CAL WATER FIX: Metropolitan Board workshop compares one-tunnel options to Cal Water Fix

Presentation compares water delivery capability, stormwater diversion capability, water quality benefits, reverse flows, seismic events, project costs

Governor Newsom sent reverberations through the California water community when he announced during his state of the state address: “I do not support the Water Fix as currently configured,” said Governor Newsom. “Meaning, I do not support the twin tunnels. But we can build on the important work that’s already been done. That’s why I do support a single tunnel.” 

So just what would a one-tunnel project look like?  A workshop for Metropolitan Water District board members compared a single tunnel project at both 3000 cfs and 6000 cfs to the California Water Fix project, looking at water delivery capability, the ability to divert stormwater flows, water quality benefits, reverse flows, seismic events, and project costs.

General Manager Jeff Kightlinger began the workshop by noting that they are working closely with the Newsom Administration and looking at the various alternatives.  The purpose of the workshop is to cover the various single tunnel alternatives that have been analyzed, including the single tunnel alternatives analyzed through the Bay Delta Conservation Plan process, as well as the staging approach that was previously proposed.  Mr. Kightlinger reiterated that no final decisions have been made, so it’s unknown where things are headed at the moment, but they are expecting decisions to be made on the new configuration and environmental analysis in the next 60 days.

Steve Arakawa, Bay Delta Initiatives Manager, began by giving background on the State Water Project and how it fits into Metropolitan’s Integrated Resources Plan (IRP).  The IRP’s goal is to stabilize the state water supply; the reliability of state water has been reduced over time due to various factors.

The IRP identified these diverse approaches to meeting the region’s water supply, including water conservation, local resources development, maintaining the Colorado River Aqueduct supply, and then stabilizing the State Water Project supplies,” he said.  “So when we say stabilize the State Water Project, we are looking to maintain the supply the Metropolitan region gets on average – not to increase supply and develop new supply through the state project, but to stabilize that supply and to develop local supply and new conservation to meet the future needs of the region.”

In many ways, the stabilization of the State Water Project really does mean to reinvest in the system to make it work for today’s needs,” he added.


Mr. Arakawa then reviewed the various processes underway regarding the state and federal water project systems and any proposed tunnel conveyance.

With respect to the existing system:

The Coordinated Operations Agreement governs the way in which the state and federal projects coordinate their respective operations for releasing flow from the reservoirs for meeting outflow requirements of the regulations and meeting in basin needs upstream.  Late last year, the state executed an addendum to the agreement that adjusted how the flows and exports would be shared; that was executed in December.  The state is now preparing environmental documentation.

The Bay Delta Water Quality Control Plan is being updated by the State Water Board who has the responsibility to set water quality and flow standards in the Delta.  There are parties in the watershed who are looking to work with the state to reach a voluntary agreement to help meet the objectives that are necessary to meet the beneficial uses.

There are Endangered Species Act processes that govern the long-term operations of the two projects; there are both federal and state requirements; the State Water Project would need to meet both the federal and state and the federal project needs to meet the federal requirements.

With respect to the new conveyance:

As with any new project, it would include new operational criteria, possibly through the State Water Board’s change in point of diversion process.

There would also be Endangered Species Act requirements to meet the state and federal endangered species laws; the new project would have to get permits for both state and federal endangered species act provisions.

The new project will have to certify consistency with the Delta Plan through the Delta Stewardship Council’s consistency determination process.

There are Army Corps requirements required for construction.


Over the last several years, Mr. Arakawa said that there have been different challenges with regard to the water supply reliability or the delivery capability of the system.  With the changing climate, there will be changes in runoff patterns, which can mean more intense storms and more intense runoff periods;  there will also be increasing sea level rise to deal with.  So being prepared to deal with intense storms and sea level rise is part of what’s necessary to manage the Delta risks for the future, he said.

With regard to seismic issues, USGS scientists that looked at earthquake risks in the Delta due to faults that either run through or are adjacent to that area, and the USGS projected a 2/3rds chance of a major earthquake in the range of 6.5 to 6.8 in the next 15 to 20 years.  The state has done a lot of work to understand what does that mean in terms of Delta levee failures, flooding, and sea water intrusion, he said.

The reduction of wetlands and tidal habitat that occurred with the channelization of the Delta as it was reclaimed and put to use for agriculture has created risks for the health of the fisheries.  There are also changing water quality regulations to increase public health protection, and the lower salinity State Water Project supplies are important to managing Metropolitan’s supplies, given the Colorado River supplies which are higher in salt content.

The chart shows different regulatory decisions over time have decreased the capability of water exports from the Delta.  “It started in the late 1980s with the real impacts of the Endangered Species Act in reducing export capability with the listings of winter run salmon and Delta smelt; others have been listed over time,” Mr. Arakawa said.   “There have been other decisions as well, including the biological opinions in 2008 and 2009 for smelt and salmon.  That has in effect reduced the flexibility of the system to manage for water supply and it’s hard to make it up in a different part of the year because there are essentially restrictions almost through the whole year, so that has really reduced the flexibility of the system with the export pump locations being in the south end of the Delta.”

In June of 2007, the Metropolitan Board of Directors approved the Delta Action Plan Framework, which included short, mid, and long-term actions.  At the time the Framework was adopted, the Bay Delta Conservation Plan process was just getting underway, as well as a California court decision in 2007 that cut back the export pumps for a time.  Hurricane Katrina had raised awareness of just what kind of catastrophic failure could occur and how the state would need to be prepared.

In September of 2007, the Board adopted policy objectives to support Metropolitan’s involvement in the Bay Delta Conservation Plan process as it related to the water conveyance or water delivery system.  Mr. Arakawa noted that the staff looks to the criteria the Board has adopted to determine whether the proposed alternatives are meeting the adopted objectives.


Mr. Arakawa then discussed the one-tunnel alternatives that have been proposed and how they compare to the California Water Fix.

When the Bay Delta Conservation Plan process began, they started with a whole range of alternatives and used a screening process to narrow them down to sixteen; those alternatives were of various sizes from 3000 cfs up to 15,000 cfs of capacity.  The reason 15,000 cfs was considered was because that is about the capacity of both the State Water Project and the Central Valley Project combined.  They also considered 6,000 cfs and 9,000 cfs capacities as well as a No Action Alternative considered as part of the environmental review.  Some options were fully isolated, meaning all of the export water went through the new conveyance, versus a dual conveyance where part of the water goes through the tunnel project and part of it would go through the Delta channels, he explained.  Cal Water Fix is a dual conveyance project where water would be diverted at both spots depending upon the situation with the fisheries and the regulatory requirements.

In 2015, rather than pursuing the Bay Delta Conservation Plan as a habitat conservation plan, the state reformulated the project, pursuing the infrastructure portion as California Water Fix using a traditional permitting approach and pursuing the habitat restoration under the Eco Restore program.  The state prepared a recirculated environmental document with three additional alternatives with varying operational requirements.   The Cal Water Fix was the preferred alternative and that was the project that was approved in 2017 in the final environmental impact report.

Of the one tunnel alternatives that have been considered, there is a 3000 cfs one-tunnel option, and the staged approach, which would have been 6000 cfs facility.  These one-tunnel alternatives will be compared to the Cal Water Fix project as well.  The cost estimates have been adjusted to 2019 dollars, using a 3% annual increase.  The analysis also assume both state and federal participation; more analysis would be necessary to determine the benefits if only the state were the only participants.


Mr. Arakawa then presented a slide showing the delivery capability of the California Water Fix project and comparing it to existing conditions, noting that it’s relevant to the comparison of alternatives.  With the existing conditions, the system currently has about 4.7 MAF average delivery capability.  The California Water Fix has a delivery capability of 4.7 MAF to 5.3 MAF, the range being whether or not there would be additional spring outflow requirements.  Staff also considered what future deliveries would be available without building California Water Fix and estimated that due to the likely ever-tightening regulations, the water supply capability could be reduced to 3.5 to 3.9 MAF.

We showed those two ranges for both with and without the project,” he said.  “We said that the incremental benefit or the supply capability that we’re trying to protect is 1.3 MAF for both projects, so that’s a key thing that we used to try to characterize the benefit of delivery capability.”

The northern diversion allows for water diversions from the northern intakes when fish are near the southern diversion and vice-versa.  The southern diversion as it is today would be maintained, but the new diversion point with three intakes on the Sacramento River would allow for more flexibility to manage around fish critical situations, he said.

In looking at delivery capability, we looked at the Cal Water Fix at 9000 cfs, and then we looked at the one-tunnel option at 6000 cfs and 3000 cfs,” said Mr. Arakawa.  “Part of what we consider when looking at flexibility is what percentage of the flow of the export that would rely on the south end of the Delta versus the north end because we know that the regulations over the last number of years have been oriented towards reducing exports in the south in order to reduce the reverse flows that are going towards the export pumps.  Those reverse flows could be harmful to fish, so we see that as the increasing trend out into the future.”

For Cal Water Fix at 9000 cfs, about half of the water would be diverted on average from the north end of the Delta and about half from the south.  At 6000 cfs, the percentage that water would be diverted from the southern diversion would increase to 56% and at 3000 cfs, the water would be diverted from the south 73% of the time.

With Cal Water Fix, the increment was 1.3 MAF; with the 6000 cfs alternative, it would be 900,000 AF and for the 3000 cfs alternative, it would be 500,000 AF.

This is a way of looking at what kind of water are we trying to protect or what kind of delivery capability benefit is there for these different options,” he said.


They also looked at the ability of the alternatives to divert water when the intense storms are occurring and to store that water, because water storage is really key to living through droughts, Mr. Arakawa said.  They looked at water year 2016 which had storms that occurred in January, February, and March.  The blue line on the chart shows the inflow coming into the Delta; any flow above 50-60,000 cfs is a relatively large storm, but event 30-40,000 cfs is also a good sized storm.

What we did was looked at what type of capability could these options provide and we started with showing what the exports actually were for the State Water Project and the Central Valley Project which is shown in orange,” he said.

Then we looked at the different options for new intakes in the Delta, what kind of increased capability would that provide.  The green line is showing the 3000 cfs capacity alternative and so it shows for much of that runoff period, you would have an increased capability to divert flow because of that high runoff and inflow into the Delta.  There’s a period of time during that March period where you would have to cut back to meet certain requirements but for the most part, there would be increases.  For the 6000 cfs which is the light blue line, it would provide some added capability shown there between the green and the blue, and then the last is Cal Water Fix which is shown in yellow.  The analysis shows that about 300,000 AF could have been captured with 3000 cfs intake, about 570,000 AF with 6000 cfs, and 790,000 AF with the 9000 cfs.”


With respect to water quality, with California Water Fix, Mr. Arakawa said there would be a 19% improvement in total dissolved solids and 31% improvement in bromide.  For the 6000 cfs, the improvement would be 15% in dissolved solid and 24% improvement in bromide.  More modeling needs to be done to look at the numbers for 3000 cfs.


Reverse flows are an important regulating factor as fishery agencies try to minimize the reverse flows as they draw fish towards the pumps, particularly Delta smelt.

If adult Delta smelt get into the south end of the Delta during spawning periods like in February and March, then they spawn in that area and then those young Delta smelt are in that area and are very susceptible to export pumps,” said Mr. Arakawa.  “That’s the reason for why they have a regulation that limits the magnitude of reverse flows in the Delta, and there’s been an increasing trend towards limiting exports during this fish critical period.

The graph was prepared looking at what type of reverse flow would occur on average during the January through June period, which is considered the fish sensitive period because of a lot of spawning activity and key migration is occurring in the Delta.  “There’s the reverse flows that we have today which is shown towards the left and is close to 2000 cfs, but as you increase the capacity of the north Delta intake, that has the effect of reducing reverse flow,  In some cases, if the capacity is large enough, it can make that a net average positive flow, which is flow going towards the Suisun Bay area rather than up towards the export pumps.  The reason this is important is because the size of the facility is related to the ability to correct for the reverse flow because if you divert from the north end of the Delta, that water doesn’t have to be drawn towards the export pumps.  It’s actually water that would go through the tunnel and down to the aqueduct and not have to be transversing through the south Delta channels.”

Mr. Arakawa said that there is updated information on what the regulatory requirements would look like for the various alternatives.  “The existing average is around -1900 or -2000 cfs,” he said.  “The Cal Water Fix option would have made it slightly positive at +53 on average; that’s net positive towards the Bay, rather than towards the export pumps.  The 6000 cfs would have -345 and the 3000 cfs would have a higher negative flow at -680 cfs.  That gives you an idea of where we are today at close to 2000 and that what these two options would provide for this fish sensitive time of January through June.


The state has done a detailed analysis of what could potentially occur during a seismic event.  They compared the capacity of the 9000 cfs of Water Fix and the capacity to 6000 and 3000 as those three projects would still be operated to some criteria.

Without the south Delta pumps being able to operate, you wouldn’t have any ability to divert from the south end of the Delta because of the levee failures, the flooded islands, and the salt water intrusion,” Mr. Arakawa said.  “Comparing this, the Cal Water Fix would have the capability through this modeling deliver 3.8 MAF in a given year; 6000 cfs would have 2.9 MAF, and 3000 would have 1.6 MAF.  The two projects, CVP and SWP are about 4.9 MAF together.  4.7 to 4.9 MAF.  So you would have some reduced capacity from not having those south Delta pumps but you would still have some capacity because of the north diversions.”


Last July, the Metropolitan Board approved the California Water Fix project at $16.7 billion in 2017 dollars.  For comparison purposes, the slide shows the cost for the 6000 cfs at $11.1 billion and the 3000 cfs at $9.2 billion in 2017 dollars.  To adjust the 2017 dollars to 2019 dollars, they applied a 3% annual increase.  The California Water Fix would be $17.7 billion, the 6000 cfs would be $11.8 billion, and the 3000 cfs would be $9.7 billion.

I think the key thing to keep in mind with the cost estimate is that one is that we’re still utilizing a lot of the detailed work that was done over a period of time to really get a sound cost estimate,” Mr. Arakawa said.  “It also considered that if only one tunnel is built, that would reduce a good amount of cost.  But then when you go to a reduced capacity with one tunnel, that would save you some money but it’s not proportional.  When you go from two tunnels to one tunnel, you have a lot of cost savings but then when you reduce the one tunnel in capacity, you’re still spending money for different types of facilities like intakes and alignment right of way, and tunnel construction.”


The chart above shows how each of the alternatives stack up in terms of delivery capability, earthquakes, reverse flows, water quality improvements, and staff even added transfer capacity because being able to divert on the north end would provide added capacity for water transfers, Mr. Arakawa said.

When looking at all of this information, there’s a couple key things that we kind of saw pop out,” he said.  “One is when looking at the comparison of capacity and cost, going from 9000 to 6000, the reduced capacity is 33%.  You’re reducing the capacity by one-third and you’re reducing the cost by about a third as well, and so it’s proportional.  A large reason for that is you’re saving the cost of another tunnel being put in, but when you go from 6000 to 3000, you’re reducing the capacity by 50% but the cost savings are not proportional to that because you’re still having to construct, you’re still having a certain right of way alignment, those kinds of things, so it’s not as proportional from 6000 to 3000.”

The other thing to consider is the resiliency to respond to challenges and changes in regulations.  The lower chart shows the resiliency capability for 9000, 6000, and 3000 cfs.  “I showed you the earlier slide of the amount of water diverted from the south end of the Delta for the 9000, 49% for the 6000, 56%, and for the 3000, 73%,” he said.  “Going less in capacity means you just divert more from the south end of the Delta.  Also that has a change in reverse flows going from the 9000 to the 3000, and then the delivery capability after earthquakes, the capability of 9000 cfs was 3.8 MAF and then down to 1.6 for the 3000 cfs.”


Moving forward, Mr. Arakawa said that they will need to understand whether the one tunnel conveyance option would include any capacity either up front or eventually for Central Valley Project participation.  “When Metropolitan took its action to support the Cal Water Fix, it was committing to funding the remaining cfs to provide for the investment of the CVP at some point possibly in the future, so we’ll need to understand whether there will be federal participation with the one tunnel approach.”

Some work is common to any tunnel alternative, so certain types of geotechnical work or other types of studies or plans that would help move the project analysis further along would be prudent to pursue regardless of the exact capacity of the tunnel, he said.

They also need to determine what level of contractor participation level is achievable and what kind of capability and commitment is there from the State Water Project contractors to fund the project.  Metropolitan will need to have discussions at the board level for how the cost of any investment would be integrated in with their rates.

There are a number of key issues to be addressed, including the size of the facility, whether there will be federal participation or not, how it will be funded, and what kind of environmental documents will be necessary.  There is also the Endangered Species Act permits and what process would be used to work a new alternative through the process.  The state has asked for a stay of 60 days in the California Water Fix at the State Water Board; they will have to make a decision on whether to withdraw that petition and initiate a new process by May 5.  There is also the Delta Stewardship consistency determination for any reformulated project.

Due to technical difficulties with the recording, the directors questions and answer period could not be covered.


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