The Department of Water Resources (DWR) hosted four informational webinars between July and September 2021 to provide background information related to the preparation of the Draft Environmental Impact Report (EIR) for the Delta Conveyance Project.  This post covers the third webinar in the series focusing on climate change.

The webinars were not a formal public input opportunity for the Delta Conveyance Project; rather, they are intended to keep the public and interested stakeholders informed about the current progress of the preparation of the draft EIR and to provide background about the approaches, methodologies, and assumptions that will be utilized in conducting impact analyses in the draft EIR.  The draft EIR is expected to be completed in mid-2022, and a formal public review and comment period will occur at that time.

The Delta Conveyance Project is a proposal by the Department of Water Resources to create an additional point of diversion in the northern Delta along the Sacramento River and a tunnel to convey water under the Delta to the export facilities in the South Delta.  The controversial project has been sought for decades and has gone through several iterations: most recently, the California Water Fix and, before that, the Bay Delta Conservation Project.  The Delta Conveyance Project is listed as one of the current priorities in the Newsom Administration’s Water Resilience Portfolio.

Delta Conveyance Project background

Carrie Buckman, the Delta Conveyance Project Environmental Project Program Manager with the Department of Water Resources, began the program by discussing the proposed project, the overall schedule, the planning processes, and future opportunities for public participation.

The purpose of these webinars is to provide background on technical topics in advance of the release of the draft environmental impact report or EIR, expected in mid-2022.  The goal is to share the methodology and assumptions the Department is using to evaluate the project’s environmental effects.

The Department is in the process of evaluating the impacts of the project, so the results aren’t known yet.  However, there will be a formal public review period once the draft EIR is published and many opportunities for public comments on that draft.

Ms. Buckman said the purpose of the Delta Conveyance Project is to modernize the aging State Water Project infrastructure in the Delta to restore and protect the reliability of SWP water deliveries in a cost-effective manner, consistent with the State’s water resilience portfolio.  The project will address sea level rise and climate change, minimize water supply disruption due to seismic risk, protect water supply reliability, and provide operational flexibility to improve aquatic conditions.

Project description

The project would construct intakes along the Sacramento River and a tunnel connecting those intakes to the south Delta. The tunnel would follow one of the routes shown on this map, either a corridor that goes through the central Delta, shown in green, or an eastern corridor closer to I-5, shown in blue.  The central and eastern corridors would come together into a southern forebay and a pumping facility that would regulate flows between the tunnel and the Bank’s pumping plant up into the California Aqueduct.

The Bethany alternative would follow the same tunnel alignment as the Eastern corridor, but rather than connecting to a southern forebay, it would instead connect to Bethany Reservoir through a pumping plant, thus eliminating the southern forebay as flows would not need to be regulated.

The proposed project is 6000 CFS, but it could range from 3000 to 7500. The number of intakes in the North Delta would vary based on the size of the intakes.

Schedule and timeline

Currently, the Department is working towards releasing a draft EIR for public comment in mid-2022.  Additionally, the Corps of Engineers is preparing a draft environmental impact statement under the National Environmental Policy Act or NEPA, and they are working to have the draft EIS completed on a similar timeline.  

Ms. Buckman noted that they will be different documents; as a regulatory agency, the Corps wanted to have a separate environmental impact statement.  But they are working to have a similar public review period that overlaps so that the public can review both documents simultaneously.

The Department is working towards a final EIR, Record of Decision, and Notice of Determination in late 2023.  Concurrently, they are working on other permitting processes, such as the biological assessment to comply with the Endangered Species Act and an Incidental Take Permit application for the California Endangered Species Act. Other permitting processes will follow in 2023-24, such as the water rights petition to change the point of diversion, the Delta Plan consistency determination, and other environmental permits.

A brief overview of CEQA

Ms. Buckman then provided a brief overview of the CEQA process, noting that it’s a complicated topic and a longer presentation on CEQA is available at the Department’s website.

The Department is preparing an environmental impact report or EIR under CEQA that will analyze the potential impacts of the proposed project on physical and environmental resources.  CEQA is a requirement for all public agencies subject to the jurisdiction of California to analyze the environmental impacts of a proposed project before its approval.  

The purpose of the EIR is to evaluate what could happen to the environment if the proposed project was implemented.  Under CEQA, agencies disclose potential significant environmental impacts, identify ways to avoid or reduce significant environmental impacts, prevent environmental damage if feasible by requiring implementation of alternatives or mitigation measures, foster interagency coordination and public participation, and show that the agency is considering environmental implications of actions before making decisions.

While EIRs may vary depending on the project, standard topics are typically included, such as a description of the proposed project and alternatives and the environmental setting, which is the baseline for analysis of impacts.  The EIR will discuss the potential for significant direct, indirect, or cumulative effects of the project and the alternatives. If significant effects are identified, potential mitigation measures will be included. 

The slide shows an overview of the CEQA process.  The first line is initial outreach; the Department filed a Notice of Preparation in January of 2020 and held scoping meetings at that time.  The process was documented in a scoping summary report, and a plan was developed to reach out to related agencies.

The second line, project description, includes defining the project, identifying and formulating alternatives, and producing technical reports.  The main focus currently, highlighted in yellow, is analyzing potential impacts and mitigation.  

This is the focus of what we’re going to talk about tonight,” said Ms. Buckman.  “We want to talk about the methods that we’re proposing to use and some of the background information that will help you understand that analysis process. We don’t have results yet, but we will be able to talk about the methods and discuss issues.”

The draft EIR will be prepared and the document circulated for public comment; it is currently expected to be released in mid-2022.  At that point, the Department will hold public meetings to hear public comments; written comments will also be accepted.  After the public comment period closes, the Department will respond to public comments, finalize the EIR, and issue a Notice of Determination.

Climate change overview

Andrew Schwarz, the State Water Project Climate Action Advisor with the Department of Water Resources, next gave an overview of climate change impacts on California that are already occurring, some projections for future impacts, and what DWR and the State are doing to address these impacts.

The greenhouse effect is a natural feature of our atmosphere and is responsible for making conditions on the Earth habitable; without it, the Earth would look more like Mars.

The greenhouse effect occurs because a thin layer of atmospheric gases allows solar radiation to come into the Earth but restricts some of it from leaving, which keeps the Earth warm. The problem is that over the last 100 years or so, emissions of greenhouse gases, such as carbon dioxide and methane, have been being released by human activities at increasing rates.  This has caused the thin layer of the atmosphere to build up and become slightly thicker, trapping more of that solar radiation that would have left out into space and resulting in some warming of the planet.

The fact that GHGs are causing enhanced warming of the climate system, and that human activities are the cause of the increase in GHG concentrations in the atmosphere, has now been validated by hundreds of studies using indicators and data from around the globe, and is considered incontrovertible by the vast majority of the world’s climate and atmospheric scientists,” said Mr. Schwarz.

However, it is important to note that California’s existing and historical climate has always been highly variable, he said. Not only does precipitation vary significantly across the state, geographically north to south and coasts to inland and mountains, but also seasonally with very dry summers and wet winters.

California has more year-to-year variability and precipitation than anywhere else in the lower 48 states,” said Mr. Schwarz, noting that the darker colors on the map represent years where precipitation varies more from the long-term average.  “Southern California in particular, but all of California in general, and particularly covering the Sierra Nevada region where we get most of our water supply from, is very highly variable year to year. We’re seeing in the last few years where we’ve seen 2017 is one of the wettest years on record, on the heels of two of the driest periods 2012 to 2016 drought, and now the two year period that we find ourselves in today.”

In addition to California’s interannual variability, California is uniquely difficult to predict how climate change will affect precipitation patterns.

Global climate models have more disagreement about whether climate change will lead to more precipitation or less precipitation across California than nearly any other region of the United States,” said Mr. Schwarz.  “This wide range of variability and predictability creates an additional challenge for California water managers.”

As for the impacts of climate change that California is already experiencing, the slide shows the observed trends and data from measurements throughout the State.

The figure on the slide from NOAA highlights how much temperatures have already changed.  “This is not any projection of the future,” said Mr. Schwarz.  “This is what has already happened.  You can see that for most of California, average temperatures are about one degree Fahrenheit warmer than they were just ten years ago. That’s a rate of change that is completely unprecedented in the historical record.

Likewise, mean sea levels are six inches higher than forty years ago, and precipitation is becoming more variable and more extreme at both the wet and dry end of the spectrum with observed very wet and very dry periods just in the last ten years, he said.

The slide shows the 20th and 21st-century observations for annual average temperature and average annual precipitation; the gray dots represent 21st-century observations, and the blue dots are 20th-century observations.  The triangle in the middle is the entire 100-year record average; 2020 is shown in red.

What you can see is all of those observations in gray are concentrated on the right-hand side of the graphic showing that these years are all generally warmer than the earlier year records, and the precipitation is more or less scattered across the range,” said Mr. Schwarz.  “We’ve only had 20 years of the 21st century, where we had 80 years of observations from 1922 to 1999, in the 20th century.  And we’re already seeing some observations that are very high on the precipitation end and very low on the precipitation ends. So we would expect that that range to expand even further as we move further into the 21st century.”

The slide above shows the California Statewide April 1 Snow Water Equivalent for 1950 through 2020, an important measurement of our snowpack.  Rain and streamflow are key aspects of California’s water supply, but California is unique in that the state has relatively small levels of surface storage in the system. Therefore, the state’s water system was designed with the snowpack in mind, assuming that winter snowpack would stay high in the watershed until the middle to late summer and spring, where it would be released slowly to refill reservoirs and be available for water supply later in the year.

So the state depends on the snowpack, and the Snow Water Equivalent is a measure of the amount of water trapped in the snow. April 1 is the traditional key annual measurement because it’s the end of the snow season and before the majority of melting has started to occur in the snowpack.

What we can see from this graphic is while this signal and the data are very noisy, we have very high snowpacks going up as high as 230+% of average down to just 5% of average,” said Mr. Schwarz.  “This trend line is disturbing, and it is decreasing considerably over the last 100 years. And we’ve seen in just the last ten years, some very low snowpack numbers – in many years below that 50% mark.”

This graphic shows the proportion of average annual precipitation that falls as rain; the years in red had more rain than the mean, and the blue are years where snow was above the mean. 

We don’t yet detect a long-term trend yet in the amount of precipitation that we’re getting, but what we do see is that the percentage of that precipitation that is falling as rain is increasing,” said Mr. Schwarz.  “This means that more of that precipitation is falling as rain during winter, and it’s falling and running off immediately through our reservoir system.  All of our major reservoirs in California are multipurpose reservoirs.  That means during the winter season, they are managed for flood control, to provide public benefits for flood protection by detaining water during big flow events, releasing it slowly, and making sure that there’s ample storage in those reservoirs to retain the next flood event.

So often, if we get additional precipitation in winter, we have to let that water pass through the reservoirs,” he continued.  “We aren’t able to hold it for water supply late in the season, and when we get to the end of the flood control season in March and April, when we’re able to refill those reservoirs, that precipitation that should have been snow that’s already gone.  So we lose that part of the water supply.  The graphic shows that we’re seeing a considerable increase, particularly in the last decade or so in the proportion of the precipitation that is falling as rain as opposed to snow.”

Where do these modeling projections come from?  Most of the projections come from Global Climate Models or GCMs.  These are complex ocean and atmospheric models of the Earth system that use mathematical equations to mimic these processes and provide information about how the atmosphere is expected to evolve in the future.

Global climate models are designed to provide general information about the global environment, but the resolution is too coarse for most regional and local climate studies.  So the data in these models is typically downscaled to a local or regional scale, which usually involves observational information from the past to downscale the coarse information on the global scale to a fine or regional scale.  He likened global climate data to the Duplo-sized Legos (extra large size) and the finer resolution data to the smaller-sized Legos.

Another important aspect of global climate model projects is greenhouse gas emissions assumptions, sometimes called RCPs, or representative concentration pathways.  These are assumptions about what will happen to greenhouse gas emissions over the next 50 to 100 years.

That is an unknown, and there is uncertainty,” said Mr. Schwarz.  “We don’t know how national governments will react and how citizens of the world will behave in terms of converting our energy systems to more renewable supplies, changing our transportation system, and how technologies will develop to facilitate that.  So there are different assumptions about whether we follow a path closer to the historical path of high GHG emissions or if we will change our behavior, reduce greenhouse gas emissions, and stop the continued warming of the system. So you’ll often see projections that have a worst case-best case bookend situation. And that is often using a worst-case scenario GHG emissions pathway or a best-case GHG emissions pathway.”

The other uncertainty is that there are dozens and dozens of global climate models put together by different research universities and governments worldwide that use different types of equations and different assumptions, so they all come up with slightly different results.  

The best practice is to use more of those models to get a wider range of what might happen to cover your uncertainty range, and that will also sometimes contribute to the range of outcomes that we might see in the future,” he said.

Climate model projections show a stark reduction in snowpack by the year 2100.  The slide shows the projections for the historical range for the April 1 snow water equivalent and the best and worst-case scenarios.  The best-case scenario is that there would be 50% less by the end of the century; the worst case could be as much as 65% loss by the end of the century. 

Warmer temperatures mean that the snow will melt earlier, and more precipitation will fall as rain rather than snow.  By the end of the century, projections show just the highest parts of the southern Sierra Nevada retaining much of their snowpack.

Projections also show much lower soil moisture, as was experienced last year with extremely low soil moisture throughout the watershed, contributing to very low runoff rates. 

The figures on the slide above show the projections for streamflow that could occur due to the loss of snowpack.  The traces are hydrographs showing the stream flows over the water year; the Sacramento River is on the left; the San Joaquin River is on the right. 

The black line is the historical record of how runoff has occurred; for the Sacramento River, historically, the runoff ramps up until January, remains high through May and then starts to decline as the snowpack diminishes. In contrast, the San Joaquin, because those mountains are much higher, has a much later and more significant peak in May as the snow melts out.  Mr. Schwarz noted that the scales are different between the two graphics; the Sacramento has about four times as much runoff as the San Joaquin.

The blue line is the projection for mid-century, centered around 2050; the red line is the projection for the late century or 2070-2100.  

You can see the shifting earlier in the year of this runoff and the much higher peaks in the winter season again when we’re managing for flood control, and we can’t capture that water and save it,” said Mr. Schwarz.  “The lowering of the runoff comes during that dry season when we really can use it to refill reservoirs and deliver for our multiple benefits in the system and when it is most helpful for the ecosystem as well.”

The slide below, from the Delta Stewardship Council’s Delta Adapts report, shows a probabilistic look at potential flooding in the Delta as a result of both sea level rise and changes in runoff.  Runoff increasing during the winter months is also a flood risk downstream and particularly in the Delta.  The darkest blue areas indicate the highest flood risk and more likelihood of flooding on a more frequent recurrence; the very lightest blue indicates areas that would flood only in the wettest of events.

The figures show that in 2020, flood protection is fairly good for most of the Delta, except for Suisun Marsh, which is mostly agricultural and marshy areas designed to flood on a more frequent basis.  But moving towards the future, large areas of the South and Central Delta become much more impacted by potential flooding, as well as some significant urban areas and legacy towns in the Delta.

I want to clarify that one of the assumptions in this model is that levee elevations throughout the Delta stay at their current levels,” Mr. Schwarz said.  “They don’t decrease with subsidence or consolidation; they also aren’t raised with any new investments in levee improvements. We know that things will change in the future. But it’s very hard to know exactly what those changes will be.”

Preparing for climate change impacts

The State has been thinking about and addressing climate change for decades now.  The fourth California Climate Change Assessment, released in 2018, outlines several anticipated climate impacts by 2100 and looks at a wide array of sectors that would be affected, including the energy sector, water sector, agriculture, and environmental justice communities.  Several academic studies and research were funded through those projects.

The California Water Resilience Portfolio lists more than 100 separate detailed actions to ensure the State’s water systems work for the communities, economy, and environment.  The Delta Conveyance Project is one of these actions listed in the portfolio, as well as other significant infrastructure upgrades.

California also has an adaptation strategy that is currently being updated; it looks at four broad approaches: maintaining and diversifying water supplies, protecting and enhancing natural systems, building connections, and being prepared.

The Sustainable Groundwater Management Act, passed in 2014, requires groundwater basins to be managed sustainably.  Groundwater is a significant source of water supply, particularly during drought periods. Therefore, it’s essential to manage it effectively and not overpump aquifers so that the water is there during dry times.

The Department of Water Resources has a three-phase Climate Action Plan. The first phase, a greenhouse gas emissions plan, was adopted in 2012 and updated in 2020. The plan commits DWR to reduce GHG emissions by 60% below 1990 levels by 2030 and be completely carbon neutral by 2045.  DWR and the State Water Project, in particular, are large users of electricity, so this is an important prong in the State’s approach to reducing GHG emissions.

The greenhouse gas emissions plan also outlines how the Department’s projects can be consistent with the plan and help achieve these goals.  Mr. Schwarz noted the Delta Conveyance Project would be part of that and consistent with the plan.

Phase two of the Climate Action Plan is consistent climate change analysis across all DWR’s programs.  This phase outlines the technical rigor and best scientific information that will be used to complete climate change analyses on the Department’s projects.  This phase also informed what should be included concerning CEQA documents and climate change information and disclosure.  

The Delta Conveyance project is following those guidelines to make sure that it’s providing information to the public on how climate change will impact the project and GHGs,” he said.

The third phase of the Climate Action Plan, a vulnerability assessment and adaptation plan, was finalized in 2019. The vulnerability assessment looked at wildfire impacts, extreme heat impacts to employees, particularly those who work outdoors, and how sea level rise would impact Delta and other coastal facilities.  It considers the effects of long-term persistent and short-term extreme hydrologic changes on water supply, flood risk, habitat, and ecosystem services.  The Department is currently working on an adaptation plan to implement and address many of the key vulnerabilities identified in that plan.

Beyond the Climate Action Plan, the Department also looks at additional operational and infrastructure improvements to facilities, including Delta Conveyance and others.  The Department is investing heavily in watershed studies to develop technical tools and resources for other watersheds and water managers throughout the state so that they can conduct rigorous climate change studies for their areas and operations and start to do their own adaptation planning.

‘Moving to Action’ is a network of professionals involved in climate change and water resource management throughout the State and the nation that DWR is spearheading and facilitating.  “This is really about talking about what actions need to be taken, facilitating that action, getting people together, combining resources, and drawing synergies out of out of those conversations,” Mr. Schwarz said.

The Sustainable Groundwater Management Act, or SGMA, is being implemented by DWR.  “DWR has provided a lot of the technical assistance and written much of the guidelines and the regulations for the implementation of SGMA and continues to provide important climate change information for the analysis of future impacts on groundwater that will be used in those plans,” he said.

Integrated Regional Water Management Planning, a DWR initiative for decades, funds and facilitates regional cooperation and collaboration to build and implement strategies to make water management more reliable and resilient.

Concluding thoughts …

Mr. Schwarz reiterated that California’s current climate is highly variable, and climate change just increases that variability.   “It leaves a lot of uncertainty for water managers, so water management flexibility is and will continue to be a key objective for DWR to adapt to climate change and the uncertainty that it brings.  Storing and moving water when it’s available to meet water needs during dry periods has always been a key function of the State Water Project, and we intend to continue to operate under those principles.”

Delta Conveyance design process

Carrie Buckman then briefly discussed the design process for the Delta Conveyance Project.  

We have included a set of conservative design assumptions to ensure the project is durable,” she said.  “So we considered the hydrologic changes with climate change at 2085, and so we used the Ocean Protection Council’s 2100 H++ scenario for sea level rise of 10.2 feet at the Golden Gate.

I wanted to mention just how conservative that is,” she continued.  “The Ocean Protection Council identifies multiple different potential future scenarios for sea level rise.  They have likely and less likely scenarios, and then they have the H++ scenario, which they don’t even assign a probability to because it is unlikely. It is a scenario that reflects the melting of the polar ice caps, so it’s a pretty extreme scenario. But we wanted to make sure that as we work on the design of facilities, because these are long-term facilities, that they would still be able to be used and would not be inundated if there was climate change that reflected this type of scenario in the future.”

So the design elevations considered sea level rise and were also based on a 200-year flood risk at 2085 that considers the hydrologic changes associated with climate change and changing runoff patterns into the future.

Those are a little different because our objective was different with the EIR; we’re looking at likely potential future conditions, reasonably foreseeable conditions.  But for the design, we are looking at a condition that is more conservative so that we are really sure that this could be durable into the future.”

Addressing climate change

Maggie Messerschmidt, Environmental Scientist and Project Manager, Climate Adaptation and Resilience with ICF International, then discussed how climate change will be addressed in the draft environmental impact report.

There are three ways that climate change is being addressed in the draft EIR:

  • Air quality and greenhouse gas emissions and how the project could contribute to those greenhouse gas emissions are being analyzed.
  • The hydrological modeling incorporates climate change projections to assess the impact of climate change on Project operation.
  • How the project could contribute to climate resiliency is being considered, especially for water resource reliability.

The subject of this webinar is primary the second and third bullets.

The hydrologic analysis incorporates sea level rise projections and downscaled temperature and precipitation projections into a no project alternative analysis at 2040 that will help understand how climate change will impact project operations.

Sea level rise, temperature, and precipitation are being considered directly in the development of the project design.  Climate change indicators are being incorporated into the climate change chapter.

The diagram shows how the climate change models feed into the hydrological models that will inform both the climate change chapter and specific resource chapters.

The time horizon for the EIR is 2040, although Ms. Messerschmidt reminded that the project design considers the 2085 scenario. 

The primary models being used are the 10 CMIP5 global climate models under two greenhouse gas scenarios: Representative Concentration Pathways (RCP) 4.5 and 8.5.  Those ten models at those two greenhouse gas scenarios complete a 20 climate model ensemble; those 20 models are then downscaled to a 2040 central tendency climate change scenario, based on those temperature and precipitation predictions.  A technical advisory group chose the 20 model ensemble out of a possible 64; the 20 models were selected because they are most representative of the hydrological features for California.

For sea level rise, the analysis is also considering the H++ scenario (the extreme scenario) and the 2018 guidance from the Ocean Protection Council, which is  1.8 feet at 2040 at San Francisco.  They are also analyzing the operations of the State Water Project and the Central Valley Project under climate change based on operational and regulatory conditions.   All of that is incorporated into the analysis of the no-project alternative in the resource chapters.

The project’s climate change assessment considers three questions:

  • How climate change could impact the study area itself: The Department will be reviewing any recent trends and climate change projections both at mid-century and towards the end of the century to understand how climate change could impact the study area.
  • How climate impacts to resources in a study area occur from climate change: The Department will review expected climate impacts in the study area itself to understand how resources may be impacted by climate change. They will review the no project alternative analysis conclusions for other resources and see how those could change existing conditions.
  • How the project could affect the resiliency of the study area, particularly in regard to California water resources: The Department will be reviewing the resource chapters that will be incorporating the 2040 analysis and the appendices to assess how the project might increase resilience in the region to the effects of climate change, especially sea level rise, temperature changes, precipitation changes, drought and other the climate variables that will affect our water resources.

Ms.Messerschmidt noted there aren’t any CEQA requirements currently for that kind of impact analysis, but DWR’s phase 2 vulnerability assessment has guidance on incorporating climate change impacts for informational purposes, so that is the guidance they are following.

Global climate trends first inform the local climate trends, so they look to the latest IPCC report on the physical science basis published in 2013.  They are also looking at the sixth assessment, just recently released.   

We are working to update anything that we’ve written about the fifth assessment with the six assessment report.  There are not any major changes anticipated, just some increased certainty around some factors, so any of the wording or edits will be based on the sixth assessment,” she said.

The California Fourth Assessment Report has a report that looks at the climate change impacts to the State Water Project and the Central Valley water resource system.  The summary report captures broader trends for the different regions of the State.  The reports from He et al. and Pierce et al. are especially relevant for the sea level rise downscaling done for California.

One of the objectives of the project is to address the sea level rise,” said Ms. Messerschmidt.  “Some of these impacts are changes to runoff and our water system. So one thing that we are hoping to do with the EIR is to illustrate how the project is actually increasing resilience to these climate trends.”

Questions and answers

QUESTION: Has the work already started on the Delta tunnel? My understanding is that land has already been moved. 

I wanted to make sure we are really clear that no, the Delta Conveyance Project has not been approved and has not started any kind of construction,” said Ms. Buckman.  “The only somewhat related activities are some soil investigations in the Delta; they were considered under a separate initial study and mitigated negative declaration. The purpose is to investigate geotechnical conditions within the Delta to provide planning information for Delta conveyance and increase DWR’s overall understanding of Delta geology. So that does include some soil borings and cone penetration tests, but it’s not moving any dirt. It’s just borings to understand geotechnical conditions. There has been no approval and no construction.

QUESTION:  Which islands pose the greatest risk of saltwater intrusion into the Delta? What is being done or can be done to protect the levees?

I think it’s been generally shown that the far western islands are really important to maintaining salinity control in the Delta,” said Andrew Schwarz.  “Those levees have been improved over the last few years.  And there is a Delta Levees program that has been functioning throughout the Delta for, I believe, over 40 years, so that continues to be an important source of funding for improving those levees moving forward.

I don’t think that the levees specifically are part of this project, but DWR has other projects and other programs that work on managing and improving those levees. Most of those levees are owned and maintained by private owners and local maintaining districts, so DWR often contributes to the funding that those districts themselves put out to help maintain and improve those levees.”

QUESTION:  Can you talk more about the Delta Adapts study and its assessment of flooded islands and water.

Delta Adapts is the Delta Stewardship Council’s vulnerability assessment for the Delta that was finalized just earlier this summer,” said Mr. Schwarz.  “It covers a wide range of resource impacts: water supply, flood, ecosystem, environmental justice communities, and extreme heat throughout the Delta. There’s rigorous new analysis on agriculture as well early all of those impacts. I showed just one of the graphics from that report, but there’s a lot of great information in there that talks about potential impacts of climate change on the Delta.”

QUESTION: Does the flood risk analysis in the Delta through Delta Adapts and the Delta Conveyance Project assume that upstream reservoirs are not expanded? Is Sites Reservoir included?

For the Delta Conveyance Project, we’re considering reasonably foreseeable projects,” said Ms. Buckman.  “So we have a set of criteria that we consider, including whether environmental planning and feasibility is complete and whether funding is secured. So at this point, expansions or new upstream reservoirs are not included in our future modeling conditions.”

Delta Adapts does not assume that upstream storage will be built,” said Mr. Schwarz.  “It’s worth noting too that like Sites Reservoir is an off-stream reservoir and its ability to reduce flood flows into the Delta is not huge. It’s not like a new big on-stream reservoir. So, yes, it would reduce the peak flows a little bit, but I don’t think it would make a dent in some of those 200-year flows or things that would really cause flooding in the Delta.”

QUESTION: You mentioned that the GHG reduction plan has a goal of 60% reduction by 2030. Does the State account for wildfire smoke in evaluating and monitoring the State’s ability to meet this goal? Now the economy is more open and people are driving more, how well is the State doing towards reaching this goal?

I can’t speak directly to the state’s goal of reducing greenhouse gas emissions writ large and how wildfires would contribute to that,” said Mr. Schwartz.  “DWR’s plan just covers the activities for which we have authority and control over, such as the operation of the State Water Project, all of our fleet vehicles, and the electricity, heat, air conditioning in our buildings, and those kinds of activities. For example, state Water Project operations are a very large user of electricity, and this is not insignificant at all.”

The other thing I would say about wildfire is generally those emissions are not accounted for because it’s not fossil fuels being burned.  The trees are in the shorter-term carbon cycle. It certainly isn’t good for all of that carbon to be released into our atmosphere, but there is at least potential to regrow those trees and retract that carbon in a shorter term than burning coal or natural gas.”

QUESTION:  There are questions on data sources and whether the most recent IPCC data is being used.

I mentioned that there is a sixth assessment out from the IPCC,” said Ms. Messerschmidt.  “Currently in California, there are a bunch of researchers working to downscale projections to California, but we won’t have those updates in time for this project.  The fourth climate assessment that was completed in 2018 does use downscaled projections from CMIP5, which is pretty darn good in the meantime. There are constant ongoing efforts to be updated. And as soon as we can use that information, we do use that information.”

QUESTION: Does DWR and ICF consulting expect to be using CMIP 6 from the sixth IPCC report with the downscaled projections for California for the draft EIR by the spring of 2022. We think you should because if you don’t, you’ll be vulnerable to a charge that you won’t have the best available science for the EIR/EIS on the DCP.

It would be great to hear what CMIP 6 downscaled information will be available for use at that time,” said Ms. Messerschmidt.  “We are incorporating any additional findings from the Intergovernmental Panel on Climate Change and would certainly incorporate into any trends and any latest studies.  So I think the big question is, with the modeling that is being performed, is the timeline is aligned with the release date of any updated CMIP 6 information.”

QUESTION: We already see changes in climate-related to drought and reduced snowpack. And it seems clear that there would be fewer but more extreme winter precipitation events.  So the question is, how would heavy downpours and major storms affect tunnel excavation and runoff on sites? How would runoff and water quality be managed at a location? Would there be erosion from construction sites? 

A lot of this is being addressed through the Delta conveyance Design and Construction Authority as part of the conceptual design is working to manage the potential for runoff and erosion,” said Ms. Buckman.  “So the sites that would be storing materials and stockpiles would have levees surrounding them that would contain everything within the site. So there would not be erosion and runoff off of the site, as all of that water would be captured for reuse and treated. Additionally, they are planning to accommodate the storm events and heavy downpours.”

QUESTION: With sea level rise, salinity is expected to push further into the Delta.  The freshwater-saline zone is important and potentially problematic for fish and agriculture.  How are you evaluating salinity intrusion and the potential effects of the Delta Conveyance Project?

Salinity intrusion is being looked at in the water quality section,” said Ms. Messerschmidt.  “Those sea level rise projections are incorporated into a model. … There are models informed by this schism, which is based on those H++ scenarios across the time horizons that we were discussing.  So for water quality, in particular, we’re looking at the 2040 to 2100 timeframe.”

QUESTION: I’m worried about saltwater intrusion into the Delta and how it will affect disadvantaged people in the area because they won’t have drinking water. I know that the water flows to mitigate against that. But I don’t see how the Delta can be kept fresh with the rising sea levels.  How does this project address salinity?

I can start by framing the question a bit,” said Carrie Buckman.  “As part of our EIR, we are focused on the effects of a potential Delta conveyance project, so we’re looking at how a Delta Conveyance Project would potentially change the environment compared to what will be happening in the baseline.  We are comparing the Delta conveyance project primarily to a baseline under existing conditions. So we will be looking at the potential for Delta conveyance to affect salinity in the Delta specifically under those conditions.  We will also be looking at a future no project without Delta conveyance, and that does capture climate change and any potential changes to salinity and other water quality parameters in the Delta.”

While CEQA does not require it, we are going to have an appendix that does look at Delta conveyance under those future conditions as well to see if it would change the way that Delta conveyance affects the environment if we look at it with climate change,” Ms. Buckman continued.  “We don’t need to include it for CEQA, not the way that CEQA requires the analysis. But we’re doing it because we think it’s good for disclosure.”

I would just add that salinity in the Delta is a function of the regulations that govern Delta water quality and are set by the State Water Resources Control Board, not DWR or anybody else,” said Andrew Schwarz.  “So the project, with or without a tunnel, is operated to meet those requirements for water quality.  Sea level rise certainly makes meeting those requirements difficult. And we end up probably currently releasing some of our stored water to repel that salinity that is the result of the sea level rise that we’ve already seen. So now and in the future, the project operates to those requirements; that’s what governs, and those requirements are met first before water deliveries are made.”

We hear a lot of concern at other meetings as well that people are concerned that by having a North Delta diversion in addition to the south facilities in the Delta, DWR would be less inclined to manage water quality in the Delta,” said Ms. Buckman.  “We have to; it’s the law. So even if we have a dual conveyance system, it is still important to us because we plan to use the south Delta facilities. But aside from that, we are required to meet those requirements from the State Water Resources Control Board. So it’s it would still be a requirement either way.”

QUESTION:  Other studies, such as Delta Adapts from the Delta Stewardship Council, have talked about water exports potentially becoming less reliable in the future, regardless of wet or dry years. How will the EIR reflect the reliability of supplies into the future?

In multiple ways,” said Ms. Messerschmidt.  “One thing that we are trying to understand is what is the role of this tunnel in increasing reliability for the south of the Delta area; it’s also understanding how storage requirements and flooding earlier in the year might change in regards to that earlier runoff. So I think we’re thinking of this project as one, not necessarily silver bullet, but one of many projects that are underway to increase the reliability of the broader system.”

Back to our project objectives, that is the main reason we’re considering this project is that we are concerned about the potential future reliability concerns associated with the change in precipitation, so more rainfall, less snowpack, and the flashier storms,” said Ms. Buckman.  “So Delta Conveyance is a way to potentially try to address some of those things. And that’s something that we are evaluating – whether it would increase resilience.”

QUESTION: Regarding a no tunnel alternative, it seems like the paradox is a complete do nothing alternative or this huge $40 billion environmentally destructive project. But there is also the option that we don’t build the tunnel but do more to repair local levees and repair things in the Delta. So it really shouldn’t be, just do nothing or build this huge tunnel.  I don’t think that’s something that has been considered enough. Can you speak more about why that isn’t something that DWR has looked at?

The fundamental reason we’re considering it is to allow the State Water Project to continue to function in the face of many problems, so having an alternative that would allow the State Water Project to continue to degrade and not to address the concerns associated with climate change, sea level rise, and earthquake risk does not meet our objectives,” said Ms. Buckman.  “That said, we understand that if the State Water Project continued to degrade, local water agencies would likely undertake projects such as recycling and desalination and potentially increased conservation if they can, and potentially increased groundwater storage or other types of local projects. So we are working to incorporate those in our no project alternatives, so our no project alternative does look at a programmatic level analysis of the implementation of those types of projects in addition to just no change in the State Water Project diversion facilities.”

QUESTION: Do the intakes north of the Delta in any way affect or reduce the amount of freshwater that flows or would flow potentially through the Delta?

Water diverted at the North Delta would potentially change diversion patterns,” said Ms. Buckman.  “So one of the things that we’re trying to capture with this new North Delta diversion would be to look at capturing flows when it is available.  In the last workshop, we talked about the operational criteria that we would apply; essentially, we can only divert a substantive amount at those North Delta facilities if flows are high. The focus is trying to capture higher flows. So it would have a small decrease of the freshwater moving into the Delta. But because there are requirements for how much flow must move past those intakes, it would be at times of high flow, as the goal is to avoid effects to the Delta by having those diversions.”

QUESTION:  Why is there a range of 3000 to 7500 CFS for the alternatives?  What is the flow at the intake locations been historically in periods of drought?

Regarding flows during periods of drought, the criteria used to divert water was discussed in the previous webinar; the project could not divert water during low flow conditions, said Ms. Buckman.  “During drought years, there are often storms that have flashy flows, and it might be possible to divert water in those short term periods. But for the most part, and drought years, the Delta conveyance project wouldn’t be operating very much, so it would be very minimal. So during drought years, if there is low flow, we wouldn’t be taking water; it wouldn’t change the flow coming into the Delta.

In terms of the range of capacity, a lot of that range of capacity is based on comments we received,” she continued.  “So we had a proposed project of 6000 CFS; we did identify a potential range based on things that we heard going up to release of the notice of preparation. And we did, in fact, receive comments about trying to include alternatives that had different capacity ranges. So we’re looking at lower and higher capacity so that we can see if that changes the range of potential effects.

QUESTION:  Regarding capacity in drought years, isn’t it a bit naive to believe that the law won’t be changed if there’s a terrible drought?  I wonder if the capacity won’t be used if there are a lot of people down there that need water? I think that perhaps that’s worth thinking about. In other words, you’re drawing boundaries that may not prevail if the rubber meets the road. Now, that’s not exactly a question but more of a statement … This is something that I’ve lived through. I can remember in the mid-70s when there was a terrible drought. Here in Northern California, we couldn’t use water to wash cars. And you could see pictures of people in Los Angeles spraying their cars with water for some reason or another. And I don’t want that to happen again.”

I have heard that concern before that during drought conditions, there may be additional diversions,” said Ms. Buckman.  “A couple of thoughts on that. One of them is that we will not be permitted to do anything higher. It’s not just DWR s decision about how much we would want to divert; in addition to our environmental compliance documents, we will also have permits from the Department of Fish and Wildlife under the California Endangered Species Act and the US Fish and Wildlife Service and National Marine Fisheries Service for the federal Endangered Species Act. We’ll have to follow water rights requirements under our water rights from the State Water Board, and we’ll have to follow water quality requirements that are part of the Water Board’s overall regulatory efforts. So what I’m saying is there’s a lot of regulation. DWR is still subject to the environmental documents that it puts out. In addition, there are a lot of other protections in place to avoid diverting more than we are permitted to divert.”


Print Friendly, PDF & Email