The Dutch Slough Tidal Marsh Restoration Project site, located in the Sacramento-San Joaquin Delta near Oakley, California. Jonathan Wong / DWR

DELTA CONVEYANCE PROJECT: Fish and aquatic species analysis

Informational webinar discusses fish and aquatic species analysis, fish screens, and operating criteria

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

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 first webinar was held in July and discussed project operations and modeling.  It is available here:  DELTA CONVEYANCE PROJECT: State Water Project operations and Delta modeling

The second webinar, held in August of 2021, covered fish and aquatic species and project operations. 

Carrie Buckman, Delta Conveyance Project Environmental Program Manager with the Department of Water Resources, began with a brief overview of the project, the planning process, and future opportunities for public participation.

Project purpose and overview

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 State Water Project water supplies in a cost-effective manner, consistent with the state’s Water Resilience Portfolio.

Generally, we want to try to protect the SWP infrastructure in the face of many challenges which are reflected in our objectives,” said Ms. Buckman.  “So we want to try to 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.”

The figure on the slide shows the proposed project and the alternatives under consideration.  The proposed project would construct two new intakes in the north Delta, each with 3000 CFS (or cubic feet per second) capacity, and a tunnel to connect those new intakes to the south Delta.  

The tunnel could follow one of two alignments: a central corridor, shown in orange, or the eastern corridor, shown in blue.  Both tunnel alignments would terminate in the south at a new pumping plant that will pump water up into a southern forebay. From there, the water would flow into the existing Banks Pumping Plant approach channel and through the Banks Pumping Plant. 

There is an additional alternative under consideration, the Bethany alternative, shown in green.  This alternative would follow the eastern alignment partway down, then veer further south, bypassing the southern forebay, with the water then pumped into Bethany Reservoir.

The need for that Southern forebay is largely driven by the fact that there would be two pumping plants that would need to work together, and so there would need to be a regulating body in between to regulate flows,” said Ms. Buckman.  “This Bethany alternative would only have one pumping plant that would pump water up into Bethany reservoir. So without that need to regulate flows, we would eliminate the need for that large Southern forebay which is really sizable and has potential to reduce impacts.”

Ms. Buckman noted that they are still in the process of developing the draft EIR, so they don’t have any results to share at this time.  This webinar focuses on methods, assumptions, and background information to help the public evaluate the draft EIR when it is released next year.

She also noted that while there is a high degree of interest in many water issues right now, including drought, climate change, and other topics, the focus of this webinar is specifically on providing information about the Delta Conveyance Projects, and so they will be keeping the Q&A and the discussions focused on Delta Conveyance.

Project schedule

The draft Environmental Impact Report is expected to be completed in mid-2022.  The Army Corps of Engineers is leading the National Environmental Policy Act process and is working on a draft environmental impact statement on a similar schedule.

At the completion of the public review period, they will respond to comments,  finalize the documents, and develop decision documents, expected in late 2023.  Other permitting efforts would be completed in 2024.

CEQA, briefly

Ms. Buckman reminded that CEQA is a long and complicated process.  This presentation will provide a brief overview, but for more information, here is a longer video on the CEQA process that provides more information.

CEQA is a requirement for all public agencies subject to the jurisdiction of California to analyze the impacts of a proposed project prior to approval.  The agency evaluates what could happen to the environment in relation to the proposed project, discloses potential significant environmental effects, and identifies ways to avoid or reduce significant environmental impacts.  The goal is to prevent environmental damage, if feasible, by requiring the implementation of alternatives or mitigation measures.  CEQA is meant to foster interagency coordination and public participation and show that the agency is considering the environmental implications of actions before making a decision.

The purpose of the Environmental Impact Report or EIR is to provide information about the project, disclose the potentially significant environmental impacts, and discuss ways to avoid,  minimize, reduce, or compensate for those impacts.  

The EIR shows that the agency has considered the environment before approving the project and that the agency has considered the environmental implications of its actions. 

CEQA requires the prevention of environmental damage, if feasible, by requiring the implementation of feasible alternatives or mitigation measures.

The slide lists the typical contents of an environmental impact report, including a project description, a description of the existing environmental setting or baseline, a discussion of significant environmental impacts.  Where significant environmental impacts have been identified, there will be a discussion of potential mitigation measures to reduce those effects.

There’s also a discussion of a reasonable range of alternatives compared in meaningful detail and a list of organizations or persons consulted.

The figure shows the overall CEQA process.  Right now, the Department is working to assess potential impacts and identify mitigation where appropriate.

Ms. Buckman noted that there will be an opportunity for public comments and participation once the draft EIR is released.  The draft will be circulated for comments from the public and other agencies, and a series of public meetings to provide information and hear comments back from the public about the process and the document.

Overview of the Fisheries and Aquatics Analysis

Mike Kendrick, a senior biologist with ICF, presented the fish and aquatic resource analysis for the draft environmental impact report.

The purpose of the analysis is to comply with the CEQA requirements.  Responsible agencies will ultimately utilize the CEQA document to support permit development and decisions. For example, the California Department of Fish and Wildlife will use the EIR to develop incidental take permits for state-listed threatened or endangered species, which could ultimately end in a take provision for listed species such as longfin smelt.

Mr. Kendrick then began with a brief biological review.  All the species analyzed exhibit the same life history: the process begins with spawning, which is the act of females laying eggs in the water and then the male fertilizing the eggs; rearing is the stage where the juvenile matures into an adult.  There are different migrations, depending on the species.

Some species are anadromous, such as salmon, which means they are born in freshwater, migrate to the ocean for some time, and then return to freshwater to spawn.  Some fish, such as Delta smelt, are semi-anadromous, meaning they’re born in freshwater and migrate to low salinity or brackish water as adults.  Other fish, such as Sacramento hitch, are resident in the estuary, remain in freshwater, and do not migrate to the ocean; they are typically found in the upstream watersheds.

The fish that will be analyzed are either native or non-native.  Native are defined as species that originated naturally in a specific location within the watershed, such as a river, stream, or lake, such as the Delta and longfin smelt.  Non-native species, such as the striped bass, originated in a location other than the Delta and were introduced.

Some of these fish are state and federally listed, such as spring-run Chinook salmon and winter-run chinook salmon, while some are of commercial or recreational importance, such as the striped bass.

The analysis will include the environmental setting for fish and aquatic resources in the study area in which impacts may occur; the analysis of impacts that could result from construction, operation, and maintenance of the project; and proposed mitigation measures to reduce the effects of potentially significant impacts.

The slide shows the general study area, which begins in the north in the Trinity River Basin and includes Trinity and Lewiston reservoirs in the Lower Klamath River.  The study area consists of the Sacramento River, including Shasta and Keswick reservoirs;  Clear Creek, Whiskeytown Reservoir; Feather River, American River,  Stanislaus, and the  San Joaquin. This study area also includes the State Water Project and the Central Valley Project export service areas.

The species to be considered for analysis in the study area are selected for analysis based on importance, vulnerability, and potential to be affected by construction activities and changes in State Water Project and Central Valley Project operations that would be implemented under potential project alternatives.

Species of management concern will also be analyzed, such as state or federally listed species, such as the Delta smelt and spring-run chinook salmon.  Species of special concern as identified by the California Department of Fish and Wildlife will also be included; these fall into categories of critical, high, or moderate importance. Some examples of these include the fall-run chinook salmon or late fall-run chinook salmon.

The slides below list some species that could be potentially analyzed just in the Trinity River and Central Valley regions. 

The species that you see listed are not necessarily all going to be analyzed, although most of them probably will, but these are the species that we are considering right now for potential analysis,” he said.  “These will be refined as the CEQA process moves forward.”

The slide shows a list of potential stressors to fish and aquatic species. Numerous studies have pointed to various stressors that negatively impact aquatic and fish species, including those potentially analyzed as part of the CEQA process. These include contaminants, entrainment, habitat quality and quantity, invasive species, fish passage, fish stranding, physical harm, noise, predators, water temperature, and water quality.  Mr. Kendrick emphasized that this is not necessarily a complete list, but these are some of the key ones that will be analyzed.

All species exhibit some sort of migration pattern, he said.  People are most familiar with salmon; they are born in freshwater, migrate to the ocean, then come back to freshwater to spawn.  The slide shows the spring run chinook salmon. The black lines show their historic range; the dark blue shows the current range; and the red shows the areas where they spawn.

All the species that are analyzed exhibit a lifecycle of some kind.  For this presentation, the Central Valley spring run chinook salmon are highlighted.  Spring run chinook salmon initiate upstream migration in the Sacramento River during the spring months and early summer. Adults will hold in the Sacramento River watershed, including the tributaries, until they spawn in the fall.  Then, as juveniles, they’ll start to outmigrate from the Sacramento River watershed, moving from freshwater down towards the ocean the following late winter and spring.

This chart shows the life cycle for the Central Valley spring run Chinook salmon for the Delta specifically. Both the adults and juveniles are present during the late winter and into the spring.  Adults are on the way upstream, and juveniles are heading towards the ocean. This is also the time of year when spring-run Chinook salmon may be salvaged at the south end of the Delta at the  Central Valley Project or State Water Project water export facilities.

The fish and aquatic resource analysis will be conducted both qualitatively and quantitatively.

Quantitative analysis involves quantities (or numbers), such as the numerical data available through various models and methods, to estimate the potential effect of change. 

Qualitative data is descriptive; for example, the area of origin for salmon: Feather River or American River. Qualitative data is generally used when more numerical data may be less available, and a determination of effect or change is based on the best available information and best professional judgment.

The analysis includes construction activities that potentially affect the in-water environment, such as the construction of intake facilities, bridge crossings, and other activities.  The potential effects from project operations and ongoing maintenance activities will be evaluated for all the various life stages of the analyzed species.

The graphic provides a basic overview of the draft EIR modeling framework. Various models will be utilized as part of the analysis. These models all require baseline information or input data, such as temperature and precipitation data, climate change hydrology, sea level rise, and many others. This information is fed into the Cal Sim 3 model, which simulates the State Water Project and Central Valley Project operations and the associated infrastructure.

Cal Sim 3 plays a key role and is utilized as a foundation model for the development of additional models that analyze potential in-Delta and upstream effects to fish and aquatic species,” said Mr. Kendrick.  “The diagram on the right is a flowchart to give an idea of how this process looks now. Any one model is dependent on others.”

The output from the models is then ultimately compared to the ‘thresholds of significance,’ such as, does the proposed project substantially reduce the habitat of a fish or aquatic species, or does the proposed project substantially reduce the number or restrict the range of an endangered rare or threatened fish aquatic species.

Clarifying questions

QUESTION: Conditions for Chinook salmon, both spring and winter-run particularly, are very much at risk. Can you talk a little bit about how you consider that as part of the existing conditions as part of the basis for your analysis?

Mike Kendrick:  “We use best available science for all of our analysis that goes into fish and aquatics as part of the CEQA effort that will include data up to … there’s the reality of the drought situation right now. There is the reality that some species are doing better than others. So yes, all that data will be considered. And ultimately, the CEQA process will form the basis for other agencies that will permit any proposed project or any project that occurs. So this will all have to go through the National Marine Fisheries Service, US Fish and Wildlife Service, California Department of Fish and Wildlife, and others before ultimately anything is permitted. So the concerns of the realities of the fish right now, drought, weather, they continue going down that will all be considered as part of the analysis.”

QUESTION: How much freshwater outflow is needed to achieve safe water quality for the aquatic life in the system?

Carrie Buckman:  “That effort is led by the State Water Resources Control Board through their potential consideration of an update to the Bay-Delta Water Quality Control Plan. So that is something where, regardless of what standards are in place, any Delta Conveyance Project would have to meet those standards established by the State Board.”

PHIL RYAN: Fish Screens

Phil Ryan, engineering design manager with the Delta Conveyance Design and Construction Authority, then dove into the specifics of fish screens.  But first, he started with the design of the intakes.

The intake structures are the main physical interface between the fisheries resources in our rivers and the project.  The slide shows a rendering of a typical intake. The river is shown along the bottom of the intake structure with fish screens in the center along the concrete structure.  The fish screens would be underwater.  There is a log boom out in front and walls on either end that curve back in to give the structure a smooth transition into the river system.

Water flows from the river through the intake screens, through the structure, and through pipes with gates on them into sedimentation basins. The sedimentation basins are needed as is there is often a lot of sediment carried in the rivers, particularly in the high flow periods in the winter.  So the sedimentation basins allow the sediment to settle out before the water goes into the 40-mile tunnel system.  There is a flow control structure at the back of the sedimentation basins to help maintain the levels.  The water then flows into the outlet shaft that leads to the tunnel system.  Sediment drying lagoons are used about once a year during the summer to remove the sediment from the basins and dry it up to be trucked off.

The intakes for the Delta Conveyance Project would be located along Highway 160 on the Sacramento River levee, which is an integral part of the flood control system.  This requires that the road and the levee have to be maintained continuously for the passage of traffic and for flood protection for the people who depend on that levee.

The DCA went through an extensive analysis of virtually all of the types of intakes that are available for diverting water essentially in the world,” said Mr. Ryan.  “We settled on on-bank structures, shown in these photos.  The intakes are on the edge of the river, rather than the middle of the river, so they are called ‘on-bank.’”

There are two different screen types: the Vertical Plate Screen shown on the left, in use at the Freeport project, and a Cylindrical T Screen system shown on the right.  Mr. Ryan said both screens are highly effective and have both been shown to provide very high-level protection to fish species at the intakes themselves.

Vertical Plate Screen Facility

Mr. Ryan then went through the details of how the fish screens work.  The slide on the lower left shows a 3D rendering of the vertical flat plate screen facility. The fish screens are located at the bottom, beneath the tan panels.  There are solid panels above, so the water only flows through the fish screen and into the open structure, and then through the box culverts into the sedimentation basin.

This slide shows a close-up view.  The screens slide down those panels shown at the upper left and sit at the bottom of the structure.  The screen material is shown on the right; that is screen material established by the regulatory agencies suitable for salmonids, Delta smelt, and other juvenile Delta species.

The screens have to be cleaned periodically because algae and other things grow on them, known as biofouling. So the screens are swept regularly and periodically pulled up and cleaned off with high-pressure jets.  The screen cleaning mechanism is shown in the red dashed circle.  Attached are brushes attached to a cable system that drives the brush back and forth, much like a toothbrush, and a counterweight system to make sure the brush stays in contact with the screens.

Cylindrical Tee Screen Facility 

The slide on the lower left shows a Cylindrical Tee Screen Facility.  The Cylindrical Tee Screens are at the bottom of the structure, essentially in the same location as in the Vertical Plate Screen Facility. However, instead of flowing into an open structure, the Tee screens feed directly into a pipe that flows directly through the sedimentation basins.

The slide on the upper right is during the construction of an intake. Most of the Tee Screens are in the raised position; the one in the middle is in the lowered position.  The screen slides down that same kind of rail system, and then they have solid panels above them so that flow only goes through the screens.

These screens are cleaned by a submersible motor inside the screens; there is a brush on the outside and a brush on the inside, and they rotate to keep the biofouling off the screen material.  The screen material is essentially the same as the Vertical Plate Screen.  The small picture on the right shows a screen fouled with invasive mussels after cleaning showing how effective these screen cleaners are.

Comparing the two options

This slide shows a comparison between the two types of screens. 

Both screen types are very effective, and they are both used quite a bit,” said Mr. Ryan.  “You can’t go wrong from a protection perspective with either of them, so other things have to come into play in trying to decide between them.”

The Cylindrical Tee Screens have a shorter structure due to the calculations that go into determining their length.  

You have individual flow control over each screen unit, so you get better flow control of uniformity and maintaining exact required and allowed diversion rates,” said Mr. Ryan.  “They have better screen cleaning; those brush systems in the rotation work better than the giant toothbrush. Because they’re underwater, completely submerged, they don’t make any noise. So that’s a big advantage to them. And even though they do have motors in there, they have easier operations and maintenance because there are just fewer things to mess around with, the motors are heavy-duty motors, and they are highly dependable. We don’t have to jet sediment from inside that structure.”

But a slight disadvantage, they do protrude into the river, so there’s possibly more debris collection and potential for damage,” he continued.  “Then, for those of you who understand refugia for fish management, as a passive structure, you can provide refugia on these structures without adding length. Another interesting feature is that the primary supplier of these screen types is a manufacturing firm in the Delta.”

For the Vertical Plate Screens, they are longer, so you can get effective flow control on them. But with the Tee Screens, you can get it by 100 CFS sections; the vertical plate screens are larger at 500 CFS sections. They’re slightly less effective for screen cleaning; the giant toothbrush has some striping issues, and a lot of O&M is required to keep the screen cleaners doing a good job. Because of the pulley systems and other parts above water, under some conditions that can be noisy, and they take O&M to keep them from being noisy, so it’s more frequent O&M at that particular facility.”

He also noted that vVrtical Plate Screens require sediment jetting, which the Cylindrical Tee Screens don’t.  An advantage is the screen sections are flat with the structure face, but the screen cleaner is still susceptible to a small amount of damage. And if you add refugia to these, it will add additional length for fish passage.

In summary …

In evaluating all these, the recommendation is to utilize Cylindrical Tee Screens,” said Mr. Ryan.  “There’s a shorter in river diversion structure; they have better screen cleaning with less O&M to keep it that way, you have better flow control over the range of diversion flows; there’s no noise, and they have an excellent track record in providing fish protection and actual performance.”

Clarifying questions

QUESTION: What are the differences between the capital and operating costs between Vertical Flat Plate Screens and Cylindrical Tee Screens?

Phil Ryan:  The capital costs are roughly the same because the screens themselves probably cost a little bit more than the vertical plate screens because there’s a full unit there, but the structure is shorter. So when you make the structure shorter, we’re talking about coffer dam sizes and piling and the whole thing. So in our estimations, they’re roughly the same in capital costs.”

In O & M costs, they’re also very similar.  The O & M costs of these screens are very low; the motors used to turn the screens are – I don’t want to say they’re less than ten horsepower, but they’re pretty small. And then, on the vertical plate screens, you have motors that are also small, but that run the giant toothbrushes for screen cleaning. And you also have to have pumps to pump for sediment jetting. So I would say that the actual power costs are probably slightly more for a vertical plate screen but not significant in the overall operation of the facility. And they require less presence and manpower to keep them functioning and in top-notch condition, so I think that the labor would favor the Tee screens as well.”

QUESTION: The project is contemplating intake sizes of 3000 – 7500 CFS, which would differ in size.  Are there any differences in the fish screens when we’re looking at smaller or larger intakes?

Phil Ryan:  “The fish screens are identical for the different systems. Now the sizes of the structures might be slightly bigger, but the screens themselves we have set everything up.  The Vertical Plate Screens are in 500 CFS units, so for 1500 CFS intake, there’d be three of them. So that’d be half the length of a 3000 which would have six units. With the T screens, with each 100 CFS, there would be 15 Tee screens on a small one and 30 on a large one. So the structures themselves are almost identical. The layout and fit and the overall capacities are the only differences.”

QUESTION: Can you explain what refugia means?

Phil Ryan:  Refugia, as it’s been described to me, is a fish hotel.  As the fish travel past the screens, they have a place to stop and rest before the fish, mainly salmonids, continue their quest downstream. So these are areas they can rest, free of predation and any of the flow impacts. These have been tried on some of the intakes in Sacramento River, and they’re being evaluated as part of the project, but no conclusions have been made.”

GARDNER JONES: Overview of operational criteria

Gardner Jones is the Aquatic Resource Program Manager at the Department of Water Resources.  He gave a brief overview of the proposed North Delta operations.

The Delta Conveyance Project proposes new North Delta intakes with new operating criteria. These operating criteria will be in addition to existing Delta operating criteria and regulations, such as Delta outflow requirements, such as those established by D 1641; Old and Middle River flow requirements, export limits, requirements by fish and wildlife agencies, and others.

The new North Delta diversions (or NDDs) would operate in coordination with existing South Delta diversions, a concept known as dual conveyance operations.

The potential flexibility in operations would be greatly enhanced by using either south or north Delta intakes,” said Mr. Jones.  “The current assumption with the dual conveyance approach is to use the NDD to augment excess flow diversions on top of the permitted diversions at the south Delta intakes. This would mainly occur during the winter and spring. The NDD would also be operated to manage salinity and realize potential carriage water savings, mainly in the summer-fall period. Overall, the goal will be to maximize benefits while minimizing impacts.

Components of the proposed operational criteria

The Freeport flow, identified on the map by the red star, would be measured above the intake reach, shown in light purple.  Sacramento River flow downstream of the intakes, shown with a green star, represents bypass flows or the flow required to remain in the river.  The Sacramento River downstream of Georgiana Slough, shown by an orange star, is also an important location in managing reverse tidal flows or when tidal energy overpowers the river and water flows upstream during a flood tide.

The fish screen approach and sweeping velocity criteria are requirements for how fast diverted water can move into and pass the fish screens. This is to minimize near-field operational effects on vulnerable fish.

Bypass flows are the proposed requirements on the flows remaining in the river and bypassing the diversions. This is mainly to protect the survival of fish migrating in the intake reach and through the Delta.

Pulse protection is a rule intended to further reduce diversions during key winter flow pulses when significant concentrations of migrating winter-run chinook salmon juveniles have historically been shown to move down the Sacramento River.

Low-level pumping is the lowest identified diversion level and is intended to reduce further operations such that they have no or only minimal effects.

A conceptual model for the North Delta Diversion operating criteria is shown on the slide.  The top shows the background numbers of fish in the river going through time, shifting to many fish and then back down again. 

Fish migration tends to be concentrated during a portion of the year, usually in the winter and spring, and is typically focused on short periods; for example, when young or juvenile Chinook salmon move downstream in response to environmental cues, like changes in flow and temperature.

The bottom of the slide shows the concept of layered protections, which the proposed NDD operating criteria are intended to provide. 

Approach and sweeping velocity criteria would minimize potential effects near the screens, while low-level pumping would limit potential diversion effects at the screens, as well as downstream from them,” said Mr. Jones.  “Bypass flow criteria would define allowable diversions, based on background presence levels of target vulnerable fish, like juvenile winter-run chinook salmon.”

The graphic shows the concept of early bypass flow protection, transitioning into pulse protection concurrently with the presence of a large group of winter-run juveniles, then transitioning back to bypass flow protection once the pulse has passed,” he continued.  “The pulse protection criteria would trigger based on storm-driven flow spikes to provide further protection during periods when larger concentrations of emigrating winter and chinook have historically been observed.”

The fish screen approach and sweeping velocity are the first layers of criteria operating at the screens themselves. The approach velocity is the velocity of water perpendicular to and going into the fish screens; the sweeping velocity is the velocity of water parallel to and going past the fish screens.  Approach and sweeping velocity criteria have been established by the National Marine Fisheries Service, the California Department of Fish and Wildlife, and the US Fish and Wildlife Service. The operating criteria are intended to minimize potential harm due to framing, which is when fish are diverted with the water through the screen into the intake, and impingement, which is when fish contact and can be held against the screen through the force of the diversion.

The Delta Conveyance Project as proposed currently assumes an approach velocity of .2 feet per second, which is consistent with criteria used to protect Delta smelt and lower than the .33 feet per second criteria used to protect salmon fry in upstream locations,” said Mr. Jones.  “The DCP also assumes an average downstream sweeping velocity of .4 feet per second or double the approach velocity.”

The bypass flow is the flow remaining in the Sacramento River downstream of the proposed North Delta Diversion intakes. The criteria are designed to minimize upstream tidal transport, or the reversing of the river flow back upstream due to diversions, and incoming tides at two points of control: the Sacramento River upstream of Sutter Slough and the Sacramento River downstream at Georgiana Slough, said Mr. Jones. These have been developed to preserve the movement and survival of listed fish in the lower Sacramento River.

The preliminary set of bypass flow criteria is shown on the slide. These criteria are used as input into the analysis of potential effects; they will then consider the potential effects and determine if any changes to the criteria are needed.

The bypass flow criteria would identify a percent of Sacramento River flow that could be diverted at the new intakes. This percentage would increase as the Sacramento River flow increases.  The predicted bypass flow would be determined based on daily average or tidally-filtered flows.

In wetter years, fish tend to do well,” said Mr. Jones.  “Fish species native to our region such as chinook salmon and Delta smelt have evolved to take advantage of periodic conditions produced when there is more precipitation in the system. Therefore, to allow for the idea that drier years should have more fish protection, the bypass flow criteria have three levels that change for drier or wetter conditions for the period when listed fish would most likely be near the facilities, which is December through June.”

The criteria would change from level one to level two after 15 total days of bypass flows over 20,000 cubic feet per second or CFS. The criteria would change from level two to level three after 30 total days of bypass flows over 20,000 CFS; flows of this magnitude generally reflect the conditions associated with increased precipitation and typically occur in the winter and spring months.”

Under all levels, the North Delta Diversions would not divert any water during low flow conditions when the Sacramento River flow is less than a daily average of 5000 cubic feet per second,” he continued.  “As flows increase over 5000 CFS, the new diversion would divert only low level pumping up to 900 CFS.

The flow range for low-level diversions varies. Under level one, only low-level pumping would occur up to river flows of 15,000 CFS. Under level two, only low-level pumping would occur up to river flows of 11,000 CFS, and under level three, later in the season of wetter years, only low-level pumping would occur up to 9000 CFS. As the river flows increased further, the diversions would slowly increase towards the maximum diversion rate of 6000 CFS.

We understand that when we talk about the proposed diversion facilities having a capacity of 6000 CFS, it may sound like they would be diverting 6000 cubic feet per second all the time,” said Mr. Jones.  “But these bypass flow criteria would limit the diversions to wetter periods when there is adequate downstream flow to meet regulatory requirements and maintain fish survival as they move through the Delta.”

Pulse protection is intended to provide an additional layer of restriction on the North Delta Diversions when storm-driven flow spikes, usually in the winter months, occur in the upper Sacramento River region.

There is evidence that large numbers of endangered winter-run chinook salmon begin moving downstream toward the intake reach in response to these storm-driven flow pulses,” said Mr. Jones.  “Preliminarily, the project is proposing to implement pulse protection criteria up to twice per year to address major pulses of juvenile winter-run migration. As noted, this approach is based on historical observations of juvenile winter-run chinook flow driven movement patterns from upstream locations into the Delta.”

Low-level pumping represents a diversion level with minimal effects on the river and aquatic resources. For low-level pumping, the DCP proposes from zero to 900 CFS total diversions at the North Delta intakes depending on flow conditions, with the diversion rate not to exceed 6% of Sacramento River flow, he said.

For example, the low level pumping a maximum of 900 CFS could only be taken with Sacramento River flows at or above 15,000 cubic feet per second.  Here the diagram highlights how pulse protection periods would reduce diversions proposed under the bypass flow criteria down to low-level pumping. This low level pumping would further minimize effects to the river and fish present near and downstream of the proposed intakes.

This figure is an example to illustrate the proposed Delta Conveyance planned operating criteria overlaid on historical flows from the water year 2016.  This is not modeling, but rather an example of how new intakes with a 6000 cubic feet per second capacity and the proposed DCP operations criteria could have looked in 2016, he said. 

Flow in CFS is on the left, and the date is shown on the bottom. He noted that a cubic foot is approximately a basketball-sized box. The Sacramento River typically has thousands to tens of thousands of these moving past a given point every second.

The vertical colors represent the bypass flow levels, with level one in the earlier part of the year in yellow, level two further along in orange, and level three shown in green.  The slide shows the progression through the levels over the year along with the Sacramento River hydrograph.

The vertical light blue bar in the late December period represents a triggered pulse flow event. The solid blue line moving up and down to the graph is Sacramento River flow measured at Freeport, while the dotted blue line tracking it is bypass flow. Finally, the red line near the bottom of the graph represents the resulting North Delta diversion flow levels.

Based on this example year, there are high flow periods with potential sustained 6000 CFS diversions, interspersed with lesser intermediate diversions, and low-level pumping for extended amounts of time.

Clarifying questions

QUESTION: In one of the earlier slides, you had a graphic that had the level pumping, and it looked a little bit like low-level pumping would be occurring all the time. Then later in the bypass flow table, it did not look like it would be happening all the time. Can you elaborate on whether a low-level pumping would occur all the time?

Gardner Jones:  “The low level pumping would be the lowest level of diversions allowed at the North Delta diversions. So they would not be in place all the time – although keep in mind that low-level pumping includes potentially zero pumping, so from that perspective, you could consider there’s always a degree of low-level pumping. The main point, though, is that with average flows in the Sacramento River below 5000 CFS, there would be absolutely no pumping.”

QUESTION: Can you clarify if the bypass flow approach velocity and sweeping velocity numbers you provided are average daily or instantaneous values?

Gardner Jones:   “There’s the approach and sweeping velocity criteria, and those are have been identified and are, generally speaking, instantaneous requirements.  The bypass flow criteria, on the other hand, that next layer of criteria, those are operating on a daily average basis.”

QUESTION: Do juvenile fish move with flow, or do they tend to collect on the outside of riverbeds?

Gardner Jones:   “It depends a lot on the species of fish. The collection of juvenile fish on the outside of bends – I’ll assume he is talking about downstream migrating Chinook salmon or salmonids.  I think the understanding is that acoustic tagging studies that have happened in the past that track movements of juvenile Chinook salmon, and as they move downstream have shown that, generally speaking, fish do move with the higher velocities of flow, or at least they concentrate in their movements. As far as collecting, I’m not sure exactly what is assumed there. They generally don’t collect as in kind of stacking up and stay there, but rather, stay with more flow.

QUESTION: Can you explain a little bit more about the term preliminary bypass flow criteria? People wanted to know, preliminary until when and what the process is?

Gardner Jones:  The term ‘preliminary’ we are using through the development of the CEQA document and the application of our analysis to the preliminary or proposed criteria. They’re preliminary because we acknowledge that we may need to revisit the criteria through the analysis and evaluation of the effects that we get from that analysis. And so that’s why generally speaking, we use the term preliminary.”

I think that there is some concern that we might continue to change operating criteria, sort of during project implementation. And that’s not the case. It’s just that we need to have a set of criteria that we look at to analyze fishery impacts. And so that’s what we’re putting into the input into the models, but depending on what the effects analysis says, we may update those. But we would do that within the CEQA document; we’re not going to continue to change them into project implementation.

QUESTION: On the slide, can you explain the lines again?  I think people thought that the blue lines might also be proposals.

Gardner Jones:What is represented here with the red line is an attempt to illustrate what a 6000 CFS capacity project operated under the proposed operating criteria would produce in this water year. So again, it’s not modeling; this just takes the flows that we historically saw here. The Sacramento River at Freeport flows is that blue line that’s kind of starts below 10,000CFS and jumps up, coincident with that first pulse protection, so that light blue bar.  Then it continues to move through time.  You can see how various precipitation events or prolonged precipitation events produce greater flows as it moves through time.  Going through on the bottom of December, we have some big flows here, towards the end of January into February, and then towards April.  Coming into the spring period flows, we’re still in the 20,000 CFS range but dropping down as they headed into June timeframe around that 10 to 15,000. CFS. So that main blue line, that’s what historically occurred. That’s the Freeport flows from the gauging station, for example.”

The dotted blue line, that’s the bypass flow criteria that’s applying so that you maintain, based on those bypass flow criteria. So that’s what you would maintain. So, in other words, instead of that blue line, what you would produce is that dotted blue line if you were to divert at the levels that the red line is showing, and that’s consistent with the proposed North Delta operations.” 

I just want to make sure people understand, so we’re only showing one application here, a 6000 CFS capacity with proposed criteria that we just gave an overview of. So hopefully, that helps clear things up. I do want to emphasize this is not modeling. And so, for example, other criteria are not captured here. So, you know, if there were constraints for other reasons in the system, those would not be shown here.”

QUESTION: Will the rates of allowed diversion be stated as instantaneous values or average daily values?  Ms. Buckman noted that the question reflects the difference that the project is not necessarily establishing a rate of allowed diversion but rather a suite of criteria that will have to be met in the system.

Gardner Jones:  “The criteria that we’re talking about are operated differently. So the bypass flow criteria is operating at a different timescale.  The daily average is trying to take into account the fact that while you might have a set flow over the day, there are tidal variations, and so that’s tidally averaged out as far as what the criteria requirement would be.  The approach and sweeping velocity criteria – the idea is that those are happening at the screen and are requirements that the facilities would need to maintain. And so they would need to operate such that we do not go over, for example, as we’re showing preliminarily here, a velocity at an intake velocity rate of .2 feet per second. And so hopefully, that helps give a little bit more context to the idea of the layering of these criteria and how they are operating at different scales, both in time and space.”


QUESTION: I was participating in the DCA’s stakeholder engagement committee meetings. We were told the intake configuration had already been determined, that it would be two 3000 CFS intakes, and the location had been determined by Fish and Wildlife before the stakeholder engagement committee met. I’m wondering what that process was that was determined by the fish agencies?

Carrie Buckman:   “I think we probably need to clarify that; I don’t think that what was being said was that Department of Fish and Wildlife determined the configuration, but rather that DWR, as part of our notice of preparation, identified that we were going to have two 3000 CFS intakes. So as the DCA was designing the intake facilities, that was part of the project they were given to design. And I think the other piece was that there was information that was used from past efforts for California Water Fix, where the fishery agencies were involved, but not making decisions – just providing input and feedback.”

Phil Ryan:  “There are a bunch of alternatives. So when we made the presentations, we confined ourselves to the proposed project that was in the Notice of Preparation, which was the two intakes at 3000 CFS.  But there’s obviously the whole range of intakes from 3000 to 7500 and includes one up to three intakes. But we did present just the 6000 CFS and two intakes to get feedback.  We did show all the different sites to the stakeholder engagement committee to clarify where we’re going. In the discussions, the analysis of the intake did take into account the analysis that was done on the previous project to evaluate the sites. We did a completely new evaluation within the reach of the river we’re looking at, but there are only so many sites available.  We ended up coming to essentially the same conclusions as they came to in the past, which actually I think shows that the work has been done pretty well, under both studies.”

QUESTION: What do you plan to do about Clifton Court? Are you going to screen it? Are you not going to use it? What are your plans for the Clifton court facility?

Carrie Buckman:  “What we’re talking about tonight is focused on the Delta Conveyance Project. And I know this is often the source of frustration that we aren’t addressing all of the known potential issues in the bigger water system, but we are trying to take a bite of those issues – the subset that we think we can tackle with this project. So as part of this project, our objectives are to look at diversion and conveyance facilities to address State Water project supplies in the long term. Looking at issues at Clifton Court specifically related to fish are not part of this effort.”

QUESTION: The Presentation indicated that you would get incidental take permits from the Department of Fish and Wildlife. Those incidental take permits pertain to threatened and endangered species under the ESA.  Then part of the presentation also said that you’re going to create self-sustaining fisheries. The problem is here is that you’re going to take threatened species, and then you’re going to make them self-sustaining, but they shouldn’t be just self-sustaining; those populations should be robust. And it’s very bothersome to me that the goal is just to have enough fish, so they don’t become extinct or get listed as threatened or endangered species.”

Carrie Buckman:   “The incidental take permit is a way to comply with the California Endangered Species Act.  What we will be doing as a project proponent, similar to other projects that would need to comply with the California Endangered Species Act, is that we would be submitting an incidental take permit application to discuss the potential effects of our project and identify mitigation for those efforts. And then, the DFW would consider it and potentially issue an incidental take permit.

“I did want to draw a distinction. Our effort is really focused on the effects of our project. There are many other efforts ongoing through the fishery agencies to restore and protect those fish. Our focus is on what types of effects our project could have.”

Mike Kendrick:  “Through the process of developing permits, if there’s an identified potential effect to a listed species, if it’s a state-listed species, then the California Department of Fish and Wildlife Service will issue take authorization for those statements to species.  And then, a similar process on from the federal Endangered Species Act side of the world. We will get biological opinions from the US Fish and Wildlife Service and or National Marine Fisheries Service, where we ultimately have any take authorization if there’s any determined potential impacts to federally listed species.”

QUESTION: In discussing the different types of screens, the underwater cylindrical screens were described as being very quiet because the motors and other pieces of gear that move around to make noise are underwater. But of course, that would make noise underwater. And as we know, sound underwater carries a long distance. So I’m wondering if any consideration has been given to the potential impact on aquatic animals?  And potentially, depending on the frequencies emitted by that gear, could it cause some problems for boats passing by with their sonar gear?

Carrie Buckman:  In the EIR, we will be analyzing the noise impacts of construction and operations of the facilities.”

Phil Ryan:  There are considerations for acoustic effects underwater. It’s often attributed to pile driving and things like that …  Really, the noise issue on the screens is about the above water pulleys on the giant toothbrush; they are fine out in agricultural areas, but we have people living across the river from it, so they’re a little bit more of a nuisance. The underwater sound levels for these motors and the vibrations are almost imperceptible; they move very slow. They’re geared to the point where there’s just not a large degree of vibration at all from them, and they have nice bushings for where the screens rotate against the manifolds and that kind of thing.

Now, I can’t say, I’d have to talk to the biologist specifically that we’ve done a detailed analysis, but the regulatory agencies are highly enamored with these screens because of the exact things we’re talking about – their rotation and cleaning underwater, and we have not noticed any kind of impact to fish. But again, I want to kind of defer to the biology people because they’ve done quite a bit of an evaluation about fish behavior around the different types of screens, and I don’t think they see major differences.

QUESTION:  In the examples Mr. Jones gave about the operating criteria, the focus was on salmonids. That leaves the impression that the salmonid criteria are governing for operations and that any criteria associated with Delta smelt, that the salmon criteria would be more protective. But I could be completely misinterpreting. So please comment on Delta smelt criteria, if any, in relation to the salmon criteria and diversions.

Gardner Jones:  The approach and sweeping velocity criteria at the screens themselves were specifically developed for Delta smelt protection. So those are at the level of what’s has been determined to be protective of delta smelt.  I did go through it relatively quickly. That’s maybe one of the main areas that we’re specifically considering an additional level of protection above and beyond what would be for salmonid fry. And that’s the .2 feet per second approach velocity as opposed to the .33 feet per second.

As far as the bypass flow criteria, generally speaking, some of the major things that we’re looking at in developing a bypass flow criteria are the effects of diverting water on the potential for reversing flow.  I talked about it very briefly … essentially, it was developed to look at two specific points downstream at Georgiana Slough and Sutter Slough.  One of the main things there is the potential to affect the movement of water, and, to some degree, the assumption being that if there are, for example, Delta smelt present there, to what degree could that change their movement? So that is one of the more general aquatic effects, but Delta smelt would definitely be a part of that consideration. And so that was one of the key considerations for bypass flow criteria specifically.

Some of the other reasons that I mentioned the salmonids specifically is that there has just been a lot more research and a lot better understanding of flow and survival of especially juvenile salmonids in the Sacramento River, the Delta, and the lower Sacramento River intake reach, and it’s where we have that information that we’re using that and trying to apply it to the criteria and really to evaluate the criteria through that lens.  We just don’t have that kind of detail for Delta smelt. That being said, we are absolutely looking at what we think could happen to Delta smelt based on those flow criteria, and based on the stressors or the potential effects that have been identified for Delta smelt as well as other fish species.

QUESTION:  Arthur Feinstein:  “In 1993, I was the executive director of the Golden Gate, Audubon Society. And in litigation, Golden Gate Audubon versus Browner et al., Carl Browner was the director of the US EPA. We sued over flows into the Bay-Delta as part of a process where the State Water Board was undergoing water quality plans for the Bay-Delta, which allowed for pretty much very low flows for fisheries.  We successfully got the EPA to set flow criteria that were considerably larger than this Water Board’s plan. But that was mooted by the Bay-Delta Accord. But what came out of that whole process of litigation there and over the water quality plan at the State Board is the recognition that flows are the critical issue for the survival of salmon, delta smelt, etc. No matter how much wetlands you provide for them, it’s the flows that are critical for their survival. So in your new plan for conveyance, what I’m suggesting is that you’ll have to defend your water levels in the face of continuing science. Flows are critical, and they need to be very robust if these species are going to exist in the future. So that’s for the scoping comments.”

Carrie Buckman:  The State Water Resources Control Board is considering options to update the Water Quality Control Plan for the Bay-Delta. We are viewing that as part of the regulatory baseline. So if the regulatory baseline changes as part of that update, we would follow the revised plan. So we would be regulated by that change. So whatever, whatever regulation is, in effect, we would need to follow it.”

QUESTION: I thought I heard it said that this was going to be operated under the 2019 biological opinion, which the state is actually litigating that. And so I don’t see how that is a good plan. It seems like a better plan would operate it to meet the doubling criteria and state laws. Because as you all know, we’re dealing with major winter run and spring run fisheries crises right now where we’re losing the majority of the fish. So wouldn’t it be a better plan to operate the tunnel based on recovery and doubling standards?

Carrie Buckman:   “Under CEQA, we set the baseline at the time of the issuing of the notice of preparation, which we issued in early 2020. So based on that, we’re using the requirement that the standards and the regulations that govern when we’re signing it, which includes the 2019 biological opinions, but many things could change over time. As I mentioned, with the State Board, we would continue to follow whatever regulatory baseline is in place. But the reason that that’s part of our baseline is because that regulation was in effect and is still in effect.

I did want to highlight the difference between the environmental baseline and what we’re looking at for a project. The environmental baseline reflects the conditions that are in the environment, absent the project. And what we’re looking at is then the change from that with our project. So we’re adding protective criteria for our project on top of what is already being operated within the system.”

QUESTION:  I wondered what the bypass flow standards you are trying to meet are, because those were mentioned, but I did not hear the actual CFS. And then my other question is, what about other operations and the cumulative impacts?  How would you look at the cumulative impacts of multiple projects and their impacts on fisheries?

Carrie Buckman:  The bypass flow criteria. One of Gardner’s slides had a table that did have a summary of the criteria, and the idea was that when the river was below 5000 CFS, all of the water needed to stand the river, and nothing could be diverted. And then from there, it deviates a little bit based on the conditions of the water year, but up to a certain amount of flow in the river, there could be low-level pumping, and then up to a higher level of the river, it would ramp up slowly. So the CFS that we’re proposing for an initial set of criteria is included in the slide earlier in the presentation.

For cumulative effects, the way that we’re analyzing cumulative effects is that we are looking at reasonably foreseeable past, present, and potential future projects. And we will be looking at the cumulative condition, whether that would have a significant effect on the environment and whether the Delta Conveyance Project could cumulatively make a considerable contribution to that effect if it is, in fact, significant. So we’re still working to identify the types of projects that would be considered reasonably foreseeable.”

QUESTION: I’m not a fish person or an engineer, so when you talk about these screens, is there any possibility that any fish will get caught up in the screens, and what’s your acceptable threshold for that? How much percentage of the fish can be sacrificed to the screens? How does that work?

Phil Ryan  [I don’t know] exactly which fish or what percentage of them are protected. They are the screen size recommended by the fish agencies with the minimum openings. We actually do quite a bit; we’re at double the allowable for open area, so the screens are more than compliant with the rules. Now, as far as where the rules come from relative to fish, I’d have to defer to the biologists.

Mike Kendrick:   “I’m going to reference back to the development of the permits that will happen post the CEQA analysis. So California Department of Fish and Wildlife Service will issue a take authorization as part of their permit. It’s impossible to anticipate what that will look like. But that may define a number or a percentage of x species that could be lost before operations need to be curtailed. That’s an oversimplification of the potential process, but that’s what it looks like.  National Marine Fisheries Service would do the same for the species under their purview. If there are potential impacts to spring run, winter run, California Central Valley steelhead, or green sturgeon, there would be an incidental take statement that would authorize a certain percentage of loss or take at a facility. And there would then be criteria that would occur based on when that may happen. The US Fish and Wildlife Service from the aquatic side of things would be the same for Delta smelt.

Gardner Jones:  From a procedural perspective, for the proposed project, we’ll use the criteria and the technology that the fish agencies require. And then, in our analysis, based on life stages and the best available information we have as far as which species would be present and their vulnerability, we will analyze the proposed project and the proposed operating criteria to look at to what degree that effect could happen. And that’s really what the CEQA document will disclose.  Then the fish agencies would evaluate it and say, yes, you did a good job of evaluating it, or if there’s a problem or if that’s too high, you need to mitigate, or you need to shut off operations or something along those lines. But where we are right now is just trying to implement the best science to drive the proposed project. So the best criteria, the best technology, and then the most up-to-date evaluation to look at if you are operating that way, what are the effects to the fish?  So, for example, we would look at larval Delta smelt size and try to come up with some estimate of if they are vulnerable, how many of them could be entrained? And that would be the type of information we would be evaluating to try to understand the impacts of the project.”

QUESTION: About the bypass flows at intakes, is DWR going to put a flow sensor there? Because there hasn’t been flow and velocity data gathered. And is DWR aware of the 1982 studies that were published of flow and velocity that were done for the original peripheral canal?

Carrie Buckman:  In terms of whether DWR is going to be considering a new flow sensor, I think that is part of the overall project implementation. If we reach that phase of the project, we would be developing a monitoring and mitigation plan to identify any necessary monitoring efforts that we would need. We’re just not there yet. So I don’t have an answer yet to that part of the question. In terms of the 1980s studies, I will say we have a large team, and I am not the only person who looks at that material. So I am not aware, but I think we probably are in the bigger picture, and we can certainly look into it.”

QUESTION:  Regarding the potential for entrainment, in regard to striped bass, they spawn in the open water of the river. And when the eggs are initially dispersed, they’re pretty small, like 1.3 millimeters. And then when they’re fertilized, they go up to 3.4. And then when it’ll be pro larva, striped bass hatch out of the little tiny egg, they’re actually smaller, and they’re very weak swimmers. So has any study been done to see the potential for the treatment of eggs, or to the larval stage of the striped bass into the screens?

MARIN GREENWOOD (ICF):  That’s certainly one of the effects we have to look at for not just striped bass, but any species … We need to identify which might be the vulnerable life stages that could be susceptible to entrainment. Consider the biology, consider the timing, obviously, in relation to when diversions might be occurring and those sorts of factors. So I think that the basic answer is yes, we do need to consider that in the environmental analysis.”

QUESTION:   I understand how fish go upstream, but how do these different fish screens and mechanisms allow fish to go downstream?

Carrie Buckman:  We’ve been talking almost entirely about juvenile salmonids and how we’re providing protections for them. But we haven’t mentioned anything about adults and providing protections to allow them to go upstream. Could you sort of explain why that is?

Mike Kendrick:  Juveniles are weaker swimmers than adults, so presumably if you provide protection for the juvenile salmonids, the protections would be in place for the adults as well. Adults behave differently than juveniles do.  Adults aren’t as concerned about predation as the juveniles are; juveniles tend to hug a little bit closer to the shore than perhaps some of the adults do. But really, the crux of it is if you have the protections in place with juveniles, it would be assumed that that would be enough for adults and that the screens won’t be posing any fish passage issues or anything that would hinder upstream movements.

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