Frequently Asked Questions

Frequently Asked Questions: General+

Will Sites Reservoir help increase water supplies in future droughts?

Yes. Sites Reservoir is an insurance policy for future droughts. Sites Reservoir does not rely on snowpack and if the scientific projections are correct about the impacts of climate change (i.e. California is expected to receive about the same annual precipitation that it currently does but more will come as rain instead of snow), then having Sites Reservoir will mean we can safely collect more water in the reservoir for use during future droughts.

Will Sites Reservoir divert water from the Sacramento River even during critically dry years?

It depends. Even during drier years there can be significant precipitation events that present conditions where water can be diverted safely from the river and placed in Sites Reservoir. All diversions will be subject to the highly protective operating conditions that are currently being proposed and will ultimately be permitted by State and Federal regulatory agencies for the Sites Reservoir Project.

Will Sites Reservoir decrease Delta flows?

Yes, slightly, when the Project is diverting. However, since the Sites Reservoir diversions occur only when there are high river flows, any reduction to Delta flows would be minor and would not impact any of the beneficial uses of the water in the Delta. Storing water in Sites Reservoir during times when there is a lot of flow in the Sacramento River for use during times with the flows are low, including during drought periods, is part of the statewide strategy for adapting to changing climate conditions and to return much needed flexibility to the statewide water management system.

Have concerns about the impact of Sites Reservoir operations on the environment been addressed in the current proposal?

The Project operations have been modified substantially over the last two years to be more protective of the environment. These modifications have reduced the Project diversions from the Sacramento River substantially, in fact diversions have been reduced almost in half, as compared to the criteria proposed in 2017. The current Project operations strikes the needed balance between environmental protections and Project affordability that must exist for the Project to proceed.

How much would have been diverted in 2021?

Zero diversions into the reservoir in 2021 would have occurred if Sites Reservoir would have been in place. This is in accordance with the highly protective operating conditions that are currently being proposed for the Project. However, the one million acre-feet estimate that would have already been stored as result of the wetter years in 2017 and 2019 is the water that would be available today. And if 2022 is another dry year it is estimated there could be approximately 400,000 acre-feet of that left in Sites. This water is badly needed addition to a severely depleted water supply system that was not built to address future climate.

Is Sites Reservoir compliant with Proposition 1?

Even with the Project changes that have occurred since the original award in 2018, the Sites Reservoir Project continues to provide the public benefits the California Water Commission conditionally approved for the Project in State Proposition 1 funding in 2018. The Project meets the Proposition 1 conditions and continues to meet all the feasibility requirements for investment by the State. In December 2021, the California Water Commission deemed the Project feasible.

Who profits from Sites Reservoir?

The Sites Reservoir Project is led by a Joint Powers Authority made up of irrigation agencies, water districts, cities, and counties in the Sacramento Valley area. The Project is being developed on a beneficiary pays principle which means that the benefits received are paid for by those receiving the benefits. The beneficiaries of the Project include the federal government, state government, and local public agencies. The water generated by the Project will be used for agriculture, meeting water demands of businesses and residents, and serving the needs of the environment throughout California.

Is Sites Reservoir a private reservoir?

No. Sites Reservoir is funded 100 percent by local, state, and federal public dollars. There are environmental, recreational and flood control benefits – as well new dry year water supplies secured for public agency ratepayers throughout California. Participation in Sites is broad and diverse, including the Bureau of Reclamation, State of California, urban areas of Southern California and the Bay Area, as well as public irrigation districts in the Sacramento Valley and San Joaquin Valley.

How does the cost of water from Sites compare to other sources during dry years?

The Sites Reservoir compares favorably to other dry year water supply alternatives which improves water affordability for Project participants and the 24 million users they serve, including disadvantaged communities. With water being one of California’s most scarce and valuable resources, it is essential to develop a diverse portfolio of sustainable water supply solutions. But it is equally important for decision‐makers and stakeholders to evaluate the most cost‐effective options available to maximize the value of these investments. The Project has been designed to put the state’s limited water resources to the best use in an affordable, flexible, and sustainable way.

How can member agencies be assured that there will be water in Sites Reservoir if they are paying for storage?

Sites Reservoir is a beneficiary pays project, which means that the benefits of the project go to those paying. Each participant (including environmental uses) has control over their portion of the storage space and a proportionate share of the water diverted into Sites Reservoir. There is flexibility in the timing and uses of the water, including for the environment. The assurance of water being in the reservoir is largely the result of the individual participant decisions in their operations of their portion of the facility. This way, each member is assured to receive what they pay for in a way that works within and complements that member’s water supply portfolio.

Why has it taken so much time to get Sites to the finish line?

Sites has been around for decades with efforts originally being led by the California Department of Water Resources and the Bureau of Reclamation. The Project had starts and stops, as is typically seen in large projects led by the state or federal government. The Sites Project Authority was formed in 2010 to move the Project more expeditiously. Big projects take time and careful consideration, and the Authority has done that over the last decade and will continue into the future. Sites Reservoir is anticipated to be operational around 2030. The Authority has made great strides over the last two years to “right-size” the Project for affordability and permitability, two critical success factors. This represents a huge milestone for Project advancement and sets a turning point that makes the Project more feasible and more likely to be built than ever before.

Why does this project make sense now, after 60 years?

Many aspects of water management in California have changed in the recent decade that put the Sites Reservoir on the fast track to completion. These changes include the implementation of the Sustainable Groundwater Management Act, the continued declining reliability of the state and federal water projects, increasing regulatory changes requiring diversification of water purveyors’ water portfolios, and the need for water resiliency to address the inevitable uncertainty of the changing climate. Additionally, never before has California had a means to invest in storing water for the environment which was made possible with the overwhelming voter passage in 2014 of Proposition 1 making $2.7 billion available for public benefits of water storage. Approximately 18% of Sites Reservoir is dedicated to delivering water for the environmental purposes as a result of Proposition 1 funds which, for the first time, creates an asset California’s regulators can use to adaptively manage for the benefit of fish and wildlife.

In hindsight, should this project have been built when originally contemplated, and if so what would be different today?

Hindsight is always 20/20 and if Sites had been built decades ago the added flexibility it would have created would have been very beneficial for California water management over the years. From a more recent perspective, if California had Sites Reservoir in a dry year like 2021 it is estimated there would be close to 1 million acre-feet of additional water supplies available for farms, cities and the environment. Sites Reservoir diverts water in wet periods and stores that water for use in the drier times.

Frequently Asked Questions: Operations+

Is Sites being built to send more water South?

Is this reservoir a stand-alone, or does it work with other regional reservoirs?

Sites Reservoir is uniquely located in relation to other major components of the state and federal water projects like Shasta Lake, Lake Oroville and Folsom Lake. Sites is complementary to these existing crucial elements of statewide water management and could act to extend the functions they serve by creating flexibility to adapt to changing river and Delta management conditions. For example, Sites can be operated in coordination with Shasta Lake to preserve and enhance cold water for endangered salmon in the Sacramento River. Or Sites could contribute to the increased fresh-water flow into the Delta during drier periods to assist with salinity management of this critical estuary. Sites would not compete for the water resources stored in these state and federal facilities but would increase the total amount of managed water in storage. With the uncertainty California water managers face in the next century, having the Sites Reservoir is a necessity for statewide water management.

Does Sites Reservoir need new Delta conveyance?

Since Sites only receives water when there is “surplus” flow in the Sacramento River, how long is it projected now before the reservoir is full under “normal” precipitation patterns?

In California water there is no “normal” water year. Based on 82 years of past hydrology analyzed using standard models and methods, it would take, on average, approximately five to seven years for the reservoir to fill completely on first fill. In contrast, in a single water year like 2016-2017 it would have been possible to fill the reservoir in one year. Similarly, if a string of dry years was to occur, it would take longer to fill, maybe as much 10 years. Surprisingly, there tends to be “surplus” flow in the river in all years. Even in dry and critically dry years, there would be filling opportunities, albeit fairly limited.

The original construction of Los Vaqueros Reservoir in Contra Costa County provides a real-life example of the possible variability in fill rates. The first fill of the 100,000 acre-foot reservoir was expected to take five to seven years. However, the first year of operation was 1997-1998, a fairly wet year of high-quality water being available at the intakes, which allowed the reservoir first fill to be completed in just two years.

How much above the statistical normal for rainfall in the region does rainfall have to be for Sites to receive “surplus” water from the Sacramento River?

Sites is designed to divert water through existing state-of-the-art fish screens only when actual flows on the Sacramento River exceed that needed by more senior water right holders, the Delta is in “excess” conditions, and based on stringent criteria to protect aquatic resources. Sites primarily diverts flows into the Sacramento River from streams and creeks downstream of Shasta/Keswick Dams. The exception is that Sites could pick up water that gets released from these dams under flood control conditions. The operations modeling typically conducted for water projects does not rely on rainfall statistics. Instead, model simulations (CalSim) calibrated to actual flow conditions for an 82-year period covering 1921-2003 are overlayed with current permit and operating constraints to evaluate with project conditions.

The beneficial thing about this approach is that you can simulate future with climate change conditions which has been done for the Sites Project. The results of these with climate change simulations demonstrate that the performance of the project actually improves 5 to 10 percent with climate change. This is good for all of the project partners including the state and federal governments which are approximately 25 percent shareholders for environmental purposes.

How will this project utilize and capitalize on existing infrastructure and what does that mean for the project footprint?

Extending the performance of existing infrastructure is good public policy, good business practice and makes for a more sustainable footprint by reducing the environmental impact of the constructed work. The Project will utilize existing facilities and infrastructure to a great extent and the existing topography of the reservoir site itself is a natural bowl perfectly situated to accommodate a water reservoir. A significant portion of the 100+ miles of conveyance (canals and pipelines) involved in the Project will be existing facilities. The only new conveyance envisioned is the inlet/outlet works for the reservoir and the four miles of 10-foot diameter pipeline to convey water back to the Sacramento River between the Tehama-Colusa Canal and the Colusa Basin Drain.

Would the proposed diversions for Sites Reservoir be permitted by regulatory agencies?

Yes. The Project will need to obtain permits under the Federal Endangered Species Act and the California Endangered Species Act for operations, including the Project’s diversions of water from the Sacramento River. The Authority views itself as partner with the environment with a firm duty to act as a steward of the natural resources. In this vein, the Authority recently incorporated further revisions to conditions for diverting water that increases restrictions and provide greater protection of the Sacramento River and Delta fishery. These changes are in response to comments from the California Department of Fish and Wildlife on the Revised Draft EIR/Supplemental Draft EIS which highlighted the most recent scientific evidence supporting certain conditions that are being implemented to protect salmon.

How can Sites Reservoir proceed with so much uncertainty in other aspects of water management such as the Bay Delta Plan, and ongoing drought conditions?

There is no time to waste and doing nothing while we wait for other actions to be completed is a sure way to continue the challenges we face today for decades into the future. Bold, swift action must be taken throughout our State to develop a diverse toolbox of measures and adaption strategies to address the climate challenges we face as a State and Nation. Sites Reservoir is one of a number of bold actions and needs to be built to provide another smart, 21st century tool to help California manage through droughts, climate change, and the stresses these conditions create for our natural and developed systems. All of the other processes underway can and should continue to completion, but tackling our issues sequentially instead of in parallel means we fall further behind which will lead to even more extreme difficulties in our future.

Frequently Asked Questions: Environmental+

What are the environmental implications of this project?

The environmental effects of the Project have been analyzed in detail in the Revised Draft EIR/Supplemental Draft EIS. Transformational projects of the magnitude and importance of Sites are not without tradeoffs. There are specific elements of the Project that are critical to enhancing environmental conditions. First, the State has made a large investment, through the 2014 passage of Proposition 1, to enhance their ability to support critical aquatic needs. Second, there are opportunities to partner with the State and Federal water projects in coordinated operations that will enhance fishery protections associated with their operations. Beyond these enhancements, the Project itself is being designed to avoid and lessen any environmental concerns and, when necessary, provide appropriate mitigation. The Revised Draft EIR/Supplemental Draft EIS Executive Summary (available here sitesproject.org/environmental-review) summarizes the environmental effects that have been identified, including those that are significant and unavoidable.

How much water will Sites take from the Trinity River? Or how will Sites impact the Trinity River?

No water will be diverted from the Trinity River to fill Sites Reservoir. The unique location of the reservoir means the Project is not competing for other water resources. Instead the Sites Reservoir will be complementary to these facilities and enhance the ability to optimize the limited water resources. All water diverted into Sites Reservoir will come from the Sacramento River, primarily from the streams and creeks that flow into the river downstream of the Shasta and Keswick Dams, with the exception of extreme events where Shasta Dam is releasing water to avoid flooding in which case some of this released water may be diverted into Sites.

Will the project harm fish species in the Sacramento-San Joaquin Delta?

No. Sites Reservoir does not threaten salmon and other fish. In fact, there are highly protective operating conditions in place that must be in place before diversions into Sites Reservoir can proceed, including adapting to evolving conditions. In addition, the intakes being used for diverting water into Sites Reservoir include state-of-the-art fish screens that are proven to be highly effective at protecting fish. And, the current proposed project includes more cold water for salmon in the driest years when it is needed most. Not only is no harm done, but there is also a net benefit from this project to Sacramento River salmon, Delta smelt, and the Sacramento-San Joaquin Delta estuary.

Has the Sites Project Authority analyzed and considered a comprehensive range of environmental mitigation and protections to support salmon and the Bay-Delta ecosystem?

Absolutely, and there are a couple of specific elements of the Project that are critical to supporting environmental needs. First, the State has made a large investment in the Project through Proposition 1 to enhance their ability to support these critical systems. Second, there are opportunities to partner with the State and Federal water projects in coordinated operations that will enhance fishery protections associated with their operations. Beyond these enhancements, the Project itself is being designed to avoid and lessen any environmental concerns and, when necessary, provide appropriate mitigation.

How does Sites address temperature management efforts for salmon protection?

All species have varying needs throughout their lives. Suitable water temperatures for cold-water fish are important but not the only important component. They need food to sustain and grow along with places to take cover and rest while migrating to the ocean among other things. While temperature management alone does not meet all of the needs of cold-water fish, it is an important component.

Sites has been shown to have the ability to assist in the Bureau of Reclamation’s temperature management efforts for salmon protection in the Sacramento and American River systems through water exchanges. The Bureau of Reclamation would establish the criteria for these exchanges through its temperature management planning which weighs risks and rewards of various potential protective actions. Sites is a potential tool for use in managing temperature but is not limited to serving this purpose only. Sites provides additional benefits to the environment, including assisting in providing stability for flows in the fall to reduce salmon redd dewatering, providing additional food resources for Delta smelt in the north Delta, among other existing and potential benefits. It would be shortsighted to conclude that the federal government should not invest in Sites based on conclusions about current temperature management efforts being less than optimal. The fact is that Sites creates new water supply for drier periods and flexibility to deal with uncertainty of climate change. Both of these attributes are beneficial to the environment and worthy of federal investment.

Is Sites being built on native lands? How will it impact tribal people?

Both the Sites Project Authority and the Bureau of Reclamation have consulted and will continue to consult with recognized Native American Tribes regarding impacts to Tribal people and resources. This is described in detail in Chapter 23 and Chapter 29 of the Revised Draft EIR/Supplemental Draft EIS. The Authority has reached out to over a dozen Tribes under Assembly Bill 52 and is in ongoing consultation under AB 52 with several tribes. There are Native American human remains and other tribal resources in the footprint of the reservoir and the Authority is working closely with the Tribes that historically inhabited the reservoir footprint to address impacts to these resources and ensure Native American human remains are addressed consistent with the Tribes’ requests. As described in Chapter 29 of the Revised Draft EIR/Supplemental Draft EIS, the Project does not occur in an area that would affect Indian hunting or water rights nor is the alternative on Indian trust lands.

Have Native American tribes been consulted?

How were the RDEIR/SDEIS virtual public meetings announced?

A variety of notification methods and channels were used to announce the virtual public meetings, availability of the RDEIR/SDEIS, and public comment period, including:
Authority’s Notice of Availability emailed to agencies, Tribes, NGOs, and interested parties
Reclamation’s Notice of Availability published in the Federal Register
Press release disseminated to media outlets
Notices posted to the Authority and Reclamation’s websites
Numerous Authority and Reclamation social media posts
Advertisement published in eight local area newspapers
Direct mailing to landowners and interested parties
A series of email blasts to interested public members

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