Posted by: Deirdre Des Jardins | August 26, 2019

Delta Levees Investment Strategy: protecting Delta smelt?

The Delta Stewardship Council has considered and rejected an alternative for the Delta Levees Investment Strategy that prioritized reducing risks to lives and property in the Delta.  It’s listed as Alternative 3 in the Initial Statement of Reasons for the regulations adopting the strategy.

The Delta Stewardship Council explains that Alternative 3 was rejected because it would not prioritize levee investments that provide “ecosystem enhancements.”  This is from p. 23 of the Initial Statement of Reasons:

Alternative 3 – Prioritize Levee Investments in High Risk to Life or Property Areas

Alternative 3 focuses on prioritizing investments in levee improvements at islands or tracts identified as having a high risk to life or property, including urban and urbanizing areas of Sacramento, West Sacramento, and Stockton. Levee improvements that support other State interests (such as improving Delta ecosystem conditions or maintaining water supply corridors) would still occur but would be prioritized lower than investments in areas with high risk to life or property. Continued funding would be provided for maintenance of levees throughout the Delta where authorized by Water Code section 12980 et seq. and consistent with the recommendations of the CVFPB.

This alternative would not be less burdensome or equally or more effective than the proposed regulation. Alternative 3 was eliminated from consideration because although it would achieve or partially achieve many of the objectives of the proposed amendment, it would not prioritize levee investments that protect ecosystem enhancements that provide high benefits over other types of levee investments.

(underlining added)

But the rejection of Alternative 3 has more to do with the Delta Stewardship Council’s rejection of the initially proposed cost allocation method than with the need for ecosystem restoration projects in the Delta. The Separable Costs — Remaining Benefits (SCRB) cost allocation method was recommended by Arcadis and presented for the Delta Levees Investment Strategy peer review.

Under Separable Costs – Remaining Benefits, the extra costs to provide ecosystem benefits would have been assessed separately from protection of lives and property, and allocated separately.  Arcadis’ consultant, Dr. McMahon, stated:

In summary, the objectives are fairness primarily, so we’re trying to allocate only the costs incurred, so we want to allocate costs in proportions of benefits received; we don’t want any purpose to subsidize other purposes. There are four steps; the first step is the SCRB cost allocation by purpose and then that will inform the subsequent three steps listed here.”

In a previous blog post on the Delta Levees Investment Strategy, we explained that the McCormack-Williamson Tract and Dutch Slough restoration projects are part of the 8,000 acres of intertidal and subtidal habitat restoration required under the 2009 Biological Opinion.  The Tule Red restoration project on Grizzly Island is also part of the 8,000 acres of tidal habitat restoration.  Changes to levees are a relatively small part of these projects.
dutch slough EIR

The California EcoRestore web page lists several future habitat restoration projects on Sherman Island and Twitchell Island, both of which are designated as “very high priority.”  These include an $88.4 million setback levee on Twitchell Island, and restoration of 1,250 acres of wetland on the west end of the island. Funds have yet to be identified for an additional 3,900 acres of emergent wetland restoration on Sherman Island.  The EcoRestore program evolved from the CALFED Ecosystem Restoration Program.  The CALFED Ecosystem Restoration Program (ERP) was part of the CALFED Record of Decision.  The ERP proposed extensive habitat restoration for mitigation of exports by the State Water Project and Central Valley Project.

As explained in a previous blog post, the Delta Levees Investment Strategy regulations will mandate that these ecosystem restoration projects take priority over protecting communities in the primary Delta from flooding. With the new prioritization, the issue of cost allocation becomes more critical.

The Davis-Dolwig Act, passed in 1961, directed that Department of Water Resources include in its water charges an amount “sufficient to repay all costs incurred for the preservation of fish and wildlife” as a result of the project.  But, according to the Legislative Analyst’s Office, the Department of Water Resources has generally not followed Davis-Dolwig in determining charges to the State Water Contractors.

This post was updated on August 27 to include future EcoRestore projects on Sherman Island and Twitchell Island.

Posted by: Deirdre Des Jardins | August 20, 2019

Vanishing funds for levee upgrades for smaller, vulnerable Delta communities

The Delta Stewardship Council will be adopting regulations to implement the Delta Levees Investment Strategy (DLIS) on August 22, 2019.  Maps of the priorities for levee investments are available here.

The proposed regulations make investments in upgrading urban levees in West Sacramento and Stockton and adjacent areas “very high priority.” These investments are long needed, particularly for Stockton.  Stockton is the 7th largest city in California, and the levees are badly in need of improvement.

Funding for improvements to urban levees has typically been tied to federal projects and funded separately from improvements to levees in the primary zone of the Delta.  Improvements to the levees in the primary zone have been funded by the Delta Levees Subvention and Special Projects Programs, separate pots of money.

The Delta Levees Investment Strategy also prioritizes investments in improving levees protecting Bethel Island in the South Delta. The US Census estimated Bethel Island’s population at 2,379 in 2017.  This is also an important investment.

But Rio Vista, population 9,009, and Discovery Bay, population 15,525, are second priority for levee improvements.   And the Delta legacy towns of Clarksburg, Courtland, Locke, and the eastern bank of Walnut Grove are the lowest priority, even though Clarksburg and Courtland have public schools.  (Walnut Grove is on both sides of the Sacramento River.)

DLIS NDDelta Levee Investment Priorities — Closeup of North Delta

SouthDelta DLIS.pngDelta Levee Investment Priorities — Closeup of South Delta

The Central Delta Water Agency has commented that, given the shortage of funds for the Delta Levees Subvention and Special Projects Programs, no or almost no funds will be available for levee improvements for islands in the second tier, and none for the lowest tier.  Thus the Delta Levees Investment Strategy codifies the somewhat chilling calculus that protecting smaller, vulnerable Delta communities from flooding is not in the state interest.

One of the main reasons there are insufficient funds to protect smaller Delta communities is that the Delta Levees Investment Strategy also assumes that public funds must be spent to protect Delta exports and pay for mitigation of impacts of the State Water Project and Central Valley Project.

The Delta Levees Investment Strategy designates as “very high priority” upgrades to the Delta islands marked as “critical for Delta exports” in a 2010 PPIC report, Levee Decisions and Sustainability for the Sacramento-San Joaquin Delta.  One of these islands has the town of Isleton, but the rest are more sparsely inhabited.

Levee analysis.png

According to the proposed Delta Levees Investment Strategy regulations, the levees on these islands must be fully improved before any state funds can be spent improving levees protecting Rio Vista, Discovery Bay, Clarksburg, Courtland, Locke, or the east bank of Walnut Grove.

The “Ability to Pay” analysis for the Delta Levees Investment Strategy did not take into account that revenues from the State Water Project could be used to improve the Delta islands that are “critical for water supply,” even though two of the islands are owned by the Department of Water Resources. Most of the land on Sherman and Twitchell Islands was acquired by DWR in the early 1990s. The acquisition and conversion of the lands to grazing and wildlife uses allowed the Department of Water Resources to move the salinity compliance point for their contract with North Delta Water Agency upstream. This was estimated in to provide a benefit to critical period SWP deliveries of more than 100,000 acre-feet per year.

ATP mapAbility to Pay analysis for Delta Levees Investment Strategy (Arcadis)

The Delta Levees Investment Strategy also makes public investments in tidal habitat restoration on Dutch Slough and McCormack-Williamson Tract highest priority.  These islands are being restored as part of 8,000 acres of intertidal and subtidal habitat restoration required for mitigation of the impacts of the State Water Project and Central Valley Project. The Ability to Pay analysis for the Delta Levees Investment Strategy includes no revenues from the State Water Project for the habitat restoration, even though mitigation of impacts of the State Water Project is legally the responsibility of the State Water Project Contractors.

Thus the result of the analysis for the Delta Levees Investment Strategy combining pots of money for upgrades to urban Delta levees, upgrades to levees in the Delta primary zone, and habitat restoration, is that funding for protecting smaller Delta communities basically vanishes.  Combining the pots of money is contrary to the originally recommended cost allocation methodology for the DLIS, the Separable Costs — Remaining Benefits method  (SCRB.)  Under SCRB, costs and benefits of projects for water supply reliability and habitat restoration would have been analyzed both jointly and separately from protection of lives and property.

The DLIS also exposes the state to considerable liability.  Many of the levees protecting North Delta legacy communities are State Plan of Flood Control Levees.  The Central Valley Flood Control Association commented that “[d]eviating from existing definitions of levee maintenance that results in the state reducing investments in maintenance of SPFC levees will ultimately increase state liability and costs to pay for flood damage caused by levee failures.”  The Central Valley Flood Control Association comments reference the 1986 SPFC Project levee failure near Yuba City “which resulted in evacuations, deaths, and hundreds of millions of dollars in property losses.”   In the Paterno decision, this failure to adequately maintain the State Plan of Flood Control Levees resulted in liability by the state of $467 million.

Following the originally proposed SCRB cost allocation method would have avoided the issue with prioritizing non-project levees which protect water supply over SFPC levees which protect lives and property.  The slide below is from a presentation by Arcadis consultants for the Delta Science program peer review of the DLIS methodology.

DLIS cost allocation

Slide from presentation to Delta Stewardship Council on DLIS methodology

Because of the failure to follow the recommended cost allocation procedure, it is difficult to see how the DLIS is consistent with the legislative mandate that the Delta Plan “attempt to reduce risks to people, property, and state interests in the Delta by promoting effective emergency preparedness, appropriate land uses, and strategic levee investments.”

This post was updated on 8/21 to include links to comment letters on the Delta Levees Investment Strategy, more maps, and information on the originally proposed method of cost allocation.




Posted by: Deirdre Des Jardins | August 12, 2019

Delta tunnel: Sea level rise and elevation of the North Delta

On May 2, 2019, the Department of Water Resources published a fact sheet on “Modernizing Delta Conveyance Infrastructure Q&A.” The fact sheet states that the California Ocean Protection Council has recommended “that projects with a lifespan beyond 2050 be built to withstand 10 feet of sea level rise by 2100.” The Department of Water Resources is to be commended for recognizing the recommendations by the Ocean Protection Council.   Hopefully DWR will be using them in assessing climate change and “efforts to modernize Delta conveyance.” per Governor Newsom’s April 29, 2019 Executive Order.

DWR’s Q& A fact sheet goes on to state:

“A reliable underground conveyance system is needed to move high flows from the northern portion of the Delta, which is over 15 feet above sea level, to the point that it can be exported to water systems in the Bay Area, Central Valley and Southern California.”

The statement that the northern portion of the Delta is over 15 feet above sea level is a bit misleading.  The US Geological Survey gives the elevation of Hood as 7 feet.   Maps from LIDAR data show that elevations at Hood over fifteen feet are on River Road, on top of the Sacramento River levee.  To the east of the levee, Hood is at 7-8 feet of elevation.


The difference between 15 feet and 7-8 feet is critical for the Delta tunnel engineering design. Under NOAA’s 10 foot sea level rise scenario, sea levels could rise 7-8 feet by 2080.  If the Delta tunnel was completed by 2040, that would be within 40 years of initial operation.

If North Delta levees are not adequately maintained and upgraded, there could be flooding even without sea level rise. Courtland, just south of Hood, is at -1 ft to 3 ft of elevation, and is subsiding.  The map below shows elevations from LIDAR data collected by DWR and URS corporation.

North Delta elev closeup


Channel profiles from the US Army Corps of Engineers show that the Sacramento River bottom in the vicinity of Hood is over 20 feet below sea level (Mean Lower Low Water in Suisun Bay.) If there was widespread levee failure in the Delta, it is unclear how far salinity would intrude up the Sacramento River at low flows.



DWR’s assessment of “efforts to modernize Delta Conveyance” should include a discussion of whether further modeling is needed to evaluate salinity intrusion at the North Delta intake locations with 5-10 feet of sea level rise.

This post was updated on 8/14 to include an elevation map of the North Delta.

Posted by: Deirdre Des Jardins | August 6, 2019

CWR comments at the Water Board’s Water Portfolio Listening Session

The State Water Resources Control Board held a listening session to receive input on the Water Portfolio.  Deirdre Des Jardins made the following comments for California Water Research on deep adaptation to extreme impacts of climate change — droughts and flooding.

Water agencies need to plan for reliability of ecosystem water during droughts. There were far too many water agencies that came before the Water Board in 2014 to request relaxation of minimum instream flow standards. This should be the last resort during droughts, and only done after implementing Stage 4 drought curtailments.  If California water agencies fail to do this, aquatic ecosystems will not survive climate change.

The Water Board also needs better funding for its core missions. In 2003, at the beginning of the state’s budget crisis, the legislature cut all general fund funding for the Water Board’s water rights division. The Legislative Analyst’s Office noted that this budget cut would increase the backlog of water rights applications.

This is now a major issue with SGMA. The solution is not for the Board to streamline water rights applications statewide, but to provide adequate funding for the Board to evaluate existing permits and instream flow needs.

Another essential need is for critical evaluation of whether climate adaptation projects will actually provide the benefits that they claim. It is being claimed that Sites Reservoir provides flood protection. But it’s an offstream reservoir. It is being claimed that the Delta tunnel will provide mitigation for sea level rise, but the performance of the North Delta intakes has never been evaluated for current estimates of high sea level rise.

The Department of Water Resources has proposed that the state provide vastly increased subsidies for water supply projects. But in adapting to climate change, the state needs to first prioritize funding for protecting vulnerable communities that do not have the resources to adapt to climate change. Their needs include not just drinking water, but also protection from inundation due to flooding or sea level rise. If we continue to fail to adequately fund flood protection, the future consequences could be disastrous.

Finally, our state patterns of land use are unsustainable. Not only do we have massive groundwater overdraft in the San Joaquin Valley, satellite mapping showed 955,000 acres on the west side of the San Joaquin Valley that is moderately to severely impaired by salinity. We simply do not have the resources, either with surface water or with funding, to sustain these patterns of land use and also deal with the disruptions of climate change.

Posted by: Deirdre Des Jardins | August 6, 2019

DWR rescinds engineering performance standards for Delta tunnel

The Department of Water Resources delegated the design and construction of the WaterFix project to the Delta Conveyance Design and Construction Authority in the October 2018 Joint Exercise of Powers Agreement.   The Joint Exercise of Powers Agreement included performance standards for the engineering design of the project. The performance standards included requirements that the Delta conveyance be designed to withstand a maximum earthquake, and to have a 100 year lifetime.

The June 2019 Amendment to the Joint Exercise of Powers Agreement rescinded the engineering performance standards.  This should be of concern to water agencies evaluating whether to participate in the Delta conveyance project.

The requirement for a 100 year design lifetime is particularly important because of sea level rise. The impact of sea level rise on the North Delta intakes was last evaluated in 2010.   The hydrodynamic modeling assumed 55 inches of sea level rise by 2100, which is about half that of current maximum estimate of 10 feet.

SLR 2200

US Army Corps of Engineers   Sea level rise in the Delta through 2200

The 2010 modeling also evaluated the impacts of widespread levee failure, but used a grid from the Delta Risk Management Strategy modeling that only went as far north as Isleton and Bouldin Island.   So the modelling implicitly assumed that only levees in the South Delta would fail.


 Grid used for modeling of salinity intrusion for DRMS and North Delta intakes

For these reasons, California Water Research  has recommended that more hydrodynamic modeling be done to assess the impacts of extreme sea level rise on the previously proposed North Delta intake locations.

The Delta Independent Science Board made similar recommendations in their 2014 review of the Delta conveyance project, stating,

If the effects of major environmental disruptions such as climate change, sea-level rise, levee breaches, floods, and the like are not considered … one must [not] assume that the actions will have the stated outcomes.

Without such an assessment, there is insufficient information for decision makers to evaluate the Delta tunnel as a water supply project.

Governor Gavin Newsom stated in his February 12, 2019 State of the State address that he did “not support the WaterFix as currently configured.  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.”  The meaning of Governor Newsom’s statement is the subject of active negotiations between the Department of Water Resources (DWR) and the State Water Contractors (SWC.)

DWR and the SWC have begun negotiations on a potential State Water Project contract amendment to pay for a single Delta tunnel.  Under a settlement agreement with Planning and Conservation League over the Monterey amendments, the negotiation meetings are required to be public. The first negotiation meeting was held on July 24, 2019.

At the July 24 meeting, the State Water Contractors presented a First Offer to DWR.  The State Water Contractors seek an Agreement in Principle that would allow the SWC to define the Delta tunnel capacity and general configuration, including the tunnel alignment, number of intakes, and pumping station capacity.

Meanwhile, in consideration of Governor Newsom’s direction, the Delta Conveyance Design and Construction Authority is reportedly considering four potential alignments for the Delta tunnel project in the DCA’s engineering design process.  The potential alignments include the “previously preferred” Waterfix tunnel alignment, and one nearer to I-5 that would avoid some of the major impacts from project construction on Delta recreation, Delta tourism, and Delta legacy towns.

Metropolitan Water District has bought two of the Delta islands in the WaterFix project main tunnel alignment, Bouldin and Bacon Islands, and CalTrans has constructed an interchange for the project at Highway 12 on Bouldin Island.  So it seems likely that the State Water Contractors are proposing that the main Delta tunnel alignment not change.

Bouldin tunnel

WaterFix main tunnel alignment on Bouldin Island with tunnel muck areas

For operations, the State Water Contractors are proposing that the Delta tunnel be a State Water Project facility, integrated into the State Water Project.  The SWC propose to define “Delta Conveyance Project Water,” which would be “the additional amount of total SWP water that can be conveyed with the Delta Conveyance Project compared to the amount that can be conveyed without the Delta Conveyance Project.”

The  State Water Contractors are also proposing that water agencies opt in to participate in the Delta tunnel project.  SWC who choose to participate would pay for a share of the available Delta tunnel capacity, up to their Table A allocation. The proposal states that the SWC believe that the Delta tunnel would be fully funded by the opt in framework, but propose an iterative procedure for determining participation as the design of the Delta tunnel is developed.

Meanwhile, the Delta Conveyance Design and Construction Authority is pushing forward with engineering work on the Delta Conveyance project and submitting the bills to DWR.  Unless agreement is reached, DWR may run out of funds to pay the DCA.

Further negotiation meetings are scheduled for July 31, and August 7, 14, 21, & 26.

Posted by: Deirdre Des Jardins | July 16, 2019

Speculative financing for Delta tunnel engineering work

The Delta Conveyance Design and Construction Authority (DCA) is a Joint Powers Authority created in 2018 by Metropolitan Water District, Santa Clara Valley Water District, Kern County Water Agency, and the State Water Contractors. The DCA was delegated the powers of the Department of Water Resources to design and construct the WaterFix / twin tunnels project.

In January of 2019, the DCA signed a $93 million contract with Jacobs Engineering for engineering design services for the WaterFix project and a $75 million contract with Fugro for geotechnical services.  In April, the DCA signed a contract for $40 million with Parsons Transportation Group for a Project Management Information System, cost and schedule controls, and program reporting.  But at the direction of Governor Newsom, all WaterFix project approvals were rescinded on May 2, 2019.  Work has nevertheless continued under the engineering contracts.

The continuing engineering work is being financed under a June 2019 amendment to the WaterFix Joint Exercise of Powers Agreement (JEPA,)  The amendment allows DWR to authorize and pay for design work on a single tunnel project, retroactive to May 2019.  The budget in the JEPA amendment (shown below) states that the DCA is planning to spend over $100 million for each of fiscal years 2019-2020, 2020-2021, and 2021-2022.

DCA budget and schedule

The DCA appears to be attempting to continue the original WaterFix engineering design schedule as much as possible, given the new direction on the project.   The WaterFix project engineering design was originally scheduled to be completed in 2022.

But how is the engineering work on the single tunnel being paid for, given that all project approvals were rescinded?   The meeting materials for the July 2019 Design and Construction Authority Board meeting show no current funding commitments. The cash flow projections (shown below) show the DCA is relying on a $19.7 million loan from DWR for expenses for the next few months. Future cash flow relies on yet-to-be-made commitments by State Water Project contractors starting in September 2019.  A footnote below the graph states that the majority of State Water Project contractors are “anticipated” to “seek and receive funding approval from their respective Boards between November 2019 and February 2020.”

DCA 7-19 cash flow

The DCA is also signing a $10 million lease for office space at 980 9th Street. According to the July meeting packet, the DCA Director is seeking authorization for a letter of credit from a bank that the landlord could draw on as necessary “if the DCA defaults on the lease.”


Posted by: Deirdre Des Jardins | July 8, 2019

Assessing the Delta tunnel project as a seismic upgrade

Governor Newsom’s April 29, 2019 Executive Order mandated that the California Natural Resources Agency and the California Environmental Protection Agency assess “current planning to modernize conveyance through the Bay Delta with a new single tunnel project.”

Part of the agencies’ assessment of that planning should include an independent, objective assessment of the Delta tunnel’s performance in a large earthquake. The assessment needs to look into why Metropolitan Water District’s analysis of whether the tunnel lining will survive a large earthquake assumes the tunnel is constructed in very dense soil.  This assumption is questionable.


In April of 2018, California Water Research collaborated with the Sierra Club and other Southern California environmental groups to send a letter to the General Managers of Metropolitan Water District, and Kern County Water Agency, and the CEO of Santa Clara Valley Water District, explaining that the Delta tunnels were not being designed to withstand a Maximum Considered Earthquake on nearby faults. The letter concluded,  “[t]he Department of Water Resources and Metropolitan Water District must analyze the performance of the Delta tunnels for all seismic hazards in the Delta, including the.. Maximum Considered Earthquake.”

MWD commissioned an evaluation of the performance of the proposed Delta tunnel lining for a Maximum Considered Earthquake in the Delta, a 2% in 50 year, or 1 in 2,475 year event.  The July 2018 analysis concluded the tunnel lining design would perform adequately and no changes to the design were needed. (Arup 2018.)

But there were major limits to the new analysis by Arup. The analysis for a Maximum Considered Earthquake only considered ground shaking at Clifton Court. The analysis also assumed that the soil column at Clifton Court was very dense. Based on this assumption, the analysis concluded that the ground shaking at the depth of the tunnel was about one-third that of the ground shaking on the surface.

chart seismic

As explained below, the assumption that the soil column at Clifton Court is very dense is inconsistent with geologic maps of the deep sedimentary deposits in the Delta. The conclusion that ground shaking at the depth of the tunnel is one-third that of the ground shaking on the surface is also not consistent with measurements from a down-hole seismic array at another site with deep sedimentary deposits, La Cienega in Southern California (Grazier 2004.) Measurements at La Cienega show that for strong earthquakes, ground shaking at the proposed Delta tunnel depths is about 70% of that on the surface (Hu 2005.)

Seismic hazard maps from the California Geologic Survey show no regions in the Delta near Clifton Court Forebay with very dense soils. The CGS map below shows the soil density for areas in the Delta near Clifton Court. (CGS 2018.)   Interpreting the CGS map requires a little explanation.

Geologists and geotechnical engineers estimate the density or stiffness of soils with shear wave velocities (Vs.)  For earthquake engineering, they consider the average shear wave velocity over the top 30 meters (100 feet) of soil.   Average shear velocities above 750 m/s correspond to rock. Average velocities above 360 m/s correspond to very dense soils. Velocities above 180 correspond to stiff soils. Velocities below 180 correspond to soft soils.

The CGS map shows that, in general, the only very dense soils near Clifton Court are in the Diablo Mountain range (at the bottom left corner.)  The soils at Clifton Court are generally stiff (Vs = 294.)  The soils at Bacon Island are generally soft (Vs = 176.)

Woodward quadrangle

Perhaps the sediments Clifton Court Forebay increase in density with depth?   The graphs below show shear velocity vs depth in two boreholes at Bacon Island and Clifton Court, from Kishida 2009. There start to be layers of very dense soil at Clifton Court at about 25 meters (82 feet depth.)  The graph shows essentially no layers of very dense soil for Bacon Island.


It is unclear how MWD could have concluded that soils at Clifton Court are “very dense,” except by cherry picking the properties of deep layers of soil.

For evaluation of the seismic performance of the Delta levees in the Delta Risk Management Strategy, on the other hand, DWR’s contractor cherry picked the lowest shear velocity values from specific boreholes.   This was criticized by the US Geologic Survey as not standard engineering practice.

If the DWR’s contractors analyze the seismic performance of the Delta levees as if they were built entirely on soft soils, and MWD’s contractors analyze the performance of the Delta tunnel lining as if it was built entirely in very dense soils, it will likely result in a large over-estimation of the seismic benefits of the Delta tunnel.

An objective, unbiased analysis of the benefits of the Delta tunnel as a seismic upgrade should use the same geotechnical assumptions for both the “without project” conditions and the “with project” conditions.


Arup, Seismic Review of Tunnel Liner Performance, Appendix M, Conceptual Engineering Report, California WaterFix Byron Tract Forebay Option,  2018. Available at

California Geological Survey, Seismic Hazard Zone Report for the Woodward Island 7.5-Minute Quadrangle, Contra Costa County, California 2018.  Available at

Graizer, V & Shakal, A. Recent Data from CSMIP Instrumented Downhole Arrays. AGU Fall Meeting Abstracts, 2004.  Available at

Hu Jin-jun & Xie Li-li. “Variation of earthquake ground motion with depth,” Acta Seimol. Sin. (2005) 18: 72. DOI:10.1007/s11589-005-0008-x.   Available at

Kishida, Tadahiro & Boulanger, Ross & A Abrahamson, Norman & W Driller, Michael & M Wehling, Timothy. Site Effects for the Sacramento-San Joaquin Delta. Earthquake Spectra. (2009) 25 10.1193/1.3111087. Available at

Schaefer, J.  Seismic Review Comments (and Responses) on Technical Memorandum Delta Risk Management Strategy (DRMS) Phase 1 Draft 3 Topical Area: Levee Vulnerability. US Army Corps of Engineers, April 11, 2008.  Available at


On June 10, 2019, the Department of Water Resources (DWR) began extensive geotechnical drilling to evaluate a single tunnel project in the WaterFix project alignment.  The drilling is currently suspended, pending resolution of a Temporary Restraining Order issued by Sacramento Superior Court at the request of Sacramento County.  The work is being done without required county permits to protect groundwater.

The geotechnical work was ordered by the Delta Conveyance Design and Construction Authority (DCA) ahead of a July 31, 2019 deadline to complete work under a court Order of Entry that DWR initially obtained in June of 2017.  Boring locations in the court order include the WaterFix North tunnel leading from Intake #5, and the WaterFix main tunnel alignment on Venice Island and Victoria Island in the South Delta. The boreholes are 6.5 to 8 inches in diameter and 150 to 200 feet deep.

Intake drilling

According to DWR’s May 22, 2019 environmental document for the drilling, the geotechnical work is being done is to complete geotechnical exploration in the WaterFix project tunnel alignment that began in 2010 and 2011.  The geotechnical work is part of ongoing work under contracts executed in January of 2019 for the WaterFix project.  The DCA signed a $93 million contract with Jacobs Engineering in January of 2019 for engineering design, and a $75 million contract with Fugro for geotechnical services.

Controversy over the geotechnical work

When the geotechnical drilling crews arrived in the Delta, DWR employees distributed flyers characterizing the work as “soil sampling” to “investigate alternative conveyance types and alignment locations.”  Delta residents were outraged.  Delta community and business groups sent a letter to DWR Director Karla Nemeth on June 12, stating

Allowing the Delta Conveyance Design and Construction Authority (“DCA”) to continue preliminary design, survey and right of way mapping, and real estate acquisition planning based on the withdrawn WaterFix project specifications is wholly unacceptable to our communities. To our knowledge, DWR has no approved plans or specifications for the new Delta conveyance.  And if the WaterFix project specifications are being used as the basis for the design of the new Delta conveyance under DWR’s authority, it is predecisional and will prejudice the new Delta conveyance CEQA process.

Gary Lippner, DWR’s Deputy Director of Delta Conveyance, responded on June 17, 2019 stating that “[n]either the Department of Water Resources (DWR) nor the Delta Conveyance Design and Construction Authority (DCA) is continuing work on that project or currently performing any new planning based on the previous WaterFix approvals.”

Kathryn Mallon, the Delta Conveyance Design and Construction Authority Executive Director, has since clarified that the current geotechnical work is being done in support of a single tunnel in the WaterFix project tunnel alignment.  She stated that the work is needed to “support the preferred alignment of the previous planning work and [is] necessary to answer critical questions related to this particular alternative (eg. pile driving methods and noise levels at the proposed intake locations.)”

With regard to alternative designs, the DCA Executive Director stated,

The DCA has budgeted for and is in the process of preparing a boring plan that is more geographically expansive and includes collecting information in corridors for alternatives that are expected to evolve from the NEPA process, including the previously preferred alternative but not limited to this alternative.

According to the DCA’s Fiscal Year 2019-2020 budget, the DCA is planning to spend $82 million over the next 12 months, including $35 million on engineering design and $20 million on field work  ($98 million with contingency.)  When the proposed 2019-2020 budget was released on June 17, Delta community and business groups expressed shock at DWR’s approval of the aggressive schedule, stating:

We strongly disagree with this approach of rushing forward with engineering design and geotechnical work. The way to mitigate impacts of the project on Delta legacy communities and fish is to first reconsider the project design in consultation with Delta stakeholders. This process must start with DWR addressing the requirements of the Delta Reform Act to reduce reliance on the Delta, and to restore, enhance, and protect the Delta as an evolving place. Pursuant to the National Historic Preservation Act DWR must also start with an early consultation on historic properties.

The Delta community groups also requested that DWR rescind authorization for the geotechnical work until the appropriate county permits were obtained.

DWR’s Deputy Director Lippner and the DCA’s Executive Director Kathryn Mallon have offered to meet with the groups to “discuss the planning process and hear their thoughts on local engagement.”  But DWR’s attorneys are simultaneously seeking to continue the geotechnical work without county permits.  The Delta Conveyance Design and Construction Authority Board also approved the $82 million budget for Fiscal Year 2019-2020 at the June 20, 2019 meeting, including $55 million for engineering design and field work.

The Department of Water Resources and the Delta Conveyance Design and Construction Authority are doing extensive engineering work to assess potential designs for a single Delta tunnel. On June 10, 2019, the Department of Water Resources began geotechnical drilling in the former WaterFix project tunnel alignment and a former WaterFix project intake location. According to the DWR website, the geotechnical drilling is at 19 sites in three Delta counties (San Joaquin, Sacramento, and Contra Costa.) The work requires drilling of 6.5 to 8 inch boreholes to a depth of 150-200 feet. The drilling reportedly requires a crew of five to six people for up to 11 days at each site.

geotech drilling2

Drilling crew in Courtland

The Sacramento-San Joaquin Delta is a sensitive area and borehole drilling requires special sealing to prevent contamination of groundwater. On June 7 and June 14, 2019 the counties of San Joaquin and Sacramento notified DWR that the geotechnical work required a well drilling permit. On Monday, June 17, 2019, the Sacramento County Environmental Management Department issued a Stop Work Order for the drilling in Sacramento County. On Thursday, June 20, 2019, the San Joaquin County Environmental Health Department gave Victoria Farms on Victoria Island in the South Delta a Notice to Abate for unpermitted well drilling. The abatement notice documented that Victoria Farms was under court order to allow the drilling.

On Thursday, June 20, the Sacramento County Superior Court granted a Temporary Restraining Order to Sacramento County to enjoin the geotechnical drilling for 21 days. Chris Hunley, the Sacramento County Environmental Specialist who issued the Stop Work Order, stated in a declaration in support of the order:

Unregulated drilling performed in connection with investigations of hydrologic or geologic conditions can be harmful and detrimental to water quality, including potable drinking water supplies, because the drilling can remove or open up preexisting underground geologic layers between aquifers and expose groundwater resources to pollutants, contaminants and sediments from other aquifers that had no prior hydrologic connection.

Most of the Delta area of Sacramento County relies upon wells for drinking water supply. The Sacramento Delta is a sensitive area with respect to groundwater quality. The Courtland area has special annular sealing material requirements to protect high quality waters from degradation by poor quality waters via pathways that are unsealed or improperly sealed. The potable groundwater supply exists at a depth of roughly 120 feet and lower. While borings are not water supply wells, improper construction of borings can potentially negatively affect the region’s drinking water aquifer by creating a hydrologic connection between the dirtier river seepage water at shallower depths and the separate, cleaner groundwater in the lower aquifer.

An improperly constructed or drilled boring could cause irreparable harm to public health because domestic well water could be infiltrated and contaminated by non-potable water from other aquifers as a result of drilling a single bore through multiple aquifers.

As reported by Matt Fleming at CalWatchdog, Sacramento County previously had problems with Caltrans claiming exemption from local agency permitting for geotechnical work and doing improper drilling. In 2014 Sacramento County threatened to fine Caltrans millions of dollars for drilling hundreds of borings over a period of decades in violation of state laws aimed at protecting groundwater. Under pressure from Sacramento and San Joaquin County and other local agencies, Caltrans announced their intent to follow local groundwater protection ordinances and outlined a plan to locate wells throughout the state and work under the proper license.

The Department of Water Resources does not have a similar policies. DWR and the Delta Conveyance Design and Construction Authority are proposing to delete Term 3b from the Joint Exercise of Powers Agreement which requires compliance with local permits:

In carrying out its obligations under this Agreement, and without regard to the named Permit holder, the Authority and its agents shall comply with all conditions of all applicable federal, State, or local Permits issued for design and construction of the Conveyance Project.

The next hearing on Sacramento County’s filing to enjoin DWR from doing further geotechnical drilling without the required county permits will be in Sacramento County Superior Court on July 11 at 2:00 pm.

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