Delta Conveyance Project FAQ
Photo: Department of Water Resources
What is the Delta Conveyance Project (DCP)?
The DCP is a proposed $20+ billion water conveyance system that would transport water from the Sacramento/San Joaquin Delta to Southern California. The project would be funded through state bonds repaid by Southern California ratepayers and other recipients of water from the State Water Project. The DCP has a long history, with multiple configurations promoted over the course of the past 80 years. [1]
When was a Delta conveyance system first considered?
A Delta conveyance system of some scope was first proposed in the 1940s as part of a much larger – if ill-defined – initiative to move water from Northern California to Southern California. [2] Originally, engineers wanted to harness every major North State river toward this end, connecting them through a massive complex of reservoirs, aqueducts, canals and tunnels, with the unconstrained annual delivery of tens of millions of acre feet of water as the goal. [3]
The two major projects to emerge from these grandiose schemes were the federal Central Valley Project (CVP) and the State Water Project (SWP). The CVP transports water from far Northern California via Shasta Lake, the state’s largest reservoir. The SWP’s main reservoir is Lake Oroville in the Northern Sierra. Both projects draw water directly from the Delta via massive pumps for transport south. The CVP first came online in 1953, [4] and the SWP was in full operation by 1967. [5]
Once both projects ramped up to full operation, their disadvantages became clear. The main issue: salt. Delta water is relatively saline due to the suction of the gigantic pumps pulling salt water inland from San Pablo Bay; this presents significant problems for agriculture. It also became evident the pumps were playing havoc with the Delta’s fisheries, particularly salmon. This gave new impetus to a plan that would avoid the Delta and its tidal influence. In 1957, the California Department of Water Resources (DWR) proposed a “trans-delta system” toward this end. [6]
By the mid-1960s, plans for a trans-Delta “peripheral canal” were refined. As its name suggests, the project would’ve skirted the eastern margins of the Delta via a 43-mile-long, 400-foot-wide and 30-foot-deep aqueduct, shuttling water from the Sacramento River directly to the SWP pumps. [7] The canal was considered an essential adjunct to the SWP, and Edmund G. “Pat” Brown, the Governor at the time and the prime mover behind the SWP, strongly supported the concept.
But the peripheral canal didn’t really pick up steam until the first gubernatorial administration (1975 -1983) of Jerry Brown, Pat Brown’s son. Jerry Brown invested a great deal of political capital into the promotion of the project, and he received considerable support from Southern California political interests. But a strange bedfellows coalition of environmentalists, Delta farmers, commercial fishermen, and sport anglers united to oppose the scheme, and it was defeated in a state referendum in 1982. [8]
What were the subsequent Delta conveyance project proposals?
There have been two concerted efforts to build a new conveyance system since the peripheral canal’s defeat. The first was the “Twin Tunnels” project promoted by Jerry Brown during his second term as Governor (2011 -2019). This was basically a rehash of the peripheral canal – except that the main conveyance infrastructure would have been two massive subterranean tunnels rather than an open aqueduct.
Resistance to the scheme was stiff, and it languished coming out of the gate. After Brown left office in 2019, his successor, Gavin Newsom, quickly modified the initiative, substituting a smaller “Single Tunnel” proposal. Newsom’s determination to build this project is strong, but – as with the Peripheral Canal and the Twin Tunnels – it has encountered broad opposition. [9]
What are the major objections to a “single tunnel” DCP?
The Single Tunnel’s flaws are a reprise of the problems that characterized the Peripheral Canal and the Twin Tunnels. They include:
Cost. The Newsom administration estimates the cost of the Single Tunnel DCP as more than $20 billion – up from the original declared cost of $16 billion. But even $20 billion is an absurdly low figure. Typically, the State underestimates the cost of its public work projects, including roads, bridges, the high-speed rail project, and a 1990s extension of the SWP to the South Coast.
No net gain to California’s water supply. As with its predecessors, the Single Tunnel does not tap into any new water supply; it merely expedites the delivery of existing water from the North State to the South State. To a real degree, this is a zero-sum game: water taken from Northern California benefits Central Valley farmers at the expense of state ratepayers, Northern California’s farmers, and Northern California’s environment. [10] Moreover, a DCP would exacerbate California’s perennial “paper water” problem – i.e., water claims exceed existing supplies by more than 500%. By allowing for additional water transfers, a DCP would make it even more difficult to bring demand in line with availability.
Accelerating the environmental degradation of the Delta. The Delta requires sufficient freshwater flows from the Sacramento River to create the brackish, dynamic system that fish and wildlife need to thrive. Freshwater is literally the Delta’s life blood; without adequate freshwater flows, the estuary and many of its native fish and wildlife species will perish. The State has not established precise export figures for the Single Tunnel. This is not an oversight; the Newsom administration wants to ensure export limits are ill-defined, the better to maintain the status quo of agricultural primacy. [11]
Violation of the public trust. Newsom’s DCP essentially ignores the water access rights of California’s ratepayers, tribes, and underserved communities. Water is a public trust resource – it belongs to everyone – but as with earlier DCP plans, the Single Tunnel will penalize millions of Californians for the benefit of a small number of corporate farms. [12]
What are the alternatives to building a DCP and why are they better for ratepayers and the environment?
The best alternative: a state agriculture sector that accommodates reduced water deliveries. Retiring land, changing crops, and modifying irrigation techniques are all essential elements for a sustainable approach to the state’s increasingly variable and diminishing water supply. [13] Reduced agricultural water use ensures adequate flows for the environment and supplies for the state’s 40 million people without the construction of unaffordable infrastructure projects.
In 2020, agricultural production of nuts, rice, alfalfa and pasture, and grapes accounted for more than half (53%) of the state’s nearly 9 million irrigated acres. [14] Most of the state’s nut crop is exported [15], and the other cited crops are grown in large quantities elsewhere, meaning current production levels are not essential for food security. California can still supply fresh fruits and vegetables to the country, even with significant reductions in water use by agriculture.
Cutting agricultural production would reduce export sales and farmworker employment, so the state should invest in vocational training and economic development in agriculture-dependent communities. However, the large agricultural businesses that profit handsomely from current water usage do not need additional subsidies; they need to adapt to 21st century climate and economic realities. [16]
Without the financial burden of huge infrastructure projects like the DCP, state and local governments can invest in local and regional water security solutions, including conservation, recycled water, and rate rebates or discounts for low-income households. The ratepayer benefits, along with the benefits to the environment of healthy river flows, far outweigh the marginal and diminishing benefits of propping up unsustainable agricultural production. [17]
If we use our collective power to find and elect leaders who are not beholden to wealthy agricultural interests, we can achieve a sustainable water future.
Agriculture uses 80% of California’s developed water, or about 34 million acre-feet a year. This water is derived from the major government conveyance projects, surface streams, and groundwater. An acre-foot is the amount of water required to cover one acre (which is approximately the size of 1 and 1/3 football fields) with one foot of water. It is 325,851 gallons, which is enough water to supply three to four households annually.
[1] https://cawaterlibrary.net/a-century-of-delta-conveyance-plans/
[2] https://cawaterlibrary.net/a-century-of-delta-conveyance-plans/
[3] https://eelriver.org/2014/10/16/californias-north-coast-water-relics/
[4] https://www.usbr.gov/mp/cvp/about-cvp.html
[5] https://water.ca.gov/Programs/State-Water-Project/SWP-Facilities/History
[6] https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Delta-Conveyance/Public-Information/DCP-Benefit-Cost-Analysis-2024-05-13__ADA.pdf
[7] https://cawaterlibrary.net/a-century-of-delta-conveyance-plans/
[8] https://calmatters.org/commentary/2017/09/half-century-later-delta-water-bypass-still-just-notion/
[9] https://www.kqed.org/science/1941123/now-its-official-newsom-administration-spikes-twin-delta-tunnels
[10] https://harder.house.gov/media/press-releases/harder-slams-new-delta-tunnel-report-after-sacramento-admits-the-project-would-irreparably-harm-delta-communities#:~:text=%E2%80%9CThis%20new%20analysis%20acknowledges%20what,gallon%20of%20water%20for%20anyone.
[11] https://baykeeper.org/stop-newsoms-deadly-delta-tunnel-project/
[12] https://capitolweekly.net/newsoms-stealthy-divide-and-conquer-delta-tunnel-campaign/
[13] https://resources.ca.gov/Home/Water-Basics/Climate-Change-Basics#:~:text=Warmer%20temperatures%20will%20lead%20to,summer%20months%20and%20growing%20seasons.
[14] https://data.cnra.ca.gov/dataset/agricultural-water-use-data-2016-2020, accessed September 12, 2024.
[15] https://fas.usda.gov/newsroom/cracking-open-new-markets-california-almonds#:~:text=An%20astounding%20two%2Dthirds%20of,term%20profitability%2C%E2%80%9D%20said%20Adams.
[16] https://www.washingtonpost.com/blogs/govbeat/wp/2015/04/03/agriculture-is-80-percent-of-water-use-in-california-why-arent-farmers-being-forced-to-cut-back/
[17] https://www.pacificcbpr.org/wp-content/uploads/2024/06/DCP-BCA-review-062424.pdf