California’s proposed water tunnel estimated to cost $20.1 billion

A new cost-benefit analysis regarding California’s Delta Conveyance Project was released on May 16, raising its expected cost to $20.1 billion from 2020’s $16 billion estimate.

Furthermore, the Delta Conveyance Project has been discussed for decades and in its current form it consists of a 45-mile (72-kilometer) long, 36-foot (11-meter) diameter, tunnel.

The proposed tunnel would be used to transfer water from the Sacramento River to the aqueducts of the State Water Project, aiming to make up for an estimated 22% climate change induced water reduction in the area by 2070.

The project’s latest state-funded cost-benefit analysis was conducted by the Berkeley Research Group and was led by UC Berkeley’s emeritus professor David Sunding, who stated that “The benefits clearly justify the costs”, with estimated benefits totaling roughly $38 billion.

In addition to this, the tunnel solution would offer far greater earthquake and climate resilience than on-ground alternatives.

However, strong opposition to the project’s realization has been presented by various organizations, which believe that the analysis might have underestimated the costs while overestimating the benefits.

This includes not taking into account the full impact that the Delta Conveyance Project would have on residents and ecosystems of the Sacramento-San Joaquin Delta, as well as not adequately exploring alternatives.

Namely, researchers from the Pacific Institute, a water think tank, released in 2022 a study claiming that California has the potential to reduce its water usage by as much as 30%.

If everything works out in favor of the tunnel’s construction, funding and permits are expected to be secured sometime in 2026, while actual construction would start in late 2029 and take about 15 years to complete.