Integrating Storage in California’s Changing Water System

University of California, Davis (UC Davis) | November 13th, 2014

Surface water reservoirs provide water supply and flood management benefits by capturing water when available and storing it for use when needed. Surface reservoirs are c

Surface water reservoirs provide water supply and flood management benefits by capturing water when available and storing it for use when needed. Surface reservoirs are commonly operated more for seasonal or short-term inter-annual needs. Groundwater aquifers generally provide longer-term storage and a source of water and seasonal storage in areas where surface water is limited. This paper reviews the benefits and challenges of water storage in California’s evolving water system, and provides some quantitative insights from an integrated analysis of this system. Water storage should not be viewed as isolated projects. For today’s water management objectives and conditions, surface water and groundwater storage should be considered and analyzed as parts of larger systems or portfolios of actions that include a wide variety of water sources, types and locations of storage, conveyance alternatives, and managing all forms of water demands. Such an integrated, multi-benefit perspective and analysis is a fundamental departure from most ongoing policy discussions and project analyses. The pilot study described in this paper focused on water storage and concludes that ability to utilize additional water storage in California varies greatly with its location, the availability of water conveyance capacity, and operation of the system to integrate surface, groundwater, and conveyance facilities. At most, California’s large-scale water system could utilize up to 5-6 million acre-feet of additional surface and groundwater storage capacity, and probably no more, which would likely provide 50-150 taf/year of additional water delivery for each million acre foot of additional storage capacity alone. The water supply and environmental performance of additional storage capacity is greatest when surface and groundwater storage are operated together. The benefits, and likely cost-effectiveness, of coordinating surface and groundwater storage and conveyance operations greatly surpass the benefits of expanding storage capacity alone, greatly expanding water delivery increases to as much as 200 taf/maf of additional storage capacity. Because we did not quantify and compare the economic value and costs of water supply and other benefits of expanding storage capacity, we cannot yet say if particular expansions would be economically justified. Similarly, because we did not comprehensively analyze the environmental impacts of expanding storage capacity or specific storage projects, we cannot yet say if particular expansions would be environmentally justified. Further, this study does not consider reoperation of existing facilities, water demand management, changes in prioritization of water uses or rights, or other policy or regulatory actions that might change the ability to supply water demands using existing water storage capabilities.

Integrating Water and Land Management: A Suburban Case Study and Locally Adaptable Tool

California Department of Water Resources (DWR) | October 15th, 2013

Managing the impacts of development on water resources is an urgent challenge in California. To support more efficient growth with fewer environmental impacts, the Califo

Managing the impacts of development on water resources is an urgent challenge in California. To support more efficient growth with fewer environmental impacts, the California Legislature and governor have adopted policies to better integrate land use and resource management. The Land Use Planning and Management Resource Management Strategy (RMS) located within California’s 2009 Water Plan Update calls for Low Impact Development (LID) and Leadership in Energy and Environmental Design (LEED) development approaches to reduce land use impacts on water resources. These strategies are suggested to decrease indoor/outdoor or residential water consumption, improve the quality of stormwater runoff, decrease the quantity and flow rates of stormwater runoff, and protect downstream riparian habitat. The 2009 RMS set in motion a study to quantify costs and benefits associated with water-smart land use practices. Following this 2009 initiative, the charter for the RMS in the 2013 California Water Plan Update proposed a land use decision tool and demonstration of its application through pilot projects. For the first time since 1957, the Water Plan will also include a land use objective linked to corresponding actions. Consistent with this approach, the California Department of Water Resources partnered with Sonoma State University’s (SSU) Center for Sustainable Communities and conducted four case studies of suburban development in Sonoma County. An “Integrated Water and Land Management Tool” was also designed and built as part of this project. This tool may be downloaded free of charge at the website for the California Water Plan Update 2013. < http://www.waterplan.water.ca.gov/cwpu2013/index.cfm > Then navigate to Volume 4. Although existing tools are available to guide practitioners, those that are easy to use generally could not be modified to reflect local conditions. And calculators that could be modified possessed challenging user interfaces that required extensive background knowledge. Thus, the project team determined that a user-friendly calculator with the ability to customize and save local data would be a valuable asset. The case studies were then compared and contrasted using the new tool. This allowed users to specify different residential land cover and infrastructure choices and compare development outcomes, especially at the lot and neighborhood levels. Guiding principles for the study and creation of the tool were to: • Create an open, locally modifiable, and user-friendly tool to help guide land use and land cover decisions • Quantify relationships between land use alternatives and key water management benefits relating to water supply reliability, flood management, water quality, habitat value, and greenhouse gas emissions • Quantify the monetary costs of implementing LID and traditional development strategies, including long-term costs • Compare and contrast outputs from different development approaches, as exemplified in four case study sites This report, “Integrating Water and Land Management: A Suburban Case Study and Locally Adaptable Tool”, proceeds in two major parts: developing the tool, and then applying the tool to four residential developments in Sonoma County, California, as a proof of concept. While preliminary conclusions are made from the analysis of the case studies, the primary contribution of this research effort is a new, open-source Integrated Water and Land Management Tool, which will further grow and develop over time as additional case studies and applications are completed.

Investigating the Role of Snow Water Equivalent on Streamflow Predictability during Drought

American Meteorological Society (AMS) | October 20th, 2022

Snowpack provides the majority of predictive information for water supply forecasts (WSFs) in snow-dominated basins across the western United States. Drought conditions t

Snowpack provides the majority of predictive information for water supply forecasts (WSFs) in snow-dominated basins across the western United States. Drought conditions typically accompany decreased snowpack and lowered runoff efficiency, negatively impacting WSFs. Here, we investigate the relationship between snow water equivalent (SWE) and April–July streamflow volume (AMJJ-V) during drought in small headwater catchments, using observations from 31 USGS streamflow gauges and 54 SNOTEL stations. A linear regression approach is used to evaluate forecast skill under different historical climatologies used for model fitting, as well as with different forecast dates. Experiments are constructed in which extreme hydrological drought years are withheld from model training, that is, years with AMJJ-V below the 15th percentile. Subsets of the remaining years are used for model fitting to understand how the climatology of different training subsets impacts forecasts of extreme drought years. We generally report overprediction in drought years. However, training the forecast model on drier years, that is, below-median years (P15, P57.5], minimizes residuals by an average of 10%in drought year forecasts, relative to a baseline case, with the highest median skill obtained in mid- to late April for colder regions. We report similar findings using a modified National Resources Conservation Service (NRCS) procedure in nine large Upper Colorado River basin (UCRB) basins, highlighting the importance of the snowpack–streamflow relationship in streamflow predictability. We propose an “adaptive sampling” approach of dynamically selecting training years based on antecedent SWE conditions, showing error reductions of up to 20% in historical drought years relative to the period of record. These alternate training protocols provide opportunities for addressing the challenges of future drought risk to water supply planning.

Irrigation Water Use in the Central Valley of California

California Department of Water Resources (DWR) | January 1st, 1985

It is Time to Expand the Geography of the Glen Canyon Dam Adaptive Management Program

Utah State University | December 2nd, 2024

It’s Time for States to Invest in Infrastructure

Center on Budget and Policy Priorities | August 10th, 2017

State investment in transportation, public buildings, water treatment systems, and other forms of vital infrastructure is key to creating good jobs and promoting

State investment in transportation, public buildings, water treatment systems, and other forms of vital infrastructure is key to creating good jobs and promoting full economic recovery. States should reject the flawed economic growth strategy of cutting taxes and offering corporate giveaways, and instead identify and make investments in infrastructure that provide the foundation for a strong economy. It’s a good time for states to make those investments.

James Groundwater Sustainability Agency Groundwater Sustainability Plan

James Groundwater Sustainability Agency (JGSA) | December 12th, 2019

James Groundwater Sustainability Agency Groundwater Sustainability Plan (Revised)

James Groundwater Sustainability Agency (JGSA) | July 22nd, 2022

*Submitted to the Department of Water Resources on July 22, 2022. No date or signature accompany the seal from the preparer at Provost and Pritchard.

*Submitted to the Department of Water Resources on July 22, 2022. No date or signature accompany the seal from the preparer at Provost and Pritchard.

Joining Forces: Innovative Co-Funding to Enhance Corporate Water Stewardship Impact in the Colorado River Basin

Pacific Institute | May 16th, 2023

The premise of this paper is that co-funding with existing and emerging funding mechanisms can help corporations tackle more complex problems at more meaningful scales in

The premise of this paper is that co-funding with existing and emerging funding mechanisms can help corporations tackle more complex problems at more meaningful scales in the Colorado River Basin and beyond. Corporations often have more flexibility than other funders, particularly federal and state agencies, in deciding how to spend their water stewardship budgets. This flexibility is an important asset, allowing funding to be deployed strategically. This white paper defines innovative co-funding as the intentional and focused use of corporate water stewardship funding alongside other funders and funding sources in new ways that expand the impact of corporate spending.

Just the Facts: Land, Water, and Agriculture in the Colorado River Basin

Babbitt Center for Land and Water Policy (Babbitt Center) | March 1st, 2022