in the simulated budget between the original and updated SRPHM is the estimates of agricultural pumping, rural domestic pumping, and return flow generated from rural water use that was not simulated in the original model.

Updating the CALVIN Hydro-Economic Optimization Model of California: Central Valley Groundwater

University of California, Davis (UC Davis) | July 11th, 2012

Updates are being made to Central Valley groundwater in CALVIN, a hydro-economic model of California’s intertied water supply and delivery system. These updates reflect

Updates are being made to Central Valley groundwater in CALVIN, a hydro-economic model of California’s intertied water supply and delivery system. These updates reflect better estimates of water demands, groundwater availability, and local water management opportunities. This poster focuses on updating CALVIN groundwater parameters based on California Department of Water Resources’ (DWR) California Central Valley Groundwater-Surface Water Simulation Model (C2VSIM) and the United States Geological Survey (USGS) Central Valley Hydrologic Model (CVHM) model inputs and results. Two CALVIN update projects, using the DWR and USGS groundwater models, are underway to improve groundwater representation including basin inflows, reuse, return flows, capacities, and pumping costs. These sub-projects will result in a CALVIN model with updated groundwater representation based on C2VSIM and CVHM. This poster shows a preliminary comparison of these sub-projects and a summary comparison between the DWR and USGS models.

Urban hydrology and water management— Present and future challenges

Urban Water (Elsevier) | March 1st, 1999

Urban hydrology is an applied science that will have an increasing role to play in the sustainability of human societies. Facing present growth of urban population, it is

Urban hydrology is an applied science that will have an increasing role to play in the sustainability of human societies. Facing present growth of urban population, it is increasingly difficult to find and utilize new sources of water necessary to satisfy growing water demand. For the poor, the residents of peri-urban and squatter areas, an ultimate poverty, the poverty of lacking clean water, is a result. To remove this kind of poverty should be a first priority target for all people and, especially, for people dealing with water management in urban areas. Growth of urban areas brings significant changes in physical properties of land surface increasing integrated vulnerability of inhabitants, agricultural land and rural ecological life supporting systems. Performance of technical solutions depends on climate as well as on social, economical and cultural conditions. Findings from urban hydrological studies based on collection of urban hydrological data, calculations and modeling constitute a necessary fundamental for meaningful water management not only in urban areas but also in entire river basins. Future challenges in urban water management include development of new technical solutions as well as logistic and organizational methods in order to turn present problems into future opportunities. The following current and emerging challenges are discussed in the paper: delivery of drinking water supply for growing cities, water for sanitation versus sanitation without water, recycling of wastewater nutrients, wastewater irrigation, urban agriculture, water to feed depleted aquifers, thoughts about possible future new system solutions, social equity and transfer of knowledge and new technology.

Urban water affordability crisis exacerbated by climate change

NATure Portfolio (Springer Nature) | July 8th, 2026

Urban Water Demand in California to 2100: Incorporating Climate Change

Pacific Institute | August 28th, 2012

Climate change will have significant impacts in California not just on water supply, but also on water demand. A new, free tool from the Pacific Institute* helps water

Climate change will have significant impacts in California not just on water supply, but also on water demand. A new, free tool from the Pacific Institute* helps water managers to forecast urban water demand with four global climate change models and compare different possible futures to the year 2100 by altering greenhouse gas emissions, population projections, conservation and efficiency measures, and more. The research shows climate change will cause increased water use in California’s cities and suburbs, even as water supply is expected to diminish. Urban water use – residential plus commercial, industrial, and institutional uses – accounts for over 20% of the water use in California, and up to half of urban water use is outdoors. The new report Urban Water Demand in California to 2100: Incorporating Climate Change describes how warming due to climate change is causing increases in water demand for landscapes, and will continue to drive up future water demand, particularly as more Californians settle in warmer, drier inland areas. The Pacific Institute ran a number of scenarios through 2100. The analysis finds that climate change alone could increase urban water demand in 2100 by 8% percent, or around 1 million acre-feet, under a medium-high greenhouse gas emissions scenario. That is the amount of water needed to satisfy the current household needs of 6.7 million Californians. “A million acre-feet of water is significant, and, of course, climate is not the only driver affecting demand. But factoring levels of climate change into the mix is critical,” said Dr. Juliet Christian-Smith of the Pacific Institute Water Program. “Future water use in California depends on a range of factors – technological, political, and economic – many of which are uncertain, but water utilities still need to plan. We created a flexible modeling tool that allows users to run their own scenarios, comparing how a range of factors in a range of climate change scenarios is likely to affect future patterns of water use in their specific areas.”

Urban Water Revolution: Sustainable Water Futures for California Cities

American Society of Civil Engineers (ASCE) | July 15th, 2020

California has consistently altered natural water resources to provide water for its growing population and to support the fifth largest economy in the world. However, th

California has consistently altered natural water resources to provide water for its growing population and to support the fifth largest economy in the world. However, the old ways of coping with the California’s urban water needs—overdraft of groundwater, stream depletion, and greater imports—will no longer meet the demands of the 21st century. We examine California’s water history and present several promising solutions to the challenge of urban water security: a combination of conservation and efficiency, desalination, stormwater capture, water re-use, and water banking. These options for urban water, including direct potable reuse, will help dry cities in California and elsewhere achieve more sustainable and diversified water supply portfolios. Pilot and demonstration-scale projects, along with innovations in systems management and new regulations, point the way toward more resilient water supplies for dry cities. Movement toward regional collaboration, implementation of new technologies, and new regulatory regimes are helping to realize a one-water vision. Different cities will develop their own water supply portfolio options appropriate for their geography, values, and urban form on a path toward meeting the urban water challenges of this century.

Urban Water Systems—A Conceptual Framework

I.B. Tauris (Bloomsbury) | December 1st, 2014

We will here show how a focus on water/urban relationships can further our knowledge of city developments, and how urban studies can deepen our understanding of the rol

We will here show how a focus on water/urban relationships can further our knowledge of city developments, and how urban studies can deepen our understanding of the role of water in societies. The basic premises for this proposal are two facts of huge importance for understanding the history and development of the city; the universal needs of water and the actual, physical waterscape at a given place. All urban dwellers1—from the first few people who settled around a natural spring in a desert in Jericho and built a wall around it almost 10,000 years ago, to the Incas living in the royal city Machu Picchu on a mountain top in the Andes, to stock traders relaxing in spacious apartments in a skyscraper on Manhattan, and to the party officials assembled for one of their meetings in a grand conference hall in Beijing—share the need for one resource: water. The theoretical and empirical importance of this state of affairs can hardly be overestimated: these people all need water to survive, and as long as they live in cities, it has to be provided in one way or another. Water is the only universal urban resource that in this sense is a must and that can be controlled in this strict understanding of the word.

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.

Vegetation Responses to 2012–2016 Drought in Northern and Southern California

American Geophysical Union (AGU) | March 7th, 2019

In this study, we investigated California vegetation responses to the recent prolonged 2012–2016 drought, which was potentially the driest 4‐year span in the last 1,2

In this study, we investigated California vegetation responses to the recent prolonged 2012–2016 drought, which was potentially the driest 4‐year span in the last 1,200 years. The overall vegetation of the state has been presumed to be severely affected. However, Normalized Difference Vegetation Index (NDVI) satellite data related to vegetation greenness show that the large‐scale drought impacts on observable vegetation health were principally focused in Southern California regions, where the vegetation communities experienced striking declines in greenness. By contrast, some areas of Northern California have demonstrated significant NDVI increase and this difference in NDVI trends is evident over the past 19 years. The distinct vegetation behavior in Northern and Southern California seems to be related to a climatic dipole in the western United States, which is influenced by the large‐scale ocean‐atmosphere interactions. Some climate models predict an extension of such a dipole with greater precipitation in Northern California and less in Southern California by the end of the 21st century. Increased water demand in the south could intensify statewide intersectoral and interregional water competition in the future. However, increasing drought damage to wildlands and their terrestrial ecosystems in the south will not be relieved by any type of traditional water reallocation and irrigation effort.